Purpose: The objective of this prospective clinical study was to document the overall treatment outcome of immediately loaded single Astra Tech Osseospeed™ (Astra Tech AB, Mölndal, Sweden) implants placed in extraction sockets, healed ridges, and grafted sites.

Materials and Methods: Forty-eight patients in need of a single implant in the anterior maxilla (15–25) were recruited. Patients were allocated to a conventional implant treatment (CIT) or immediate implant treatment (IIT) group on the basis of specific criteria. If the buccal bone plate was damaged or missing upon tooth removal, patients were allocated to a grafted implant treatment (GIT) group. Irrespective of the treatment concept, implants were immediately provisionalized. Hard and soft tissue alterations, aesthetic parameters (pink and white esthetic scores, [PES and WES]) and patient's opinion (Oral Health Impact Profile [OHIP-14] questionnaires) were registered at different time points.

Results: After 1 year of function, the overall implant survival rate was 98% with one failure following IIT. The mean bone level to the implant-abutment interface was 0.65 (SD 0.79), 0.85 (SD 0.64), and 0.56 mm (SD 0.44) for CIT, IIT, and GIT. Complete papilla loss was rare following either strategy. Mean midfacial recession amounted to 1.00 (SD 1.15), 0.12 (SD 0.78), and 0.49 mm (SD 0.82) for CIT, IIT, and GIT, respectively. The aesthetic outcome showed a mean PES of 10.30 (SD 1.89) and mean WES of 7.11 (SD 2.14), all patients considered. Patient's satisfaction showed a significant improvement after 1 year of function on all seven domains (p < .001).

Conclusions: This prospective study showed that single implants clinically and aesthetically perform well under immediate non-occlusal loading conditions in the premaxilla. In this context, it is of pivotal importance to stress that patients were carefully selected for IIT and GIT.

Background: During the last decade, high success rates have been reported for implants placed with immediate loading procedures, especially when bone quality and quantity provide good implant stability. In many of these studies, straight-walled implants with moderately rough surfaces were employed. Tapered implants are becoming increasingly more popular due to standardized drilling protocols and reports of high initial primary stability.

Purpose: The aim of the present prospective, single center clinical study was to evaluate surface topographical analysis and the clinical and radiographic outcomes of the NanoTite™ (BIOMET 3i, Palm Beach Gardens, FL, USA) Tapered Implant when used for immediate loading of fixed prostheses and single-tooth restorations.

Materials and Methods: Forty-two patients who needed implant treatment and met admission criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 30 Ncm prior to final seating and an implant stability quotient above 55. A total of 139 NanoTite Tapered implants (112 maxillary and 27 mandibular) were placed by one investigator, and the majority of these implants (n = 77/55%) were placed in posterior regions, and in soft bone (n = 90/65%). A total of 57 prosthetic constructions were evaluated consisting of 20 single-tooth restorations, 30 fixed partial dentures, and 7 complete, fixed maxillary restorations. Radiographs were taken at baseline and at 12 months of follow-up.

Results: Of the 139 study implants, one implant failure was declared. The overall cumulative survival rate at 1 year is 99.4%. Mean marginal bone resorption is 1.01 mm (SD 0.85) during the first year of function.

Conclusion: Although limited to the short follow-up, immediate loading of NanoTite Tapered implants seems to be a viable option in implant rehabilitation, when insertion torque of at least 30 Ncm is achieved. Further studies are needed to authenticate the finding of this study.

Purpose: The relationship of conventional multi-slice computed tomography (CT)- and cone beam CT (CBCT)-based gray density values and the primary stability parameters of implants that were placed by stereolithographic surgical guides were analyzed in this study.

Materials and Methods: Eighteen edentulous jaws were randomly scanned by a CT (CT group) or a CBCT scanner (CBCT group) and radiographic gray density was measured from the planned implants. A total of 108 implants were placed, and primary stability parameters were measured by insertion torque value (ITV) and resonance frequency analysis (RFA). Radiographic and subjective bone quality classification (BQC) was also classified. Results were analyzed by correlation tests and multiple regressions (p < .05).

Results: CBCT-based gray density values (765 ± 97.32 voxel value) outside the implants were significantly higher than those of CT-based values (668.4 ± 110 Hounsfield unit, p < .001). Significant relations were found among the gray density values outside the implants, ITV (adjusted r² = 0.6142, p = .001 and adjusted r² = 0.5166, p = .0021), and RFA (adjusted r² = 0.5642, p = .0017 and adjusted r² = 0.5423, p = .0031 for CT and CBCT groups, respectively). Data from radiographic and subjective BQC were also in agreement.

Conclusions: Similar to the gray density values of CT, that of CBCT could also be predictive for the subjective BQC and primary implant stability. Results should be confirmed on different CBCT scanners.

Objectives: The aim of the present study was to assess long-term survival and success rates of implants in the edentulous maxilla restored with an implant-supported fixed prosthesis.

Materials and Methods: Seventeen edentulous patients received six to eight implants and implant-supported fixed prostheses by one surgeon. Yearly recalls were conducted by two examiners over a period of 11 years. Survival and success rates (biological complications) were determined; marginal bone loss was examined radiographically. Furthermore, microbiological tests as well as test for interleukin-1 composite genotype were assessed and potential risk factors were evaluated.

Results: After a mean time of 11.26 years, 15 patients of 17 could be reexamined. Out of 94 implants, three were lost in one patient. Mean marginal bone loss reached 0.88 mm, two patients (at seven implants) showed bone loss of ≥3.2 mm. Survival rate of implants reached 96.8%. Success rates on implant level hit 92.6% according to the criteria of Albrektsson and colleagues and 83.0% in accordance with Karoussis and colleagues. One prosthesis had to be renewed.

Conclusion: Within the limitation of this study, restoration of the edentulous maxilla with an implant-supported fixed prosthesis represents an effective tool for rehabilitation over a period of 11 years.

Purpose: In this study the de novo bone formation capacity of a nanocrystalline hydroxyapatite bone substitute was assessed 3 and 6 months after its insertion into the human sinus cavity.

Materials and Methods: Sinus cavity augmentation was performed in a total of 14 patients (n = 7 implantation after 3 months; n = 7 implantation after 6 months) with severely atrophic maxillary bone. The specimens obtained after 3 and 6 months were analyzed histologically and histomorphometrically with special focus on bone metabolism within the residual bone and the augmented region.

Results: This study revealed that bone tissue formation started from the bone-biomaterial-interface and was directed into the most cranial parts of the augmented region. There was no statistically significant difference in new bone formation after 3 and 6 months (24.89 ± 10.22% vs 31.29 ± 2.29%), respectively.

Conclusions: Within the limits of the present study and according to previously published data, implant insertion in regions augmented with this bone substitute material could be considered already after 3 months. Further clinical studies with bone substitute materials are necessary to validate these findings.

Purpose: Deviations of implants that were placed by conventional computed tomography (CT)- or cone beam CT (CBCT)-derived mucosa-supported stereolithographic (SLA) surgical guides were analyzed in this study.

Materials and Methods: Eleven patients were randomly scanned by a multi-slice CT (CT group) or a CBCT scanner (CBCT group). A total of 108 implants were planned on the software and placed using SLA guides. A new CT or CBCT scan was obtained and merged with the planning data to identify the deviations between the planned and placed implants. Results were analyzed by Mann-Whitney U test and multiple regressions (p < .05).

Results: Mean angular and linear deviations in the CT group were 3.30° (SD 0.36), and 0.75 (SD 0.32) and 0.80 mm (SD 0.35) at the implant shoulder and tip, respectively. In the CBCT group, mean angular and linear deviations were 3.47° (SD 0.37), and 0.81 (SD 0.32) and 0.87 mm (SD 0.32) at the implant shoulder and tip, respectively. No statistically significant differences were detected between the CT and CBCT groups (p = .169 and p = .551, p = .113 for angular and linear deviations, respectively).

Conclusions: Implant placement via CT- or CBCT-derived mucosa-supported SLA guides yielded similar deviation values. Results should be confirmed on alternative CBCT scanners.

Purpose: The aim of this study was to compare the use of hand mallet versus electrical mallet (magnetic mallet, Meta-Ergonomica, Turbigo, Milan, Italy) in osteotome-assisted surgery for condensing bone procedure in edentulous molar and premolar maxillary regions.

Materials and Methods: Patients edentulous in maxillary premolar and molar regions with type 3 or 4 bone were enrolled in this prospective clinical study. The patients were randomly divided in two groups: in the test group, the implant site was prepared with osteotomes pushed by magnetic mallet, while in the control group, the implant site was performed with osteotomes pressed by hand mallet. Intraoral digital radiographic measurements were reported at 6, 12, and 24 months.

Results: Thirty-six patients were enrolled in the study. Eighteen patients (21 women and 15 men) were included in the test group and 18 patients in the control group. The mean patient age was 56.1 years (range 41–71 years). Fifty dental implants were placed. In 10 cases, five in control and five in test group, sinus elevation was performed. After 24 months follow-up, a survival rate of 96.0% was reported. In the control group, two patients claimed benign paroxysmal positional vertigo following the use of osteotomes with hand hammer. Marginal bone levels remained stable over time for both groups, and not statistically significant differences were found. After 12 months, the bone height incremented in both groups and, at 24 months, was stable. Statistical analysis reported not statistically significant differences between test and control group.

Conclusions: These results demonstrated a stable marginal bone levels over time and a significant increase in bone height between 6 and 12 months in osteotome technique (not sinus elevation). The use of magnetic mallet provided some essential clinical advantages during surgical procedure in comparison with hand mallet.

Purpose: The aim of this study was to evaluate the early bone response of tapered and cylindrical root form implants with two different surface treatments in fresh extraction sockets after 4 and 8 weeks.

Materials and Methods: Surface treatments and implant design comprised (n = 9 each): tapered with dual acid-etched surface; tapered with dual acid-etched and sandblasted surface (T DAE SB); cylindrical with dual acid-etched surface (C DAE); and cylindrical with dual acid-etched and sandblasted surface (C DAE SB). Implants were placed in the distal sockets of mandibular premolars (₂P_2,3P_3,4P₄) of six beagle dogs, remaining in vivo for 4 and 8 weeks. After sacrifice, the implants were subjected to torque to the point of interface fracture and subsequently nondecalcified for histomorphological study. Statistical analysis was performed by a General Linear Model (GLM) analysis of variance model with a significance level of 5%.

Results: Torque to interface fracture was significantly greater for the C DAE SB group than for the other groups (p < .001). Histomorphological analysis showed woven bone formation around all implant surfaces at 4 weeks and its replacement by lamellar bone at 8 weeks. Study time (4 or 8 weeks) did not affect torque measures.

Conclusions: The double acid-etched and sandblasted sample surface increased early bone biomechanical fixation of both cylindrical and tapered root form implants. The cylindrical root form implants showed higher torque to interface fracture values when compared with the tapered root form implants. The C DAE SB surface group showed the highest biomechanical fixation values (p < .001).

Purpose: The purpose of this study was to evaluate the rotational freedom between implant and abutment counterpart of two abutments types over external hexagon implants submitted to mechanical cycling.

Materials and Methods: Ten implants with external hexagon (3.75 mm × 13 mm), five cast abutments, and five premachined abutments both with 4.1 mm plataform size were used in this study. Ten metallic crowns were fabricated using the two types of abutments and were fixed to each implant using titanium screws (Ti6Al4V). Rotational freedom measurements were made before and after the cast procedure and after the mechanical cycling. Groups were classified according to the rotational misfit register using University of California, Los Angeles abutment and implants as new (group 1 = G1); using crowns and implants after crown casting (group 2 = G2); and using crowns and implants after mechanical cycling (group 3 = G3). Oblique loading of 120N at 1.8 Hz and 5 × 10⁵ cycles was applied on specimen.

Results: Statistical analysis (p < .05) showed that no significant difference was observed when cast abutment was compared with premachined abutment after casting (p = .390) and mechanical cycling (p = .439); however, significant difference was noted before the casting (p = .005) with higher values for the cast abutments.

Conclusions: Within the limitations of this in vitro study, it could be concluded that the abutment type used do not influenced the rotational freedom after casting and the amount of applied cycles (500,000 cycles) was not sufficient to significantly alter the values of rotational freedom at the implant/abutment joint.

Purpose: Within the fossa of the submaxillary gland (FSG), there is a portion superior to the mandibular canal (SMCP) that can affect implant placement. Our study evaluated this specific portion's prevalence and its average dimensional difference between the first and the second molar regions in a dental implant population.

Materials and Methods: From 112 patients' mandibular cone beam computerized tomography scans, the SMCPs of the FSG's horizontal and vertical dimensions in the first and second molar positions on both sides were digitally measured.

Results: The SMCP of the FSG is larger in the second molar region than in the first molar region in >90% of cases. Average differences were 2.3 mm horizontally and 2.7 mm vertically. Gender difference and intraindividual's left/right variation were both clinically less significant in magnitude than the difference between the molar regions. Taking the 2-mm safety margin above the mandibular canal into consideration, the SMCP of the FSG remained high in prevalence.

Conclusions: The SMCP of the FSG may complicate implant placement more in the second molar region than in the first. Implant planning in the posterior mandibular molar regions should include a SMCP of the FSG evaluation using computer tomography especially in the second molar region.

Purpose: The aim of this study was to show prognostic equivalence between implant loading in the maxilla after 12 weeks versus 4 weeks.

Materials and Methods: One hundred four patients, from four centers in this open-labeled randomized multicenter prospective controlled clinical trial, were assigned to either 12 weeks or 4 weeks of unloaded healing. Two hundred sixty-nine implants (sand blasted large-grid, acid etched [SLA] surface, ≥4.1 mm diameter; ≥10 mm length) were inserted and evaluated during an individual 5-year follow-up. Primary outcome was implant success after 12 months; prognostic equivalence was characterized by a maximum difference of ±5% in implant failure rates.

Results: Implant-wise 1-year failure rates were estimated 3.1% (5/163 implants) in the 4 weeks group versus 3.6% (4/112 implants) in the 12 weeks group (95% confidence interval [CI] for the difference −3.2 –+4.2%); implant-wise evaluation demonstrated statistically significant prognostic equivalence of 4 and 12 weeks loading. Patient-wise 1-year failure rates were estimated 6.7% (n = 4 patients) in the 4 weeks group versus 5.1% (n = 2 patients) in the 12 weeks group (95% CI for the difference −9.6 –+6.5%). All implant failures occurred within the first 3 months of the individual observation period. Prior bone augmentation, underdimensioned drilling, bone quality, implant type, implant length, implant diameter, residual teeth, and fixing of the restoration did not reveal associations with the implant outcome: trial site, posterior jaw region, and splinting were associated with a higher failure rate. Resonance frequency analysis did not serve as a predictor of implant failures at the time of implant insertion.

Conclusion: Loading of standard SLA implants in the maxilla 4 weeks versus 12 weeks after insertion resulted in statistically equivalent failure patterns within a 1-year follow-up period; nevertheless, the observed patient-wise failure patterns of the interim analysis requires further understanding of patient-individual aspects of the early loading concept.

Background: Customized zirconia abutments are increasingly applied for the fabrication of esthetic implant restorations aimed at imitating the natural situation. These abutments are individually shaped according to the anatomical needs of the respective implant site.

Purpose: This study sought to compare the fracture resistance and fit accuracy of prefabricated and customized zirconia abutments using an internal hexagonal implant system (TSV®, Zimmer, Carlsbad, CA, USA).

Materials and Methods: Two zirconia abutment groups were tested: prefabricated zirconia abutments (ZirAce, Acucera, Seoul, Korea) and customized zirconia abutments milled by the Zirkonzahn milling system. Twenty zirconia abutments per group were connected to implants on an acrylic resin base with 30-Ncm torque. The fracture resistance of zirconia abutments was measured with an angle of 30° at a crosshead speed of 1 mm/min using the universal testing machine (Z020, Zwick, Ulm, Germany). Marginal and internal gaps between implants and zirconia abutments were measured after sectioning the embedded specimens using a digital microhardness tester (MXT70, Matsuzawa, Tokyo, Japan).

Results: The customized abutments were significantly stronger (1,430.2 N) than the prefabricated abutments (1,064.1 N). The mean marginal adaptation of customized abutments revealed a microgap that was increased (11.5 µm) over that in prefabricated abutments (4.3 µm).

Conclusion: Within the limitations of this study, the customized abutments are significantly stronger than prefabricated abutments, but the fit is less accurate. The strength and fit of both abutments are within clinically acceptable limit.

Purpose: To document the outcome of single implants in the anterior maxilla following four routine treatment modalities when performed by experienced clinicians in daily practice using the same implant system and biomaterials.

Material and Methods: A retrospective study in patients who had been treated by two periodontists and two prosthodontists in 2006 and 2007 was conducted. The four treatment modalities practically covered every clinical situation and included standard implant treatment (SIT), immediate implant treatment (IIT), implant treatment in conjunction with guided bone regeneration (GBR), and implant treatment in grafted bone (BGR) harvested from the chin. All implants were installed via flap surgery. Patients were clinically and radiographically examined. Complications were registered and the aesthetic outcome (pink esthetic score [PES] and white esthetic score [WES]) was rated. A blinded clinician who had not been involved in the treatment performed all evaluations. Patient's aesthetic satisfaction was also registered.

Results: One hundred four out of 115 eligible patients (44 SIT, 28 IIT, 18 GBR, and 14 BGR) received at least one single NobelReplace tapered TiUnite® (Nobel Biocare, Göteborg, Sweden) implant in the anterior maxilla and were available for evaluation. Clinical parameters (implant survival: 93%, mean plaque level: 24%, mean bleeding on probing: 33%, and mean probing depth: 3.2 mm) and mean bone level (1.19 mm) did not differ significantly between treatment modalities. Postoperative complications were more common following GBR/BGR (>61%) when compared with SIT/IIT (<18%) (p < .001). BGR was in 4/14 patients associated with permanent sensory complications at the donor site. Technical complications occurred in 9/104 patients. SIT and IIT showed similar soft tissue aesthetics (PES: 10.07 and 10.88, respectively), however major alveolar process deficiency was common (>15%). PES was 9.65 for GBR. BGR showed inferior soft tissue aesthetics (PES: 9.00; p = .045) and shorter distal papillae were found following GBR/BGR (p = .009). Periodontal disease (odds ratio [OR]: 13.0, p < .001), GBR/BGR (OR: 4.3, p = .004), and a thin-scalloped gingival biotype (OR: 3.7, p = .011) increased the risk for incomplete distal papillae. WES was 7.98 for all patients considered. Poor agreement was found between objective and subjective aesthetic ratings.

Conclusions: All treatment modalities were predictable from a clinical and radiographic point of view. However, advanced reconstructive surgery, especially BGR, increased the risk for complications and compromised aesthetics. Research is required on the prevention and minimally invasive treatment of buccal bone defects at the time of tooth loss to avoid complex therapy.

Background: To date, only few studies have reported on the clinical outcomes of immediate postextraction implant placement and immediate loading.

Purpose: The purpose of this retrospective study was to report the results of immediately loading four implants placed in fresh extraction sockets in the mandible after a follow-up of 24 months.

Materials and Methods: Between January 2001 and January 2009, 50 patients (28 women and 22 men, average age 54 years), had 347 teeth extracted and a total of 200 dental implants placed in the mandible. The patients received a provisional fixed bridge the same day and a permanent one 3 months later. Clinical checkups were performed after 1, 2, 3, 6, 12, and 24 months. Marginal bone measurements were made in intraoral radiographs taken 1 day after surgery and after 1 year. A questionnaire was used to evaluate self-perceived factors related to comfort, aesthetics, and function.

Results: All bridges were stable and no implant failures were recorded during the follow-up, giving a survival rate of 100%, at 2 years. The marginal bone loss amounted to 1.33 ± 0.36 mm after 1 year and 1.48 ± 0.39 mm after 2 years. Ten patients showed prosthetic complications with the provisional bridge, but all the definitive prostheses remained stable throughout the study period without any complications. The patients reported satisfaction with the treatment.

Conclusions: The present retrospective study showed that immediate loading of four implants immediately placed in extraction sockets is a valid treatment modality for the totally edentulous mandible.

Aim: This in vivo split-mouth randomized controlled trial compared a synthetic bone substitute with a bovine bone mineral to cover bone dehiscences after implant insertion.

Materials and Methods: Fourteen patients received four to six implants to support an overdenture. Two comparable dehiscences within the same patient were first covered with a layer of autogenous bone, followed by a layer of either Bio-Oss® (group 1; Geistlich Pharma AG, Wolhusen, Switzerland) or Straumann BoneCeramic® (group 2; Institut Straumann AG, Basel, Switzerland) and sealed by a resorbable membrane. The change in vertical dimension of the defect was measured at implant placement and at abutment connection (6.5 months). Clinical and radiological parameters were evaluated up to 1 year of loading.

Results: The vertical size of the defect at surgery was 6.4 ± 1.6 mm for group 1 and 6.4 ± 2.2 mm for group 2 sites, measured from the implant shoulder. After 6.5 months, the depth of the defect was reduced to 1.5 ± 1.2 mm and 1.9 ± 1.2 mm for group 1 and group 2 sites, respectively (p > 0.05). No implants failed during follow-up. Mean marginal bone loss over the SLActive surface was 0.94 mm (group 1), 0.81 mm (group 2), and 0.93 mm (group 3, no dehiscence) after 1 year of loading.

Conclusion: Both bone substitutes behaved equally effectively.

Background: Platelet concentrate/platelet-rich plasma (PRP) has been studied extensively in various experimental models and there is some agreement among workers to its early effect in bone regeneration and healing. We have earlier showed in vitro that titanium in whole blood activates the thrombogenic response to a higher degree than PRP and that a fluoridated test surface augmented the effect compared with control.

Purpose: We designed this study to evaluate the effect of PRP and whole blood on bone regeneration in a dog implant defect model and, in addition, the effect of a test surface modified in hydrofluoric acid. A correlation attempt between platelet count, release of growth factors, and bone regeneration was made.

Materials and Methods: Six dogs were used and simultaneously with the experimental surgery and implant installation, autologous PRP was prepared. Defects were prepared (6 mm in diameter and 5 mm deep), and implants were installed (TiO₂ gritblasted and hydrofluoric acid treated [test] or TiO₂ gritblasted [control], 5 mm in diameter and 9 mm long) in defects filled with either PRP or whole blood. Randomization of sides between PRP and whole blood, and sites for test and control implants were made. Blood samples were collected from PRP and whole blood. The dogs were killed after 5 weeks of healing, and samples with implants and surrounding bone were collected and processed for analysis. Enzyme linked immunosorbent assays were used for detection of growth factors in PRP.

Results: The mean increase of platelet count was 424% in PRP. A correlation for platelet counts and transforming growth factor β was found in each dog (r² = 0.857). Approximately 50% of the region of interest (ROI) in the defects was filled with new bone after 5 weeks. No difference could be observed in ROI by using PRP or whole blood in the defects regarding new bone formation, bone in contact with implant, or distance to first bone contact. However, the fluoridated implants exhibited more new bone formation (p = .03) compared with control, regardless of comparing PRP or whole blood, and also displayed a shorter distance from first bone contact to the margin of the bone envelope (p = .05).

Conclusions: Platelet concentrate/PRP failed to show more new bone regeneration in a peri-implant defect model compared with whole blood. Implants treated with hydrofluoric acid displayed higher percentages of bone fill in the defect.

Background: Studies about the effect of grinding procedures as well as material thickness on the resistance of zirconia implant abutments are in short supply.

Purpose: This study evaluated the effect of wall thickness as well as preparation on the resistance of zirconia implant abutments.

Materials and Method: Sixty-four implants received titanium (group Ti) and zirconia abutments (groups Zr-8, Zr-18, and Zr-1). The abutments of group Zr-8 had a 0.8-mm wall thickness, whereas the wall thickness of group Zr-18 was reduced by preparation from 1 mm to 0.8 mm. The abutments of group Zr-1 had a wall thickness of 1 mm. Standardized maxillary central incisor metal crowns were cemented on all abutments. All specimens were then tested in a universal testing machine for their resistance to fracture before and after masticatory simulation (n = 8).

Results: The median resistance to fracture values (N) before and after aging were, respectively: group Ti: 500–504; group Zr-8: 487–491; group Zr-18: 490-451; and group Zr-1: 519-480. No significant effects of group, aging, or combinations were found (p > .05).

Conclusion: All tested abutments have the potential to withstand physiologic occlusal forces in the anterior region (>200 N). The applicability of the results to other implant systems should be verified.

Purpose: The purpose of this retrospective study was to assess if there was a difference in the likelihood of achieving passive fit when an implant-supported full-arch prosthesis framework is fabricated with or without the aid of a verification jig.

Materials and Methods: This investigation was approved by the University of Rochester Research Subject Review Board (protocol #RSRB00038482). Thirty edentulous patients, 49 to 73 years old (mean 61 years old), rehabilitated with a nonsegmented fixed implant-supported complete denture were included in the study. During the restorative process, final impressions were made using the pickup impression technique and elastomeric impression materials. For 16 patients, a verification jig was made (group J), while for the remaining 14 patients, a verification jig was not used (group NJ) and the framework was fabricated directly on the master cast. During the framework try-in appointment, the fit was assessed by clinical (Sheffield test) and radiographic inspection and recorded as passive or nonpassive.

Results: When a verification jig was used (group J, n = 16), all frameworks exhibited clinically passive fit, while when a verification jig was not used (group NJ, n = 14), only two frameworks fit. This difference was statistically significant (p < .001).

Conclusions: Within the limitations of this retrospective study, the fabrication of a verification jig ensured clinically passive fit of metal frameworks in nonsegmented fixed implant-supported complete denture.

Purpose: Many authors have emphasized that immediate loading protocols enable better esthetic results to be achieved compared with delayed loading, especially in the case of postextraction implants that are capable of maintaining the original esthetics of soft tissues. The aim of this study was to establish correlations between the interproximal crest, interproximal papilla, and marginal facial gingiva of immediately loaded postextraction implants by evaluating clinical and radiographic data.

Materials and Methods: Fifty-eight consecutive patients underwent a tooth extraction and immediate implant placement with 64 postextraction implants, which were immediately loaded using a provisional single crown from June 2005 to December 2006. At 6 months after surgery, all implants were restored with a definitive single crown. Clinical and radiographic data were recorded at the time of surgery, at the time of definitive restoration, and after 3 years of functioning, in order to evaluate soft tissues esthetics and bone tissue condition. Statistical analysis was used to assess significant correlations between the interproximal crest, interproximal papilla, and marginal facial gingiva (p = 0.05).

Results: After 3 years of functioning, the implant success rate was 100% because no implants had failed. All parameters were stable and steady during the 3-year follow-up. The regression test revealed a statistically significant correlation between interproximal crest levels and interproximal papilla volume (p = 0.0134), and also between interproximal crest levels and marginal gingiva levels (p = 0.0226).

Conclusions: Postextraction immediately loaded implants represent a predictable technique that should be considered the treatment of choice in cases of single anterior tooth restoration and other cases. Esthetic results seem to depend on correct positioning of the implants, considering the correlation between bone tissue and related soft tissues. Maintaining the original condition of both bone and soft tissues around the tooth to be removed is the key to obtaining optimal esthetic outcomes.

Purpose: The poor bone quality that exists in the posterior maxilla is associated with lower initial stability and higher failure rates in implants. This study examined the bone densities of edentulous posterior maxillae by computed tomography (CT).

Materials and Methods: Based on CT images, the voxel values representing implant replacement in the posterior maxillary regions of 30 patients were calculated in the range from 150 to 2,000 Hounsfield units (HU). The bone densities of these regions were categorized according to Misch's classification and compared among individuals and between sexes.

Results: The average of the median individual CT values was 495 HU (95% confidence interval: 442–547 HU) and was significantly higher in males than in females. Most of the bone in the posterior maxillae was classified as D3 (350–850 HU) or D4 (150–350 HU) according to Misch's classification, comprising 50% and 32% of the entire regions, respectively.

Conclusions: More than 80% of the edentulous posterior maxillae consisted of porous cortical crest or no cortical bone according to CT, although the bone densities varied markedly among individuals. More detailed assessments of bone density may be useful to enhance initial stability of implants in the posterior maxilla.

Purpose: The purpose of this study is to evaluate implants placed at different times of bone augmentation.

Materials and Methods: Four implants were placed in seven dogs: one at a 6-month bovine mineral grafted site (6-month Bio-Oss® grafted site [6mBio]), one at a grafted membrane-protected simultaneously augmented (Fresh Bio-Oss® grafted site [FrBio]) site, one at a clotted (nongrafted clotted membrane-protected site [Clot]) membrane-protected site, and one at a pristine (nongrafted uncovered site [Cont]) site. Implants were exposed after 6 months. The same protocol was repeated on the contralateral side, at a delay of 8 months. Peri-implant care was performed throughout the hygienic phase (2 and 10 months, respectively) every 48 to 72 hours. Probing depth and bleeding on probing were recorded. Implant stability was determined by a Periotest® (Medizintechnik Gulden, Modautal, Germany). Statistical analysis was conducted using analysis of variance with repeated measures.

Results: Average probing depth at the simultaneously grafted sites was 2.21 mm and 2.03 mm at 8 and 16 months, respectively. At the 6-month grafted sites, it was 1.96 mm and 1.57 mm. At the Clot sites, it was 2.68 mm and 2.07 mm, and 2.21 mm and 1.82 mm at the Cont sites, respectively. The average bleeding on probing was 0.50 and 0.42 at the FrBio sites, and 0.35 and 0.07 at the 6mBio sites during the respective periods. At the Clot sites, it was 0.50 and 0.28, and at the Cont sites, 0.43 and 0.21, respectively. Probing depth significantly reduced over the time at 6mBio, Clot, and Cont sites (p < .03). Average implant stability score at the FrBio sites was −0.24 and −0.27, and −0.50 and −0.46 at the 6mBio sites, at 8 and 16 months, respectively. At the Clot sites, it was −0.35 and −0.46. Cont sites averaged −0.37 at both periods. Implant stability was significantly higher (p < .005) comparing 6mBio over FrBio, 6mBio over Cont, and Clot over FrBio sites.

Conclusions: Immediate and delayed augmentations are safe modes. Probing depth and bleeding indices gradually improved along time. Implant stability was higher at the delayed mode.

Purpose: The purpose of this longitudinal study was to evaluate the success of bovine bone and calcium sulfate (CaSO₄) as sinus augmentation material with osteotome maxillary sinus lift.

Materials and Methods: Thirty-one osteotome sinus lift procedures were performed for 18 healthy patients (7 males and 11 females). A mixture of bovine bone and CaSO₄ (ratio, 4:1) was used as sinus augmentation material with simultaneous implant placement. Implants were loaded 4 to 5 months postimplant surgery. Cases were followed for an average of 23.4 months postloading (range, 12–60 months).

Results: The mean age of the study group was 49.7 ± 10.66 years. The residual height of the alveolar ridge ranged from 5.5 to 11 mm (mean, 8.16 ± 1.52 mm). Four to 5 months after implant placement, the x-ray showed a 1.5 to 5 mm apical shift of the sinus floor (mean, 3.47 ± 0.97 mm), which was maintained to the end of the evaluation period. At 12 months postloading, crestal bone loss ranged from 0.5 to 1.5 mm (mean, 0.87 ± 0.26 mm), and pocket depth ranged from 2 to 4 mm (mean, 2.9 ± 0.67 mm). No significant change in crestal bone loss or pocket depth was noticed afterward.

Conclusion: Bovine bone plus CaSO₄ can be used successfully as a sinus augmentation material with osteotome sinus elevation. The use of CaSO₄ significantly improved the handling properties of bovine bone and helped to stabilize the bone graft particles during healing.

Purpose: This study histomorphometrically analyzed the effect of autogenous platelet-rich plasma (PRP) on healing of fresh frozen bone allograft (FFBA) in bony defects in rat calvaria.

Materials and Methods: A 5 mm–diameter defect was created in the calvarium of 30 rats. Animals were divided into three groups: C (defect was filled by blood clot only), FFBA (defect was filled with 0.01 mL of FFBA), and FFBA/PRP (defect was filled with 0.01 mL of FFBA combined with 100 µL of PRP). All animals were euthanized at 30 days postoperatively. Histomorphometry and histology analyses were performed. Data were statistically analyzed (analysis of variance, Tukey, p < .05).

Results: FFBA had a statistically smaller new bone area than groups FFBA/PRP and C. No statistically significant differences were observed between groups FFBA and FFBA/PRP with regard to remaining bone graft particle area.

Conclusion: It can be concluded that (1) PRP improved the incorporation of FFBA, increasing the amount of new bone formed; (2) PRP has not influenced the resorption of nonviable particles of the FFBA; and (3) presence of remaining FFBA particles might have accounted for the smaller amount of new bone observed in group FFBA when compared with control group.

Background: There is a lack of well-designed prospective, randomized clinical trials evaluating the efficacy of immediate and early loading of implants placed in the partially edentulous posterior maxilla or mandible.

Purpose: The aim of this study was to evaluate crestal bone level changes over 3 years following immediate or early loading of Straumann implants with a chemically modified surface (SLActive®, Institut Straumann AG, Basel, Switzerland) placed in the posterior maxilla and mandible.

Materials and Methods: Subjects received temporary restorations immediately or 28 to 34 days after surgery, with permanent restorations placed at 20 to 23 weeks. Bone level changes were measured by comparison of standardized radiographs taken on the day of implant placement and 5, 12, 24, and 36 months thereafter.

Results: Two hundred thirty-nine of two hundred sixty-six patients (89.9%) completed the trial. Implant survival rates were 97.4% and 96.7% in the immediate and early loading groups, respectively (p = not significant). Over 36 months, the mean bone level change for immediately loaded implants was 0.88 ± 0.81 mm versus 0.57 ± 0.83 mm for the early-loaded group (p < .001). After adjusting for a slight difference in initial placement depth, the time of loading had no significant influence on bone level change.

Conclusions: Changes in crestal bone level occurred mostly during the first 5 months postloading. After this bone remodeling period, crestal bone level was stable up to 36 months. Implants with a chemically modified surface are safe and predictable for immediate and early loading in the posterior maxilla and mandible.

Background: Comparisons between different techniques measuring fit of implant-supported frameworks are few.

Purpose: The purpose of this study was to compare data on precision of fit from two highly accurate measuring techniques and, also, to compare results using software programs for fit assessments considering both a “virtual” as well as a “physical” (i.e., more clinical) situation.

Materials and Methods: Five computer numerical control-milled titanium frameworks (Procera® Implant Bridge, Nobel Biocare AB, Göteborg, Sweden) were fabricated from individual model/pattern measurements, simulating a clinical situation. Measurements of fit between frameworks and models were performed by means of a coordinate measuring machine (CMM; Zeiss Prismo Vast, Carl Zeiss Industrielle Messtechnik GmbH, Oberkochen, Germany) linked to a computer and an optical, high-resolution, three-dimensional scanner (Atos 4M SO, GOM International AG, Widen, Switzerland). Collected data on distortions between frameworks and models were analyzed and compared between the two measurement techniques. A comparison between “virtual” and “physical” fit assessments was also performed, based on data from the three-dimensional scanner.

Results: When using “virtual” fit assessment programs, overall mean three-dimensional distortion between implant and framework center points in absolute figures was 37 (SD 22) and 14 µm (SD 8) for the CMM and three-dimensional scanning measurements, respectively. Corresponding mean three-dimensional distortion when using a “physical” fit assessment program in the scanner was 43 µm (SD 24) (p < 0.001). Mean horizontal (x-axis) measurements of the distance between the two terminal implants of the models and the frameworks were 33.772 and 33.834 mm for the CMM technique. Corresponding measurements for the three-dimensional scanner was 33.798 and 33.806 mm, respectively. Horizontal distances from the three-dimensional scanner were, for most measurements, greater than for the CMM measurements.

Conclusion: Measurements of fit between frameworks and models may vary depending on what technique is used and how fit assessments regarding “virtual” or “physical” fit is approached.

Purpose: The aim of this study was to investigate the relationship between surgical techniques and implant macro-design (self-tapping/non-self-tapping) for the optimization of implant stability in the low-density bone present in the posterior maxilla using resonance frequency analysis (RFA).

Materials and Methods: A total of 102 implants were studied. Fifty-six self-tapping BlueSkyBredent® (Bredent GmbH&Co.Kg®, Senden, Germany) and 56 non-self-tapping Standard Plus Straumann® (Institut Straumann AG®, Waldenburg, Switzerland) were placed in the posterior segment of the maxilla. Implants of both types were placed in sites prepared with either lateral bone-condensing or with bone-drilling techniques. Implant stability measurements were performed using RFA immediately after implant placement and weekly during a 12-week follow-up period.

Results: Both types of implants placed after bone condensing achieved significantly higher stability immediately after surgery, as well as during the entire 12-week observation period compared with those placed following bone drilling. After bone condensation, there were no significant differences in primary stability or in implant stability after the first week between both implant types. From 2 to 12 postoperative weeks, significantly higher stability was shown by self-tapping implants. After bone drilling, self-tapping implants achieved significantly higher stability than non-self-tapping implants during the entire follow-up period.

Conclusions: The outcomes of the present study indicate that bone drilling is not an effective technique for improving implant stability and, following this technique, the use of self-tapping implants is highly recommended. Implant stability optimization in the soft bone can be achieved by lateral bone-condensing technique, regardless of implant macro-design.

Background: Alternative implant designs may reduce the need for complicated and costly bone augmentation procedures in situations with limited bone height.

Purpose: Wide dental tube implants have been manufactured and tested in three patients and followed for 5 years to evaluate if such implants are capable to support fixed prosthetic constructions with good prognosis in areas with limited bone height.

Materials and Methods: Four machined-tube implants with a height of 6 mm, an outer diameter of 7.4 mm, and an inner diameter of 6.0 mm were placed in three patients. After a healing period of 3 months, ceramometal suprastructures were constructed to supply the implants. Annual clinical and radiographical follow-ups were done up to 5 years. At the 5-year follow-up, all three patients were examined with a cone beam computed tomography technique.

Results: All implants and the suprastructures were clinically stable after 5 years. In one patient, vertical bone loss and a 6-mm deep pocket appeared after 1 year. The pocket has remained throughout the observation period and has been regularly debrided and kept it free from clinical signs of inflammation. In the other two patients, the soft tissue surrounding the implants was in good health with no or only slight inflammation throughout all observations. Pocket probing revealed no or slight bleeding and pocket depths amounting to less than 3 mm.

Conclusion: It was shown that this new type of implant will function excellent during follow-up times of several years. Further studies should be done to explore in more detail indications for such implants.

Purpose: To investigate osseointegration of oral implants, which were retrieved from a patient after 29 years in situ, we use novel three-dimensional analysis methods and visualization techniques that supplement conventional two-dimensional analysis.

Materials and Methods: The sample processing involved nondecalcification and embedment in resin. Conventional two-dimensional histomorphometrical methods were conducted. Additionally, the quantification was extended to three-dimensional by using synchrotron radiation micro-computed tomography (SRµCT) technique and two relevant visualization methods for the three-dimensional data were introduced.

Results: The three-dimensional results involved three-dimensional quantification and visualization of two implant samples with methods beyond state-of-the-art. Traditional two-dimensional histomorphometrical results revealed a mean bone-implant contact (BIC) of about 50%. In most samples, bone area (BA) was lower inside the treads compared with out-folded mirror images, which were confirmed by the three-dimensional quantification. The BIC along four selected regions showed highest percentages in the bottom/valley region and lowest in the thread-peak region. Qualitative observations revealed ongoing bone remodeling areas in all samples. The apical hole demonstrated high osseointegration.

Conclusion: The novel techniques including an animation and an out-folding of BIC and BA enabled a simultaneous visualization of the three-dimensional material obtained from SRµCT data. However, the two-dimensional histological sections were needed for qualitative and quantitative evaluation of osseointegration and, thus, both methods are considered equally important.

Purpose: This study aimed to measure and compare strains generated by splinted implant crowns retained by cement or screws for two implants with applied load.

Materials and Methods: A stereolithic resin model was printed using computed tomography data from a patient missing all mandibular molar teeth. Two 4 × 6 mm implants were consecutively placed in the left side. One set of splinted cement and screw-retained crowns were made to fit the two implants. Image correlation technique was used for full-field measurement of strains using an image correlation software and two synchronized high-resolution digital cameras. A random dot pattern was applied to the model surface. Cameras recorded changes in random dot patterns as prostheses were loaded up to 400 N in vertical and oblique directions using a universal testing machine. Testing was repeated three times for cement and screw-retained prostheses. An image correlation algorithm used the dot pattern to define correlation areas or virtual strain gauge boxes. Three-dimensional coordinates of gauge box centers were determined for each recorded photograph and used to calculate strains. Strain distribution data were compared for major, minor, and von Mises strains for each loading condition, as well as peak and average strains for the field of view using an analysis of variance (α = 0.05).

Results: Patterns and magnitudes of strain for cement- and screw-retained splinted crowns were similar under vertical loading. Neither peak nor mean strains were significantly different for the two retention methods. For oblique loading, peak strains were lower for the screw-retained crowns; however, there were no statistically significant differences between the two groups when strains were averaged throughout the entire field of view.

Conclusions: Cement retention did not improve the magnitude of transferred strains for splinted implant crowns using either loading condition.

Background: Studies have pointed out that the mere elevation of the maxillary sinus membrane might suffice to allow for bone formation indicating the additional use of augmentation materials to be redundant.

Purpose: The purpose of this study was to assess whether elevation of the sinus mucosal lining combined with applying an autologous bone graft as a ceiling and placement of a short implant would allow for bone formation around the implant thus surpassing the need for applying augmentation materials around the installed implants.

Materials and Methods: Fourteen consecutive patients were subjected to maxillary sinus floor elevation surgery and simultaneous placement of an implant. Using the lateral bone-wall window technique, the membrane was exposed and elevated. Next, a bone graft taken from the zygomatic rim was placed as a ceiling above the inserted implant to ensure that the sinus membrane would not collapsed around a significant part of the implant. Finally, the bone window was returned in place. After connecting the healing abutment, the wound was closed.

Results: All implants were stable and no implants were lost. There were no complications after harvesting the bone graft. Radiographic evaluation showed a bone gain of 3.2 ± 0.9 mm after 3 months and 3.6 ± 0.9 mm after 1 year. Less than 6% of the implant was not covered by bone after 1 year.

Conclusion: Maxillary sinus membrane elevation and simultaneous placement of short endosseous implants with a bone graft as a ceiling on top of the implant result in predictable bone formation around the implant and good osseointegration on radiographs.

Background: Despite the causal association between variant Creutzfeldt – Jakob disease and bovine spongiform encephalopathy (BSE), bovine origin graft materials are widely used during dental surgical procedures. The aim of this study was to assess the risk of BSE transmission through anorganic bovine bone substitutes.

Methods: Electronic database of MEDLINE was searched to identify relevant studies regarding our focused questions, presence of BSE prion infectivity in raw bovine bone, BSE prion inactivation by bone substitute manufacturing process, protein contents in anorganic bovine bone substitutes, and validity of current BSE diagnostic methods. Search terms yielded 1,704 titles. After title/abstract screening and duplicates removal, 36 full-text articles were screened for inclusion.

Results: A total of 16 studies were included in the final analysis. No eligible studies were identified regarding the efficacy of BSE prion inactivation by the treatments used for anorganic bovine bone manufacturing. BSE infectivity and PrP^Sc, pathological prion, were detected in bovine bone marrow and serum samples. Proteins were detected in Tutoplast® (bovine), Bio-Oss®, and tibia samples treated at the similar condition for Bio-Oss deproteinization. Inconsistent results of different BSE diagnostic tests were not unusual findings (Iwata et al. 2006; Arnold et al. 2007; Murayama et al. 2010), and a study by Balkema-Buschmann and colleagues showed an apparent discrepancy between BSE infectivity and detection of PrP(27-30), the current surrogate marker for prion disease infectivity.

Conclusion: This review indicates that bovine-derived graft biomaterials may carry a risk of prion transmission to patients.

Purpose: Precise preoperative implant planning and its exact intraoperative transfer are crucial for successful implant-supported rehabilitation of partially or completely edentulous patients. In the present pilot study, optical laser scanning was used to evaluate deviations between three-dimensonal computer-assisted planned and actual implant positions by indirect methods.

Material and Methods: Five patients receiving a total of 15 implants were included in this study. The used planning software was SimPlant 12.0 (Materialise Dental, Leuven, Belgium) to visualize the implant positions, and with an appropriate guided surgery protocol (Navigator™, Biomet 3i, Palm Beach Gardens, FL, USA) implant positions were implemented via tooth-supported stereolithografic surgical guides. All implants (Osseotite™, Biomet 3i) were inserted in a flapless approach and immediately provided with prefabricated temporary splinted restorations. Intraoral pickup impressions were taken postoperatively, and the implant positions of the master casts were compared with presurgical casts. Implant replica deviations were evaluated by three-dimensional optical laser scanning providing distances and angulations between implant replicas.

Results: Overall, the postsurgical implant replica positions were found to deviate from the positions in the preoperative cast by a mean of 0.46 ± 0.21 mm (range: 0.09–0.85 mm). Positional deviations were 0.27 ± 0.19 mm (range: 0.04–0.60 mm) along the x-axis representing the buccal-lingual directions, 0.15 ± 0.13 mm (range: 0.0–0.34 mm) along the y-axis representing the ventrodorsal direction, and 0.28 ± 0.19 mm (range: 0.02–0.59 mm) along the z-axis representing cranial and apical directions. Rotational deviations amounted to 14.04 ± 11.6° (range: 0.09–36.47°).

Conclusions: The results of this pilot study demonstrate precise transfer of implant replica position by means of simulated guided implant insertion into a preoperative cast and a postoperative cast obtained from impressioning. Further studies are needed to identify appropriate evaluation techniques and mechanisms to increase the transfer precision of three-dimensional planning and guiding systems.

Background: Tooth extraction is associated with dimensional changes in the alveolar ridge. The aim was to examine the effect of single versus contiguous teeth extractions on the alveolar ridge remodeling.

Material and Methods: Five female beagle dogs were randomly divided into three groups on the basis of location (anterior or posterior) and number of teeth extracted – exctraction socket classification: group 1 (one dog): single-tooth extraction; group 2 (two dogs): extraction of two teeth; and group 3 (two dogs): extraction of three teeth in four anterior sites and four posterior sites in both jaws. The dogs were sacrificed after 4 months. Sagittal sectioning of each extraction site was performed and evaluated using microcomputed tomography.

Results: Buccolingual or palatal bone loss was observed 4 months after extraction in all three groups. The mean of the alveolar ridge width loss in group 1 (single-tooth extraction) was significantly less than those in groups 2 and 3 (p < .001) (multiple teeth extraction). Three-teeth extraction (group 3) had significantly more alveolar bone loss than two-teeth extraction (group 2) (p < .001). The three-teeth extraction group in the upper and lower showed more obvious resorption on the palatal/lingual side especially in the lower group posterior locations.

Conclusion: Contiguous teeth extraction caused significantly more alveolar ridge bone loss as compared with when a single tooth is extracted.

Purpose: This study aimed to investigate whether push-in and pull-out tests measure mechanical properties of the bone–implant interface differently, and which test is more sensitive to changes over the healing period.

Materials and Methods: Two identical self-threading dental implants (3.3 × 8.5 mm) were placed in medial surface of the proximal condyles of left and right tibias of 20 rabbits (40 implants total). Five rabbits each were sacrificed after 1, 4, 8, and 12 weeks of healing. Push-in test was performed on one side's tibia implant and pull-out on the other side's implant, at a rate of 6 mm/min. Primary and secondary implant stabilities and tibia weight were measured on all implants.

Results: The push-in test generated significantly higher failure load (p = .0001; 530 N vs 279 N), lower displacement at failure (p = .0003; 0.436 mm vs 0.680 mm), and higher interface stiffness (p < .0001; 1,641 N/mm vs 619 N/mm) than pull-out test. Failure load, stiffness, and secondary implant stability were significantly higher for longer compared with shorter healing periods, while displacement, tibia weight, and primary stability were not. Failure load and stiffness differed significantly for four healing times for the push-in but not for the pull-out test. Failure load was significantly correlated with secondary implant stability for both push-in (r = 0.66) and pull-out (r = 0.48) tests, but stiffness was significantly correlated with secondary stability only for the push-in test (r = 0.72; pull-out test r = 0.40).

Conclusion: The push-in test appeared more sensitive than pull-out to changes in mechanical properties at bone–implant interfaces during healing in rabbit tibia model.

Background: Surgical reconstruction of peri-implant defects is challenging and unpredictable due to, for example, the extent of the bone defect or the osteogenic potential of adjunctive materials used.

Purpose: To study the healing capacity of a new bone xenograft material in the treatment of peri-implant defects.

Material and Methods: In three cases with advanced peri-implant defects, flap surgery was performed. After thorough debridement including cleaning of the exposed implant surface, prehydrated and collagenated porcine bone (PCPB) particles were placed into the defect. A bioresorbable collagen barrier was adapted and placed over the defect and the flaps were relocated. After 6 and 12 months of healing, clinical and radiographic examinations were done. In one case, the surgical procedure was repeated 6 months postoperatively. One year after the second surgery, a bone biopsy was harvested and analyzed with histology.

Results: All defects healed uneventfully. At 6 months, probing depths were reduced by 3–4 mm with no bleeding on probing or pus formation. At 12 months, healthy peri-implant conditions were found. Intra-oral radiographs showed gain of the marginal bone level by 2–4 mm. In the case where reconstructive surgery was repeated, histology showed osteoconductive properties as bone formation with typical osteoblastic seams was observed directly on the surface of the grafted particles.

Conclusion: The presented cases show that PCPB have favorable properties enhancing bone regeneration in peri-implant bone defects.

Background: Ceramic biomaterial blocks like hydroxyl apatite are too brittle for simple simultaneous vertical augmentation and dental implant placement. Biological scaffolds of xenogenic or allogenic origin are known to be advantageous.

Purpose: The aim of this study was the proof of principle for combined vertical bone augmentation and dental implantation with marginal cuffs made of biological scaffolds with interconnecting porous system and titanium dental implants.

Materials and Methods: Cylindrical porcine biomaterial rings (processed, mineralized bone matrix) were placed in combination with titanium dental implants in the tibia model using six chinchilla bastard rabbits (n = 12 samples). Histological examination included undecalcified histological examination with toluidine blue staining and fluorescence microscopy. Animals were sacrificed after 30 days.

Results: The results showed bony healing in the scaffolds with immature bone tissue ingrowth following the trabecular structure, showing lamellar cancellous bone healing. Fluorescence microscope showed analogous results.

Conclusion: The biological scaffold proved a biocompatibility in a xenogenic setting. The vertical bone augmentation with simultaneous implantation was successful and proved the feasibility of the concept.

Background: The relative contributions of different, potential factors to new bone formation in periosteal distraction osteogenesis are unknown.

Purpose: The aim of the present study was to assess the influence of original bone and periosteum on bone formation during periosteal distraction osteogenesis in a rat calvarial model by means of histology and histomorphometry.

Methods: A total of 48 rats were used for the experiment. The contribution of the periosteum was assessed by either intact or incised periosteum or an occlusive versus a perforated distraction plate. The cortical bone was either left intact or perforated. Animals were divided in eight experimental groups considering the three possible treatment modalities. All animals were subjected to a 7-day latency period, a 10-day distraction period and a 7-day consolidation period. The newly formed bone was analyzed histologically and histomorphometrically.

Results: New, mainly woven bone was found in all groups. Differences in the maximum height of new bone were observed and depended on location. Under the distraction plate, statistically significant differences in maximum bone height were found between the group with perforations in both cortical bone and distraction plate and the group without such perforations.

Conclusions: If the marrow cavities were not opened, the contribution to new bone formation was dominant from the periosteum. If the bone perforations opened the marrow cavities, a significant contribution to new bone formation originated from the native bone.

Purpose: The aim of the present study was to systematically evaluate the implant survival rate after osteotome-mediated maxillary sinus augmentation with or without using grafting materials.

Materials and Methods: MEDLINE database was searched using a combination of specific search terms. Furthermore, a hand searching of the relevant journals and of the bibliographies of reviews was performed. Prospective and retrospective clinical studies with at least 20 patients treated by osteotome-mediated sinus floor elevation were included.

Results: Nineteen studies were selected for data analysis. A total of 1,822 patients, accounting for 3,131 implants were considered. Mean weighted cumulative implant survival at 1, 2, 3, and 5 years was estimated as 98.12%, 97.40%, 96.75%, and 95.81%, respectively. No significant difference was found in relation to the use of grafting material nor in relation to implant length. Overall implant survival was 92.7% for 331 implants placed in <5 mm ridge height and 96.9% for 2,525 implants inserted in ≥5 mm ridge height. The difference was significant (p = .0003).

Conclusions: The transalveolar sinus augmentation technique could be a viable treatment in case of localized atrophy in the posterior maxilla even in case of minimal residual bone height. The prognosis can be more favorable when the residual ridge is at least 5 mm high.

Background: An adequate alveolar crest is essential for implant placement in terms of esthetics and function. The objective of this randomized clinical trial was to compare the preservation of the alveolar ridge dimensions following tooth extraction using porcine-derived xenograft combined with a membrane versus extraction-alone (EXT) sites.

Methods: Fifteen patients who required double extraction of contralateral premolars and delayed implant placement were randomly selected to receive both ridge-preservation procedure and EXT. The test sites (alveolar ridge preservation [ARP]) included 15 sockets treated using a corticocancellous porcine bone xenograft (OsteoBiol® Gen-Os; Tecnoss srl, Giaveno, Italy) associated with a soft cortical membrane (OsteoBiol® Lamina; Tecnoss srl), while the corresponding control sites (EXT) were left without grafting for EXT. Horizontal and vertical ridge dimensions were recorded at baseline and 6 months after extractions.

Results: After 6 months, the EXT sites showed a significantly greater reabsorption of the buccolingual/palatal dimension of the alveolar ridge (3.7 ± 1.2 mm) compared with the ARP sites (1.8 ± 1.3 mm). The mean vertical ridge height reduction in the control sockets was 3.1 ± 1.3 mm at the buccal sites and 2.4 ± 1.6 mm at the lingual sites compared with 0.6 ± 1.4 and 0.5 ± 1.3 mm, respectively, in the test sockets. The differences between test and control sockets were not significant for the mesial and distal measurements.

Conclusions: The placement of a porcine xenograft with a membrane in an extraction socket can be used to reduce the hard tissue reabsorption after tooth extraction compared with EXT.

Purpose: The aim of this study was to compare endodontic and implant treatments and to evaluate their predictability over an 8-year period on the basis of an analysis of survival data and a retrospective clinical study.

Materials and Methods: A group of 40 partially edentulous patients were selected for this study. Their teeth had been endodontically treated and rehabilitated using gold alloy and ceramic restorations. In these patients, 65 osseointegrated implants were restored with single gold alloy–ceramic crowns and monitored on a yearly basis for 8 years with standardized periapical radiographs, using a polivynilsiloxane occlusal key as a positioner. A total of nine patients who did not attend the yearly follow-up were excluded from the study. The Melloning and Triplett criteria were used to evaluate the clinical results obtained in the implant sites. The clinical results of the 56 endodontically treated teeth, restored with the fixed prosthesis of 40 patients, were analyzed according to probing depth as well as an assessment of the correct apical and coronal seals. The survival rate was calculated using the Kaplan–Meier method and the statistical significance was calculated using the chi-square test.

Results: During the follow-up of the endodontically treated elements, seven failures were detected (83.34%) and the success rate of implants inserted in the same patients was equal to 80.8%, with nine implants lost in 8 years. The survival analysis of the elements treated with both therapies was not statistically significant (p = .757) and the confidence interval was between 0.2455 and 2.777.

Conclusion: In view of the superimposable results between the two therapies, it should be noted that the endodontically treated teeth could be interested by different pathologies while the restoration of the atrophic edentulous ridge with an implant support is predictable when patients comply with correct oral hygiene and when the occlusal loads are axially distributed in implant-protected occlusion.

Purpose: To retrospectively compare the fixation modalities semipermanent and permanent for all cemented single crowns and Fixed Dental Prostheses (FDPs) placed at the Department of Prosthodontics in the years 2002 to 2010 with regard to the incidence of survival and complications.

Materials and Methods: Two hundred forty-one patients (48.5% male, mean age 57.3 years) received 166 FDPs and 232 single crowns. A total of 50.6% of the FDPs and 54.7% of the single crowns were fixed using semipermanent cements. Aside from fixation, age, gender, type, location, and material of the suprastructures were assessed as possible factors affecting complications, namely de-cementation, chipping, framework, or abutment fracture.

Results: During an observation period of up to 6.6 years (mean 2.24 years; standard deviation 1.38), the survival rates were 96.4% and 100% for FDPs (semipermanent/permanent cementation), and 98.4% and 92.4% for single crowns (semipermanent/permanent). The success rates achieved, counting every complication, for the FDPs were 61.9% and 70.7% (semipermanent/permanent) and for single crowns were 75.6% and 77.1% (semipermanent/permanent). The cement used had a significant effect on loss of retention of the FDPs (p = .006), but no significant effect on the retention of the single crowns. Cementation procedure exhibited no significant impact on chipping for both FDPs and single crowns. The frequency of framework or abutment fractures was too low for further statistical analyses.

Conclusion: Both semipermanent and permanent cementation of FDPs and single crowns resulted in high survival rates. Within the limitations of the study design, because of the amount of chairside aftercare required, implant-borne FDPs could be recommended for permanent cementation.

Statement of problem: Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable treatment protocol. However, there is limited long-term data available in the literature, when an electroeroded definitive cast-titanium fixed prosthesis is used for this treatment protocol.

Purpose: The aim of this study was to evaluate the clinical effectiveness of dental implants (Astra Tech Dental, Mölndal, Sweden) in the edentulous mandible immediately loaded with an electroeroded cast-titanium screw-retained fixed prosthesis.

Materials and Methods: Forty-five patients received five implants each in the interforaminal area. All the implants were inserted with torque up to 40 Ncm and the distal implants were distally tilted approximately 20 to 30 degrees to minimize the length of posterior cantilevers. Implants were loaded within 48 hours of placement with an acrylic resin-titanium screw-retained prosthesis fabricated by electroerosion.

Results: Two of the 225 inserted implants failed after 3 and 16 months of healing, respectively, with a cumulative survival rate of 99.1% and a prosthetic survival rate of 97.8%.

Conclusion: Immediate loading of tilted dental implants inserted in the edentulous mandible with a screw-retained titanium definitive prosthesis fabricated with electrical discharge machining provide reliable and predictable results.

Background: Immediate implant function has become an accepted treatment modality for fixed restorations in totally edentulous mandibles, whereas experience from immediate function in the edentulous maxilla is limited.

Purpose: The purpose of this study was to report on the medium- and long-term outcomes of a protocol for immediate function of four implants (All-on-4™, Nobel Biocare AB, Göteborg, Sweden) supporting a fixed prosthesis in the completely edentulous maxilla.

Materials and Methods: This retrospective clinical study included 242 patients with 968 immediately loaded implants (Brånemark System® TiUnite™, Nobelspeedy™, Nobel Biocare AB) supporting fixed complete-arch maxillary all-acrylic prostheses. A specially designed surgical guide was used to facilitate implant positioning and tilting of the posterior implants to achieve good bone anchorage and large interimplant distance for good prosthetic support. Follow-up examinations were performed at 6 months, 1 year, and thereafter every 6 months. Radiographic assessment of the marginal bone level was performed after 3 and 5 years in function. Survival was estimated at patient level and implant level using the Kaplan–Meier product limit estimation with 95% confidence intervals.

Results: Nineteen immediately loaded implants were lost in seventeen patients, giving a 5-year survival rate estimation of 93% and 98% at patient and implant level, respectively. The survival rate of the prosthesis was 100%. The marginal bone level was, on average, 1.52 mm (standard deviation [SD] 0.3 mm) and 1.95 mm (SD 0.4 mm) from the implant/abutment junction after 3 and 5 years, respectively.

Conclusion: The high survival rates at patient and implant level indicates that the immediate-function concept for completely edentulous maxillae using the present protocol is viable in the medium- and long-term outcomes.

Objectives:Background Intraoral autogenous bone grafts are a convenient source of bone in reconstruction of the residual ridge before dental implant placement.

Purpose: The aim of this study was to evaluate bone volume of symphysis donor defects filled with bone substitute compared with unfilled symphysis donor defects.

Patients, Materials and Methods: The study included 26 patients who underwent either alveolar ridge reconstruction or maxillary sinus elevation. Two groups were studied: symphyseal donor defects filled with bone substitute and unfilled symphyseal donor defects. Pre- and postoperative volumetric variables were determined using computed tomography scans and the software program SimPlant® (Materialise Dental Italia, Roma, Italy).

Results: At 6 months postsurgery, the filled donor defects exhibited a significant increase in bone volume compared with unfilled donor defects (97.7% and 73.4%, respectively). At 18 months postsurgery, volume of unfilled donor defects was reevaluated with no significant increase in bone volume.

Conclusions: Six months following block harvesting procedure, filled donor defects maintained bone volume, while unfilled donor sites generated defects that cannot achieve full regeneration; even not 18 months postblock harvesting.

Purpose: Cone beam computerized tomography (CBCT) provides three-dimensional information and could absolutely be useful for evaluating circumferential implant bone levels. However, the accuracy and precision of the technique has not been described. The aim of the study was to assess the accuracy and precision of CBCT (i-CAT®, Imaging Sciences International®, Hatfield, PA, USA) using periapical radiographs (PA) as a reference and to evaluate the circumferential bone level on CBCT around immediately loaded single implants placed in healed ridges (CIT, conventional implant treatment) and extraction sockets (IIT, immediate implant placement).

Materials and Methods: PA and CBCT radiographs were obtained from 26 single Astra Tech Osseospeed™ implants (Astra Tech AB, Mölndal, Sweden) 1 year after loading in respectively healed ridges (CIT) or extraction socket (IIT). For accuracy analysis, the three mesial and three distal interproximal levels obtained by CBCT were pooled to enable a comparison with PA. Precision was analyzed by intra- and interexaminer reliability calculation from mesial and distal sites on CBCT. The circumferential bone level considered all eight positions assessed on CBCT.

Results: Accuracy of CBCT was low (R = 0.325/p = .019) given the fact that bone level of the total group was 0.70 mm (standard deviation [SD] 0.78, range 0.00–3.20) on PA and 0.23 mm (SD 0.27, 0.00–1.20) on CBCT (p < .001) with only 42% of the measurements showing deviation within 0.2 mm. However, intra- and interexaminer reliability were favorable (R ≥ 0.611/p < .001, ≥83%). The mean circumferential bone level on CBCT was 0.21 mm (SD 0.30) and 0.26 mm (SD 0.18) for IIT and CIT, respectively. The impact of the treatment strategy was not significant.

Conclusion: PA should be the standard technique to assess interproximal bone level but correlates poorly with the CBCT measurements. However, the precision of CBCT was high. CBCT requires further improvements of hardware and/or software. Within the limitations of the study, there is an indication that the buccal bone 1 year after implant treatment is evenly preserved when implants are immediately loaded in extraction sockets or in healed bone.

Purpose: The aims of the study are to introduce a new parameter to measure primary stability and to evaluate the possible correlations between this parameter and bone density, initial bone-to-implant contact (IBIC), Resonance Frequency Analysis (RFA), and peak insertion torque (IT).

Material and Methods: The study was performed on three different types of fresh humid bovine bone: type I, type II, and type III. A total of 90 XiVE implants (30 per bone type) were used; implant insertion was performed with a calibrated maximum torque of 70 Ncm at predetermined 30 rpm. The IT data were recorded and exported as a curve; using a trapezoidal integration technique, the area underlying the curve was calculated: this area represents the variable torque work (VTW). Furthermore, peak IT and RFA were recorded; finally IBIC was calculated from histological specimens.

Results: Spearman correlation analysis of the entire sample reveals that VTW presents a significant (p < .01) positive correlation with bone density; a significant (p < .05) positive correlation with IBIC, and a significant (p < .01) positive correlation with all the other primary stability parameters. Spearman correlation analysis of the three different groups show that VTW presents a significant positive correlation with IT in all three types of bone; on the other hand, VTW shows a negative not significant correlation with RFA in bone I, a positive significant correlation in bone II, and a positive not significant correlation in bone III. Furthermore, VTW shows a negative significant correlation with IBIC in bone I and a positive significant correlation in bone II and III.

Conclusions: Within the limitations of an in vitro study, the VTW seems to be a promising parameter to measure implant primary stability.

Introduction: The Co-Axis® implant (Southern Implants®, Irene, South Africa) has a 12-degree angle in the implant neck to overcome angulation problems.

Aim: To examine bone loss, peri-implant health, and aesthetical outcome after 1-year follow-up.

Materials and Methods: Fifteen single implants were placed in 14 patients in the premaxilla and immediately loaded with a screw-retained full ceramic crown. Periapical radiographs and standardized photographs were taken to determine bone loss and soft tissue changes. Plaque and bleeding levels were assessed. Patients' satisfaction was measured using the Oral Health Impact Profile-14 questionnaire.

Results: After 1 year, all implants survived and mean bone loss was 1.20 mm, with no significant changes after 6 months. Plaque levels were low and no significant changes were observed. Bleeding levels decreased during the initial 3 months, but were constant thereafter. Before final torqueing was performed after 6 months, four cases of screw loosening occurred. Also, one crown had a piece of porcelain chipped off. Patients reported an overall increase in well-being. A mean midfacial recession of 0.37 mm was observed. The mesial papilla showed a slight increase of 0.14 mm, while the distal papilla decreased 0.35 mm.

Conclusion: With 100% survival and stable bone levels after 6 months, the Co-Axis implant showed a good clinical outcome when immediately loaded. The use of a full ceramic crown as a first and final restoration resulted in a good aesthetic outcome with few changes in papilla fill, although midfacial soft tissue was stable only after 1 year.

Objective: Severely atrophied alveolar ridges are most commonly reconstructed with free autologous bone grafts from the iliac crest. The use of these grafts, however, is frequently associated with bone resorption as possible late complication after implant surgery and prosthetic loading. Other donor sites, especially intraoral donor sites, show limited availability. The aim of this present study was to evaluate the clinical and radiographical outcome of alveolar ridge reconstruction with bone from the calvarium and subsequent implant rehabilitation.

Patients and Methods: Reconstruction was performed by using calvarial split grafts in case of severe and complex alveolar ridge defects induced by trauma or bone atrophy. Fifteen patients were treated at 19 different intraoral recipient sites (15 sites in the maxilla, four in the mandible). Autologous block grafts were used for combined vertical and horizontal grafting. After a 3-month healing period, patients received dental implants. A total of 99 dental implants (OsseoSpeed™, Astra Tech AB, Mölndal, Sweden) were inserted and left to heal in a submerged position for 3 months before the prosthetic implant-based rehabilitation was performed.

Results: No donor site complications occurred during or after surgery. At the intraoral recipient sites two infections occurred, leading to partial loss of the grafts. Implant placement, however, was possible in all cases. Two of 99 implants were lost in two patients prior to prosthetic loading. Patients were followed up clinically and radiographically for an average observation period of 28 months. Implant survival rate and success rates were 97.85 and 95.7%, respectively, and a minimal marginal bone loss was documented.

Discussion: The low morbidity at the donor sites and the good marginal bone stability in the reconstructed regions indicate that calvarial bone grafts represent a viable treatment alternative to grafts from the iliac crest.

Background: There have been very few long-term controlled studies (i.e., over 5 years duration) focusing on marginal conditions for implants with a sandblasted, large grit, and acid-etched (SLA) surface.

Purpose: To evaluate and report 10-year data on outcomes of implants with an SLA surface placed in the edentulous maxilla.

Materials and Methods: In a randomized controlled trial (RCT) cohort of 24 patients, the outcomes of implants with an SLA surface were registered. The RCT cohort has previously been reported after 1 year, 3 years, and 5 years of loading.

Results: One patient dropped out of the study prior to the 10-year control. Of the 23 remaining patients, the implant survival rate was 95.1%. If implants of unknown status were also considered lost, that is, one drop-out patient with three implants for whom no information could be obtained, the implant survival rate was 93%. The mean marginal bone loss from baseline (139 implants) to 10 years (102 implants) was 1.07 mm (standard deviation 0.98). One implant out of 102 available for radiographic examination according to the original protocol showed a bone loss exceeding 4 mm. Of the 84 implants available for clinical examination, none showed a Plaque Index or sulcus bleeding index of 3. The mean implant stability quotient was significantly higher for mesial–distal versus buccal–palatal measurements.

Conclusion: The implant survival was 95.1%. The mean value of bone loss after 10 years was 1.07 mm. Peri-implantitis were noted at the 5-year follow-up for one patient with a previous history of periodontitis; this patient did not attend the 10-year follow-up. This study shows that sandblasted and acid-etched implants offers predictable long-term results as support for full-arch maxillary prostheses.

Purpose: The objective of this retrospective study was to compare the incidence of chipping of implant-supported, all-ceramic, and metal–ceramic single crowns.

Material and Methods: One hundred fifty-three patients (51.7% male, mean age 55.0 years) received 232 cemented implant-supported single crowns. One hundred and seventy-nine crowns had a metal framework (gold alloy) and 53 crowns were all-ceramic (zirconia framework and glass–ceramic veneer material). Age, gender, kind of cementation, and location of the restorations were assessed as possible factors affecting chipping.

Results: During the observation period of up to 5.8 years (mean 2.1 years; standard deviation 1.4), a total of 13 (24.5%) all-ceramic and 17 (9.5%) metal–ceramic crowns suffered from chipping, a difference that was statistically significant. A total of ten single crowns had to be remade resulting in survival of 86.8% (all-ceramic) and 98.3% (metal–ceramic). The other possible factors did not have a significant effect on the chipping.

Conclusion: Chipping was found to be more frequent for all-ceramic implant-supported single crowns. If the reasons for the vulnerability of all-ceramic crowns remain unknown, implants with all-ceramic single crowns should generally be recommended with care.

Purpose: With the improved macro- and micro-designs, dental implants enjoy a high survival rate. However, peri-implant bone loss has recently emerged to be the focus of implant therapy. As such, researchers and clinicians are in need of finding predictable techniques to treat peri-implant bone loss and stop its progression.

Materials and Methods: Literature search on the currently available treatment modalities was performed and a brief description of each modality was provided.

Results: Numerous techniques have been proposed and none has been shown to be superior and effective in managing peri-implant bone loss. This may be because of the complex of etiological factors acting on the implant-supported prosthesis hence the treatment approach has to be individually tailored.

Conclusion: Due to the lack of high-level clinical evidence on the management of peri-implant bone loss, the authors, through a literature review, attempt to suggest a decision tree or guideline, based on sound periodontal surgical principles, to aid clinicians in managing peri-implantitis associated bone loss.

Purpose: The aim of this study was to develop and evaluate a new stereoscopic technique for conversion of radiographic guide into surgical guide for dental implant placement.

Materials and Methods: Ten partially dentate patients requiring 18 implants for tooth replacement were recruited. Radiographic guides were modified with the addition of index rods for double computed tomography scanning. Implant positions were planned with implant planning software, and the stereoscopic angulations were measured. The radiographic guides were converted into surgical guides using either a generic bench drill (Group A, n = 9) or a milling machine (Group B, n = 9). Stereolithographic surgical guides were also made for three patients (Group S, n = 5). Differences between the planned and actual angulations were tested by pair-sample t-test. Difference of mean angle deviation among groups was tested by Brown–Forsythe test. Differences were considered significant if p < .05.

Results: Eighteen implant sites were successfully treated with the converted surgical guides. The mean angle deviation of Group A (1.3 ± 0.6°) was significantly greater than Group S (0.4 ± 0.6°), while no differences were found between Group B (0.9 ± 0.3°) and Group S. The linear error was greatest in Group A with 1.5 mm at the head and 1.8 mm at the apex of the implant.

Conclusions: The use of this new stereoscopic technique appears to be an acceptable alternative method for converting radiographic guide into surgical guide.

Background: The relationship between the immune response and red and white blood cell homeostasis is cited in literature, but no studies regarding the balance of these cell populations following maxillary bone-graft surgeries can be found.

Aim: The aim of this study was to evaluate the possible impairments in the blood cell balance following fresh–frozen allogeneic bone-graft augmentation procedures in patients who needed maxillary reconstruction prior to implants.

Material and Methods: From 33 patients elected to onlay bone grafting procedures, 20 were treated with fresh–frozen bone allografts and 13 with autologous bone grafts. Five blood samples were collected from each patient in a 6-month period (baseline: 14, 30, 90, and 180 days postsurgery), and the hematological parameters (erythrogram, leukogram, and platelets count) were accessed.

Results: All evaluated parameters were within the reference values accepted as normal, and significant differences were found for the eosinophils count when comparing the treatments (30 days, p = .035) and when comparing different periods of evaluation (allograft-treated group, baseline × 180 days, p ≤ .05 and 90 × 180 days, p ≤ .01; autograft-treated group, 30 × 90 days, p ≤ .05 and 30 × 180 days, p ≤ .05).

Conclusions: Both autologous and fresh–frozen allogeneic bone grafts did not cause any impairment in the red and white blood cell balance, based on quantitative hemogram analysis, in patients subjected to maxillary reconstruction.

Background/Aim: Evidence from head-to-head comparison trials on peri-implantitis treatment is limited, and it is therefore impossible to conduct a direct meta-analysis. We propose an alternative statistical method, network meta-analysis, for evidence synthesis, which enables to compare the results of multiple treatments.

Methods: We searched, in triplicate, for randomized controlled trials (RCTs) and controlled trials in the PubMed, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and Latin American and Caribbean Health Sciences Literature databases up to and including August 2010. We also conducted a manual search of the reference lists regarding published systematic reviews and searched for gray literature in OpenSIGLE. We assessed changes in clinical attachment level (CAL) and pocket probing depth (PPD) after nonsurgical and surgical treatments of peri-implantitis. The risk of bias of selected studies was determined by the use of specific criteria, and it was performed in triplicate and independently. We used multilevel mixed modeling to perform the network meta-analysis and Markov Chain Monte Carlo simulation to obtain confidence intervals for the fixed and random effects.

Results: Eleven studies were included in the review. All RCTs are at unclear or high risk of bias. Surgical therapy in conjunction with bone grafts and non-resorbable membranes achieved 3.52 mm greater PPD reduction than nonsurgical therapy alone, 95% high-probability density (HPD) intervals: −0.19, 6.81. Surgical treatment in conjunction with bone grafts and resorbable membranes achieved 2.80 mm greater CAL gain than nonsurgical therapy alone, 95% HPD intervals: −0.18, 5.59.

Conclusion: Surgical procedures in peri-implantitis treatment achieve more PPD reduction and CAL gain than nonsurgical approaches. Nevertheless, these results should be interpreted with caution because of the limited number of studies included and their low methodological quality. Network meta-analysis is a useful statistical methodology for evidence synthesis and to summarize the strength and limitation in the current evidence.

Background: Long-term follow-up studies (i.e., over 5 years), focusing on prosthetic outcomes and maintenance of implant-supported reconstructions in the edentulous maxilla, are scarce in the literature.

Purpose: The purpose of this study was to evaluate and report 10-year data on outcomes and maintenance of screw-retained implant-supported full-arch casted titanium-resin prostheses in the edentulous maxilla.

Materials and Methods: In the randomized control trial cohort of 24 patients, the outcome and maintenance of 23 bridges were registered.

Results: One patient dropped out of the study prior to the 10-year control. Of the 23 remaining patients, 21 still had their original frameworks; one framework fractured after 8 years and one was remade after 7 years to create better support for the acrylic. The remaining 23 prostheses showed criteria of success, survival, and failure in 9, 82, and 9%, respectively. Tightening of two assembly screws was necessary in one patient. No detrimental effects were seen because of long cantilever extensions or opposing dentition. A total of 4.7 resin-related complications per prosthesis were observed; tooth fracture was the most common prosthetic complication. There was an indication of greater prevention in the number of resin-related complications with the use of lingual gold onlay compared with a resilient mouth guard, 0.71 and 1.67, respectively per bridge. The bridges were removed and reinserted 0.83 times per patient. No abutment or abutment screw fractures were registered.

Conclusion: Fracture or wear of the reconstruction materials were considered predictable risks when using resin-based suprastructure materials. Status of opposing dentition and length of cantilevers did not confer additional risk. The use of a lingual gold onlay indicated prevention of resin-related complications. Future research should focus on the suprastructure materials to predict better overall treatment results of implant-supported full-arch bridges in the edentulous maxilla.

Background: In the absence of autologous bone for harvesting, fresh-frozen bone allografts turned into an alternative for bone reconstruction procedures.

Purpose: The purpose of this study was to make a histological analysis of fresh-frozen onlay bone allografts (ALs), compared with autografts, in patients who needed maxillary reconstruction prior to dental implants placement.

Materials and Methods: Twelve patients with bone deficiencies (width inferior to 4 mm) in the sites where the implants were planned were enrolled in the study. From these, six were elected to be treated with autogenous (AT) bone grafts and six with fresh-frozen bone AL. This last group included the patients who had absence of a convenient amount of bone in donor sites. Each patient received from one to six graft blocks, totalling to 12 ATs and 17 ALs. Seven months after grafting procedures, biopsies of the grafts were made using 2-mm internal diameter trephine burs, and processed for histological analysis. One biopsy was retrieved from each patient.

Results: Clinically, all grafts were found to be firm in consistency and well-incorporated to the receptor bed. Histological analysis showed a large amount of necrotic bone surrounded by few spots of new-formed bone in the AL group, suggesting low rate of graft remodeling. In the AT group, an advanced stage of bone remodeling was seen.

Conclusions: Human fresh-frozen bone block AL showed clinical compatibility for grafting procedures, although associated to slow remodeling process. Further studies are needed to define, at long term, the remodeling process chronology the clinical longitudinal results for fresh-frozen bone AL.

Background: Various levels of infraposition of single-implant restorations have been observed in long-term follow-up studies, but little knowledge is available on the biological mechanism behind this pattern.

Purpose: The primary aim of this study is to report the frequency and severeness of implant infraposition in the anterior single-implant application after 17 to 19 years in function and, secondly, to try to relate these observations to anatomical appearance of the shape of the face of the patient.

Materials and Methods: The present study comprised of 57 patients who were provided with 65 CeraOne™ single-tooth restorations (Nobel Biocare AB, Gothenburg, Sweden) between 1989 and 1991. Altogether 46 of these patients were treated with single implants in the anterior region. Besides clinical and radiographic data, clinical photographs, study casts, and patient's assessment of the long-term aesthetic result (visual analog scale) was collected at the termination of the present study. The degree of implant crown infraposition was related to assessed facial shape and to patient and clinical assessment of the aesthetic result by means of Pearson's correlation test. To increase the numbers of patients, another group of 25 patients presented in another similar study were pooled with the present material for prevalence calculations.

Results: Altogether 47 patients showed up for the final examination after an average of 18 years (82%). Two implants failed (18 years cumulative survival rates [CSR]– 96.8%) and eight original single-crown restorations were replaced (CSR 83.8%). Three of the replaced crowns were replaced because of infraposition of the crowns. About 40% of the patients showed signs of infraposition, similar in younger and older age groups, but more frequently observed in female patients at termination of the study (p < 0.05). There was a weak trend indicating an association between “long-face” appearance and infraposition of the crown restoration (p > 0.05), and patients were more satisfied with the aesthetic clinical result than the participating clinicians (p < 0.05).

Conclusion: Single-implant restorations in the anterior upper jaw may present small degrees of infraposition in long-term perspectives. Female patients seem to be at a higher risk of infraposition (p < 0.05), but no clear relationship between age at implant placement or facial shape and degree of infraposition was possible to establish (p > 0.05). Patients were more satisfied with the aesthetic result, as compared with the clinicians (p < 0.05), and patients seemed to pay less attention to the degree of infraposition in their aesthetic assessments, as compared with most of the clinicians.

Purpose: This prospective study was performed to evaluate the outcomes of XiVE® S plus implants (Dentsply Friadent, Mannheim, Germany) following conventional restoration with bar structures and overdentures in the edentulous mandible.

Materials and Methods: A total of 39 patients were treated with four interforaminal implants (n = 156) splinted by a Dolder bar. Overdentures were attached to the bars after 3 months of healing. As primary outcome measures, clinical and radiological parameters were evaluated at the time of implant placement (baseline) and once a year (1, 2, 3, 4, 5 years) after functional loading. Secondary outcome measures included (i) primary stability and surgical complications, as well as (ii) Periotest® (Medizintechnik Gulden, Modautal, Germany) values, implant survival, and prosthetic complications at baseline and follow-up.

Results: A total of 156 implants were placed. The vast majority (n = 149) were tightened to >30 Ncm, while torques in the range of 20–30 Ncm were obtained in the remaining cases (n = 7). Mean crestal bone levels around the implants were 0.41 mm at baseline and 1.04/1.20/1.34/1.45/1.44 mm after 1/2/3/4/5 years respectively. The mean values of the plaque, calculus, bleeding, and mucosal indices remained low throughout this period. The reported follow-up periods involved one implant loss after 3 months (survival rate: 99.4%) and one implant failure after 4 years (success rate: 98.4%). Prosthetic complications included factures of bars (n = 3) and denture teeth (n = 7). Prosthetic survival was 100%.

Conclusions: Dolder bars to restore oral implants in the edentulous mandible appear to offer a high rate of implant survival, good stability of the peri-implant tissue, and a low rate of prosthetic complications.

Background: Insufficient bone volume often hamper placement of dental implants in the posterior maxilla.

Purpose: The aim of the present clinical study was to evaluate retrospectively the clinical outcome of implant placement in the resorbed posterior maxilla using an osteotome technique without adding any grafting material.

Materials and Methods: Twenty patients with 5 to 9 mm of residual alveolar bone height in the posterior maxilla received twenty-nine implants (Neoss Ltd., Harrogate, UK) using an osteotomy technique without bone grafts. Intraoral radiographs were taken before and after implant placement, at the time of loading and after 11 to 32 months of loading (mean 16.4 months), to evaluate bone formation below the sinus membrane and marginal bone loss. Implant stability measurements (Osstell^TM, Gothenburg, Sweden) were performed after implant installation and at abutment connection 5 months later. All implants were installed with the prosthetic platform level with the bone crest.

Results: No implant was lost giving a survival rate of 100% after a mean follow-up time of 16.4 months. The average vertical bone height was 7.2 ± 1.5 mm at placement and 10.0 ± 1.0 mm after 11 to 32 months. The average increase of 2.8 ± 1.1 mm was statistically significant. There was a statistically significant improvement in implant stability from 70.7 ± 9.2 implant stability quotient (ISQ) at placement to 76.7 ± 5.7 ISQ at abutment connection, 5 months later. The mean marginal bone loss amounted to 0.7 ± 0.3 mm after 11 to 32 months of loading.

Conclusion: It is concluded that the osteotome technique evaluated resulted in predictable intrasinus bone formation, firm implant stability, and good clinical outcomes as no implants were lost and minimal marginal bone loss was observed.

Background: Extensive atrophy of the alveolar process may require a bone-grafting procedure prior to implant treatment. Autogenous bone grafts from the iliac crest, used as onlay block and particulate bone, have been used together with sinus-lift procedure in order to rehabilitate patients with extremely resorbed maxillae. However, there are to our knowledge no 5-year follow-up studies evaluating the extent of bone-level change in patients treated with respectively block and particulate autogenous bone grafts.

Purpose: The purpose of this prospective clinical study was to conduct a 5-year follow-up analysis with focus on bone-level alteration in block versus particulate onlay bone grafts.

Material and Methods: Fifteen out of originally 19 patients who were treated with iliac bone grafts and oral implants in the maxilla have been followed through the first 5 postoperative years. In a first study conducted on 19 patients, the role of platelet-rich plasma in conjunction with autogenous bone was evaluated. In this 5-year follow-up study, the marginal bone alterations have been documented at base line, 1 year and 5 years of loading to the nearest 0,1 mm at mesial and distal surfaces of the implants. Two implants were installed on each side of the midline in either block or particulate bone grafts giving test and control sides in each patient. Additionally, two implants on each side were installed in residual bone/grafted sinus floor.

Result: Marginal bone alteration in the anterior maxilla appeared larger at the side augmented by block bone at baseline, and after 1 and 5 years of loading, but the change was not statistically significant. Moreover, there was a significantly higher degree of marginal alteration during the first year of loading, compared with the examinations after 5 years.

Conclusion: The present follow-up study showed that there is no significant difference in the extension of resorption between block- and particulate autogenous bone grafts over a 5-year period. Most of the resorption occurred during the first year in function.

Purpose: The aim of this prospective randomized controlled clinical study was to assess the crestal bone loss and the implant stability in implants that were placed by the osteotome technique compared with the conventional drilling technique.

Materials and Methods: Forty-six screw type Straumann SLA® oral implants (Straumann AG, Waldenburg, Switzerland) were inserted in the anterior segment of maxilla of 30 patients. The implant site was prepared randomly using either osteotome technique (test group) or the conventional drilling technique (control group). Radio frequency analysis (RFA) values at implant placement and after 3 months were recorded. The crestal bone loss was measured using digital subtraction radiography technique after 3, 6, and 12 months.

Results: RFA demonstrated a statistically significant higher primary stability for implants in the osteotome group than that of the conventional group (p = .026) at the time of implant insertion. However, there was no statistically significant difference between both groups 3 months after the surgery (p = .06). At month 3, the osteotome group caused significantly more crestal bone loss than the conventional group (p = .04). At months 6 and 12, both groups had comparable bone levels (p = .29).

Conclusion: Osteotome technique yielded higher primary stability than conventional drilling technique. However, this technique was not superior to conventional technique after 3 months.

Background: Strain, frequency, loading time, and strain rate, among others, determine mechanical parameters in osteogenic loading. We showed a significant osteogenic effect on bone mass (BM) by daily peri-implant loading at 1.600 µε.s⁻¹ after 4 weeks.

Purpose: To study the peri-implant osteogenic effect of frequency and strain in the guinea pig tibia by in vivo longitudinal micro-computed tomography (CT) analysis.

Material and Methods: One week after implant installation in both hind limb tibiae, one implant was loaded daily for 10′ during 4 weeks, while the other served as control. Frequencies (3, 10, and 30 Hz) and strains varied alike in the three series to keep the strain rate constant at 1.600 µε.s⁻¹. In vivo micro-CT scans were taken of both tibiae: 1 week after implantation but before loading (v1) and after 2 (v2) and 4 weeks (v3) of loading as well as postmortem (pm). BM (BM (%) bone-occupied area fraction) was calculated as well as the difference between test and control sides (delta BM)

Results: All implants (n = 78) were clinically stable at 4 weeks. Significant increase in BM was measured between v1 and v2 (p < .0001) and between v1 and v3 (p < .0001). A significant positive effect of loading on delta BM was observed in the distal peri-implant marrow 500 Region of Interest already 2 weeks after loading (p = .01) and was significantly larger (11%) in series 1 compared with series 2 (p = .006) and 3 (p = .016).

Conclusions: Within the constraints of constant loading time and strain rate, the effect of early implant loading on the peri-implant bone is strongly dependent on strain and frequency. This cortical bone model has shown to be most sensitive for high force loading at low frequency.

Aim: The first objective of this study was to qualitatively and quantitatively assess the bone formation process, particularly the long-term behavior and three-dimensional volume stability of subsinusal bone regeneration, using titanium (Ti) or bovine hydroxyapatite (BHA) granules, in a rabbit model. The second objective was to evaluate the effect of the hydration of the BHA particles with a therapeutic concentration of doxycycline solution on the osteogenesis and biomaterial resorption.

Materials and Methods: Rabbits underwent a double sinus lift procedure using one of three materials: grade 1 porous Ti particles, BHA, or BHA hydrated with doxycycline solution (0.1 mg/ml) (BHATTC). Animals were sacrificed after 1 week, 5 weeks, or 6 months. Samples were analyzed using µCT and nondecalcified histology.

Results: The materials used in each of the three groups allowed an optimal bone formation; bone quantities and densities were not statistically different between the three groups. At 6 months, more stable three-dimensional volume stability was found with Ti and BHATTC (p = .0033). At 5 weeks and 6 months, bone to material contact corroborating osteoconduction was significantly higher with BHA and BHATTC than with Ti (p < .0001).

Conclusions and Clinical Implications: Even though the studied biomaterials displayed different architectures, they are relevant candidates for sinus lift bone augmentation prior to dental implants because they allow adequate three-dimensional stability and osteogenesis. However, to recommend the clinical use of Ti, both an observation on the drilling effects of Ti particles and clinical trials are needed.

Aim: To evaluate the aesthetic outcome of single-tooth implants in the aesthetic zone with different neck designs from a professional's and patient's perception.

Materials and Methods: Ninety-three patients with a missing anterior tooth in the maxilla were randomly assigned to be treated with an implant with a smooth neck, a rough neck with grooves or a scalloped rough neck with grooves. Implants were installed in healed sites. One year after definitive crown placement (18 months post-implant placement), photographs were taken and the aesthetic outcome was assessed according to two objective aesthetic indexes: pink esthetic score/white esthetic score (PES/WES) and implant crown aesthetic index (ICAI). A questionnaire was used to assess the aesthetic outcome and general satisfaction from a patient's perception. Standardized radiographs were taken to measure marginal bone level changes.

Results: One implant was lost. Although there was a significant difference in marginal bone loss between the different implant neck designs (smooth neck 1.19 ± 0.82 mm, rough neck 0.90 ± 0.57 mm, scalloped neck 2.01 ± 0.77 mm), there were no differences in aesthetic outcome. According to the professional's assessments using PES/WES and ICAI, 79.3% and 62% of the cases showed acceptable crown aesthetics, and 59.8% and 56.5% of the cases showed acceptable mucosa aesthetics. Overall, patients were satisfied about the aesthetics of the mucosa (81.5%) and crown (93.3%), and general patient satisfaction was high (9.0 ± 1.0 out of a maximum of 10). According to the professional's assessment, a pre-implant augmentation procedure was associated with less favorable aesthetics of the mucosa.

Conclusion: This study shows that the aesthetics of single-tooth implants in the maxillary aesthetic zone appears to be independent of the implant neck designs applied but dependent on the need for pre-implant surgery.

Background: Lack of osseointegration between a dental implant and the walls of the alveolar bone is a common problem in immediate implantation. Injectable tissue-engineered bone (ITB) may be an effective and minimally invasive solution to the problem. In this study, an injectable bone cement, nHAC/CSH, which consists of nano-hydroxyapatite/collagen (nHAC) and calcium sulfate hemihydrate (CaSO₄.½H₂O; CSH) was investigated as a tissue-engineered scaffold material with blood-acquired mesenchymal progenitor cells (BMPC) as seeding cells.

Purpose: The aim of the study was to assess the new bone formation around immediate dental implants using nHAC/CSH loaded with dog blood-acquired mesenchymal progenitor cells (dBMPC) in a canine model.

Materials and Methods: dBMPC were first isolated from peripheral blood of healthy adult dogs. Alizarin red and oil red O staining were then used to evaluate the potential of dBMPC to differentiate into bi-lineage mesenchymal tissues in vitro. Four healthy mongrel dogs were used in this study. The alveolar bone defects around immediate implants of dogs were created. Each defect was randomly assigned to one of the following three groups: (1) the ITB group (dBMPC + nHAC/CSH); (2) injectable bone cement nHAC/CSH; or (3) no materials (controls). Methylene blue staining was used to examine the bone formation after 3 months.

Results: Studies in vitro revealed that dBMPC could be induced to osteoblasts and adipocytes. The ITB group (dBMPC + nHAC/CSH) showed significantly more bone-implant contact and bone density than either nHAC/CSH or control groups in the areas with peri-implant defects 3 months after implantation.

Conclusion: The results indicate that the ITB composed of nHAC/CSH and dBMPC may represent a useful strategy for the clinical reconstruction of bone defects around immediate implantation. However, further investigation is needed involving the use of human BMPC as well as possible use of stem cells.

Objectives: This preliminary investigation aimed to evaluate the potential of contaminated implants to reosseointegrate into pristine sites and, in addition, to assess the potential of osseointegration of new implants in peri-implantitis sockets in a canine model.

Methods: All mandibular premolars were bilaterally extracted from two mongrel dogs. Following 12 weeks of healing, two dental implants were inserted on each hemiarch. Forty-five days following implant placement, a silk ligature secured with cyanoacrylate was placed around the implants' cervical region in order to induce peri-implantitis. After another 45 days from ligature placement, the implants were mechanically removed using counter rotation with a ratchet and were reimplanted without any decontamination (neither rinsing nor chemical or mechanical cleaning) in adjacent pristine zones. In sites where implants were removed, new, wider-diameter implants were placed in the infected sockets. Forty-five days following reimplantation surgery, the dogs were sacrificed; nondecalcified specimens were processed and toluidine blue stained for morphologic and morphometric (bone-to-implant contact [BIC]) assessment under an optical microscope.

In dog 1 all the implants (both in the pristine and in the infected sites) survived and osseointegrated while in dog 2, six out of eight implants failed to osseointegrate and exfoliated. Overall, the mean BIC of all implants was 51.08% (SD 20.54). The mean BIC for the infected implants placed into pristine sites was 51.48% ± 26.29% (SD) and the mean BIC for the new implants in peri-implantitis socket was 50.58% ± 14.27% (SD).

Conclusions: Within the limitations of this preliminary investigation, especially the small number of animals, osseointegration seems to be achievable both in infected sites and around contaminated implant surfaces.

Background: There remains controversy regarding the clinical reasons for late-implant bone loss, which is a critical factor in the long-term success of implant-supported overdentures.

Purpose: Assessment of the effect of such factors as attachment type, number of implants, gender, age, and maximum bite force (MBF) on marginal bone loss (MBL) around implants supporting mandibular overdentures.

Materials and Methods: Sixty-two edentulous patients rehabilitated with two-, three-, or four-implant-supported mandibular overdentures at a university clinic between January 2006 and January 2007 and having a digital panoramic radiograph at the time of loading, were included in this study. All patients received digital panoramic radiographs, and MBL was measured by subtracting bone levels from the first radiograph. MBF was measured using a bite force transducer.

Results: The amount of bone loss 48 months after loading was found to be unrelated to gender, age, implant number, attachment type, and splinting (p = .741, p = .953, p = .640, p = .763, p = .370, respectively). A significant correlation was observed between the MBF and the MBL of distal implants on the right side (p < .01, 79.9%) and the MBF and the MBL of distal implants on the left side (p = .011, 34.6%).

Conclusions: MBL around implants supporting mandibular overdentures seems not to be affected by number of implants, attachment type, age, or gender; however, MBL is affected by MBF.

Background: The use of computer software and stereolithography for dental implant therapy has significantly increased during the last few years. The aim of this study was to evaluate and compare the mean accuracy and maximum deviations values of dental implant placement using two stereolithographic (SLA) guide systems.

Materials and Methods: Twenty patients were selected and 227 implants were inserted using bone-, tooth- and mucosa-supported SLA surgical guides. Thirty-one guides, both single- and multiple-type, were used. Some of the single-type surgical guides were fixed with osteosynthesis screws. A postoperative computer tomography (CT) was performed and an iterative closest point algorithm was used to match the jaw of the CT preoperative with the jaw of the postoperative CT. Quantitative data of each group were described. The t-test was used to determine the influence of the utilization of the different types of SLA on accuracy values.

Results:t-Test demonstrated a better accuracy of the multiple-type guides in almost all deviation values when the mucosa-supported guides were considered. Regarding the bone-supported template, the single-type fixed group showed a better accuracy while the highest values of deviation were registered by the multiple-type guides. The single-type group showed a better accuracy when the tooth support was considered.

Conclusions: The results of the present study indicated best accuracy of the single-type guide using a bone or tooth support. The multiple-type guide recorded the best accuracy data when the mucosa support was considered comparing either a fixed and a not-fixed single-type guide.

Purpose: Evaluate correlations between volume change for iliac crest bone grafts in maxillary reconstruction (graft volume change [GVC]) and bone mineral density (BMD), bone volume fraction (BVF), hematologic bone metabolic factors (I), and identify indicators of implant failure (II).

Material and Methods: Forty-six consecutive patients had their edentulous atrophic maxilla reconstructed with free autogenous bone grafts from anterior iliac crest. Endosteal implants were placed 6 months after graft healing. Computer tomography was performed after 3 weeks and 6 months after grafting. Bone biopsies were taken from the internal table of donor site for calculation (BVF), and blood samples were collected. Implant stability was measured at placement with resonance frequency analysis and expressed as implant stability quotient (ISQ). Implant failure was registered.

Results: GVC in onlay bone graft was 37%. The BVF in iliac crest biopsies was 32%. Serum-IGFBP3 differed with 79% of the samples over normal range. Fifteen patients had one or more implant failures prior to loading (early failures). Forty-two patients were followed for a minimum of 3 years after implant loading and, in addition, 6/42 patients had one or more implants removed during the follow-up (late failures). GVC correlated to decreased BMD of lumbar vertebrae L2-L4 (Kruskal–Wallis test, p = .017). No correlation was found between GVC and hematologic factors (Pearson correlation test) or between GVC and BVF (Kruskal–Wallis test). No correlation was found between ISQ and GVC (Pearson correlation test, p = .865). The association between implant failures and the described factors were evaluated, and no significant correlations were found (unconditional logistic regression).

Conclusion: Onlay bone grafts decrease 37% during initial healing period, which correlate to BMD of lumbar vertebrae L2-L4. No other evaluated parameters could explain GVC. The evaluated factors could not explain implant failure.

Background: Immediate loading of full-arch restorations yields good results in selected cases, but long-term follow-up and the outcome in compromised bone are scarcely evaluated.

Purpose: To evaluate immediately loaded Osseotite implants (Biomet 3i, Palm Beach, FL, USA) installed in healed or grafted bone, with regard to implant survival and peri-implant bone loss up to 7 years in function.

Materials and Methods: Information was retrospectively retrieved from 83 patients' records with 749 Osseotite implants supporting immediately loaded semipermanent full-arch acrylic restorations. Five hundred sixty-eight (75.8%) implants were placed in healed bone and 181 (24.2%) in augmented bone, regenerated with sinus lifting and/or onlay/inlay grafts with/without biomaterials and membranes. Implant survival and success based on radiological peri-implant bone loss were registered. Wilcoxon rank sum tests evaluated peri-implant bone loss in compromised versus healed bone or between jaws or time intervals with p < .05 as statistically significant.

Results: Sixteen of 749 implants failed (2.1%), 11/343 in maxilla (3.2%) and 5/406 (1.2%) in mandible. After 7 years, the cumulative failure rate was 9%. Mean peri-implant bone loss increased to 1.2 mm (SD 1.0) during the first 2 years but remained unchanged thereafter. Around implants in grafted bone, on average, 0.3 mm more bone loss was found.

Conclusion: The Osseotite implants offer a predictable long-term outcome in terms of implant survival and stable peri-implant bone under immediate loading even in grafted bone. However, the high incidence of technical repair because of fractures of the semipermanent provisionals requires attention because it may be negative from a cost-benefit perspective. Implants in grafted bone show a tendency to a more pronounced initial bone remodeling without clinical consequence in the long term.

Background: Implantoplasty is one of the options in treating peri-implantitis. The efficacy of the dental bur used can reduce the time needed for the procedure and, as a consequence, minimize the risk of overheating that can negatively affect the remaining bone surrounding the implant.

Purpose: The aim of this study was to evaluate the efficacy of three dental burs in removing implant substance (titanium) and to determine the amount of heat generated by each bur.

Materials and Methods: Four burs with different surface properties (diamond, diamond – Premium Line, carbide, and smooth bur – control [Strauss Co., Raanana, Israel]) were attached to a high-speed handpiece and applied to a titanium implant for a total of 60 seconds after cooling by water spray. Variations in temperature were recorded every 5 seconds, and the amount of implant substance removed (reduction in weight of the implant) was evaluated.

Results: The diamond Premium Line bur removed 59.24 mg; carbide, 29.39 mg; diamond, 11.35 mg; and smooth bur (control) 0.19 mg, statistically significant. Only minimum thermal changes (∼1.5°C) were recorded for all four burs.

Conclusions: There are considerable differences in efficiency of different burs working on titanium. Selecting the proper bur can reduce working time. Under proper cooling conditions, implantoplasty does not generate excess temperature increases that can damage soft tissue or bone surrounding the treated implant.

Background and Purpose: Implant-supported mandibular overdentures have recently become a popular treatment alternative for edentulous patients desiring increased retention of complete dentures. The goal of this study was to evaluate and present treatment outcomes of mandibular overdentures retained by two unsplinted, early-loaded implants and compare these results with those for delayed-loaded implants.

Material and Methods: Twenty-six edentulous patients had two interforaminal implants placed with a one-stage protocol. The patients were each treated with a mandibular overdenture supported by ball abutments. In the test group, the overdenture was loaded 1 week after surgery and in the control group, the overdenture was loaded 3 months after surgery. Standardized clinical and radiographic parameters were recorded at surgery, and after 3, 6, 12, and 18 months, and 2, 3, 4, 5, and 7 years.

Results: Because two patients did not make the 7-year recall, only 24 patients (48 implants) were evaluated in this study. No implants were lost, and 1.31 ± 0.2 mm marginal bone resorption was noted for all implants after 7 years. Implant stability measurements, clinical peri-implant parameters and marginal bone levels exhibited no statistically significant differences between the two groups over 7 years.

Conclusion: The results of this clinical trial show that there is no significant difference in the clinical and radiographic outcomes of patients treated with mandibular overdentures supported by TiUnite implants that are either early or delayed loaded.

Aim: The aim of this study was to assess the performance of conventional rotative instruments and a piezoelectric device for maxillary sinus floor elevation surgery, and to assess whether application of a resorbable membrane reduces resorption of an augmented site in a randomized clinical trial.

Materials and Methods: Thirty-six consecutive patients (59.2 ± 10.7 years, range 38–76 years) needing bilateral sinus floor elevation surgery agreed to participate in this study. In a parallel split mouth design randomized clinical trial, in which the allocation of the surgical technique to be used on the determined sites was randomly assigned, one site was always treated with conventional rotative instruments (control group) and the other site with piezosurgery (test group). In addition, in a random order, the grafted sites were covered with a collagen membrane or no membrane. After a healing period of 3–4 months implants were placed.

Results: Comparison of clinical features of the test and control sites revealed no differences with regard to wound healing and complications (perforations of the sinus membrane) during or postsurgery (p = .458, p = 1.0, respectively). A clinically insignificant, but statistically shorter operation time was observed when using conventional rotative instruments (11.1 ± 2.4 minutes) than using piezosurgery (15.1 ± 2.9 minutes; p < .001). In both groups, application of a resorbable membrane did not result in less horizontal bone resorption (membrane: 1.43 mm, no membrane: 1.06 mm; p = .062); All 193 implants could be placed with primary stability. One year after functional loading, survival rate was 100%.

Conclusion: It can be concluded that, for maxillary sinus floor elevation surgery, a piezoelectric device shows no advantages over rotative instruments as well as that placement of a barrier membrane did not reduce resorption of the augmented site.

Background: Periodontal disease often results in severely bony defects around the teeth and leads to eventual extraction. Remaining bone morphology often compromises ideally restoration-driven positions and deteriorates the success rates for dental implants.

Purpose: The present investigation illustrates the clinical outcome of immediately installing an implant following orthodontic forced eruption and atraumatic extraction.

Material and Methods: The subject of this study is a 40-year-old Asian female with a right mandibular first molar that had a deep probing depth on the mesial side and mobility. Via the aid of radiographic examination, the tooth that had an angular bony defect and apical lesion was diagnosed as having deep caries and chronic periodontitis with a poor prognosis. After consultation with the patient, we developed a treatment plan incorporating a forced eruption with immediate implantation, intended to augment the alveolar bone volume and increase the width of keratinized gingivae, in a nonsurgical manner.

Results: Following 12 months of orthodontic treatment, the tooth was successfully moved occlusally in conjunction with an 8 mm vertical interdental bone augmentation. Because of sufficient volume of bone and satisfactory gingival dimensions, the implant showed adequate initial stability in the correct position to facilitate physiological and aesthetic prerequisites. After 6 months of ossteointegration, a customized impression coping was utilized to transfer the established emergence profile to a definitive cast for the fabrication of a customized abutment. The final prosthesis was made using a customized metal abutment and ceramometal crown.

Conclusion: In the face of difficult clinical challenges, meticulous inspection and a comprehensive treatment plan were crucial. Interdisciplinary treatment through the careful integration of multiple specialists suggests the possibility of optimal results with high predictability.

Background: Surface modifications of dental implants have gained attention during several years and the thrombotic response from blood components with these materials has become more important during recent years.

Purpose: The aims of this study were to evaluate the thrombogenic response of whole blood, in contact with clinically used dental surfaces, Sandblasted Large grit Acid etched titanium (SLA) and Sandblasted Large grit Acid etched, and chemically modified titanium with hydrophilic properties (SLActive).

Methods: An in vitro slide chamber model, furnished with heparin, was used in which whole blood came in contact with slides of the test surfaces. After incubation (60-minute rotation at 22 rpm in a 37°C water bath), blood was mixed with ethylenediaminetetraacetic acid (EDTA) or citrate, further centrifuged at +4°C. Finally, plasma was collected pending analysis.

Results: Whole blood in contact with surfaces resulted in significantly higher binding of platelets to the hydrophilic surface, accompanied by a significant increase of contact activation of the coagulation cascade. In addition, the platelet activation showed a similar pattern with a significant elevated release of β-TG from platelet granule.

Conclusions: The conclusion that can be drawn from the results in our study is that the hydrophilic modification seems to augment the thrombogenic properties of titanium with implications for healing into bone of, that is titanium dental implants.

Purposes: The aims of this study were to evaluate a surgical/prosthetic protocol for the immediate rehabilitation of the augmented edentulous maxilla, and to compare the outcomes of implants placed in grafted (test group) versus native (control group) sites in the same patients.

Materials and Methods: Twenty patients were included in the study. Each patient was treated with a bilateral sinus augmentation procedure using a 50:50 composite graft of autogenous mandibular bone and bovine hydroxyapatite. Four to 5 months later, 155 implants (90 test and 65 control) were placed and restored with screw-retained fixed definitive prostheses supported by titanium frameworks within 1 week. All patients were followed for 1 year. Implant stability quotient (ISQ) measurements and radiographic evaluation of the marginal bone resorption (MBR) were performed.

Results: Two test implants failed in two patients, giving a cumulative 1-year success rate of 98.7%; the prostheses success rate was 100%. Insertion torque and ISQ values for test implants were significantly lower than those for control implants (unpaired t-test, p < .0001). The mean MBR around control and test implants at the 1-year evaluation were similar (0.47 ± 0.25 mm and 0.43 ± 0.21 mm, respectively).

Conclusions: The combination of implants placed in sinus-grafted and native sites can be immediately loaded with a fixed full-arch prosthesis and yield short-term successful outcomes.

Background: The inflammatory process induced by implant surfaces is an important component of the tissue response, where limited knowledge is available regarding the role of surface topography. With laser ablation, a combined micro- and nanoscale surfacemodification could be created, which have been shown to enhance bone growth and biomechanical stability in vivo.

Purpose: The aim of this article was to evaluate the early in vivo inflammatory response to laser-modified titanium disks, with machined titanium disks and sham operation sites serving as controls.

Materials and Methods: Circular disks were installed in a subcutaneous rat model for 24 and 72 hours, where the cell number, cell types, and cytokine levels were evaluated.

Results: The results revealed that significantly fewer inflammatory cells (mononuclear and polymorphonuclear) were attracted to the sites with the laser-modified implants compared with the machined titanium implants. Similar concentrations of pro-inflammatory cytokines (TNF-a and MCP-1), together with slightly higher cell viability, were observed around the laser-modified surface compared with the machined surface.

Conclusions: The results in the present study suggest that the combination of surface micro and nano features of the laser-treated surface contributes to the downregulation of early inflammatory events.

Purpose: The purpose of this study was to document the long-term outcome of Brånemark implants installed in augmented maxillary bone and to identify parameters that are associated with peri-implant bone level.

Material and Methods: Patients of a periodontal practice who had been referred to a maxillofacial surgeon for iliac crest bone grafting in the atrophic maxilla were retrospectively recruited. Five months following grafting, they received 7–8 turned Brånemark implants. Following submerged healing of another 5 months, implants were uncovered and restorative procedures for fixed rehabilitation were initiated 2–3 months thereafter. The primary outcome variable was bone level defined as the distance from the implant-abutment interface to the first visible bone-to-implant contact. Secondary outcome variables included plaque index, bleeding index, probing depth, and levels of 40 species in subgingival plaque samples as identified by means of checkerboard DNA–DNA hybridization.

Results: Nine out of 16 patients (eight females, one male; mean age 59) with 71 implants agreed to come in for evaluation after on average 9 years (SD 4; range 3–13) of function. One implant was deemed mobile at the time of inspection. Clinical conditions were acceptable with 11% of the implants showing pockets ≥ 5 mm. Periodontopathogens were encountered frequently and in high numbers. Clinical parameters and bacterial levels were highly patient dependent. The mean bone level was 2.30 mm (SD 1.53; range 0.00–6.95), with 23% of the implants demonstrating advanced resorption (bone level > 3 mm). Regression analysis showed a significant association of the patient (p < .001) and plaque index (p = .007) with bone level.

Conclusions: The long-term outcome of Brånemark implants installed in iliac crest-augmented maxillary bone is acceptable; however, advanced peri-implant bone loss is rather common and indicative of graft resorption. This phenomenon is patient dependent and seems also associated with oral hygiene.

Background: The extremely resorbed edentulous mandible, with a bone height of 8 mm or less, is still a challenge in implant dentistry. Recently, dental implants of 6 mm in length have been developed.

Purpose: The purpose of this 1-year prospective cohort study was to evaluate treatment outcome of mandibular overdentures supported by four 6-mm dental implants.

Materials and Methods: Twelve edentulous patients with a mandibular height between 6 and 8 mm participated. The patients were treated with an overdenture supported by four 6-mm OsseoSpeed™ dental implants (Astra Tech AB, Mölndal, Sweden). Clinical and radiographic parameters were evaluated 1 year after completion of the prosthetic treatment. Patients' satisfaction was scored before implant surgery and 1 year after prosthetic treatment.

Results: One-year implant survival rate was 96% (two implants were lost). One patient had a fracture of the mandible in the region of one of the implants 3 weeks after implant surgery. Mean scores for plaque, calculus, gingiva, bleeding, and pocket probing depth were low. Patients' satisfaction was high.

Conclusion: One-year follow-up data revealed that four 6-mm dental implants inserted in an extremely resorbed edentulous mandible provided a solid basis for a bar-retained overdenture.

Purpose: The purpose of this clinical follow-up was to document the 7-year outcome of immediately loaded implants exhibiting an oxidized surface.

Material and Methods: Thirty-eight patients received a total of 51 implant-supported fixed prostheses. The restorations were supported by 102 implants, the majority of which were placed in posterior regions (88%) and primarily in soft bone quality (76%). Radiographic examinations were performed at prosthesis insertion, at 1- and 6-month follow-ups, and annually at the 1- through 5-year follow-up visits. Marginal peri-implant soft tissue evaluations were conducted at all these follow-ups. This report presents the results after at least 7 years of loading.

Results: After 7 years of prosthetic loading, the cumulative implant survival rate was 97.1% and the mean marginal bone remodeling was −1.51 mm (SD 1.00, n = 73) with significantly more initial remodeling at sites having received marginal guided bone regeneration procedures. A low rate of biological and technical complications was detected after 7 years of function. The quantification of intrasulcular plaque sampling showed no significant difference between teeth and implants.

Conclusion: The 7-year follow-up data indicate that the introduced immediate loading protocol is a successful treatment alternative also including regions exhibiting soft bone conditions.

Background: Smoking is considered as a factor for implant survival and peri-implant bone loss of dental implants. Several studies revealed the negative effect of smoking on osseointegration and its dose-related effect.

Purpose: To evaluate the effect of smoking habits on accuracy of implant placement using mucosally supported stereolithographic surgical guides.

Material and Methods: Six OsseoSpeed™ implants (Astra Tech AB, Mölndal, Sweden) were inserted into the maxilla in 13 patients. Patients were excluded if they suffered from any systemic disease or if they were actually taking any kind of medication. Software (Mimics® 9.0) was used to fuse images of the virtually planned and actually placed implants, and locations and axes were compared between the nonsmoking and smoking subgroups. As the mucosal biotype could probably influence accuracy data, 12 reference points were defined within each patient to define a mean mucosal thickness value.

Results: In the smoking subgroup, 36 implants were placed compared with 42 in the nonsmoking subgroup. Mean coronal deviation was 1.04 mm (range: 0.29–2.45 mm) among the smokers compared with 0.80 mm among the nonsmokers (range: 0.29–1.67 mm). At apical point, mean deviation was 1.26 mm (range: 0.39–3.01 mm) among the smokers compared with 1.02 mm among the nonsmokers (range: 0.32–2.59 mm). Mean angular deviation was 2.64° (range: 0.41–6.81°) among the smokers compared with 2.57° among the nonsmokers (range: 0.16°–8.86°). Significant differences were found when comparing global coronal and apical deviation between the smokers and the nonsmokers (p < .05). Evaluating mucosal thickness, mean value was 3.19 mm (range: 2.39–4.01 mm) among the smokers compared with 2.43 mm among the nonsmokers (range: 1.44–3.03 mm).

Conclusions: Statistically significant differences were found when comparing the accuracy of dental implant placement of the smokers with the nonsmokers. Smokers have significant thicker supporting mucosal tissues compared with nonsmokers, which may explain inaccuracy due to less stability of the surgical guide or the scanning prosthesis.

Background: Primary stability can be improved by using a tapered implant in a slightly underprepared implant site. This may lead to high compression forces and elevated insertion torques. It has been postulated that disturbance of the local microcirculation may occur, leading to necrosis of the osteocytes and bone resorption.

Purpose: Report on the clinical outcome of 42 implants placed with an insertion torque equal or greater than 70 Ncm and evaluate bone levels around these implants.

Materials and Methods: This prospective study included 48 patients treated with 66 4.5 mm diameter Tapered Screw-Vent implants (Zimmer Dental®, Carlsbad, CA, USA). Maximum insertion torque (MIT) was recorded with an electronic torque measuring device (Tohnichi® STC200CN, Hitachi, Tokyo, Japan).

Nine implants (control group) presented MIT between 30 and 50 Ncm (mean = 37.1 Ncm) and 42 implants (experimental group) MIT greater than 70 Ncm (mean = 110.6 Ncm, range: 70.8–176 Ncm). Marginal bone levels were recorded at the time of loading and 1 year later for the two groups.

Results: After 2–3 months of non-sumerged healing, all implants were clinically stable. Mean marginal bone resorption was 1.03 mm (SD = 0.44) for the control group (low torque) and 0.72 mm (SD = 0.56) for the experimental group (high torque) at time of loading, and 1.09 (SD = 0.62) and 1.24 mm (SD = 0.75), respectively, after 1 year. There were no significant differences between the two groups for bone stability and implant success rate.

Conclusions: The use of high insertion torques (up to 176 Ncm) did not prevent osseointegration. Marginal bone levels in the control and experimental groups were similar both at the time of loading and 1 year later.

Purpose: The aim of this study was to examine healing over time after implant body placement in a senile osteoporosis model and a control group.

Materials and Methods: In this study, 16-week-old male mice were used. The senile osteoporosis model consisted of senescence-accelerated prone 6 mice and the control group consisted of senescence-accelerated resistant 1 mice. Titanium-coated plastic implants were used as experimental implants whose dimensions were 3.0 mm in length, 1.1 mm in apical diameter, and 1.2 mm in coronal diameter. Bone samples were collected at 5, 7, 14, 21, and 28 days after implant placement. A micro-quantitative computed tomography (QCT) system was used to scan these samples and a phantom in order to quantitate bone mineral measurements. Bone mineral density (BMD) of each sample was measured. Each sample was also examined by light microscopy after QCT imaging. At 14 and 28 days after implant placement, the bone-implant contact (BIC) ratios were calculated from light microscopy images and were divided into cortical bone and bone marrow regions.

Results: When BMD was compared between the osteoporosis and control groups using micro-QCT, the osteoporosis group had a significantly lower BMD in the region 0–20 µm from the implant surface in the bone marrow region at 14 days onward after implant placement. Compared with the control group, the osteoporosis model also had significantly lower BMD in all regions 0–100 µm from the implant surface in the bone marrow region at 14 days after placement. However, in the cortical bone region, no statistically significant difference was observed in the regions at the bone-implant interface. Light microscopy revealed osseointegration for all implants 28 days after implant placement. The osteoporosis model tended to have lower BICs compared with that of the control group, although this did not reach statistical significance.

Discussion: Our results showed that osseointegration was achieved in the osteoporosis model. However, the BMD was 30–40% lower than that of the control group in the region closest to the implant surface in bone marrow region. Peri-implant BMD was lower in a relatively large area in the osteoporosis model during an important time for osseointegration. Therefore, this result suggests that osteoporosis might be considered as a risk factor in implant therapy.

Conclusion: The osteoporosis model had a lower BMD than the control group in the region closest to the implant during an important time for osseointegration. This result suggests that senile osteoporosis might be a risk factor in implant therapy. However, the osteoporosis model and the control group had no difference in peri-implant BMD in the cortical bone region. This suggests that risk might be avoided by implant placement that effectively uses the cortical bone.

Purpose: This study investigated how the primary stability of a dental implant as measured by the insertion torque value (ITV), Periotest value (PTV), and implant stability quotient (ISQ) is affected by varying thicknesses of cortical bone and strengths of trabecular bone using synthetic bone models.

Materials and Methods: Four synthetic cortical shells (with thicknesses of 0, 1, 2, and 3 mm) were attached to four cellular rigid polyurethane foams (with elastic moduli of 137, 47.5, 23, and 12.4 MPa) and one open-cell rigid polyurethane foam which mimic the osteoporotic bone (with an elastic modulus 6.5 MPa), to represent the jawbones with various cortical bone thicknesses and strengths of trabecular bone. A total of 60 bone specimens accompanied with implants was examined by a torque meter, Osstell resonance frequency analyzer, and Periotest electronic device. All data were statistically analyzed by two-way analysis of variance. In addition, second-order nonlinear regression was utilized to assess the correlations of the primary implant stability with the four cortex thicknesses and five strengths of trabecular bone.

Results: ITV, ISQ, and PTV differed significantly (p < .05) and were strongly correlated with the thickness of cortical bone (R² > 0.9) and the elastic modulus of trabecular bone (R² = 0.74–0.99).

Conclusions: The initial stability at the time of implant placement is influenced by both the cortical bone thickness and the strength of trabecular bone; however, these factors are mostly nonlinearly correlated with ITV, PTV, and ISQ. Using ITV and PTV seems more suitable for identifying the primary implant stability in osteoporotic bone with a thin cortex.

Background: The use of osteotome for vertical bone augmentation and localized sinus elevation with minimal surgical trauma represents a suitable procedure to increase the vertical dimension of available bone for implant placement.

Purpose: The aim of this study was to report clinical and radiographic results of localized management of sinus floor (LMSF) in fresh molar sockets at 13-year follow-up.

Materials and Methods: Fifty-three patients, needing one or two maxillary molar extraction, were enrolled in this study. LMFS procedure was performed and 68 implants were positioned. A presurgical distance from the alveolar crest to the floor of the maxillary sinus and the amount of new radiopacity between the sinus floor and alveolar crest were measured from the mesial and distal surfaces of each dental implant surface.

Results: After a mean follow-up period of 9.76 ± 5.27 years (ranged from 4 to 17 years) a survival rate of 100% was reported. Mean bone height at temporary prosthesis placement was 7.99 ± 1.16 mm. They were stable over time, reporting a mean value of 8.01 ± 1.46 mm at 13-year follow-up.

Conclusions: The results of this study demonstrated that LMSF procedure in fresh molar sockets allowed to expand the dimensions of resorbed posterior maxillary alveolar bone both vertically and horizontally with a success rate of 100% of implant osseointegration over time.

Objectives: To examine whether oral lichen planus (OLP) affects the success rate of dental implants and if the manifestations of OLP are altered by implant-borne prostheses.

Materials and Methods: OLP patients, treated in the oral medicine department, with (the study group) and without (control group) dental implants were included. Pocket depth, mobility, bleeding on probing, erythema, pain and radiolucency around the implants, as well as clinical findings and OLP symptoms were recorded. Follow-up ranged from 12–24 months. Ordinal variables and visual analog scale score were compared using the Mann–Whitney test. The significance of the trend within each of the groups was assed using the Friedman test. Categorical variables were compared using Pearson chi-squared test and Fisher's exact test.

Results: Fourteen patients in the study group with 1–15 implants per patient and 15 in the control group were included. No implant failures were recorded. Comparison between the clinical manifestations of OLP in both groups did not reveal any significant differences.

Conclusions: Success of implant rehabilitation among treated OLP patients does not seem to be different from the success rate in the general population. Nor does implant placement influence the disease manifestations.

Background: Reduced alveolar bone volume complicates implant dentistry.

Purpose: In this prospective multicenter study, a new, 4-mm long Straumann SLActive implant (Ø 4.1 mm) supporting a fixed dental prosthesis (FDP) in the severely resorbed posterior mandible was evaluated for two years.

Material and Methods: Thirty-two patients (11 men, 21 women; mean age 64.1 years) participated. Ten to 12 weeks after single-stage surgery, a screw-retained FDP was attached to three or four 4-mm implants.

Results and Discussion: One hundred implants were inserted. Three failed at surgery and four were lost before loading. Twenty-eight patients received FDPs (93 implants). Two patients were discontinued because of secondary exclusion criteria; therefore, 26 patients were followed up from baseline (BL). After 1 year, one patient insisted on removal of all implants and one patient died because of nonstudy-related complications. Twenty-four patients (87 implants) were eligible for examination 2 years post-loading. All implants were found to be stable [survival rate 95.7% (confidence interval, CI 88.8–98.3) after 1 year and 92.3% (CI 84.5–96.2) after 2 years]. The mean change from BL to 12 months was – 0.43 mm (CI 0.31–0.59; p < .001) and from 12 to 24 months – 0.11 mm (CI –0.01–0.23; p = .056). The survival rate is only slightly lower than in similar studies on 6 to 8.5 mm implants. This may be related to high initial stability and effective use of the residual bone volume with high primary bone-to-implant contact in dense bone structures. The surgical handling of the tested implant was found to be similar to that of implants of common length. However, the preparation procedure must be done with great care to avoid overdrilling. Careful planning and design of the prosthetic construction is mandatory to prevent unfavorable occlusion and avoid harmful shear forces.

Conclusion: This study showed that 4 mm implants can support an FDP in severely resorbed posterior mandibles for at least 2 years and with healthy peri-implant conditions.