Absorbable versus nonabsorbable membranes and bone grafts in the treatmentof ligature-induced peri-implantitis defects in dogs: A histometric investigation

The purpose of this study was to histometrically evaluate an absorbable col lagen membrane (Bio-Gide) and a nonabsorbable polytetrafluoroethylene membr ane (PTFE), associated with or without bone grafts, regarding "re-osseointe gration" after treating ligature-induced peri-implantitis defects in dogs. All mandibular premolars were removed from five 2-year-old mongrel dogs. Af ter 3 months of healing, 3 titanium implants were placed on each side of th e mandible. Experimental peri-implantitis was induced with ligatures after abutment connection. Ligatures and abutments were removed after 1 month and the bone defects were randomly assigned to one of the following treatments : debridement alone (DB), debridement plus PTFE membrane associated with mi neralized bone graft (Bio-Oss) (GBR+BG-I), debridement plus collagen membra ne (Bio-Gide) associated with mineralized bone graft (GBR+BG-II), debrideme nt plus PTFE membrane (GBR-I), debridement plus collagen membrane (GBR-II), or debridement plus mineralized-bone graft (BG). The dogs were sacrificed after 5 months. Data analysis did not reveal significant differences among the treatments regarding the percentage of bone-to-implant contact ("re-oss eointegration") within the limits of the threads of the implant (P = .997). Thus, in the treatment of peri-implantitis, debridement alone as well as g rafting alone had the same effect as did either membrane.