Bisphosphonates--what the dentist needs to know: practical considerations.

T s c t b a s m n e c steonecrosis of the jaws has been identified as a otential adverse side effect of nitrogen-containing isphosphonate (nBP) medications. These medicaions are also known as amino bisphosphonates. Earier bisphosphonates usually did not have nitrogenontaining side chains or the opposed hydroxyl group nd thus were less effective. The overall risk of steonecrosis in individuals taking the nBPs has not een clearly defined; however, epidemiologic studies nd clinical experience have indicated that an inreased risk exists of bisphosphonate-related osteonerosis of the jaws (BRONJ) developing in patients eceiving intravenous nBPs and a lesser risk with oral BP medications. The jaws are preferentially inolved, likely related to the dynamics of bone-forming steoblasts and bone-resorbing osteoclasts of the aleolar bone compartment, because cellular activity in one is controlled by hormones, cytokines, and mehanical loading. A recent study has identified a potential genetic redisposition for the development of BRONJ in a roup of myeloma patients treated with the intraveous nBP pamidronate or zoledronic acid. In addiion, Scheper et al suggested that zoledronic acid, at ow concentrations, directly affected oral mucosal issues by induction of gene-regulated apoptotic proesses; thus, these soft tissue effects of the medication ight induce or potentiate osteonecrosis. Landesberg t al have also identified inhibitory effects of bisphoshonates on oral keratinocyte cell proliferation and ound healing. However, the specific mechanism by hich osteonecrosis of the jaws develops is not