A Comprehensive Evaluation of Flapless Dental Implant Treatment in Posterior Maxilla and the Conservative Regeneration of Bone in Osteoporotic Rats

Abstract

The aim of this study is to perform a comprehensive evaluation of clinical procedures used in dental implant treatment in posterior maxilla using flapless technique; to assess osseo-integration of surface-treated implants in the posterior maxilla of osteoporotic (OP) rats, and the conservative regeneration of poor quality bone in (OP) rats with simvastatin. Materials and methods: This comprehensive consists of a systematic review of the literature on dental implant flapless technique, a retrospective study of 1241 dental implants using flapless technique, and an osseo-integration study on osteoporotic (OP) rats. The osseo-integration study used a cohort of sixty-four female Sprague-Dawley rats, aged 3 months old, split into three groups: Sham-operated (SHAM; n=20), ovariectomized (OVX; n=20) and ovariectomized treated with simvastatin (OVX+SIM; n=20). Eighty-four days following ovariectomy, screw-shaped titanium implants were immediately placed into the posterior maxilla. Simvastatin was fed orally at 5 mg/kg each day after the implant placement in the OVX+SIM group. The animals were sacrificed at either 28 or 56 days for histological analysis. The osseo-integration indices used were: bone formation rate (BFR), bone to implant contact (BIC), and bone density (BD). Results and Discussion: The systematic review showed flapless surgery had comparable, similar & high survival rate compare with flap surgery, and its cumulative 5 and 10 years implant survival rate of 97.9% and 96.5% respectively and complication rate of 6.0%. The osseo-integration indices (BFR, BIC and BD) in the three groups showed significant variations among the SHAM > OVX+SIM > OVX group, which suggested that simvastatin could encourage bone regeneration and mineralization in OVX rats. Conclusion: This study shows that implant flapless surgery has been proven to be a successful procedure, osteoporosis reduced osseo-integration, and simvastatin can positively influence on bone regeneration through the osseo-integration indices, and successfully promoted osseo-integration in the posterior maxilla in OP rats.