Comparison of bioactive glass to demineralized freeze-dried bone allograftin the treatment of intrabony defects around implants in the canine mandible

Background: The purpose of this study was to evaluate and compare the heali ng of different bone grafting materials adjacent to titanium plasma-sprayed (TPS) endosseous dental implants. Methods: Implant osteotomy sites were prepared and standardized 3-walled in trabony defects (3 mm x 5 mm x 5 mm)were created at the mesial of each impl ant site. Thirty-two TPS implants were placed in edentulous mandibular ridg es of the 4 dogs. Periodontal dressings were placed in the defect sites so as to create a defect simulating bone loss around an implant. After 3 month s, the periodontal dressing was removed, the defect sites debrided and eval uated for size, and intra-marrow penetration performed. The graft. material s tested were 1) canine demineralized freeze-dried bone allograft (cDFDBA); 2) bioactive glass granules of a broad size range 90 to 710 microns (BRG); and 3) bioactive glass granules of narrow size range 300 to 355 microns (N RG). One site on each side of the mandible was not filled and served as a c ontrol. Dogs were sacrificed 4 months after graft placement. Results: Histologically, differences in percent bone-to-implant contact in the defect area were observed between the treatment groups. cDFDBA> control =BRG=NRG with statistical significance found between cDFDBA and control (P = 0.0379), but no statistically significant difference between control or e ither bioactive glass material. When comparing percent bone height fill of the defect in the grafted area, cDFDBA (65.7%) was significantly better tha n the control (48.9% P less than or equal to 0.05) with no statistically si gnificant difference between control, broad range bioactive glass (57.3%) a nd narrow range bioactive glass(56.6%). When total bone area was measured, the percentage of new bone in the grafted area was cDFDBA(42.1%) broad rang e glass (33.1%) and narrow range glass (22.6%) with significance found betw een cDFDBA and NRG (P = 0.0102). The content of residual graft particles in soft tissue was significant (P = 0.0304) between cDFDBA (1.4%) and NRG (11 .4%) with no significant difference between graft material for residual par ticle content in bone tissue. Conclusions: The results of this study indicate that percent bone-to-implan t contact and percent bone height fill in an intrabony defect around titani um plasma-sprayed implants are statistically significantly higher with the use of DFDBA when compared to bioactive glass material.