A comparison on the amount of root coverage by two techniques: Connective tissue graft and bioabsorbable bovine collagen membrane

Periodontal diseases are one of the most prevalent diseases among human population and of them gingival recession has a high prevalence. The goal of this study was to compare the amount of root coverage by two techniques: Guided tissue regeneration (GTR) with a bioabsorbable bovine collagen membrane (Biomend) and the connective tissue graft with Harris technique.. In this controlled clinical trial, twenty anterior and premolar teeth were selected. All samples had Miller class I and II gingival recession. Following oral hygiene instruction and reevaluation of all teeth, they were randomly assigned to treat with either guided tissue regeneration(GTR) or connective tissue graft (CTG). In order to insert a connective tissue graft, Harris technique was used. Guided tissue regeneration technique was performed via a sulcular and two oblique incisions. The full thickness flap was replaced by a blunt dissection to expose the bone and then the apical protion was dissected by a sharp dissection. The later dissection was continued in a manner to facilitate the coronally repositioned flap. A bioabsorable membrane was adapted in the area so as at least 3mm of the apical and lateral were covered by the membrane. Finally, the flap was sutured coronally by sling sutures. Patients were visited in one and two weeks, one and six months periods. Information about recession depth (RD), probing depth (PO), the width of attached gingiva and the amount of root edzcoverage were recorded at the base line and six months after surgery. The gathered data were analy using wilcoxaon Signed Ranks test, U-Mann-Whitney test and SPSS software. The mean root coverage, after six months, were(71.22±10.2)% for GTR procedure and (80.67±16.06)% for the connnective tissue graft technique. the difference was not statistically significant (P= 0.134). Both procedures produced similar reductions in recession and probing depth but the connective tissue graft procedure gained a greater increase in keratinized tissue comparing to GTR technique (3/4mm vs 0/1mm respectively). The difference was statistically significant (P<0.001). Both techniques can be successfully applied in the treatment of periodontal recession defects but when an increase in keratinized tissue is desirable, the connective tissue graft technique is preferred to GTR technique. On the contrary, if keratinized tissue increase is not required, an absorbable membrane, due to the lack of need to a donor tissue, is more suitable.