Randomized controlled clinical trial comparing implant sites augmented with a volume-stable collagen matrix or an autogenous connective tissue graft: 3-year data after insertion of reconstructions

Abstract

Aim: To assess mid-term clinical, radiographic and profilometric outcomes at implant sites, previously grafted with a volume-stable collagen matrix (VCMX) or an autogenous subepithelial connective tissue graft (SCTG). Methods: VCMX or SCTG were randomly applied to single implant sites in 20 patients. Following abutment connection and insertion of final reconstructions (baseline), patients were re-examined at 6 months (6M), at 1 year (FU-1) and at 3 years (FU-3). Measurements included the following: clinical data, radiographic measurement of first bone to implant contact (fBIC), soft tissue thickness and volumetric outcomes. Non-parametric tests and estimates were applied for the statistical analysis. Results: The median buccal mucosal thickness increased by 0.5 mm (Q1: -0.5; Q3: 1.25) (VCMX) (p =.281) and by 0.8 mm (Q1: 0.0; Q3: 2.5) (SCTG) (p =.047) between BL and FU-3 (intergroup p =.303). The profilometric changes of the buccal soft tissues demonstrated a median decrease between BL and FU-3 of −0.2 mm (Q1: −0.5; Q3: −0.1) (p =.039) for VCMX and a decrease of −0.1 mm (Q1: −0.8; Q3: 0.1) (p =.020) for SCTG, respectively (intergroup p =.596). Peri-implant soft tissues and bone levels remained healthy throughout the entire study period. PROMs did not show any significant differences between the groups nor significant changes over time. Conclusion: Minimal changes of the peri-implant tissue contour as well as of the soft tissue thickness were observed at implant sites previously grafted with VCMX or SCTG.