Comparison of periosteal pedicle graft and subepithelial connective tissue graft for the treatment of gingival recession defects

Authors


Dr Ajay Mahajan
Department of Periodontics
Himachal Pradesh Government Dental College and Hospital
Shimla 171001
India
Email: julius05@rediffmail.com

Abstract

Background:  The use of periosteum as a pedicle graft in the treatment of gingival recession defects is a recent advancement. The subepithelial connective tissue graft (SCTG) is considered the gold standard for the treatment of gingival recession defects. The present randomized controlled trial was done to compare periosteal pedicle graft (PPG) with SCTG for the treatment of gingival recession defects.

Methods:  10 males and 10 females between the ages of 16 and 40 years (mean age 25.2 years) with Miller’s Class I and II recessions ≥3 mm participated in this one-year clinical study. They were assigned randomly to test group (PPG) and control group (SCTG). Results were evaluated based on parameters measuring patient satisfaction and clinical outcomes associated with two treatment procedures. Significance was set at p < 0.05.

Results:  At the end of the study, the defect coverage was 3.1 ± 0.13 mm or 92.6% in the test group compared to the control group in which the defect coverage was 2.70 ± 0.11 mm or 88.5%. The difference between the two groups was statistically significant (p < 0.0001). The average residual defect was comparable between the two groups, i.e. 0.3 ± 0.67 and 0.5 ± 0.84 in the PPG and SCTG group respectively. The test group was rated higher in terms of overall patient satisfaction (p < 0.02) and comfort during and after the procedure (p < 0.001).

Conclusions:  PPG and SCTG have comparable clinical effectiveness, but PPG is superior to SCTG in terms of patient-centred outcomes, reflecting improved patient comfort and overall patient satisfaction.

Abbreviations:
CEJ

cemento-enamel junction

PPG

periosteal pedicle graft

SCTG

subepithelial connective tissue graft

Introduction

Multiple techniques have been developed to obtain predictable root coverage.1–3 Periodontists can choose among many surgical techniques to achieve predictable optimal results. The purpose of developing newer methods for root coverage is to increase predictability, reduce the number of surgical sites, and improve patient comfort together with a need to reconstruct the lost periodontal tissues. The selection of one rather than another technique depends on factors related to defect (size of recession, absence or presence of keratinized tissue adjacent to defect, width and height of interdental soft tissue, depth of vestibulum or the presence of frenenuli), while others related to the patient included the attempt to reduce the number of surgeries and intraoral surgical sites together with the need to satisfy the patient’s aesthetic demands such as final colour and tissue blend of the grafted area. Among all the techniques used for the treatment of gingival recession defects, the subepithelial connective tissue graft (SCTG) is considered the gold standard4–6 but has a number of shortcomings; the surgery requires a second operation to obtain the donor tissue from the palate; the amount of donor tissue is limited; and the procedure significantly increases the complications and pain resulting from the surgery due to the need to surgically open a second site to obtain the donor tissue. There has long been a need for a graft which has its own blood supply that can be harvested adjacent to the recession defect in sufficient amounts without requiring any second surgical site and has the potential to promote the regeneration of lost periodontal tissue. The adult human periosteum is highly vascular and is known to contain fibroblasts, osteoblasts and their progenitor cells, and stem cells.7 Recently, the periosteum has been used successfully as a pedicle graft to treat isolated as well as multiple gingival recession defects.8,9 To date, no study has been done to compare and evaluate the results of periosteal pedicle graft (PPG) with other techniques used for the treatment of gingival recession defects. The present study was undertaken to evaluate PPG in terms of patient satisfaction and its effectiveness and efficiency in the treatment of gingival recession defects, and to compare the results with the established SCTG technique.

Materials and Methods

Study design

The present study was a randomized controlled trial with a parallel group design. The Consolidated Standards of Reporting Trials (CONSORT) guidelines for clinical trials were followed. A clinician not involved with the study sequenced the study subjects to the therapy allocated. When performing their study tasks, the study examiner and the operator were not jointly present with the study subjects. Study subjects were instructed not to discuss therapy with the study examiner. The study examiner was unaware of study treatment allocations and performed all clinical measurements. The operator was well experienced and had performed both the techniques in the past. Based on a coin toss, subjects (10 males and 10 females between the ages of 16 and 40 years [mean age 25.2 years]) with isolated gingival recession defects in relation to the buccal aspect of maxillary or mandibular teeth were randomly selected from the outpatient department of the Department of Periodontics, Himachal Pradesh Government Dental College and Hospital, Shimla, India. Subjects were divided into test (PPG) and control (SCTG) groups. A consent form was signed by all subjects. Subjects reporting between 1 October 2009 and 1 January 2011 were included in the study.

Cases were chosen based on the following inclusion criteria: non-compromised systemic health and no contraindication for periodontal surgery; Miller Class I or II recession defect >3 mm in upper and/or lower anterior teeth; the involved tooth was well aligned in the dental arch and free of periapical pathology. Exclusion criteria were: smokers and chewers of tobacco; endodontically treated test or control sites; root surface restorations on test or control sites; pregnant and lactating women; use of fixed orthodontic or removable appliances; and a previous root coverage procedure at test or control sites.

Clinical parameters

Patient’s satisfaction was assessed using a three-point rating scale: ‘fully satisfied’, ‘satisfied’ and ‘unsatisfied’ in which the patient was questioned about his/her satisfaction with regard to the following patient-centred criteria: (1) root coverage attained; (2) relief from dentinal hypersensitivity; (3) colour of gums; (4) shape and contour of gums; (5) surgical procedure – patient was asked to rate the procedure depending upon the pain during surgery and discomfort he/she experienced related to the duration of the procedure and handling by the operator; (6) post-surgical phase – patient’s opinion regarding pain, swelling and postoperative complications was assessed based on his/her view of the post-treatment phase; (7) cost-effectiveness – patients were asked whether the treatment given to them justified the time and money they spent for their treatment.

The following scores were given by the patients:

ScoreInterpretation

3 fully satisfied

2 satisfied

1 unsatisfied

Objective criteria used to assess the treatment outcome included measurement of: (1) length of recession – gingival recession was measured as the distance between the cemento-enamel junction (CEJ) and the most apical point of the gingival margin; (2) probing depth – probing depth was measured as the distance from the bottom of the pocket to the most apical portion of the gingival margin; (3) width of keratinized gingiva – the width of keratinized gingiva was measured from the most apical point of the gingival margin to the mucogingival junction; and (4) width of attached gingiva – the width of attached gingiva was calculated by subtracting the probing depth from the width of keratinized gingiva.

All measurements were recorded to the nearest millimetre preoperatively, i.e. 0 day (just before surgery) and postoperatively at 12 months with a calibrated UNC-15 probe (Hu-Friedy, Chicago, IL, USA).

Pre-surgical management

A general assessment of patients was made based on their history, clinical examination and routine laboratory investigations. All the selected patients received Phase 1 therapy, which included oral hygiene instructions, scaling and root planing by both ultrasonic and hand instruments. One month after Phase 1 therapy, the patients were subjected to surgical procedure.

Surgical procedure

Test group (PPG)

After local anaesthesia with a solution of 2% lignocaine with 1:80 000 adrenaline, an intrasulcular incision was made at the buccal aspect of the involved tooth. Two horizontal incisions were then made perpendicular to the adjacent interdental papillae at the level of the CEJ preserving the gingival margin of the neighbouring teeth, followed by two oblique vertical incisions extending beyond the mucogingival junction. A full thickness trapezoidal flap was raised 3–4 mm apical to the osseous crest which was then pulled buccally to create tension on the periosteum. An incision was made through the periosteum where the flap was still attached to bone to create a partial thickness flap. The partial thickness flap was extended to expose a sufficient amount of the periosteum which was then separated from the underlying bone using a periosteal elevator. The process of harvesting the periosteal graft was initiated at the apical extent of the periosteum which was lifted slowly in a coronal direction. The periosteum was not separated completely from the underlying bone, leaving it attached at its coronal most ends. Thus, the periosteal pedicle graft obtained was then turned over the exposed root surface and sutured with a synthetic 5-0 bioabsorbable suture (Ethicon Johnson and Johnson, Aurangabad, India). After stabilizing the periosteal graft, the flap was coronally positioned and sutured using a sling suture technique with a non-resorbable 4-0 silk suture. The releasing incisions were closed with interrupted sutures after which the operated site was covered with non-eugenol periodontal dressing for protection. Postoperative instructions were given to the patient. Nimesulide 100 mg twice daily was also prescribed for 1 week. During the recovery phase of the wound, the subjects were advised to follow scrupulously all normal oral postoperative hygiene instructions including not to brush the operated tooth for 2 weeks and to rinse the oral cavity with chlorhexidine (0.2%) mouthwash twice daily for at least 2 weeks. After 1 week the periodontal dressing and sutures were removed and the surgical area was flushed with antimicrobial solution. Subjects were recalled every week for the first 4 weeks, then every 2 weeks for the next 8 weeks, and monthly until the end of the study. Figures 1a to 1g show treatment over time.

Figure 1.

 (a) Marked gingival recession defect in relation to maxillary left canine. (b) Partial thickness flap raised to expose the periosteum. (c) Periosteal pedicle graft. (d) Periosteal pedicle graft sutured to cover the gingival recession defects. (e) The graft covered with the overlying mucosal flap and sutured. (f) Postoperative (1 week). (g) Treatment outcome after 1 year.

Control group (SCTG)

The traditional subepithelial connective tissue graft technique described by Langer and Langer10 was used to cover the gingival recession defects. The recipient site was prepared by raising a partial thickness flap created with two vertical incisions placed at least one-half to one tooth wider mesiodistally than the area of gingival recession. The coronal margin of the flap was started with a horizontal sulcular incision to preserve all existing facial gingiva. The proximal papillae were left intact. Care was taken to extend the flap to the mucobuccal fold without perforations that could affect the blood supply. The area was irrigated with sterile saline solution. A second surgical site was created on the palate where the location of a greater palatine neurovascular bundle was detected. The incisions were placed between the distal aspect of the canine and the midpalatal region of the first molar area with the trap-door technique. A connective tissue graft in an adequate size of 2 mm thickness was harvested, and pressure was applied to the donor area with gauze soaked in saline after the graft was taken. The donor area was closed with silk 4-0 sling sutures and graft stabilization was done in a similar manner as for the test group after which the operated site was covered with non-eugenol periodontal dressing for protection. Postoperative instructions were given to the subjects similar to the test group. Subjects were recalled every week for the first 4 weeks, then every 2 weeks for the next 8 weeks and monthly until the end of the study.

Statistical analysis

Mean and standard deviation were calculated for both test and control groups for all the clinical parameters. Analysis of variance was used to evaluate the degree of variation from the mean within a group and among the group. On the basis of this variation, a ratio (F-ratio) was calculated. Paired ‘t’ test was used to test the significance of change. To test the significance of change in groups, the unpaired ‘t’ test was used. P was the level of significance calculated. A p  0.05 result was considered statistically significant.

Results

Healing was uneventful and the subjects were satisfied with the treatment outcome. As the postoperative time increased, the progressive adaptation of the edges of the graft to the surrounding tissues and increased morphologic and chromatic resemblance was observed. At the end of the study, sites treated with PPG had a mean defect coverage of (92.6%). For SCTG, the mean defect coverage was (88.5%). Significant reduction in gingival recession length was noticed at the end of the study for both PPG (Fig. 1g) and SCTG groups. No statistically significant differences were observed between the groups in the remaining clinical parameters at the baseline. The results of intragroup analysis are summarized in Table 1. Tables 2 and 3 show change in gingival recession and root coverage predictability in PPG and SCTG groups respectively. No statistically significant differences were observed between the groups in any of the parameters except in the parameter measuring reduction in length of gingival recession, which was higher in the PPG group than the SCTG group. There was a statistically significant difference between the two groups when overall patient satisfaction scores were compared (p < 0.02). When the two groups were compared in terms of individual satisfaction criteria, statistically significant differences were noticed only in parameters measuring patient satisfaction relating to comfort during and after the procedures (p < 0.001); in these criteria PPG was rated higher than the SCTG group. For the remaining criteria, there were no statistically significant differences among the two groups.

Table 1.   Measurement of clinical parameters (in mm) at baseline and at 12 months for PPG and SCTG treated sites
Clinical parametern = 10PPGCTG
Initial examination (mean + SD [mm])Final examination (mean + SD [mm])Mean changes in clinical parameters (in mm) at baseline and at 6 months for PPG and SCTG treated sites ‘t’ value‘p’ valueInitial examination (mean + SD [mm])Final examination (mean + SD [mm])Changes in clinical parameters (in mm) at baseline and at 6 months for PPG and SCTG treated sites‘t’ value‘p’ value
Gingival recession length 3.6 ± 0.840.3 ± 0.673.3 ± 0.1712.6<0.0001 (S)3.30 ± 0.950.50 ± 0.842.70 ± 0.1114<0.0001 (S)
Probing depth 2.10 ± 0.322.40 ± 0.520.30 ± 0.201.550.13 (NS)2.30 ± 0.48 2.60 ± 0.520.30 ± 0.041.30.19 (NS)
Width of keratinized gingiva 3.50 ± 0.533.80 ± 0.420.30 ± 0. 111.40.17 (NS)3.10 ± 0.573.40 ± 0.520.30 ± 0.051.230.23 (NS)
Width of attached gingiva  1.40 ± 0.521.60 ± 0.700.20 ± 0.180.720.47 (NS)1.30 ± 0.481.20 ± 0.630.10 ± 0.780.390.69 (NS)
Table 2.   Measurement of gingival recession (in mm) at baseline and at 12 months (PPG group)
Tooth numberInitial recession [in mm]Final recession [in mm]Recession defect coverage [in mm]% age defect coveragePredictability frequency ≥90% root coverage
134041001
233031001
234041001
213031001
31523600
415051001
113031001
233031001
13312660
323031001
Mean ± SD3.6 ± 0.840.3 ± 0.673.3 ± 0.17Predictability 8 of 10
80%
Table 3.   Measurement of gingival recession defects (in mm) at baseline and at 12 months (SCTG group)
Tooth numberInitial recession [in mm]Final recession [in mm]Recession defect coverage [in mm]% age defect coveragePredictability frequency ≥90% root coverage
134041001
233031001
33413750
213031001
31523600
31422500
112031001
232031001
133031001
233031001
Mean ± SD3.3 + 0.950.5 + 0.842.7 + 0.11Predictability 7 of 10
70%

Discussion

Successful coverage of exposed roots for aesthetic and functional reasons has been the objective of various mucogingival procedures. Recently, the criteria for success of root coverage procedures has focused not only on objective outcomes (percent root coverage) but also on patients’ requirements (aesthetic satisfaction in terms of colour match, intra and postoperative discomfort and cost-effectiveness). This generates a need for the clinician to develop newer techniques to fulfil these requirements without compromising aesthetics and comfort. The periosteum is a highly vascular connective tissue sheath covering the external surface of all bones except sites of articulation and muscle attachment.11 The use of periosteum in medicine and dentistry is not new. Various research papers have been published explaining the osteogenic potential of human periosteal grafts.7,12–14. The use of periosteum as a barrier membrane for the treatment of periodontal defects was published by Lekovic et al. in 199115 and again in 1998 by Lekovic et al.16 and Kwan et al.17 Recently, the use of periosteum for the treatment of gingival recession defects has also been suggested.8,9,18,19

In the present study, 92.6% of root coverage was obtained in the cases treated with PPG with 90% or greater root coverage 80% of the time. In contrast, the SCTG group had a mean root coverage of 88.5% and predictability of 70%. The results, although impressive, cannot be compared to other studies as to our knowledge this is the first long-term study utilizing PPG for the treatment of gingival recession defects. The percentage of root coverage obtained and predictability of more than 90% root coverage in the SCTG is in accordance with the earlier studies which show a mean defect coverage ranging from 57% to 98% with a mean of all studies of 84% and predictability of 68%.1 The better predictability and high percent of root coverage in PPG treated cases may be attributed to the fact that wound healing after mucogingival surgery relies on clotting, revascularization and maintenance of blood supply.20 Also, a vascular graft is more likely to survive on an avascular root surface. The periosteum has a rich vascular plexus and a recent study has shown that periosteal cells release vascular endothelial growth factor.21 These qualities make periosteum a suitable graft over an avascular root surface; also, having an adequate vascularity prevents necrosis of the PPG even if it is left uncovered by the overlying flap.

Other than gingival recession, no other clinical criteria showed a significant change. Probing depth did not show any significant change (p = 1) which was expected because only patients whose baseline probing depth was compatible with a condition of gingival health were included in the study. The fact that there was no change in the width of keratinized gingiva and probing depth for the two groups, the width of attached gingiva, which is a dependent factor, did not change.

When the results were compared in terms of patient satisfaction, PPG emerged as the preferred treatment option as it was rated better in terms of comfort during and after the surgical procedure and overall satisfaction by the subjects. The better patient satisfaction obtained by the PPG may be attributed to the less traumatic surgical procedure which involved harvesting of the graft adjacent to the gingival recession defect. This not only reduced intraoperative time but also favoured uneventful postoperative healing, in contrast to the SCTG which increased the complications and pain resulting from the surgery because of the need to surgically open a second site to obtain the donor tissue.

The periosteum is comprised of at least two layers, an inner cellular or cambium layer and an outer fibrous layer.22 The inner layer contains numerous osteoblasts and osteoprogenitor cells23 and the outer layer is composed of dense collagen fibre, fibroblasts and their progenitor cells;24 hence the regenerative potential of the periosteum is immense. Although this aspect was not seen in our study, it is recommended that future studies should also undertake histological aspects of healing after the use of PPG for the treatment of gingival recession defects. Periosteum, being an autogenous graft which can be harvested in sufficient amounts adjacent to the gingival recession defects, has immense potential to be used for the treatment of wider gingival recession defects. Although the results show statistically significant difference between the two groups, the small study group warrants future studies with a larger number of subjects. Further studies utilizing PPG technique for the treatment of multiple gingival recession defects should be done and the results compared with already established techniques for the treatment of multiple gingival recession defects.25

Conclusions

Although this is the first study comparing PPG with SCTG, the results are encouraging. Periosteum has immense potential to be used as a pedicle graft for the treatment of gingival recession defects and the results produced are better in terms of percent root coverage, predictability and patient satisfaction when compared to the connective tissue graft technique.

Acknowledgements

We would like to thank Dr Jaya Dixit, Professor and Head of the Department of Periodontics, King George University of Dental Sciences (CSMMU), Lucknow, India, for her guidance and support.

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