Interim tissue changes following connective tissue grafting and two-stage implant placement. A randomized clinical trial.

Abstract

To determine tissue changes at implants placed either conventionally or in combination with a connective tissue graft (CTG). Forty-eight partially edentulous subjects were randomized into two treatment Groups, and 46 completed the study. Group-A (NA =23) received crestal implant placement. In Group-B (NB =23), a CTG harvested from the palate was stabilized over the implant neck. At the time of implant placement (T0), Groups were categorized as having thin mucosa≤2.5mm at the surgical site (NSubgroup-AI =12, NSubgroup-BI =11) or thick mucosa>2.5mm (NSubgroup-AII =11, NSubgroup-BII =12). Mucosa thickness, width of keratinized tissue (WKT), crestal bone levels and relative bone thickness were determined at T0 and at the two-stage surgery (T1). At T1, on the alveolar crest, mucosa thickness significantly decreased in the thick mucosa Subgroups (-AII/-BII, both p=0.001), but increased at thin mucosa grafted sites (p=0.049). No significant changes were noted in the WKT for either group. Thin mucosa grafted Subgroups (-AI/-BI) demonstrated significant decreases in crestal bone levels (both p≤0.008). Crestal relative bone thickness decreased in all Subgroups (p≤0.027 for significant changes). Connective tissue grafting resulted in smaller reductions of mucosa thickness on the alveolar crest and appeared to have the greater effects at sites with initially thin mucosa.