Regenerative potential of subepithelial connective tissue graft in the treatment of periodontal infrabony defects.

BACKGROUND: Due to high prevalence and progression of infrabony defects lead to increase in the possibility of tooth loss. Various regenerative techniques such as guided tissue regeneration, bone grafts, and biomimetic agents have been proposed. Subepithelial connective tissue graft (SCTG) is an autogenous membrane, which contains mesenchymal cells and has osteogenic, chondrogenic, and osteoblastic activities. The present study investigates the effective application of SCTG as an autogenous barrier membrane in the treatment of periodontal infrabony defect.
MATERIALS AND METHODS: Ten patients in the age group of 30-45 years suffering from chronic periodontitis with clinical and radiographic evidence of vertical defects were selected for the study. Clinical parameters evaluated were gingival index, plaque index, probing pocket depth, clinical attachment level, and gingival recession. These parameters were assessed at baseline, 6 and 9 months. Radiographic parameter (defect fill) was evaluated at baseline, 6, and 9 months postoperatively. Sites were treated with PERIOGLAS® and connective tissue graft. Statistical analysis was done using paired t-test.
RESULTS: All the patients finished the study. A significant improvement was observed regarding clinical parameters from baseline to 9 months. The radiographic defect fill was seen in all the cases at the end of 9 months, which was statistically significant in comparison with baseline scores.
CONCLUSION: SCTG could be effectively used as a barrier membrane for the treatment of periodontal infrabony defects.

INTRODUCTION

The ultimate goal of periodontal therapy is to regenerate the lost periodontal structures, to regain its original form and function, and to prevent the niche for microorganism to cause the destruction of tissues. Successful regeneration of periodontium includes the regeneration of cementum, alveolar bone, periodontal ligament, and connective tissue fibers which attaches to the root surface.[1]

To promote this regeneration, the befitting guidance of cells capable of synthesizing collagen, cementum, and bone to damaged site is required.[2] Infrabony periodontal defects can be complex and difficult to treat. Surgical techniques, including guided tissue regeneration (GTR), have been used for the regeneration of tissues in this areas.[3]

The biologic basis of GTR is the hypothesis of preventing the migration of epithelial and connective tissue cells of the flap into the defect by placing a physical barrier. This way, periodontal ligament cells and mesenchymal cells will get the chance to migrate to the root surface.[4] Numerous absorbable and nonabsorbable membranes have been used for GTR. Because of the higher cost, need for a second surgery for membrane removal, complexity, and bacterial accumulation of nonresorbable and absorbable membranes are preferable.[56]

The palatal connective tissue is an autogenous membrane. Available literature regarding the application of connective tissue as a membrane is scarce; however, most of them have shown that connective tissue can be used as a membrane.[7] A subepithelial connective tissue graft (SCTG) also could be used as a barrier for furcation defects and infrabony defects. Palatal connective tissue graft is autogenous membranes which have shown successful results in the previous studies.[89] Mesenchymal cells are seen in the palatal connective tissue, and these cells are osteogenic.[10]

Using connective tissue graft as a barrier during GTR makes it possible to restore the hard tissue while enhancing the soft-tissue profile in the same procedure.[11] Hence, the present study was undertaken to estimate the potential of SCTG as a GTR membrane in the regeneration of infrabony defect.

MATERIALS AND METHODS

A total of 10 patients with complaints of loosening of teeth, food lodgment, bleeding on probing, and increased spacing were selected from the Outpatient Department of Periodontology. The sample size was determined using standard normal variate to be 1.96 (95% confidence interval), and the prevalence from the previous study keeping the allowable error in consideration. The patients were informed about the nature of the study, and written informed consent was obtained from them in accordance to the Helsinki Declaration of 1975, as revised in 2000. Ethical approval was attained from the Ethical Committee of the Institution. This study was a prospective analysis which started between February 2016 and completed in March 2017.

Selection criteria

Inclusion criteria

The patients included in the study were those having as follows: (1) patients with good general health, (2) patients who were nonsmoker, (3) patients having preoperative probing pocket depth (PPD) ≥5 mm, (4) infrabony defect with vertical bone loss of 3 mm or more as visible on radiograph, (5) patients having no history of periodontal therapy for the past 6 months, and (6) patients having no history of any medication affecting periodontal healing. The deepest defect either in the premolar or molar region was selected. One defect from each patient was selected.

Exclusion criteria

The patients having the one or more of the following were excluded from the study: (1) any history of systemic diseases, (2) pregnant or lactating patients, (3) inadequate oral hygiene after Phase I therapy, (4) allergic to any medication, and (5) patients with thin palatal connective tissue.

Clinical parameters

The following parameters were recorded at baseline, 3, 6, and 9 months: Plaque index (PI) (Silness and Loe, 1964),[12] gingival index (GI) (Loe and Silness, 1963),[12] (PPD, deliberated as distance between gingival margin to base of pocket), clinical attachment level (CAL, deliberated as distance between cement-enamel junction to base of pocket), and gingival recession (GR, deliberated as distance between cement-enamel junction to gingival margin) using a UNC-15 probe (Hu Friedy, USA). Phase 1 therapy was done for the patients. Oral hygiene instructions were given to the patients. Radiographic parameters as follows: standardize and reproducible intraoral periapical radiographs were taken using the long-cone paralleling technique at baseline, 6 and 9 months. The area of defect on the radiograph was calculated according to the landmarks described by Eickholz et al.[13] The area has been calculated as the following: cementoenamel junction-base of defect (CEJ-BD): distance from CEJ to base of defect, CEJ-AC: distance from CEJ to alveolar crest, H: length of the perpendicular from the vertex opposite the base of the triangle, and area of the defect A = ½ × CEJ − BD × H. This was repeated at each follow-up. The site with the deepest probing depth was selected to be the study site. Since only one site was involved, no randomization was done as there was only one group. The parameters were judged by the same clinician at every follow-up. All surgical procedures were carried out by a different operator who did not record the parameters to avoid bias.

Surgical procedure

Local anesthesia was obtained (2% lidocaine, epinephrine 1: 100,000) at the site of the surgery. The crevicular incision was given at facial and palatal/lingual within extent to the defect site, so that unnecessary trauma was avoided [Figures 1 and 2]. Mucoperiosteal flaps were elevated so that adequate exposure of the defect site was obtained. Debridement and root planing were done using hand and ultrasonic instruments. Degranulation was done on the inner side of the flap as required. Thorough irrigation of the surgical site was done. Probing depth was measured [Figure 3]. The size of connective tissue required to cover the defect was measured using a template, and marking was done on the palate.

Figure 1

Preoperative probing depth inpatient residential treatment 46

Figure 2

Incision being placed

Figure 3

Intraoperative probing inpatient residential treatment 46

The SCTG of adequate thickness was obtained using trap-door approach [Figure 4]. After procuring the graft, palate wound was sutured back, and hemostasis was obtained. The graft was examined carefully, and any tissue tags were removed to obtain uniform thickness. The defect site was then isolated, presutured, and PERIOGLAS® bone graft was placed into the defect [Figure 5]. The SCTG was then deposed over the defect, and suturing was done using 3-0 silk suture [Figures 6 and 7]. The periodontal dressing was placed.

Figure 4

Procurement of subepithelial connective tissue graft

Figure 5

Bone graft (PERIOGLAS®) being placed into the defect

Figure 6

Subepithelial connective tissue graft being placed into the defect

Figure 7

Suture placed at defect site

Postoperative instructions and care

The patients were asked to rinse two times daily with 10 ml of 0.2% chlorhexidine mouthwash for 15 days. They were refrained from brushing on the surgical site for 10 days. Postoperative pain control was using ibuprofen, 400 mg, and every 8 h. Amoxicillin 500 mg was prescribed for postoperative infection control. The patients were recalled after 10 days for suture removal. The patients were not subjected to any oral hygiene measure until the end of the follow-up period.

Statistical analysis

The patients were recalled after 3, 6, and 9 months. All the parameters recorded at the baseline were reevaluated at the follow-up appointments. Paired t-test was used Statistical Package for Social Sciences Version 17.0 (Chicago: SPSS Inc.)statistical analysis software. The values were represented as the mean ± standard deviation (SD).

RESULTS

All ten patients (four females and six males) returned for follow-up. Healing was uneventful, no postoperative complications were reported. There was a statistically significant reduction in all parameters [Tables 1 and 2].

Table 1

Changes in clinical parameters at each follow-up period

Table 2

Comparison of change in clinical parameters after treatment

The mean PI at baseline was 1.93 ± 0.61 (mean ± SD) which declined to 0.88 ± 0.36 after 6 months. The mean GI at baseline was 1.39 ± 0.16 (mean ± SD) which reduced to 0.94 ± 0.07 at 6-month interval. Both gingival and PI showed regress at 9-month interval which was 1.10 ± 0. 13 and 1.38 ± 0.30, respectively; this may be due to no professional oral hygiene measure taken until the end of the study. However, the improvement was statistically significant when compared to baseline scores. There was a statistically significant reduction in PPD from baseline (6.30 ± 0.67) to 9 months (2.80 ± 0. 78). This trend was followed by CAL score too; a baseline score of 6.30 ± 0.67 was ameliorated to 2.90 ± 0.56 after 9 months. This difference was statistically significant, indicating defect resolution. GR is seen after the surgery which was statistically nonsignificant at the end of 9 months. The defect fill was calculated regarding defect resolution was measured by using the aforementioned method. The baseline score was 94.90 ± 32.24 [Figure 8], which came down to 73.42 ± 27.00 and to 57.39 ± 22.33 after 9 months. This reduction was statistically significant [Figures 9, 10 and Tables 3, 4].

Figure 8

Preoperative intraoral periapical

Figure 9

Postoperative probing inpatient residential treatment 46 after 9 months

Figure 10

Postoperative intraoral periapical

Table 3

Changes in radiographic parameters at each follow-up period

Table 4

Comparison of change in radiographic parameters after treatment

DISCUSSION

Regeneration of lost structures has become the primary therapeutic goal in periodontics over the past several decades.[14] Till date, numerous materials have been used from nonresorbable membrane such as polytetrafluoroethylene to resorbable membrane such as collagen and polylactide membrane/polyglycolic membrane. However, nonresorbable membrane requires second surgery, and resorbable membrane has an unpredictable rate of dissolution. The search for optimum and better material is perpetual.

Langer and Langer (1985) introduced and outlined the indications and procedures necessary for achieving success with the SCTG.[15] It is considered to be the gold standard for recession coverage. The concept of using SCTG as a barrier membrane is relatively new. It was proposed that the gingival connective tissue contains mesenchymal cells. These cells are osteogenic, chondrogenic, osteoblastic, and have immunomodulatory capacity.[16] In addition to this, the easy availability, cost-effectiveness, and versatility of the SCTG membrane were also appealing. Hence, the quest of evaluating the potential of SCTG as a barriers membrane was undertaken.

It has been stated that proliferation of the membrane harvested from the palatal connective tissue into the defect is unlikely. Therefore, it can very well play the role of a biologic membrane than can be well tolerated in the body. There is no risk of disease transmission, it is well tolerated by the body and if exposed into the oral cavity does not compromise the treatment outcome.[7] There is no proliferation of tissue graft into the defect is observed.[16]

In the present study, oral hygiene of the patients was evaluated using full-mouth PI, and gingival inflammation was estimated using full-mouth GI. There was a significant reduction in both indices from baseline to 9 months. However, the reduction was seen maximum at 6 months, and after which there was a slight increase in scores from 6 to 9 months [Table 1]. The results were similar to that of Stein et al.[17] There was a significant improvement regarding PPD and CAL gain which was 3.5 and 3.4 mm, respectively. The results were similar to that of Kwan et al.[9] and Moghaddas et al.[18] There was a slight increase in GR which was statistically insignificant. Moghaddas et al.,[18] in their study, comparing palatal connective tissue with collagen has shown a significant difference regarding GR in both the groups.

The radiographic parameter which was calculated as defect fill has shown statistically significant improvement from baseline to 9 months. The mean defect fill was measured as 37.54 mm2 from baseline to 9 months. These results coincide with that of studies conducted by Paolantonio et al.[19] and Esfahanian et al.[20] A bone graft was used as filling material beneath the membrane. It has been proved in many studies that a combination of bone grafts and GTR membrane effectuates more attachment gain than with the use of membrane alone.[21] The potency of SCTG to cripple the epithelial migration into the defect is similar to that of a bioabsorbable membrane and filling material used can transcend the results obtained.[22] Hence, it is assumed that the use of a bioactive glass for defect fill can also contribute to the amount of defect fill in addition to the benefits of SCTG barrier membrane.

Although the study has demonstrated the effectiveness of SCTG as a barrier membrane, the use of an autologous material, such as palatal connective tissue graft, demands a second surgical site, causes additional morbidity and discomfort for the patient, and not to mention the extrasurgical time.[23] The lack of comparison with negative and positive control is also one of the limitations of the study. No reentry or histological examination has been done.

CONCLUSION

Within the bounds of the present study, it can be concluded that the efficacious application of SCTG as a barrier membrane can be done for the treatment of periodontal infrabony defects.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.