Evaluation of autogenous PRGF plus -TCP with or without a collagen membrane on bone formation and implant osseointegration in large size bone defects. A preclinical invivo study

ObjectivesThe aim of this study was to evaluate whether the adjunctive use of a collagen membrane enhances bone formation and implant osseointegration in non-contained defects grafted with chair-side prepared autologous platelet-rich growth factor (PRGF) adsorbed on a -TCP particulate carrier. Materials and methodsLarge box-type defects (10x6mm; WxD) were prepared in the edentulated and completely healed mandibles of six Beagles dogs. An implant with moderately rough surface was placed in the center of each defect leaving the coronal 6mm of the implant not covered with bone. The remaining defect space was then filled out with chair-side prepared autologous PRGF adsorbed on -TCP particles and either covered with a collagen membrane (PRGF/-TCP+CM) (6 defects) or left without a membrane (PRGF/-TCP) (5 defects). ResultsHistology 4months post-op showed new lamellar and woven bone formation encompassing almost entirely the defect and limited residual -TCP particles. Extent of osseointegration of the previously exposed portion of the implants varied, but in general was limited. Within the defect, new mineralized bone (%) averaged 43.29.86 vs. 39.9 +/- 13.7 in the PRGF/-TCP+CM and PRGF/-TCP group (P=0.22) and relative mineralized bone-to-implant contact (%) averaged 26.2 +/- 16.45 vs. 35.91 +/- 24.45, respectively (P=0.5). First, bone-to-implant contact from the implant top was 4.1 +/- 1.5 and 3.2 +/- 2.3 (P=0.9), in the PRGF/-TCP+CM and PRGF/-TCP group, respectively. ConclusionsImplantation of chair-side prepared autologous PRGF adsorbed on a -TCP carrier in non-contained peri-implant defects resulted in large amounts of bone regeneration, but osseointegration was limited. Provisions for GBR with a collagen membrane did not significantly enhance bone regeneration or implant osseointegration.