Bone Remodeling around Implants in Ovariectomized Rats after Implantation

Abstract

This study was conducted to investigate the effect of osteopenic bonetissue around the implants in ovariectomized rats. Thirty-two-week-old female Wistar rats were used in this study. Cylindrical hydroxyapatite-coated implants were placed in the proximal part of the tibiae, and the rats underwent bilateral ovariectomy or sham surgery. The animals were sacrificed 28, 84, and 168 days after surgery. Undecalcified sections were prepared and examined by routine microscopy and microradiography. Histomorphometric measurement were obtained with a computer-based image analyzer to quantify the percentage of implant-bone contact and trabecular bone around the implants. Ovariectomy significantly reduced the density of trabecular bone around the implant. In the cortical bone area, ovariectomy did not affect bone contact with the implant. However, the rate of implant-bone contact in the medullary cavity of the test group tended to decrease and was significantly lower than that in the control group more than 84 days after implantation. These results suggested that when placing dental implant in menopausal patients, the progress of the implant must be carefully observed during reduction of bone density.