An evaluation on the effect of osteoporosis on osseointegration around titanium implants in posterior maxilla following a tooth extraction

Abstract

Background: The surgical placement of implants into maxillary extraction sites in ovariectomized (OVX) rats could mimic implant placement in compromised bone in humans, such as is seen in osteoporosis. Purpose This study was designed to evaluate the effects of osteoporosis on osseo-integration around titanium implants following extraction in the posterior maxilla of OVX rats. Materials and Methods: Forty-four 3 month old female Sprague-Dawley rats were used in this study. The rats were randomly divided into two groups: Sham-operated group (SHAM; n = 22) and ovariectomized group (OVX; n = 22). Surface-treated screw-shaped titanium implants were immediately inserted into the mesial extraction sites of the first molar in the posterior maxilla following tooth extraction. The animals were sacrificed at either 28 or 56 days post-surgery, and undecalcified tissue sections were processed for histological analysis. Bone-to-implant contact (BIC) and bone density (BD) were evaluated. Results: With a carefully planned and executed surgical implant protocol, implant placement following extraction in the posterior maxilla can produce reproducible results. The BIC and BD in the OVX group were significantly inferior to those in the SHAM group at both 28 and 56 days, which indicated that osteoporosis could reduce the amount of osseo-integration of dental implants in the posterior maxilla. Conclusion: This study demonstrated that osseo-integration (BIC and BD) was inferior in implants following extraction in the posterior maxilla of OVX rats, especially in the early healing period, indicating that lower local bone quality in OVX rats can reduce early bone formation on implant surfaces.