Use of a new cross-linked collagen membrane for the treatment of dehiscence-type defects at titanium implants: a prospective, randomized-controlled double-blinded clinical multicenter study.

OBJECTIVES: The aim of the present randomized-controlled double-blinded clinical multicenter study was to assess the use of either a new cross-linked (VN) or a native collagen membrane (BG) for the treatment of dehiscence-type defects at titanium implants.

MATERIAL AND METHODS: A total of n=54 patients were recruited in four German university clinics. According to a parallel-groups design, dehiscence-type defects at titanium implants were filled with a natural bone mineral and randomly assigned to either VN or BG. Submerged sites were allowed to heal for 4 months. Primary (e.g., changes in defect length - DeltaDL, quality of newly formed tissue [0-4] - TQ) and secondary parameters (e.g., membrane exposure, tissue conditions at dehisced sites) were consecutively recorded.

RESULTS: Four patients were excluded due to an early wound infection (VN:3; BG:1), and one patient was lost during follow-up (VN). The mean DeltaDL was 3.0 +/- 2.5 mm in the VN, and 1.94 +/- 2.13 mm in the BG group. The assessment of TQ revealed comparable mean values in both groups (VN: 3.05 +/- 1.66, BG: 3.46 +/- 1.48). A significant correlation between membrane exposure and inflammation of the adjacent soft tissue was observed in the VN group. In both groups, the mean DL and TQ values were not significantly different at either non-exposed or exposed implant sites.

CONCLUSION: The results of the present study have indicated that VN supported bone regeneration on a level non-inferior to BG. However, in case of a premature membrane exposure, cross-linking might impair soft-tissue healing or may even cause wound infections.