The purpose of the present study was to evaluate the effect of anorganic porous bovine-derived bone
mineral (
Bio-Oss) and expanded
polytetrafluoroethylene (ePTFE) membrane in the treatment of
peri-implantitis. A total of 64 implants with a
titanium plasma-sprayed (TPS) surface was inserted in eight cynomolgus monkeys (Macaca fascicularis). After a 3-month healing period with plaque control, experimental
peri-implantitis characterized by a bone loss of 4-6 mm was induced during a period of 9-18 months. Surgical treatment involving Bio-Oss+membrane,
Bio-Oss, membrane, or a conventional flap procedure (control) only was carried out. The animals were sacrificed six months
after treatment. Evaluation by clinical parameters, radiography including quantitative digital subtraction radiography, histology, and stereology demonstrated healthy peri-implant tissue irrespective of the applied
surgical procedure. However, the amount of re-osseointegration and the total amount of bone (
Bio-Oss and regenerated bone) were significantly higher in defects treated with membrane-covered
Bio-Oss as compared with the other three treatment procedures. A mean bone-to-implant contact of 36% was obtained within defects treated with membrane-covered
Bio-Oss. The corresponding values for the three other treatment procedures were 13-23%. The
Bio-Oss particles were in general highly integrated within the regenerated bone, but the particles in the occlusal part of the defects were entirely surrounded by connective tissue irrespective of membrane coverage. The present study demonstrates that surgical treatment involving
Bio-Oss covered by an ePTFE membrane is a useful treatment modality of experimental
peri-implantitis around implants with a TPS surface in cynomolgus monkeys. However, the treatment outcome is not as encouraging as seen with membrane-covered autogenous bone graft particles documented in a study with same experimental design.