Enhancing Effect of Intermittent Parathyroid Hormone Administration on Bone Formation After Titanium Implant Placement in an Ovariectomized Rat Maxilla

Objective: This study examined the effect of intermittent parathyroid hormone (PTH) administration on the bone response around implant on the maxilla of rats with ovariectomy-induced osteoporosis. Material and Methods: A total of 27 female Sprague-Dawley rats were divided into 3 groups (n = 9) and were ovariectomized (OVX). Eight weeks after, upper right molar was extracted and an implant was placed at 4 weeks after extraction. The PTH group received PTH, and the OVX group and the control group received vehicle only. Beginning after implant placement, 30 mu g/kg of PTH was subcutaneously administered in the dorsum 3 times a week. Three rats in each group were killed at 1, 2, and 4 weeks and histologic sections were evaluated. Results: After 4 weeks, the amount of newly formed bone around implants in the PTH group was comparable with the control group, with bone covering the implant surface in both groups. However, the OVX group displayed relatively small amount of new bone. Conclusion: Intermittent PTH has the potential to increase new bone formation around implant. These findings have clinical implications in prosthetic restoration by implants with poor bone quality.