Absorbable versus nonabsorbable membranes and bone grafts in the treatmentof ligature-induced peri-implantitis defects in dogs Part I. A clinical investigation

The purpose of this study was to clinically evaluate an absorbable collagen membrane (Bio-Gide(R)) and a nonabsorbable polytetrafluoroethylene membran e (PTFE), associated or not with bone grafts, for the treatment of ligature -induced peri-implantitis defects in dogs. The bilateral mandibular premola rs were removed from 52-year-old mongrel dogs. After 3 months of healing, 3 titanium implants were placed on each side of the mandible. Experimental p eri-implantitis was induced after abutment connection. Ligatures and abutme nts were removed after 1 month and the bone defects were randomly assigned to one of the following treatments: DB: debridement alone; GBR+BG-I: debrid ement plus PTFE membrane associated with mineralized bone graft (Bio-Oss(R) ); GBR+BG-II: debridement plus collagen membrane (Bio-Cide(R)) associated w ith mineralized bone graft; GBR-I: debridement plus PTFE membrane; GBR-II: debridement plus collagen membrane; BG: debridement plus mineralized bone g raft. The periimplant bone defects were measured before and 5 months after treatment. Results showed the greatest percentage of vertical bone fill for GBR+ BC-II (27.77 +/- 14.07) followed by GBR-II (21.78+/-16.19), BG (21.26 +/-6.87), GBR+ BG-I (19.57+/-13.36), GBR-I (18.86+/-10.63) and DB (14.03+/- 5.6). However, the values were not statistically significant (ANOVA, contra st F test, P=0.612). Within the limits of the present investigation, it can be concluded that no difference was detected among treatments.