Comparative evaluation of periosteum as a barrier membrane with and without an alloplastic bone graft in periodontal osseous defects: A 9 months follow-up study

Abstract

Background:

Regenerative procedures frequently include the use of barrier membranes and bone grafting materials to encourage the growth of key surrounding tissues. The present study aims to evaluate and compare the ability of periosteum in intrabony defect regeneration.

Materials and Methods:

A total of ten intrabony defects were equally divided in two treatment groups. Group I consisted of Periosteum used as a barrier memebrane and Group II of periosteum as barrier membrane alongwith graft material. Nine months post operative evaluation of defect fill was done radiographically.

Results:

Mean defect fill (CEJ-BBD) was found to be significantly lower in Group II as compared to Group I (P = 0.041).

Conclusion:

Within the limitations of this study, alloplastic graft material supplimentation results in better regeneration with Periosteum used as a barrier membrane.

INTRODUCTION

Full regeneration of the periodontium after periodontal treatment modalities has been difficult to achieve because of differences in healing abilities among periodontal tissues. Down growth of the junctional epithelium along the denuded root surface is one of the most important factors limiting the achievement of predictable regeneration.

Traditional approaches to treat periodontal defects include nonsurgical debridement of root surfaces, as well as surgical approaches that provide better access to clean the root surfaces. Although these procedures can be effective, bone is sometimes removed for access or to create better physiologic contours and healing is almost always by repair. Repair is defined as the healing of a wound by tissue that does not fully restore the architecture or function of the part. Because this is not ideal, newer approaches such as regenerative procedures that aim to restore lost tissue have been introduced. This has an advantage over traditional approaches in that after healing, the tissues surrounding the teeth are restored near to their original state. Clearly, regeneration is the most desirable outcome for any therapy. However, this is also the most difficult to achieve. Consequently, a wide variety of treatment modalities have been developed, all with the goal of attaining tissue/bone regeneration. Regenerative procedures frequently include the use of barrier membranes and bone grafting materials to encourage the growth of key surrounding tissues, whereas excluding unwanted cell types such as epithelial cells.[1] Although regenerative therapies have great potential, they remain unpredictable in their ability to consistently produce acceptable outcomes in all situations.

The periosteum, as a structure rich in osteoprogenitor cells, has been viewed as having regenerative potential.[2,3] Periosteal grafts have the potential to stimulate osteogenesis in the periodontally involved area by the ability to stimulate osteogenic factors. At the same time, periosteal grafts provide the wound area with an additional number of osteoprogenitor cells that may compensate for the deficient cells available in the periodontal defect.

The present study was designed to evaluate the efficacy of periosteum as a barrier membrane in periodontal osseous defects and to compare the periosteum as a barrier membrane with an alloplastic bone graft in periodontal osseous defects.

MATERIALS AND METHODS

Subjects with chronic periodontitis in the age group ranging from 18 to 50 years irrespective of their sex were selected from the out-patient Department of Periodontics.

Inclusion criteria

• Subjects physically and mentally fit, free of any systemic diseases that could influence the outcome of the therapy

• A good level of oral hygiene with probing pocket depth >5 mm after phase-I therapy

• Initial assessment of vertical osseous defects with intraoral periapical radiographs

• Presence of two or three wall intrabony defects.

Exclusion criteria

• Subjects taking any medications or antibiotic therapy within 6 months prior to study

• Subjects having any deleterious habits such as smoking and tobacco chewing

• Subjects with one wall intrabony defects

• Pregnant or lactating women.

Study design

The subjects were randomly divided into two groups on the basis of treatment procedure. Ten intrabony defects were equally divided in groups of five each.

• Group-I: Subjects treated with open flap debridement and periosteum used as a barrier membrane

• Group-II: Subjects treated with open flap debridement and periosteum used as a barrier membrane along with alloplastic graft.

All baseline clinical parameters were obtained immediately before surgery. Recording for clinical parameters were repeated at 9 months after surgery. Using customized film holders and long cone paralleling technique, radio-visiographs were taken at the time of the initial examination and at 9 months post-surgery using the parallel cone technique. Linear measurements of distance from cemento-enamel junction to base of bone defect (CEJ-BBD) were made on computer digitized images of the radiographs. CDR Dicom version 3.5 by Schick tech. software was used for measurement on Radio Visio Graphy (RVG) digitized images.

All subjects completed a comprehensive medical and dental history examination. Subjects were then given an explanation of the study purpose including benefits and associated risks, finally a signed informed consent form were obtained from the subjects. At 4 weeks after scaling and root planning, just prior to the surgical procedure, baseline data was recorded. The surgical procedure followed for harvesting the periosteal graft is the same as Singhal et al.[4]

At 7 days after surgery, periodontal dressings and sutures were removed, the site was cleaned, and the dressing was replaced if needed. Subjects were recalled after every 4 week for a period of 9 months for oral hygiene evaluation and prophylaxis.

The statistical analysis was performed using SPSS (Statistical Package for Social Sciences) Version 15.0 statistical Analysis Software. The values were represented in number (%) and mean ± standard deviation.

RESULTS

All the subjects enrolled in the study showed good compliance to treatment. No post-operative complications were observed during the course of the study. Ten intrabony defects were assessed for the study protocol.

Before treatment both groups were matched for CEJ-BBD distance showing no statistically significant intergroup difference (P > 0.05). On after procedure evaluation, mean CEJ-BBD was found to be significantly lower in Group II when compared to Group I (P = 0.041). On comparing the proportional change in CEJ-BBD between Groups I and II, the difference between two groups was found to be significant statistically (P = 0.026) [Table 1].

Table 1.

Intergroup statistical analysis

DISCUSSION

Regenerative periodontal therapy aims to predictably restore the tooth supporting periodontal tissues (i.e. new periodontal ligament, new cementum with inserting periodontal ligament fibres and new bone) that have been lost due to periodontal disease or dental trauma.[5] Several modalities of periodontal regeneration include osseous grafts, guided tissue regeneration (GTR), or combination of both. Bone grafting is the most common form of regenerative therapy although effective in decreasing probing depths and improving attachment levels, do not promote true regeneration of the periodontal unit on a predictable basis.

Several bioresorbable and non-resorbable materials have been used for GTR, which includes ethyl cellulose, collagen, polylactic acid and expanded polytetrafluoroethylene. The ideal barrier membrane materials should be biocompatible; easy to obtain, harvest and manipulate, abundant; bioresorbable (thereby eliminating the need for a second surgical procedure); and economical.

Barrier membranes serve the purpose of preventing epithelial downgrowth, thereby allowing progenitor cells of the bone and periodontal ligament to regenerate desirable tissues from the base of the defect. Autogenous periosteal grafts are an attractive alternative to existing barrier membrane materials since they meet the requirements of an ideal material and they are biologically accepted. Moreover, periosteum is highly vascular and is known to contain fibroblasts and their progenitor cells i.e. osteoblasts and stem cells. The cells of periosteum retain the ability to differentiate into fibroblasts, osteoblasts, chondrocytes, adipocytes, and skeletal myocytes. The tissue produced by these cells includes cementum with periodontal ligament fibres and bone.[6,7] This is the reason for using the periosteum as a barrier membrane in the present study.

In the present study, the autogenous periosteum is surgically mobilized and placed over exposed intrabony defect covering it properly and hence that cambium layer juxtaposed to exposed intrabony defect. The autogenous periosteum was attached at one site to mucoperiosteal flap maintaining its vascular supply, which is important for healing and maintaining vital cambium layer which has the potential to stimulate bone formation. Multiple factors influence the predictability of treatment outcomes after GTR procedures. Clinically, the amount of new attachment achieved may be directly related to patient factors (oral hygiene, smoking and systemic health), root anatomy and the surgical technique. Degree of periodontal destruction and remaining periodontal-osseous components (depth, width and number of osseous walls) are other critical factors that may cause wide variations in the outcome of GTR.

In the present study, all patients showed good compliance, with uneventful postoperative healing in both groups. Patient related factors were minimal as systemically healthy, non-smokers subjects were enrolled in the study. Currently, osseous grafting alongwith GTR is the technique with the most histologic documentation of periodontal regeneration.[8] The use of synthetically produced bone-substitute materials (i.e. alloplasts) circumvents some of the disadvantages of autogenous, allogenic, or xenogenic bone grafts. For example, autografts show unpredictable resorption; require additional surgical sites, time and costs; and result in added morbidity of the donor site,[9,10] whereas the performance of allografts largely depends on the type and processing of donor tissue and theoretically creates a certain risk for immune-mediated rejection of the graft and the transmission of infectious diseases.[11] In addition, compared with xenogenic materials, alloplasts theoretically have the advantage that their physicochemical characteristics can be more or less adjusted to the need of the specific indication.

The surgical procedure consisted of sulcular incisions, and where possible, the papillary preservation technique with the retention of the marginal gingiva. This was followed by the reflection of full thickness mucoperiosteal flaps to expose the bony defect and to attain an adequate coverage of the treated site.

Although histologic methods have been considered as standard in assessing true periodontal regeneration,[12] due to ethical considerations and patient management limitations,[1] no histologic evidence was obtained in the present study.

Radiographic bone measurement following regenerative procedures is a non- invasive, painless alternative to direct bone measurements. A study by Wolf et al.,[13] assessed the reliability of digital radiography in measuring interproximal bone loss. They found that overall measurement on the digitized images come quite close to the gold standard of intrasurgical measurement.

The measurement of intrabony defects was done with the help of RVG. The CEJ- BBD distance of intrabony defects was decreased in both the treatment procedures. The findings were comparable with the finding of Joly et al.[14] The amount of bone defect fill was more in Group II treated with periosteum as barrier membrane and with alloplastic bone graft (β-tricalcium phosphate + hydroxyapatite). Similar results were reported by Mellado et al.[15] and Singhal et al.[4] However, in Group I inconsistent results were obtained. One out of five cases showed bone loss. In Group II encouraging results were seen, four out of five cases showed greater reduction in defect size. This variation can be attributed to morphologic features of the defects, duration of healing, flap position and additional benefit of alloplastic material in regeneration.

Limitations of this study include a comparatively small sample size and short study period. Further studies with longer follow-up period and a larger sample size can be done.