Acellular dermal matrix allografts to achieve increased attached gingiva. Part 1. A clinical study

Background: Freeze-dried acellular dermal matrix (ADM) allograft, originally used for full-thickness burn wounds, was recently introduced as an alternative to the autogenous free gingival graft (FGG) in achieving increased attached keratinized tissue. The aim of part 1 of this study was to investigate the clinical efficacy of the ADM allograft for this particular purpose. Methods: Twelve patients, 7 males and 5 females, with attached gingiva less than or equal to1 mm on the facial aspect of mandibular anterior teeth demonstrating a tendency of progressive marginal tissue recession, were randomly assigned to either test or control treatment. Six patients received ADM graft (test) and 6 patients received an autogenous FGG harvested from the hard palate (control). Clinical variables including plaque index (PI), gingival index (GI), probing depth (PD), attached tissue width (AT), and gingival recession (GR) were recorded immediately before surgery and at the 6-month postoperative visit. Patients were seen at 2, 4, 6, 8, and 12 weeks to monitor wound healing and oral hygiene performance (PI and GI). Graft width was also measured, in corono-apical direction, on individually involved teeth during the surgery. Results: When values between baseline and 6 months were compared in both groups, there was no statistically significant difference in changes of PI, GI, PD, and GR (P >0.05) with the exception of PD in the FGG group (1.01 +/- 0.03 versus 1.27 +/- 0.20 mm, P = 0.042). There was a statistically significant (P <0.05) increase in AT in both groups. Although the ADM group received wider grafts than the FGG group (8.81 +/- 0.46 versus 6.70 +/- 0.89 mm), the AT gain was significantly smaller (2.59 +/- 0.92 versus 5.57 +/- 0.44 mm) and the graft shrinkage significantly greater (71 +/- 10% versus 16 +/- 12%) in the ADM group than in the FGG group (P <0.01). Conclusions: The results of this study suggest that in procedures aiming at increasing the width of attached gingiva: 1) the ADM allograft was less effective and less predictable than the autogenous FGG in terms of increasing attached keratinized tissue due to considerable shrinkage and inconsistent quality of the attached tissue gained and 2) the esthetic results using the ADM allograft might be better than those using the autogenous FGG.