Risk of Bisphosphonate-Associated Osteonecrosis (BON) Following Dental Extraction

Grant Winners

Dean

Abstract

Bisphosphonates are potent inhibitors of osteoclastic activity. Oral formulations include the aminobisphosphonates alendronate (FosamaxÆ), residronate (ActonelÆ) and ibandronate (BonivaÆ) which are used for the prevention and treatment of osteoporosis. Several millions of these compounds are prescribed each year. Intravenous bisphosphonates are used in patients with multiple myeloma, Pagetís disease of bone and patients with breast, prostate or lung cancer that has metastasized to bone. The most common IV formulations are zoledronic acid (ZometaÆ) and pamidronate (ArediaÆ). Amongst several adverse events associated with the use of bisphosphonates, bisphosphonate-associated osteonecrosis (BON) was recently recognized as a new oral complication in patients with cancer and osteoporosis. First reported in 2003, BON is defined as the unexpected appearance of exposed necrotic bone anywhere in the oral cavity of an individual receiving a bisphosphonate and who has not received radiation to the head and neck. Bisphosphonates accumulate over extended periods of time in mineralized bone matrix. Depending on the duration of treatment and the specific bisphosphonate prescribed, the drug could potentially remain in the body for years. The development of BON increases with time of use and antiresorptive potency of the drug. Dental extractions and oral surgery have been associated with the development of BON. The role of other factors like systemic and oral co-morbidities, other therapeutic drugs (chemotherapy, corticosteroids, etc) is unknown. There are no scientifically based recommendations for the routine dental management of patients treated with bisphosphonates. The goal of this prospective study is to evaluate outcomes of dental extractions in patients taking bisphosphonates. This information is lacking in the literature and will allow for additional guidelines on dental management. This project will be instrumental in developing a systematic way of assessing the risk of developing BON.