Effects of Implant Surface on Bone Healing Around Titanium Screw Implants in Ovariectomized Rats

Purpose: The aim of this study was to investigate whether estrogen deficiency interrupts bone healing around titanium implants and to evaluate whether bone healing around implants under a condition of estrogen deficiency is affected by variations in implant surface characteristics. Materials and Methods: Forty-eight female rats were divided into two groups: ovariectomized rats (OVX; n = 24) and sham-operated rats (SHAM; n = 24). Each group was further divided into two groups: a machine-polished implants group and a sandblasted implants group. One implant was placed into the left femur of each rat 84 days after OVX or sham surgery. After 28 or 56 days, the rats were killed, and nondecalcified sections were obtained. Bone-to-implant contact (BIC) and bone area (BA) around the implants were assessed for cortical and cancellous bone. Furthermore, bone density (BD) was evaluated in a 500-mm-wide zone of cancellous bone lateral to the implants. Results: At 28 and 56 days after implantation, no significant differences were found between the OVX and SHAM groups for BIC and BA in cortical bone. BIC, BA, and BD with cancellous bone were lower in the OVX group than in the SHAM group. However, BIC and BA tended to increase with the sandblasted implant surface. Conclusions: Estrogen deficiency affected bone healing and bone density around titanium implants, especially in cancellous bone, but the sandblasted surface has the possibility to improve osseointegration. However, the positive effect of this rough surface is limited at the implant surface.