To evaluate prosthetic parameters in the edentulous anterior maxilla for decision making between fixed and removable implant prosthesis using virtual planning software.

CT- or DVT-scans of 43 patients (mean age 62 ± 8 years) with an edentulous maxilla were analyzed with the NobelGuide™ software. Implants (≥3.5 mm diameter, ≥10 mm length) were virtually placed in the optimal three-dimensional prosthetic position of all maxillary front teeth. Anatomical and prosthetic landmarks, including the cervical crown point (C-Point), the acrylic flange border (F-Point), and the implant-platform buccal-end (I-Point) were defined in each middle section to determine four measuring parameters: (1) acrylic flange height (FLHeight), (2) mucosal coverage (MucCov), (3) crown-Implant distance (CID) and (4) buccal prosthesis profile (ProsthProfile). Based on these parameters, all patients were assigned to one of three classes: (A) MucCov ≤ 0 mm and ProsthProfile≥45⁰ allowing for fixed prosthesis, (B) MucCov = 0–5 mm and/or ProsthProfile = 30⁰–45⁰ probably allowing for fixed prosthesis, and (C) MucCov ≥ 5 mm and/or ProsthProfile ≤ 30⁰ where removable prosthesis is favorable. Statistical analyses included descriptive methods and non-parametric tests.

Mean values were for FLHeight 10.0 mm, MucCov 5.6 mm, CID 7.4 mm, and ProsthProfile 39.1⁰. Seventy percent of patients fulfilled class C criteria (removable), 21% class B (probably fixed), and 2% class A (fixed), while in 7% (three patients) bone volume was insufficient for implant planning.

The proposed classification and virtual planning procedure simplify the decision-making process regarding type of prosthesis and increase predictability of esthetic treatment outcomes. It was demonstrated that in the majority of cases, the space between the prosthetic crown and implant platform had to be filled with prosthetic materials.

This investigation focused on a comparison of clinical and histological characteristics after sinus floor augmentation with biphasic calcium phosphate (BCP, Straumann BoneCeramic^®), anorganic bovine bone (ABB, Geistlich Bio-Oss^®), mineralized cancellous bone allograft (MCBA, Zimmer Puros^®), or autologous bone (AB).

Thirty consecutive patients with a posterior edentulous maxillary situation and a vertical bone height less than or equal to 4 mm were included in this study. A two-stage procedure was carried out. After augmentation of the maxillary sinus with ABB, BCP, MCBA, or AB followed by a healing period of 5 months, biopsies were taken with simultaneous implant placement. The samples were analyzed using microradiography and histology.

Ninety-four implants were placed in the augmented positions and 53 bone biopsies were taken and evaluated. The bone volume fraction of newly formed bone was measured as 30.28 ± 2.16% for BCP, 24.9 ± 5.67% for ABB, 41.74 ± 2.1% for AB, and 35.41 ± 2.78% for MCBA with significant increases in bone volume of AB vs. BCP and ABB, and MCBA vs. ABB samples. Significantly different residual bone substitute material was measured as 15.8 ± 2.1% in the BCP group and 21.36 ± 4.83% in the ABB group.

As it provides the highest rate of de novo bone formation, AB can be considered to remain the gold standard in sinus floor augmentation. All tested control materials showed comparable results and are suitable for maxillary sinus augmentation.

The purpose of this prospective clinical study was to evaluate the outcome of telescopic crown-retained removable dental prostheses (TCR-RDPs) on implants and teeth according to different numbers of abutments.

Between 2000 and 2002, 33 patients received implant or tooth-implant-supported TCR-RDPs. The patients were divided into four subgroups (group_1: 3–4 abutments/maxilla, group_2: 5–6 abutments/maxilla, group_3: 2–4 abutments/mandible, group_4: 5–6 abutments/mandible). They received a total number of 85 implants. Sixty-two natural teeth were integrated in the TCR-RDPs. After a healing period of 3–6 months, both implants and teeth were treated with a TCR-RDP. There were no standardized recall appointments. Prosthetic service was performed only in case of problems. In 2010, the prostheses' conditions, the retention forces of the telescopic crowns and the Oral Health-Related Quality of Life (OHRQoL) of all patients were measured in a follow-up appointment.

After a mean observation time of 8.7 years, all prostheses were still in function. One implant (survival rate 98.8%) and two abutment teeth (survival rate 96.6%) were lost. The mean quality of the prostheses was satisfying with no significant differences between groups. No significant differences between the groups regarding the mean retention forces were observed. The OHRQoL revealed no significant differences between the groups.

Telescopic crown-retained removable dental prostheses on implants and teeth seem to be a promising treatment option for patients with a strongly reduced dentition.

The objective of this study was to investigate the stability of voxel values from cone-beam CT (CBCT) using a flat panel detector in changing surrounding circumstances mimicking clinical situations.

Seven hydroxyapatite (HA) rods (0, 40, 80, 120, 160, 199, and 239 mg Ca/cm³) were set in a 16 cm diameter water phantom and scanned with CBCT (FineCube) and also with multislice CT (MSCT) used as reference. The voxel values from CBCT were measured by the obtained images with OsiriX software (http://www.osirix-viewer.com), and compared with the CT numbers from MSCT. We examined the correlation between the voxel values and the HA contents, the variance of voxel values, and the influence of changing surrounding circumstances on the voxel values.

The voxel values from CBCT were different from the CT numbers from MSCT, but there was a linear Pearson correlation between the voxel values and the HA contents. The voxel values were greatly influenced when the samples were scanned surrounded in air. However, the voxel values were not affected significantly in the existence of materials simulating oral hard tissues and/or a metal core post.

There was a linear correlation between the voxel values of CBCT and the contents of HA rod samples. Our study indicated that it might be possible to evaluate bone mineral content(BMC) from the voxel values of CBCT for dental implant treatment.

To evaluate the clinical performance as well as patients' and clinicians' satisfaction on two different prosthodontic retention systems for implant-overdentures in the mandible.

In this retrospective study, patients provided with four intraforaminal implants with at least 12 months of follow-up since overdenture delivery were evaluated. A total of 39 patients were treated either with Locator^® attachment or with cad-cam milled bar. Clinical parameters such as Peri-implant Probing Depth (PPD), Plaque Index (PI), and Bleeding on Probing (BOP) were evaluated. Patients' and clinicians' perceptions regarding the outcome were assessed on visual analog scales (VAS).

The mean follow-up was 13 months in the Locator^® group and 18 months in the Bar group and no implants were lost. The Locator group showed better results for PPD, PI, and BOP values. Patients' satisfaction was high in both groups, whereas the clinicians found better hygienic conditions and soft tissue health in the Locator group.

Although the patients' satisfaction was similar in both groups the Locator^® system demonstrated better soft tissues scores because hygienic maintenance was more complicated around bars. This may increase the frequency of chronic inflammations around the implants.

To evaluate hard and soft tissue healing to implants with a dual acid-etched surface with and without deposition of calcium-phosphate crystals.

Three months after extraction of mandibular premolars in six Labrador dogs, four osteotomy preparations, 8 mm deep and 3 mm wide, were performed. The prepared canals were widened in the marginal 4 mm zone to 3.74 mm. Implants with an 8 mm long and 3.75 mm wide intraosseous portion and a 5.0 mm high and 4.0 mm wide transmucosal part were placed in such a way that the base of the wider neck-portion of the implant coincided with the crestal bone. The implants were dual acid – etched (Osseotite^®; Biomet 3i). The surface of the test implants was, in addition, modified by a discrete deposition of calcium-phosphate crystals (Nanotite™; Biomet 3i). Every second implant placed was a test unit. After 2 weeks the implant installation procedure was repeated in the opposite side of the mandible. Two weeks later the animals were euthanized and biopsies were obtained and prepared for histological analysis.

The degree of bone-to implant contact (BIC%) was larger at implants without (Osseotite) than in those with (Nanotite) calcium-phosphate crystals. No differences were found regarding soft tissue dimensions and composition between the two types of implants.

It is suggested that deposition of nanometer-sized calcium-phosphate crystals to implants with a dual acid-etched surface does not improve early tissue integration.

To evaluate the effect of implant length (6 mm vs.11 mm) on osseointegration (bone-to-implant contact) of implants installed into sockets immediately after tooth extraction.

In six Labrador dogs, the pulp tissue of the mesial roots of ₃P₃ was removed and the root canals were filled. Flaps were elevated bilaterally, the premolars hemi-sectioned and the distal roots removed. Recipient sites were prepared in the distal alveolus and a 6 mm or an 11 mm long implant was installed at the test and control sites, respectively. Non-submerged healing was allowed. After 4 months of healing, block sections of the implant sites were obtained for histological processing and peri-implant tissue assessment.

No statistically significant differences were found between test and control sites both for hard and soft tissue parameters. The bone-to-implant contact evaluated at the apical region of the implants was similar as well. Although not statistically significant, the location of the top of the bony crest at the buccal aspect was more apical in relation to the implant shoulder at the test compared with the control sites (2.0 ± 1.4 and 1.2 ± 1.1 mm, respectively).

Shorter implants (6 mm) present with equal osseointegration than do longer implants (11 mm).

The inclusion of biomaterial particles used for alveolar bone regeneration in a carrier or in binding agents such as collagen gel or fibers is of interest as a means to help with surgical handling. However, the possible influence of collagen on bone tissue response to biomaterials is poorly studied. The objective of the present study was to investigate, in a sub-sinus bone augmentation model in rabbits, the effect of collagen at different stages of the osteogenesis process. Histologic, histomorphometric and volumetric analyses were performed.

Rabbits underwent a double sinus lift procedure using bovine hydroxyapatite (BHA), collagenated bovine hydroxyapatite (BHAColl), and prehydrated and collagenated porcine hydroxyapatite (PHAColl). Animals were sacrificed at 1 week, 5 weeks or 6 months. Samples were subjected to X-ray micro-tomography and histology. Qualitative analysis was performed on the non-decalcified sections and quantitative histomorphometric analyses were conducted using scanning electron microscopy (SEM). Volume variations of bone augmentations were calculated at different time points.

The three biomaterials allowed an optimal bone formation and were able to equally withstand sinusal reexpansion. A comparable percentage of new bone, as well as 3D volume stability, was found between the groups at each time point. However, the PHAColl resorption rate was significantly higher than the rates in other groups (P = 0.0003), with only 3.6% of the particles remaining at 6 months. At 1 week, both collagenated groups displayed the presence of inflammatory cells although BHA did not show any sign of inflammation. At 5 weeks and 6 months, the inflammatory process had disappeared completely in the BHAColl groups, whereas some inflammatory-like cells could still be observed around the remaining particles of PHAColl.

Within the limitations of this study in rabbits, the findings showed the presence of inflammatory-like cells at the early stage of bone regeneration when collagenated xenogenic biomaterials were used compared to xenogenic granules alone. Nevertheless, similar bone formation occurred and comparable 3D volumes were found at 6 months in the different groups.

Edentulism is an important issue and will remain so due to high numbers of edentate individuals worldwide. For many years, complete dentures have been the only treatment option for this population. Implant overdentures have been shown to have many advantages over conventional complete dentures. However, although dissatisfied with their mandibular dentures, some edentate elders are reluctant to undergo even simple implant treatment due to factors such as cost and fear of surgery. To address these obstacles, this paper reports on a review of small-diameter implant (SDI) studies that were performed in the last two decades. The aim of this study is to (i) determine the survival of narrow diameter implants, (ii) determine whether survival is dependent on whether these implants are placed using a flap or flapless approach, and (ii) determine whether there is a relationship between length and implant survival in SDIs.

In this review, studies were included that (i) involve implants with 3.5 mm diameter or less, (ii) have a randomized clinical trial, retrospective or prospective cohort design with human subjects, (iii) provide a follow up duration of at least 5 months following implant placement, (iv) include data on the survival rate of the implants.

Forty one studies meeting the above criteria were published between 1993 and 2011 using SDIs from a variety of companies and surface characteristics with diameters of 1.8 mm to 3.5 mm and lengths of 8 mm to 18 mm. A total of 10,093 SDIs were inserted in approximately 2762 patients. Twenty-six studies involved flap reflection techniques for implant placement, six studies used a flapless technique and two studies used both techniques; in the remaining studies, the technique was not specified. Follow up duration varied from 5 months to over 9 years. The survival rate reported in all screened studies was over 90%, including eight studies in which a 100% survival rate was reported. In 22 studies, the reported survival rate ranged from 95% to 99.9%. Failure was reported most often in short SDIs (less than or equal 13 mm) (n = 88) compared to longer ones (more than 13 mm).

Survival rates reported for SDI are similar to those reported for standard width implants. These survival rates did not appear to differ between studies that used flapless and flap reflection techniques. The failure rate appeared to be higher in shorter SDIs than in longer ones in the studies in which the length of the failed implants was reported. SDIs could be considered for use with fixed restorations and mandibular overdentures, since their success rate appears to be comparable to that of regular diameter implants. They might also be an efficient, low-cost solution for elders who wish to reduce problems with denture instability.

The aim of this prospective cohort study was to compute the long-term clinical survival and complication rates of alumina-toughened zirconia abutments used for implant-supported restorations and to evaluate the effects of several clinical variables on these rates.

From May 1998 to September 2010, 213 patients aged 18 years or older were recruited. The patients received 611 external hex implants and 328 implant-supported fixed restorations using alumina-toughened zirconia abutments. During the follow-up, each restoration was coded as a dental event, which included loosening or fracture of abutment screws, and abutment fracture. From the coded data, the effects of the investigated clinical variables—restored area (anterior/posterior), number of prosthodontic units (one/two units or over), prosthesis type (single-unit/multiunit without pontic/multiunit with pontic), implant system, and patient gender—on the survival of the abutments were evaluated. Survival analysis using Kaplan–Meier method and Cox proportional hazard model was applied. The 5-year survival and complication rates of the abutments were assessed.

The number of prosthodontic units and the type of prosthesis had a significant association with complication rates (P < 0.05). Kaplan–Meier survival analysis estimated that the cumulative 5-year complication rate of the abutments used in single restorations was 19.7%. Multiunit-fixed dental prostheses without and with pontics had complication rates of 3.9% and 3.8%, respectively. The 5-year survival rate of the abutments was more than 95%, regardless of the type of prosthesis.

Alumina-toughened zirconia abutments are likely to exhibit excellent long-term survival in clinical use for fixed restorations. Single tooth replacement with the abutment at the molar region may require special care and extra attention.

The current study aimed to evaluate the osteogenic potential of electrosprayed organic and non-organic surface coatings in a gap-implant model over 4 and 12 weeks of implantation into the dog mandible.

Sixteen Beagle dogs received experimental titanium implants in the mandible 3 months after removal of left premolars (P2, P3 and P4). Three types of implants were installed in each animal: non-coated implant, nano-CaP coated implant and implant with type 1 collagen coating. Both micro-CT and histomorphometry were used to evaluate peri-implant bone response after implantation periods of 4 and 12 weeks. The bone area percentage was assessed histomorphometrically in three different zones (inner: 0–300 μm; middle: 300–600 μm; and outer: 600–1000 μm) around the implant surface. Bone-bridging of the gap was also calculated for each sample.

Four weeks after implantation, nano-CaP and collagen-coated implants showed significantly higher bone volume (BV) in the inner zone compared with non-coated implants (P < 0.05 and P < 0.01). After 12 weeks, histomorphometric analysis showed comparable amounts of BV between all experimental groups. Also, no significant difference was found in the BV, as measured using micro-CT, between the implant groups. Absolute bone ingrowth measurements were highest for collagen-coated implants, but these differences were not significant.

The obtained data failed to provide a consistent favourable effect on bone formation of the collagen coating over 3 months of implantation. It is concluded that the source of the collagen as well as the limited osseous environment overshadowed a possible effect of the applied implant surface modifications. Similarly, the tested nano-apatite surface coating did not improve peri-implant bone ingrowth into a gap-implant model.

The aim of this study was to carry out an ultrastructural study of the biomaterial-to-bone interface and biomaterial mineral degradation in retrieved bone biopsies following maxillary sinus augmentation using collagenized porcine xenografts (Osteobiol^® Mp3) in 15 clinical cases.

Nine months after sinus lifting, bone cores were harvested from the maxillary sinus. The specimens were processed for observation under a scanning electron microscope with backscattered electron imaging (SEM-BSE). In addition, chemical analysis and elemental mapping of the mineral composition were generated using a microanalytical system based on energy-dispersive X-ray spectrometry (EDX).

No clinical complications were evident during surgery. Scanning electron microscopy revealed that newly formed bone had become closely attached to the xenograft. Statistical analysis showed a significantly high Ca/P ratio in the biomaterial (2.46 ± 0.16) and at the bone interface (2.00 ± 0.48) compared to bone (1.97 ± 0.36), which suggests that there may be a gradual diffusion of Ca ions from the biomaterial into the newly forming bone at the interface as part of the biomaterial's resorption process. EDX analysis of the residual porcine biomaterial at different points showed some particle categories with different mean ratios of Ca/P according to size, pointing to different stages of the resorption process.

The biomaterial proved to be biocompatible, bioreabsorbable and osteoconductive when used as a bone substitute for maxillary sinus elevation. SEM-BSE revealed that newly formed bone had become closely attached to the xenografts. EDX analysis monitored the resorption process of the porcine bone xenograft. Elemental mapping showed that there was a gradual diffusion of Ca ions from the biomaterial to the newly forming bone at the interface.

Implant dentistry in the posterior maxilla often requires bone augmentation. The gold standard, autogenous bone graft, requires additional surgery with associated morbidity, while bone biomaterials may not support relevant bone formation. Recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS), however, induces significant, clinically relevant bone formation in several settings including the maxillary sinus floor.

The objective of this study was to compare local bone formation and osseointegration following maxillary sinus augmentation using rhBMP-2/ACS or a particulate autogenous cancellous bone graft obtained from the iliac crest in conjunction with immediate placement of dental implants.

Bilateral sinus augmentation using an extraoral approach including rhBMP-2 (0.43 mg/ml)/ACS or the autogenous bone graft, alternated between left and right sinus cavities in five adult male Yucatan mini-pigs, was performed. Two 12-mm dental implants were inserted into the sinus wall protruding approximately 8 mm into the sinus cavity. Surgical sites were closed and sutured in layers; block biopsies collected for histometric analysis at 8 weeks.

rhBMP-2/ACS induced bone of significantly greater and consistent quality compared with the iliac crest autogenous bone graft; bone density averaging 51.9 ± 3.0% vs. 32.9 ± 2.5% (P = 0.01). However, there were only numerical differences in augmented bone height (9.3 ± 0.5 vs. 8.6 ± 0.7 mm) and bone-implant contact (37.4 ± 3.0% vs. 30.7 ± 5.9%) between treatments.

rhBMP-2/ACS induces bone of superior quality compared with an iliac crest particulate autogenous cancellous bone graft when used for maxillary sinus augmentation, and should perhaps be considered the new standard for this indication.

The aim of the present study was to present the results of patients followed for at least 3 years who underwent horizontal distraction osteogenesis DO and a final implant prosthesis.

A total of 13 sites in 12 patients (three men, nine women; mean age 45.4 years, range 21–63 years) who presented with severe horizontal atrophy of a partially edentulous maxilla or mandible were treated using horizontal DO. The horizontal distraction device was set on the transport bone which was osteotomized as bone splitting method and fixed to the segment using microscrews.

The median of latency period was 9 days (range: 7–17); the median of amount of device activation was 5.6 mm (range: 4.4–9.6); the median of distraction period was 14 days (range: 8–24); and the median of consolidation period, from the end of activation until implant placement, was 13 weeks (range: 11–20). The median of actual gain in bone width at the end of the consolidation period was 3.6 mm (range: 1.1–5.6). A total of 35 implants were inserted in the augmented area with primary implant stability. The median of follow-up from the start of prosthetic loading was 5.4 years. Consequently, the implant survival and success rates were 100% and 94.2%, respectively.

This article reports the long-term results of horizontal alveolar DO using a mesh device for patients with an atrophic alveolar region. Our results confirm that this technique is a predictable and effective regenerative procedure for implant preprosthetic treatment in patients with severe horizontal atrophy of the alveolar ridge.

A limited number of experimental animal studies and in vitro studies have confirmed that nicotine impairs bone healing, diminishes osteoblast function, causes autogenous bone graft morbidity, and decreases graft biomechanical properties. The aim of this study was the histomrphometric assessment of the effect of nicotine on guided bone augmentation in a rat model.

Twenty-four male Wistar rats were randomly divided into a nicotine group and a control group. All animals received either nicotine (3 mg/kg) or saline 4 weeks before the surgical procedure and continued to receive nicotine or saline from surgery until death at 12 weeks. Two plastic caps were placed in the exposed calvaria of rats. Images of bone augmentation within the plastic caps were then taken using microfocus computed tomography (micro-CT). Histological sections were cut along the same plane as that used for micro-CT images.

Bone augmentation beyond the skeletal envelope occurred in both the nicotine and control groups. However, the nicotine group showed significantly smaller increases in bone volume and bone height than the controls.

Nicotine jeopardized, but did not prevent, the process of guided bone augmentation in a rat model.

In the replacement of missing teeth, a paradigm shift is currently observed with immediate implant placement and/or restoration, particularly in the aesthetic zone. In molar sites, however, anatomical, occlusal and biomechanical considerations remain deterrent factors influencing the outcome of this treatment paradigm. The aim of this report was to evaluate immediate placement and immediate restoration of strongly tapered wide-diameter implant in fresh mandibular molar extraction sockets.

Twenty-four 8- or 9-mm diameter implants were placed in either a fresh molar extraction socket or a healed site. All the implants received provisional crowns within 48 h. The provisional crowns were replaced with full ceramic crowns after 8 weeks of implant placement.

The overall implant success rate after 1 year of service for the 24 implants in two treatment groups was 75%. Success rates were 83.3% and 66.7% for the delayed and immediate placement groups respectively, with no significant difference observed between the two groups (P = 0.35). Implant stability measurements identified the immediately placed implants to be more stable immediately after surgery than delayed placed implants. In contrast, the delayed placed implants were more stable after 8 week healing time.

The rehabilitation of single missing mandibular molars by immediately placed and restored wide-diameter implants was associated with a relatively high failure rate.

Two fractured one-piece experimental (commercially unavailable) zirconia implants were analyzed using scanning electron microscope (SEM) analysis to identify failure origins and aid in understanding the failure mechanisms. Modifications to the zirconia implant design are suggested to minimize such fracture incidences.

Two zirconia implants fractured during the final torquing in the maxillary ridge using the prescribed hand torque wrench. The implants were subsequently retrieved and prepared for optical and SEM evaluation. Critical attention was given to the fractography (crack morphology) of the fractured implants to identify the fracture origin.

Events related to initiation and propagation of the crack front could be detected from the morphology of the fractured surfaces. Unfavorable torque and bending forces applied on the implant during surgical placement and the inherent flaws in the material may have resulted in crack initiation and implant failure.

Caution must be exercised when placing zirconia implants in dense bone sites. Modification of surgical protocols for the intended implant site may be necessary. Improvement in design features specific to zirconia implants, and strict quality control during manufacture is essential to minimize the likelihood of fracture.

Sensory information provided by the periodontal mechanoreceptors (PMRs) is used by the nervous system to optimize the positioning of food, force levels, and force vectors involved in biting. The aim of this study was to describe motor performance during a novel manipulation-and-split task and to assess the extent to which control of this performance involves information from the PMRs.

A total of 10 subjects with natural teeth, 10 with bimaxillary tooth-supported fixed prostheses (TSP) and 10 with bimaxillary implant-supported fixed prostheses (ISP) (61–83 [mean 69] years of age) were asked to perform an intraoral manipulation-and-split task that involved positioning a spherical chocolate dragée between the front teeth and then splitting it into two parts of equal size. The vertical jaw movement, sound of food cracking and masseter muscle activity were monitored during this task and the accuracy of the split was evaluated.

The group with natural teeth was significantly better than the other groups at splitting the candy with high precision. The jaw movements were similar between groups, but the contact phase prior to the split was significantly longer for those with natural dentition.

The present findings support the conclusion that the nervous system collects rich information about contact between the teeth and food from the PMRs prior to powerful jaw action. Impairment (TSP) or absence (ISP) of this information alters motor behavior and impairs performance during the natural biting task employed here.

This study assessed the osseointegration of grit-blasted titanium (Ti) implants with a hydrophilic phosphate ion-incorporated oxide surface in rabbit cancellous bone, and compared its bone healing with commercially available phosphate-incorporated clinical implants obtained by micro-arc oxidation (TiUnite, TU implant).

The hydrophilic phosphate-incorporated Ti surface (P implant) was produced by hydrothermal treatment on grit-blasted moderately rough-surfaced clinical implant. The TU surface was used as a control. The surface characteristics were evaluated by field emission-scanning electron microscopy, X-ray photoelectron spectroscopy, optical profilometry, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Thirty-two threaded implants with lengths of 10 and 3.3 mm diameter (16 P implants and 16 TU implants) were placed in the femoral condyles of 16 New Zealand White rabbits. Histomorphometric analysis, removal torque tests, and surface analysis of the torque-tested implants were performed 4 weeks after implantation.

The P and TU implants displayed micro-rough surface features with similar R_a values at the micron-scale. ICP-AES analysis revealed that both the P and TU implants released phosphate ions into the solution. The torque-tested P and TU implants exhibited a considerable quantity of bone attached to the surface. The P implants exhibited significantly higher bone-implant contact percentages, both in terms of the all threads region and the total lateral length of implants compared with the TU implants (P < 0.01), but no statistical difference was found for the removal torque values.

These results suggest that the phosphate-incorporated Ti oxide surface obtained by hydrothermal treatment achieves rapid osseointegration in cancellous bone by increasing the degree of bone-implant contact.

The purpose of this study was to investigate the effect of photo-induced hydrophilic titanium dioxide (TiO₂) on serum fibronectin (sFN) attachment, and further to evaluate initial osseointegration responses in the dog mandibles.

To apply the anatase TiO₂ film, plasma source ion implantation (PSII) method followed by annealing was employed for the titanium disks and implants, which were then illuminated with UV-A for 24 h for the experimental groups. Non-deposited titanium disks and implants were prepared for the control group. Surface characterization was performed using the interferometer and contact angle analyzer. The attachments of sFN were evaluated using fluorescence emission analysis. Thereafter both groups of implants were placed in the mandible of six beagle dogs. Bone response was investigated with histological and histomorphometrical analyses after periods of 2 and 4 weeks.

The experimental groups exhibited strong hydrophilicity under UV-A illumination and showed significant improvement in sFN attachment. And further, the experimental implants enhanced the bone formation with the bone-to-implant contact of 42.7% after 2 weeks of healing (control: 28.4%).

The combined applications of plasma fibronectin and PSII to produce hydrophilic titanium surfaces could accelerate early osseointegration.

The aim of this study was an in vitro comparison of osteoblast adhesion, proliferation and differentiation related to six dental implants with different surface characteristics, and to determine if the interaction between cells and implant is influenced by surface structure and chemical composition.

Six types of implants were tested, presenting four different surface treatments: turned, sandblasted, acid-etched, anodized.

The implant macro- and microstructure were analyzed using SEM, and the surface chemical composition was investigated using energy-dispersive X-ray analysis.

SaOS-2 osteoblasts were used for the evaluation of cell adhesion and proliferation by SEM, and cell viability in contact with the various surfaces was determined using cytotoxicity MTT assays. Alkaline phosphatase (ALP) enzymatic activity in contact with the six surfaces was evaluated. Data relative to MTT assay and ALP activity were statistically analyzed using Kruskal–Wallis not parametric test and Nemenyi-Damico-Wolfe-Dunn post hoc test.

All the implants tested supported cell adhesion, proliferation and differentiation, revealing neither organic contaminants nor cytotoxicity effects. The industrial treatments investigated changed the implant surface microscopic aspect and SaOS-2 cell morphology appeared to be influenced by the type of surface treatment at 6, 24, and 72 h of growth. SaOS-2 cells spread more rapidly on sandblasted surfaces. Turned surfaces showed the lowest cell proliferation at SEM observation.

Sandblasted surfaces showed the greatest ALP activity values per cell, followed by turned surfaces (P < 0.05).

On the base of this in vitro investigation, differently surfaced implants affected osteoblast morphology, adhesion, proliferation, and differentiation. Sandblasted surfaces promoted the most suitable osteoblast behavior.

This study aimed to evaluate mandibular denture base deformation along with three impression techniques used for implant-retained overdenture.

Ten edentulous patients (five men and five women) received two implants in the canine region of the mandible and three duplicate mandibular overdentures which were constructed with mucostatic, selective pressure, and definitive pressure impression techniques. Ball abutments and respective gold matrices were used to connect the overdentures to the implants. Six linear strain gauges were bonded to the lingual polished surface of each duplicate overdenture at midline and implant areas to measure strain during maximal clenching and gum chewing.

The strains recorded at midline were compressive while strains at implant areas were tensile. Clenching recorded significant higher strain when compared with gum chewing for all techniques. The mucostatic technique recorded the highest strain and the definite pressure technique recorded the lowest. There was no significant difference between the strain recorded with mucostatic technique and that registered with selective pressure technique. The highest strain was recorded at the level of ball abutment's top with the mucostatic technique during clenching.

Definite pressure impression technique for implant-retained mandibular overdenture is associated with minimal denture deformation during function when compared with mucostatic and selective pressure techniques. Reinforcement of the denture base over the implants may be recommended to increase resistance of fracture when mucostatic or selective pressure impression technique is used.

To evaluate the clinical and radiographic changes at implants in posterior maxillary and mandibular areas supporting single-unit crowns (SCs) and fixed dental prostheses (FDPs) with one mesial or distal cantilever extension after an observation period of at least 3 years.

Seventeen subjects with 19 implant-supported SCs and 21 subjects with 21 implant-supported FDPs fulfilled the inclusion criteria. All FDPs were supported by two implants and had a span of 3–4 units. All reconstructions were incorporated in the posterior maxilla or mandible. The mesial and distal radiographic marginal bone loss from baseline (i.e. delivery of the reconstruction) to the follow-up examination was averaged and compared between SCs supporting one cantilever extension with that of implants supporting FDPs adjacent to or distant from the cantilever extension. Changes in mean pocket probing depth (PPD) were calculated and compared between the three groups.

The mean observation period was 78.2 ± 34.5 months for SCs supported by one implant and 67.8 ± 29.8 months for FDPs supported by two implants. No implant loss occurred, yielding a 100% survival rate. At baseline, the mean radiographic bone levels ± SD were 2.6 ± 0.3 mm for implants supporting SCs, 2.6 ± 0.3 mm for implants of FDPs adjacent to the cantilever extension, and 2.4 ± 0.5 mm for implants of FDPs distant from the cantilever extension. At follow-up, the corresponding mean bone levels ± SD were 2.7 ± 0.4, 2.7 ± 0.5, and 2.8 ± 0.5 mm, respectively. No statistically significant differences (P > 0.05) were observed comparing the mean marginal bone loss between the three groups. Moreover, mean changes in PPD between baseline and follow-up were not statistically significantly different (P > 0.05) between the three groups.

The presence of one mesial or distal cantilever extension in the posterior maxilla or mandible does not jeopardize the marginal bone levels of implants supporting SCs or short-span FDPs after a mean observation period of at least 5 years.

The aim of this study was to objectively assess the reliability of the cone-beam computed tomography (CBCT) as a tool to pre-operatively determine radiographic bone density (RBD) by the density values provided by the system, analyzing its relationship with histomorphometric bone density expressed as bone volumetric fraction (BV/TV) assessed by micro-CT of bone biopsies at the site of insertion of dental implants in the maxillary bones.

Thirty-nine bone biopsies of the maxillary bones at the sites of 39 dental implants from 31 edentulous healthy patients were analyzed. The NobelGuide™ software was used for implant planning, which also allowed fabrication of individual stereolithographic surgical guides. The analysis of CBCT images allowed pre-operative determination of mean density values of implant recipient sites along the major axis of the planned implants (axial RBD). Stereolithographic surgical guides were used to guide implant insertion and also to extract cylindrical bone biopsies from the core of the exact implant site. Further analysis of several osseous micro-structural variables including BV/TV was performed by micro-CT of the extracted bone biopsies.

Mean axial RBD was 478 ± 212 (range: 144–953). A statistically significant difference (P = 0.02) was observed among density values of the cortical bone of the upper maxilla and mandible. A high positive Pearson's correlation coefficient (r = 0.858, P < 0.001) was observed between RBD and BV/TV, with the regression equations: (1) Axial RBD = −19.974 + 10.238·BV/TV; (2) BV/TV = 14.258 + 0.72·Axial RBD. RBD was also positively correlated with the trabecular thickness (Tb.Th) and trabecular number (Tb.N), but negatively correlated with trabecular separation (Tb.Sp), structural model index, and inverse connectivity (Tb.Pf). Density values upper than 450 were associated with BV/TV upper than 50%, mean Tb.Th upper than 0.2 mm, mean Tb.Sp lower than 0.3 mm, and mean Tb.N upper than 2.

RBD assessed by CBCT has a strong positive correlation with BV/TV assessed by micro-CT at the site of dental implants in the maxillary bones. Pre-operative estimation of density values by CBCT is a reliable tool to objectively determine bone density.

Little is known about the recently introduced ultrasonic implant site preparation. The purpose of this study was to compare material attrition and micromorphological changes after ultrasonic and conventional implant site preparations.

Implant site preparations were performed on fresh bovine ribs using one conventional (Straumann, Freiburg, Germany) and two ultrasonic (Piezosurgery^®; Mectron Medical Technology, Carasco, Italy and Variosurg^®; NSK, Tochigi, Japan) systems with sufficient saline irrigation. Sections were examined by environmental scanning electron microscopy (ESEM). Energy-dispersive X-ray spectroscopy (EDX) was performed to evaluate the metal attrition within the bone and the irrigation fluid.

ESEM: After conventional osteotomy, partially destroyed trabecular structures of the cancellous bone that were loaded with debris were observed, whereas after ultrasonic implant site preparations, the anatomic structures were preserved. EDX: None of the implant site preparation methods resulted in metal deposits in the adjacent bone structures. However, within the irrigation liquid, there was significantly higher metal attrition with ultrasonic osteotomy (P < 0.0001 and P < 0.0001 for Mectron and NSK, respectively). Whereas for Straumann system used, 15.5% of the SEM/EDX findings were drill-origin metals, this percentage increased to 37.3% and 37.9% with the application of Mectron and NSK, respectively.

Ultrasonic implant site preparation is associated with the preservation of bone microarchitecture and with the increased attrition of metal particles. Therefore, copious irrigation seems to be even more essential for ultrasonic implant site preparation than for the conventional method.

The mandibular incisive nerve can be subjected to iatrogenic injury during bone graft harvesting. Using cone beam computed tomography (CBCT), this study aims to determine a safe zone for bone graft harvesting that avoids injuring this nerve.

Sixty CBCT examinations of patients were included in this study. The examinations were taken using the i-CAT CBCT imaging system, applying a standardized exposure protocol. Image reconstruction from the raw data was performed using the SimPlant dental implant software. The distances of mandibular incisive canal (MIC) to the inferior border and the labial and lingual cortices of the mandible were measured at 3, 5, 7 and 9 mm mesial to the mental foramen.

The MIC was visible in all (100%) CBCT images. The median distance and interquartile range from the lower border of the mandible was 9.86 (2.51) mm, curving downwards toward the inferior mandibular border at the symphysis menti. It was located closer to the buccal border of the mandible (3.15 [1.28] mm) than lingual cortex (4.78 [2.0] mm). The MIC curves toward the lingual side at the symphysis menti. There was gender difference in a number of these measurements. Current recommendation for chin bone graft harvesting can be applied to Asian subjects.

While acknowledging that there is human variability, this study provides an accurate anatomic location of the MIC, which in turn helps to determine a safe zone for chin bone graft harvesting. This information can become a useful guide in centers where CBCT is not available.

This study utilized the constitution and expression of Runx2/Cbfa1 to conduct 6-month-post-operation histomorphometrical and histochemical analysis of osteocalcin in bone regeneration following sinus-floor augmentation procedures using β-tricalcium phosphate (β-TCP) and autogenous cortical bone.

Thirteen sinuses of nine patients were treated with sinus-floor augmentation using 50% β-TCP and 50% autogenous cancellous bone harvested from the ramus of the mandible. Biopsies of augmented sinuses were taken at 6 months for histomorphometric and immunohistochemical measurements.

Runx2/Cbfa1- and osteocalcin-positive cells were found around TCP particles and on the bone surface. Approximately 60% of cells found around TCP particles stained positive for Runx2/Cbfa1. Fewer cells stained positive for osteocalcin. These positive cells decreased apically with increasing vertical distance from the maxillary bone surface. Histomorphometric analysis showed that the augmented site close to residual bone and periosteum contained approximately 42% bony tissue and 42% soft connective tissue, and the remaining 16% consisted of TCP particles. On the other hand, the augmented bone far from residual bone and periosteum contained 35% bony tissue and 50% soft connective tissue.

Our data suggest that TCP particles attract osteoprogenitor cells that migrate into the interconnecting micropores of the bone-substitute material by 6 months. The augmented site close to residual bone contained a higher proportion of bony tissue and a lower proportion of soft connective tissue than did the augmented site far from residual bone.

The present study evaluated the clinical validity of cone-beam computed tomography (CBCT) scans in comparison to panoramic radiographs regarding preoperative implant planning in combination with sinus grafting procedures.

Preoperative assessment of the maxillary sinuses and implant planning using panoramic radiographs and CBCT scans was performed on 16 sinuses (13 patients) and comprised choice of treatment, timing of implant placement, sinus morphology, level of confidence, complication prediction and graft volume assessment. Six examiners were involved in the study.

In the majority of cases there was a concordance between the treatment type based on either panoramic radiographs or CBCT. If any difference was found, this was due to an overestimation of bone quantity and quality on panoramic radiographs. The assessment of sinus morphology showed a significantly higher detection rate of sinus mucosal hypertrophy on CBCT. The most appealing result is a significant increase in surgical confidence and a significantly better prediction of complications when using CBCT.

A preoperative planning based on CBCT seems to improve sinus diagnostics and surgical confidence.

The purposes of this study were (1) to investigate the bucco-lingual course of the mandibular canal in the bony structure and (2) to figure out the relationship between the position of mental foramen on panoramic radiographs and the horizontal course of the mandibular canal.

A database of panoramic radiography and spiral computed tomography (CT) scans was searched and 100 subjects were selected based on the criteria. Mental foramina were classified into four groups according to its antero-posterior position. Three measurements were made on each slice of coronal CT scans at three different points: (1) apex of second premolar; (2) median point of two root apexes of first molar; and (3) median point of two root apexes of second molar. The bucco-lingual ratios were calculated to access the relative bucco-lingual position of the mandibular canal.

The distribution of subjects according to the type of mental foramen was: (1) type 3, 67%; (2) type 2, 26%; (3) type 4, 5%; and (4) type 1, 2%. The overall horizontal course of the mandibular canal was relatively constant from the second molar to first molar, whereas much significant directional change was found on the remaining course. Between types 2 and 3, no statistically significant differences were found at the level of the second molar and first molar (P = 0.461 and 0.965, respectively). Only below the second premolar, significant differences were found (P = 0.001).

Based on the findings of our computed tomographic image analysis, the position of mental foramen on panoramic radiographs was affected by its horizontal course of inferior alveolar nerve. The significant horizontal direction change of the course was found after the canal passing below the mandibular first molar regardless of the antero-posterior position of mental foramen.

Bioactive TiO₂ coatings have been found to enhance fibroblast adhesion and gingival attachment on the titanium surfaces, but no information is available whether the coatings also promote the adhesion of periodontal pathogens.

The purpose of this study was to investigate protein adsorption and the adhesion of Aggregatibacter actinomycetemcomitans (Aa) and Fusobacterium nucleatum (Fn) on bioactive TiO2 surfaces.

Commercially pure titanium discs (diameter 11.0 mm, grade 2) were coated with sol-gel derived bioactive TiO2 coatings (MetAlive, Vivoxid, Turku, Finland) and preincubated in 1.5 ml PBS/diluted serum/diluted saliva at room temperature to mimic the clinical situation after implantation and to allow serum/saliva proteins to adhere on the substrates. Uncoated titanium discs were used as controls.

SDS-PAGE revealed similar protein profiles on bioactive and control titanium substrates. No differences were noticed in Aa or Fn adhesion between bioactive and control titanium. However, serum and saliva conditioning diminished Aa adhesion on both surfaces (p<0.001).

It can be concluded that bioactive TiO2 coating does not promote adhesion of Aa and Fn.

The aim was to investigate histomorphometrically whether or not implant surface nanotopography improves the bone response under immediate loading simultaneous to sinus grafting.

Dual acid-etched titanium microimplants with/without crystalline surface deposition of calcium phosphate particles were placed in bilateral sinuslift areas grafted with a mixture of iliac crest bone and BioOss. Surface topography of microimplants was characterized using interferometry. Loaded microimplants (MsL) were immobilized in a provisional bridge supported by four normal size implants. Some patients had unloaded microimplants as controls (MsU). Biopsies were trephined after 2 or 4 months and histomorphometric analysis of bone area (BA) and bone-to-implant contact (BC) was performed. Nonparametric methods for dependent data were used to compare effect of surface modification, and healing time (2 vs. 4 months).

A total of 53 biopsies were available from 13 patients. A total of 4/28 and 1/11 MsL failed after resp. 2 and 4 months vs. 0/6 and 1/5 MsU. Many loaded biopsies were damaged at the apical portion and showed no bone adhesion. MsL decreased in BA from coronal to apical from 2 to 4 months; Coronal > Middle (P = 0.047), Coronal > Apical (P < 0.001) and Middle > Apical (P < 0.001). This gradual decrease was not observed for BC; Coronal < Middle and Middle > Apical (P < 0.001). Only the middle part showed significant bone contact after 2 months. For MsL there was no statistically significant difference between surface or time indicating that improvement of osseointegration over time due to maturation of the graft was poor. The MsU did not show any difference between Osseotite and Nanotite for BIC and BA (P > 0.05) but doubled both their BA and BIC (P < 0.05) between 2 and 4 months.

Osseointegration in sinus-grafted bone mixed with BioOss was poor irrespective of healing time or nanotopographical surface modification. The apex of MsL showed minimal bone contact suggesting that the graft does not add to the loading capacity. Surface enhancement was not beneficial despite the enlarged surface area. Overloading, most critical coronally of an implant, increases risks for implant failure and jeopardizes bone healing especially under immediate loading conditions with high load.

Nowadays, aesthetic appearance is receiving more and more attention from clinicians and patients. Therefore, it is of paramount importance for the surgeon to maintain or to improve the quality and the stability of the soft tissue–implant interface. The scientific literature supports the idea that the immediate placement and provisionalization of endosseus implants and abutments can indeed offer additional clinical control over the peri-implant tissue architecture. On this basis, this prospective study aims to evaluate the changes in soft tissues around immediately loaded dental implants in full-arch rehabilitations, over a period of 3 months.

Fifteen subjects were treated for immediate full-arch rehabilitations. Following implant placement, provisional rehabilitations made of bisphenol-A-glycidyldimethacrylate (BIS-GMA) and resin were placed. All records were made using a periodontal probe. The facial soft-tissue level was measured evaluating the distance between the soft-tissue margin and the incisal edge of the crown. Moreover, papilla levels were measured at the mesial and distal sites from a reference line connecting the occlusal edge of the crowns.

The average value at the mesial site was −0.035 mm (±1, median 0 mm), while at the midfacial site, it was 0 mm (±0.76, median 0 mm) and at the distal site, −0.05 mm (±0.92, median 0 mm). The plaque score index showed a reduction during the follow-up period.

Our data indicate that no differences at the midfacial point were detectable over the observation period. This is in agreement with several studies; it is plausible that these results are linked to a correct position of the implant in the alveolar socket. Moreover, comparing our results with what has been reported by other authors, it is surprising that while other studies highlight that papilla loss at the mesial and distal aspect is an expected consequence of immediate implant restorations, our data do not show any changes. The explanation of these results remains unclear. Further studies are needed to support our data and to clarify what mechanisms are involved in the maintenance of soft tissue.

Over the last years so many efforts have been made in order to indentify natural sources of osteogenic cells for the success of bone bioengineering. Among them, periosteum tissue has emerged as an interesting candidate. Thus, we decided to evaluate the osteogenic potential of periosteal-derived cells by describing a sequence of biological events since initial morphological changes to mineralization of extracellular matrix (ECM).

Periosteal-derived cells were obtained from calvarial of adult rats. After the primary culture and expansion, the adherent cells were cultured at 7, 14, 21 and 28 days under a classical osteogenic culture medium in order to evaluate the differentiation of those cells in mature osteoblast. It was monitored by evaluating a time-line of alkaline phosphatase (ALP) activity (biomarker of osteoblast differentiation) and afterwards nodules of mineralization (measured by von Kossa staining and calcium content).

Analysis from phase-contrast microscopy revealed mainly morphological changes ranging since fibroblast-shaped (7 days, semi-confluent culture at exponential growth) to polyhedral-shaped cells (14–28 days, confluent culture during differentiation process). ALP activity was linearly increased since 14–28 days while amount of protein remained unchanged. Interesting, our data from von Kossa staining reveled a highest incidence of mineralization nodules at 28 days.

Taken our results together, we can suggest that periosteal-derived cells present an interesting potential to differentiate in mature osteoblast able to promote mineralization in vitro by incorporating to ECM circulating calcium from extracellular compartment. From our point of view, this source of osteogenic cells can be explored by bioengineers in order to advance therapeutic protocols able to solve bone degenerative lesions.

This study evaluated the effect of implant surface blasting variables, such as blasting media size, velocity, and surface coverage and their two- and three-way interaction in surface roughness parameters.

Machined, grade IV titanium-alloy implants (n = 180) had their surfaces treated by a combination of 36 different blasting protocols according to the following variables: aluminum oxide blasting media particle size (50, 100, and 150 μm); velocity (75, 100, 125, and 150 m/s), and surface coverage (5, 15, 25 g/in.²) (n = 5 per blasting protocol). A single 0.46 inch nozzle of the blaster was pointed at the threaded area and spaced 0.050 inches away. Surface topography (n = 5 measurements per implant) was assessed by scanning electron microscopy. Roughness parameters Sa, Sq, Sdr, and Sds were evaluated by optical interferometry. A GLM statistical model evaluated the effects of blasting variables on the surface parameters, and their two- and three-way interaction (P < 0.05). Statistical inferences for Sa and Sq were performed after a log₁₀ transformation to correct for data skewness.

Prior to the log₁₀ transformation, Sa and Sq values for all processing groups ranged from ~0.5 to ~2.6 μm and from ~0.75 to 4 μm, respectively. Statistical inferences showed that Sa, Sq, and Sdr values were significantly dependent on blasting media, velocity, and surface coverage (all P < 0.001). Media × velocity, media × coverage, and media × velocity × coverage also significantly affected Sa, Sq, and Sdr values (P < 0.002). The highest levels were obtained with 100 μm blasting media, coverage for 5 g/in.², and velocity of 100 m/s. No significant differences were observed for Sds (P > 0.15).

The blasting variables produced different surface topography features and knowledge of their interaction could be used to tailor a desired implant surface configuration.

A novel technique based on plasma immersion ion implantation (PIII) is presented to modify titanium implant surfaces.

Initially, the implants are cleaned with argon to remove contaminants and the nanostructures are created by the bombardment of the surface with a mix of noble gases. Desired crystal structure of the titanium is obtained by the implantation of oxygen on the contaminant-free surface with particular nanostructures.

In this study, turned implants modified by PIII revealed a high density of rutile-TiO₂ nanostructures. Turned implants used as control revealed mainly microstructures and amorphous crystal structure. Surface roughness values were similar at the microscale for both turned and turned + PIII implants. Bone response was evaluated by removal torque tests of implants placed in the rabbit tibia and femur. After 4 weeks of healing, turned + PIII demonstrated higher removal torque values (P = 0.001) compared to turned implants.

The presence of rutile-TiO₂ nanostructures may explain the improved bone formation to turned + PIII implants.

To quantify metal artifacts obtained from a wide range of cone beam computed tomography (CBCT) devices and exposure protocols, to compare their tolerance to metals of different densities, and to provide insights regarding the possible implementation of metal artifact analysis into a QC protocol for CBCT.

A customized polymethyl methacrylate (PMMA) phantom, containing titanium and lead rods, was fabricated. It was scanned on 13 CBCT devices and one multi-slice computed tomography (MSCT) device, including high-dose and low-dose exposure protocols. Artifacts from the rods were assessed by two observers by measuring the standard deviation of voxel values in the vicinity of the rods, and normalizing this value to the percentage of the theoretical maximum standard deviation.

For CBCT datasets, artifact values ranged between 6.1% and 27.4% for titanium, and between 10.% and 43.7% for lead. Most CBCT devices performed worse than MSCT for titanium artifacts, but all of them performed better for lead artifacts. In general, no clear improvement of metal artifacts was seen for high-dose protocols, although certain devices showed some artifact reduction for large FOV or high exposure protocols.

Regions in the vicinity of the metal rods were moderately or gravely affected, particularly in the area between the rods. In practice, the CBCT user has very limited possibilities to reduce artifacts. Researchers and manufacturers need to combine their efforts in optimizing exposure factors and implementing metal artifact reduction algorithms.

The present study investigated the efficacy of a biphasic calcium phosphate as a bone grafting material for maxillary sinus augmentation in humans.

Half of the thirty patients selected for sinus augmentation were grafted with biphasic calcium phosphate, whereas the other half were grafted with autogenous bone chips harvested intraorally. After 9 months of healing, bone cores were retrieved from implant sites for histologic and histomorphometric evaluation.

The areas augmented with autogenous bone chips showed newly formed bone with a pattern very similar to that of the native area. Histomorphometry demonstrated that the amount of newly formed bone in the autogenous bone group was significantly greater than in the biphasic calcium phosphate group (P < 0.05). In the biphasic calcium phosphate group, less bone formation was observed in the area further away from native bone interface than in the area closer to native bone interface (P < 0.05), whereas no significant differences were observed between both areas in the autogenous group. In both groups, the implant survival rate was 100% with a minimum 1-year follow-up.

The data presented in this work confirm the osteoconductive properties of biphasic calcium phosphate, as well as its use in association with maxillary sinus floor augmentation procedures with successful outcomes.

Evaluate hBMP-2 expression following gene delivery from plasmid multilayers formed on sandblasted titanium in vitro and bone formation around similarly prepared implant surfaces in vivo.

Multilayers of cationic lipid/rhBMP-2 plasmid DNA complex (LDc) and anionic hyaluronic acid (HA) was assembled on sandblasted-dual acid etched pure titanium disks or implant surfaces using layer-by-layer (LBL) assembly. Gene delivery and hBMP-2 expression in cells exposed to the LDc multilayers was measured in vitro. To determine the effect of BMP delivery from such multilyaers in vivo, roughened implants coated with BMP-2 LDc multilayers or uncoated control implants (n = 15 for both) were implanted in the femurs of NZW rabbits. After 2, 4, 8 weeks, femurs were retrieved and prepared for histomorphometric evaluation (n = 5 rabbits per time point).

MC3T3-E1 cells cultured directly on the BMP-2 LDc coated titanium disks showed EGFP and hBMP-2 expression after 48 h in culture. Increased gene delivery occurred by increasing the number of assembly layers when cells were cultured for 48 h. Cells cultured on LDc coated surfaces had significantly higher cell viability than control cells cultured on uncoated porous titanium surfaces. Histologic observation of the implants showed that after 4 weeks healing, the bone to implant contact (BIC) on the LDc coated surface was much lower than that on the control surface, but didn't reach significant. In contrast, the percentage of bone within the implant's threads was significantly higher than the control group (P = 0.047).

The BMP-2 gene coated sandblasted dual acid etched titanium implants slightly accelerated early bone formation around implants.

To compare immediate and staged approach implant placement in circumferential defects treated with deproteinized bovine bone mineral (DBBM); hidroxyapatite/tricalcium phosphate (HA/TP); autogenous bone (Ab); and coagulum (Cg); upon implant stability, osseointegration and alveolar crest maintenance.

Six dogs underwent extractions of lower premolars, bilaterally. Twelve weeks later four bone defects (6 mm wide/4 mm long) were drilled at one side and randomly filled with DBBM; HA/TP; Ab; and Cg, respectively, and left to heal (staged approach). Eight weeks later one implant (Osseospeed^™, AstraTech) was placed in experimental sites. At the same session four defects were drilled on contra-lateral side and implants were inserted immediately after biomaterials grafting (immediate approach). Animals were euthanized 8 weeks later. Implant stability was measured by resonance frequency analysis (RFA) at installation and after sacrifice. Ground sections were prepared for bone contact (BIC); bone area (BA); distance implant shoulder-bone crest (IS-C); distance implant shoulder first bone contact (IS-B); and areas occupied by soft tissue.

The BA and BIC were superior in the staged approach. The Cg exhibited higher BIC and BA as compared with other materials at the total implant body (P = 0.004 and 0.012, respectively). The DBBM, HA/TP and Ab groups rendered similar BA and BIC. The immediate approach resulted in less crest resorption compared to staged approach. The biomaterials did not affect the IS-C and IS-B measurements. Particles area tended to be higher in DBBM group than HA/TP (P = 0.15), while soft tissue infiltrate was higher in DBBM group when used in the immediate approach (P = 0.04). The RFA indicated gain in stability in the staged approach (P = 0.002). The correlation test between RFA vs. BIC and BA demonstrated inferior stability for DBBM group in immediate approach (P = 0.01).

Implants placed in healed defects resulted in better stability as a consequence of higher BIC and BA. The Cg alone rendered increased BIC compared to other materials in both approaches. Immediate approach should be preferable to staged approach in terms of alveolar crest maintenance. The BIC and BA values did not vary between micro and macro-threads in this experimental model. Implants installed in sites filled with DBBM in immediate approach were less stable.

Tooth extraction is considered as the starting point of jaw atrophy via osteoclast activity stimulation. The maintenance of dental alveolar bone depends on surgery procedure and use of materials to maintain prior space favoring bone regeneration. Among substitutes used in dentistry to fill bone defects, Ostim-Pastes (Ostim^®) is a nanocrystalline paste tested for treatment of severe clinical conditions. This research first investigated the effect of Ostim on alveolar healing, comparing in the same healthy subjects, an Ostim^®-filled socket with a not-filled one. Moreover, it also proposed a new surgical protocol for the post-extractive socket treatment using the graft materials without elevation of full-thickness flaps.

Fourteen patients were enrolled to bilateral maxillary or mandibular extraction that was performed without elevation of full-thickness flaps. In each patient, one socket was filled using Ostim^®, and the other one was allowed to undergo natural healing. No suture was carried out. Clinical and biologic parameters were screened at 1, 7, and 14 days.

Obtained results evidenced that nanocrystalline hydroxyapatite supports bone regeneration, increasing the synthesis of pro-osteogenic factors as bone morphogenetics protein (BMP)-4, BMP-7, alkaline phosphatase, and osteocalcin. Moreover, filling post-extractive socket with nanocrystalline hydroxyapatite paste leads to a complete epithelialization already at 7 days after extraction, despite the fact that the teeth were extracted without elevation of full-thickness flaps . The improved epithelialization is mediated by increased vascular endothelial growth factor (VEGF) expression. No significant change was observed in inflammatory parameters, with exception of an early and transient IL-1β induction, that could trigger and improve alveolar healing.

Clinical and biomolecular observations of this explorative study evidenced that nanocrystalline hydroxyapatite improves alveolar socket healing, increasing angiogenesis, epithelialization, and osteogenesis, also in absence of elevation of full-thickness flaps.

Modifications of titanium (Ti) implant surfaces have a significant effect on early biofilm formation and the outcome of implant procedures. The aim of this study was to examine the role of plasma proteins and electrostatic forces in the adhesion mechanism of oral bacteria to modified Ti surfaces.

Ti discs with three different types of surface modifications, machined, acid-etched, and acid-etched and blasted, were examined for adhesion of oral bacteria: Streptococcus mutans,Porphyromonas gingivalis, and Fusobacterium nucleatum. Following pretreatment of the Ti with ion rich solutions or coating by human serum albumin or fibronectin, bacterial adhesion was examined by scanning electron microscopy and assessed quantitatively by DNA analysis. Ti coating by proteins as well as bacterial adhesion and their interrelationships were further investigated through confocal scanning laser microscopy.

Acid-etched and blasted Ti surfaces exhibited significantly higher amounts of bacteria adhesion than the other two surfaces. Calcium was found to serve as a bridging agent in the adhesion process of S. mutans and F. nucleatum to Ti surfaces. Although albumin coating of the Ti reduced the adhesion of S. mutans to all surfaces, it had no influence on the adhesion of P. gingivalis or F. nucleatum. Coating the Ti with fibronectin enhanced P. gingivalis and F. nucleatum adhesion.

Bacterial adhesion to Ti surfaces is roughness-dependent, and the adhesion mechanism is influenced by ions and proteins of the initial coating derived from the blood.

To evaluate the effect of two different abutment designs on soft tissue healing and the stability of the mucosal margin in vivo.

Twenty-nine subjects received two, non-adjacent endosseous implants in the esthetic zone. Subsequently, conventional (control) and curved abutments (experimental) were placed in combination with a temporary restoration (left–right randomization). Plaster models of the healed sites were made to assess the stability of the soft tissues at baseline and after 6 weeks. To measure deseating force, a dontrix gauge was used while removing the abutments after 6 weeks.

Although visually, differences in the transmucosal area were observed, the differences in marginal recession and in deseating force between abutments from the experimental and the control group never reached a statistically significant level. In general, some gain in soft tissue height was seen in both groups. Angled abutments elicited recession at all buccal sites (P = 0.003–0.02).

Abutments with a circumferential groove do not lead to a different response of the mucosal margin compared with a regular abutment, and are no more resistant upon removal than regular abutments after 6 weeks of function.

Vitamin D deficiency is highly prevalent in the population and associated with impaired peri-implant bone regeneration. Yet, there is a gap in understanding the impact of vitamin D supplementation on the process of osseointegration. In this study, the effect of vitamin D supplementation on peri-implant bone regeneration was investigated.

Fifty ovariectomized Sprague–Dawley rats were divided into three groups. The depletion group was fed a vitamin D-free diet for 8 weeks. The repletion group received vitamin D-free diet for 6 weeks, before animals were switched to standard diet containing 2400 IU/kg vitamin D. The control group was fed the standard diet. Two titanium mini-implants were placed in the tibia. All groups remained on their previous diet until sacrifice. Blood sample testing and histomorphometric analysis were performed.

Vitamin D depletion caused a significant reduction in 25-hydroxvitamin D in rat serum that returned to control levels in the repletion group. This vitamin deficiency was associated with a decrease in bone-to-implant contact in the cortical area, which was leveled to controls in the repletion group. No significant changes by vitamin D depletion were noticed in the medullar compartment. Moreover, also the peri-implant bone area and the mineral apposition rate remained unchanged upon vitamin D depletion.

These results indicate that vitamin D deficiency has a negative impact on cortical peri-implant bone formation in ovariectomized rats, which can be compensated by vitamin D supplementation. This study provides first insight into the potential beneficial effect of vitamin D supplementation in implant dentistry.

Over the years, several modifications have been made to the sinus augmentation technique and to the materials used. However, there is still controversy about the need for using a barrier concurrently with a graft in sinus augmentation procedures. On this basis, the aim of this randomized clinical study was to investigate the effect of resorbable collagen membrane over the osteotomy window on maxillary sinus augmentation healing.

Patients who required maxillary sinus augmentation were evaluated and selected to enter the study. After maxillary sinus grafting, each patient was randomly assigned to control (membrane over the osteotomy window) or test (no membrane) group. After 6 months, one bone biopsy was harvested from the lateral window and sent to the histology laboratory. The Mann–Whitney nonparametric test was used for comparing the two groups. P-value was set at 5%.

Eighteen patients entered the study and were randomly allocated in control (nine patients) or test group (nine patients). The histomorphometric measurements revealed that newly formed bone was 30.7% ± 15.5% of the total volume from the membrane group (control). The average percentage of connective tissue was 50.6% ± 18.7% and residual graft percentage was 18.4% ± 20.3%. On the other hand, data regarding the nonmembrane group (test) showed that the percentage of newly formed bone was 28.1% ± 19.4%. The mean percentage of connective tissues was 59.3% ± 15.4% and 12.6% ± 12.4% for the residual graft particles. No significant difference was detected in the histomorphometrical evaluation between the two groups.

Our results showed that, compared with sites not covered, the use of the membrane did not substantially increase the amount of vital bone over a period of 6 months. On the other hand, the use of membrane seems to reduce the proliferation of the connective tissue and the graft re-absorption rate. It is plausible that blood supply of maxillary sinus can play a role in such a result. Further studies are needed to explore whether the use of membrane could really be advantageous for the sinus augmentation procedure and to evaluate what influence this method can have on the amount and quality of reconstructed bone.

The purpose of this study was to evaluate the effects of tissue-engineered bone (TEB) on osteotome technique with simultaneous implant placement that is applied to the severe bone resorption in the maxilla for earlier bone regeneration and minimal invasive operation.

We applied injectable TEB, which was composed of bone marrow-derived mesenchymal stem cells (BMMSCs) as stem cell source and platelet-rich plasma as an autologous scaffold and signal molecules, with osteotome technique for 23 cases. After dental implants were pre-prepared with pilot drills and/or using the Summers Osteotome Kits, TEB was injected and followed by dental implants insertion. The outcomes were evaluated by radiographs. Statistical evaluation was performed by Friedman test and Wilcoxon signed-rank test (P ≤ 0.05).

The grafted BMMSCs possessed a phenotype of mesenchymal stem cells. The lift-up bone height by TEB using BMMSCs showed the increase of 6.1 ± 1.5 mm. Moreover, the mean regenerated bone height was 8.2 ± 1.6 mm and 8.0 ± 1.4 mm, and the average alveolar bone height was 15.6 ± 1.2 mm and 15.1 ± 1.4 mm, at 3 and 6 months, respectively. There were significant differences between pre-operative values and post-operative ones (at 3, 6 months). No perforations of the Schneider membrane were found and the inserted implants were successful after 1 year.

This novel application using osteotome technique with injectable TEB would stably predict the success of bone formation and dental implants, and provide minimally invasive cell therapy.

The aim of this study was to investigate the characteristics of implant sites on the edentulous alveolar ridge in the anterior maxilla. We studied the bone quantity and quality of implant sites at the anterior maxilla using CT images for the 33 implant sites on patients who underwent dental implant therapy in our Department since 2006.

Computed tomography (CT) images of 33 patients (20 women: 13 men) encompassing 33 implant sites were chosen and examined. The recipient sites for implant placement were determined based on CT data using an implant planning software (Simplant 11.0). The mean bone density values in Hounsfield unit (HU) were recorded using Simplant for both the simulated implant areas and the trabecular bone width. We classified the edentulous alveolar ridge and bone quality according to a classification based on Lekholm and Zarb (1985).

Incisors had higher bone densities than canines. Women had lower bone densities than men. Canines displayed greater trabecular bone density and alveolar bone widths than incisors. No maxillary sites were judged to have a bone quality of 1 in this group. Quality 3 accounted for 69.7% of the total samples.

An assessment of bone quality in the anterior alveolar ridge may well reflect age-related systemic pathological conditions and should be used in dental implant treatment planning to avoid associated risk factors.

To investigate the combined effect of macro and pitch shortened threads on primary and secondary stability during healing, but before dynamic loading.

Two sets of turned implants with different macro geometry were prepared. The test group possessed pitch shortened threads in between the large threads and the control group did not have thread alterations. The two implant groups were placed in both femur and tibiae of 10 lop-eared rabbits, and at the time of implant insertion, insertion torques were recorded. After 4 weeks, all implants were subjected to removal torque tests.

The insertion torque values for the control and test groups for the tibia were 15.7 and 20.6 Ncm, respectively, and for the femur, 11.8, and 12.8 Ncm respectively. The removal torque values for the control and test groups in the tibia were 7.9 and 9.1 Ncm, respectively, and for the femur, 7.9 and 7.7 Ncm respectively. There was no statistically significant difference between the control and test groups.

Under limited dynamic load, the addition of pitch shortened threads did not significantly improve either the primary or the secondary stability of the implants in bone.

The aim of this systematic review was to evaluate the relationship between genetic polymorphisms and dental implant biological complications.

All prospective, cross-sectional and retrospective studies reporting on dental implant loss/peri-implantitis/peri-implant marginal bone loss after loading in association with genetic polymorphism were considered for inclusion. A thorough search of electronic databases, supplemented by checking bibliographies of review articles was performed by two independent reviewers. Quality assessment of the included studies was conducted independently and in duplicate by two reviewers as part of the data extraction process.

The search provided 344 related articles. Twenty-two publications were identified for possible inclusion and finally, seven articles met the defined inclusion criteria. Four studies which investigated the potential relationship between early implant loss and IL-1, IL-2, IL-6, TNF-α or TGF-β1 genotype revealed no evidence to support this association. In two of the three studies which evaluated peri-implantitis in relation to IL-1 genotype, the findings indicate that IL-1RN (intron 2), IL-1A (–899), IL-1B (+3954) gene polymorphisms were correlated to increased peri-implant tissue infection and destruction.

Methodological and study design issues restricted the possibility to draw robust conclusions. Within the limits of this review, it might be concluded that there is no obvious association between specific genetic polymorphism and dental implant failure in terms of biological complications, although a tendency should be underlined showing the potential link between IL-1 genotype and peri-implantitis. Well designed and adequately powered prospective cohort studies are needed to provide further information.

This study addressed the suitability of a polyethylene glycol (PEG) matrix as scaffold for cell-mediated local BMP-2 gene transfer in a calvarial critical size defect (CSD) model.

PEG matrix (degradation time 10 days) and PEG membrane (degradation time 120 days) were used in the pig calvarial model. Cylindrical (1 × 1 cm) CSD (9 per animal; 20 animals) were filled with: (i) HA/TCP, covered by PEG membrane (group 1); (ii) HA/TCP, mixed with PEG matrix (group 2); and (iii) HA/TCP mixed with BMP-2 transfected osteoblasts and PEG matrix (group 3). BMP-2/4 gene transfer: liposomal in vitro transfection of BMP-2/V5-tag fusion-protein. Quantitative histomorphometry (toluidine blue staining) after 2, 4 and 12 weeks assessed bone formation. Semiquantitative immunohistochemistry estimated the expression of BMP-2 and V5-tag.

Group 3 showed significantly higher new bone formation than groups 1, 2 at 4 (P < 0.05) and 12 (P < 0.02) weeks. BMP-2-V5-tag was detected for 4 weeks. BMP-2 expression in group 3 was higher compared to all other groups after 2 and 4 (P < 0.02) weeks.

The PEG matrix serves as scaffold for cell-mediated BMP-2 gene delivery in guided bone regeneration facilitating cell survival and protein synthesis for at least 4 weeks. Local BMP-2 gene delivery by PEG matrix-embedded cells leads to increased bone formation during critical size defect regeneration.

Autologous bone augmentation to rebuild compromised alveolar ridge contour prior to implant placement allows for favorable three-dimensional implant positioning to achieve optimum implant esthetics. The aim of the present study was to evaluate peri-implant soft tissue conditions around single-tooth implants following bone grafts in the esthetic zone of the maxilla.

Sixty patients underwent autologous bone augmentation of deficient maxillary sites prior to placement of 85 implants in the esthetic zone. In case of multiple implants per patient, one implant was randomly selected. Objective evaluation of 60 single-tooth implants was performed using the Pink-Esthetic-Score (PES) and Papilla Index (PI) and supplemented by subjective patient evaluation, as well as clinical and radiologic examination.

Objective ratings of implant esthetics were satisfactory (median PES: 11, median PI: 2) and significantly correlated with high patient satisfaction (mean VAS score: 80%). Both esthetic indices demonstrated respectable levels of inter- as well as intra-observer agreement. Poor implant esthetics (low PES and PI ratings) were significantly associated with increased anatomic crown height, while no influence of horizontal implant-tooth distance could be found.

The present investigation indicates that favorable esthetic results may be achieved in the augmented anterior maxilla. However, bony reconstruction of compromised alveolar ridges does not guarantee optimum implant esthetics.

The objective of this study is to evaluate the anatomical structures in the maxillary sinus with relation to lateral approach sinus elevation utilizing cone beam computed tomography (CT) scans taken prior to sinus elevation surgery.

A total of 150 CT images were acquired from 150 patients (90 men and 60 women; mean age, 49.4 years, range 23–86 years) who were being treated with implant-supported restorations in the posterior edentulous maxilla. Of the 150 CT scans, 65 were of the right sinus and 85 of the left sinus. Measurements of the anatomical structures in the maxillary sinus were conducted on the CT images.

In the mean width of the lateral wall, there were statistically significant values among the measurement points (P < 0.05). The anterior area of the sinus lateral wall was thicker than the posterior lateral wall. There was a statistically significant difference between the vessel diameter and lateral wall width (P < 0.05). As sinus lateral wall width increased, so did the vessel diameter. The mean distance to the inferior border of the vessel from the sinus floor and from the alveolar crest was 8.25 and 17.03 mm, respectively. The intraosseous group among the vessel position was 64.3%, so the intraosseous vessel could be visualized in CT scans at 64.3%. In angle A, the group of less than 30° was 4.8%. Schneiderian membrane perforation by narrow angle had a low risk. The prevalence of the septa related to Schneiderian membrane perforation was 44%. The distance to the inferior border of the vessel from the alveolar crest being less than 15 mm was 31%. The vessel diameter greater than 1 mm was 37.8%.

Based on present research about utilizing cone beam CT scans for sinus elevation, the alteration of the lateral approach sinus elevation technique is highly recommended if complications such as membrane perforation or bleeding are expected.

The study aimed to assess the clinical results after osteotome technique to lift sinus floor, without graft materials in the residual bone height (RBH), below 8 mm.

Twenty-two patients aged from 19 to 70 years old in need of maxillary sinus floor augmentation were enrolled in this study. Preoperative and postoperative cone beam computerized tomography (CBCT) were taken to guide the surgery. Twenty-seven implants were inserted and followed clinically, another CBCT exam was taken at 6 months postoperatively. The diameter of the implants was 4.7 mm (SD 0.4 mm), the length was 10 mm (SD 1.0 mm). The average residual bone height was 6.7 mm (SD 1.2 mm).

No implants were lost after the surgery and the 2 years follow-up. There was no obvious marginal bone loss during the 6 months follow-up verified by CBCT. The mean bone gain at the implant sites was 2.5 mm (SD 1.5 mm).

The study verified the good and stable clinical result of the OSFE technique without using bone grafting materials when the RBH was only 4.1–8 mm.

A cemented mandibular endoprosthesis is a potentially viable option for mandibular reconstruction after ablative surgery. The commonly used PMMA cement has the inherent weakness of a lack of bioactivity. Improvement by the addition of porosities and bioactive compounds like calcium phosphates may resolve this issue.

The objective of this study was to assess the bone and tissue response to two modified PMMA cements with post-operative radiation as an additional influencing factor.

An in vivo animal study was performed using a mandibular rabbit model. A porous PMMA cement (A) and a porous cement incorporated with Beta-tricalcium phosphate particles (b-TCP) (B) were placed in bilateral mandibular defects with exposed roots and mandibular nerve of 20 animals. Half of the animals underwent additional post-operative radiation.

The animals were healthy with only a minor complication in one rabbit. Temperature analysis showed no significant risk of thermal necrosis with the maximal in vivo cement temperature at 37.8°C. Histology demonstrated: (1) good bone ingrowth around the defect as well as within the pores of the cement and defect bridging was achieved in 70% of the specimens after 12–15 weeks of implantation, (2) no pulpal injury with minor secondary cementum response, (3) an intact mandibular nerve with no inflammation, (4) extensive degradation and resorption of the b-TCP particles by 12–15 weeks, and (5) presence of an intervening thin fibrous tissue at the bone-to-cement interface. Histomorphometrical analysis revealed that there was no difference between the different cements and the presence or absence of post-operative radiation. The 12–15 weeks specimens showed significantly more bone ingrowth and bone maturity than the 4–7 weeks specimens.

Both modified PMMA cements have good biocompatibility, bioactivity and support bone ingrowth and additional post-operative radiation did not show any negative effects.

To radiographically analyze extraction sites left untreated or treated using a socket preservation technique.

A total of 20 patients scheduled for single extraction in the maxilla from second to second premolar were enrolled in this study. All sites showed a bone defect >5 mm at the buccal wall and no soft tissue recession. At baseline (T0), tooth extraction was performed; subsequently, sites were randomly allocated to the control (CG: left to heal without grafting) or test group (TG: grafted using hydroxyapatite). Two months later (T1), implants were inserted and eventual GBR procedure was performed. Three months later, the definitive crown was placed. Follow up was 24 months (T2). A cone-beam computed tomographic examination (CT) was performed at each time point. At each radiographic analysis, horizontal and vertical widths of the sockets were measured. Comparisons between CG and TG were performed by a Wilcoxon non-parametric test.

At the end of the study, no patient dropped out and all implants inserted (10 in each group) resulted integrated. GBR procedures were performed at T1 only in the CG. In the CG, the mean value of the horizontal width in the coronal CT slices was 0.98 mm (±0.37), 7.70 mm (±0.92), 7.45 mm (±0.69) at T0, T1 (after bone regeneration) and T2, respectively. In the TG, the mean value of the horizontal width in the coronal CT slices was 0.96 mm (±0.41), 8.97 mm (±1.91), 9.48 mm (±1.56); at T2, it was 9.52 mm (±1.87) at T0 (pre- and post-socket preservation) T1 and T2, respectively. At each follow up, the mean horizontal bone width in TG was statistically significantly greater than in the control group (P < 0.05). At T0, mean value of the vertical bone defect length (BDL) was 6.93 mm for TG, 6.5 mm for CG. At T1 and T2, mean BDL value was 0 for both groups. Statistically significant difference was not found between TC and CG at any time point (P > 0.05).

This randomized controlled trial suggested that in sites with buccal bone defects >5 mm, the application of HA can minimize alveolar crest resorption following tooth extraction. Furthermore, compared with traditional regenerative procedure carried out following socket healing, this preservation technique seems to result in better horizontal regeneration of the buccal bone wall.

To compare the interproximal cleansing efficacy of the novel, waist-shaped Circum^® brush (Topcaredent^®, Switzerland; CB) with that of a straight soft interdental brush (IB) (TePe^®, Sweden; SB) on posterior surfaces.

Eight patients after completion of initial periodontal therapy abolished oral hygiene for 3 days. Baseline plaque scores (PlI, Silness & Löe ) were assessed on eight surfaces of all premolars and molars. Subsequently, an instructed nurse applied at random one of the two IB, three times per interdental space . Following this, registration of the PlI was repeated by the same blinded examiner. After a 2-week recovery, patients abolished oral hygiene practices for another 3 days. Again, pre-and post-brushing PlI were recorded by the same examiner. The second IB was now applied.

Patient mean PlI and site PlI were evaluated before and after application of the SB or CB respectively. Paired t-tests were performed to yield statistically significant differences. The reduction of biofilm from before to after the use of the IB on a subject basis was highly significant (P < 0.0001). The mean PlI after the use of the CB was significantly lower than after the use of the SB (P < 0.0001). Comparing the PlI of the line angles (MB, ML, DB, DL), significantly more biofilm had been removed by applying CB compared with SB (P < 0.0001). Moreover, comparing the PlI of the buccal (MB, DB) or the lingual line angles (DL, ML) yielded a significantly higher reduction of biofilm in favour of the CB (P < 0.0001). The reduction of the PlI in the mid-interproximal portion, both mesially and distally did not differ significantly between CB and ST. No biofilm reduction was seen on the buccal sites with either IB.

The application of the waist-shaped Circum^® IB resulted in significantly lower PlI scores than the use of a straight IB. This was predominantly due to the higher cleansing effect of the waist-shaped CB on the buccal and lingual line angles.