Abstract
The aim of this study was to evaluate the effects of alendronate immobilization on bone formation following the implantation of apatite-coated titanium implants in rats. Thin carbonate-containing apatite coatings were deposited onto titanium implants (Ti implants) using a molecular precursor method. Alendronate was then immobilized on apatite-coated titanium implants (HA implants) by immersing the HA implants in alendronate solution (Ald implants). The rat molars were extracted, and the implants were immediately placed in the tooth sockets. Bone labeling was performed 14 and 7 days before sacrifice. At 3 and 9 weeks after implantation, undecalcified sections were prepared and bone histomorphometry was performed. Greater bone mass was found around the Ald implants than around either the Ti or HA implants at both 3 weeks and 9 weeks. At 3 weeks, fluorochrome bone labeling was greater around the Ald implants than around the Ti implants, and the values of bone to implant contact (BIC) and bone mass (BM) were significantly greater around the Ald implants than around the HA and Ti implants. At 9 weeks, bone labeling decreased and the values of BIC and BM increased compared with those at 3 weeks for all types of implant. In conclusion, we found that immobilized alendronate triggered pronounced bone formation around the implants at an early stage of bone healing. These results suggest that alendronate immobilization accelerates implant fixation early in the healing phase.
