Abaloparatide Enhances Bone Regeneration in Extraction Socket Dental Implant Defects: An Experimental In Vivo Study

Abstract

Objective: Abaloparatide (ABL) is a synthetic parathyroid hormone-related protein analog developed as an anabolic drug to treat osteoporosis. ABL increases bone mineral density (BMD) of the long bones and spine; however, the influence of ABL on alveolar bone regeneration remains unknown. This study assessed the effects of systemic ABL administration on tooth extraction socket healing and dental implant osseointegration in a preclinical rodent model. Methods: Sprague-Dawley rats received daily subcutaneous injection of ABL (25 μg/kg) or vehicle (VEH) at the time of maxillary first molar (M1) extraction surgery; animals underwent either: (1) unilateral M1 extraction followed by sacrifice at 10 or 42d or (2) bilateral M1 extraction followed by staged implant placement in osteotomies with standardized defects and sacrifice at 21 or 28d. Results: Micro-computed tomography (micro-CT) analysis demonstrated that ABL increased bone volume fraction (p = 0.004) and bone mineral density (BMD) (p = 0.006) of regenerated extraction sockets at 42d. Micro-CT of the femur validated systemic effects of ABL, showing greater trabecular BMD after 6 (p < 0.01), 9 (p < 0.001), and 14 (p < 0.001) weeks of treatment. Histomorphometry confirmed a higher mineralized bone area with ABL treatment in extraction sockets at 42d (p = 0.03) and in the regenerated peri-implant bone at 21d post-implant placement (p = 0.01) compared to control. Conclusion: Systemic ABL administration enhances osteogenesis in extraction sockets prior to implant placement and accelerates peri-implant bone formation in the early phase of healing in the present rodent model.