Osteonecrosis and spontaneous exfoliation of dental implants associated with oral bisphosphonate therapy: a case report.

Bisphosphonates (BPs) have long been used for the treatment of osteoporosis and diseases like bone malignancies, active Paget's disease of bone, severe osteogenesis imperfecta and fibrous dysplasia among others. They bond highly to the bone surface and inhibit bone resorption. As BPs have a long half-life in bone because of their irreversible binding to bone, patients retain their risk profile even after drug cessation. This property also explains the complications wherein the cessation of bone resorption leads to halt in bone turnover. Usually with alendronate the risk of bisphosphonate-related osteonecrosis of jaw (BRONJ) wears off after 12 months. Reporting of the development of BRONJ is commonly associated with the intravenous BPs. Invasive surgical procedure associated with the placement of implants has been shown to be a major reason for the occurrence or initiation of BRONJ in susceptible patients. The prognosis of implants placed in the jaws of patients under or past BP medication is still uncertain. The present case report describes a patient on long-term oral BP therapy with spontaneous exfoliation of implant supported bone due to osteonecrosis.