ZOLENDRONATE E ALENDRONATE DOSING IN BONE SEQUESTRA FROM BISPHOSPHONATE-RELATED OSTEONECROSIS OF THE JAWS: A MULTICENTER OBSERVATIONAL STUDY

Bisphosphonates (BP), syntetic analogues of inorganic pyrophosphate are able to inhibit the osteoclastic activity, quickly bonding the mineral component of bone structure. BPs are excreted unchanged by glomerul filtration in urine, except for a very small fraction, which is excreted in the bile. After they are absorbed by the bone, BPs are released from hydroxyapatite during bone resorption, taken-up by osteoclasts, and then they are released again when the bone is resorbed. This explain the very slow and long elimination of all BPs from skeleton [ Drake MT et al., 2010]. Consequently, a long time accumulation in the osseous tissue has benn speculated. Nevertheless, a direct method to measure these drugs in the human bone tissue is not available in literature. In man, the concentration of BPs stored in bone is estimated on basis of administred dose and quantity of drugs detected in serum and, most of all, in urine. Considering the complete absence of information on this topic, the aim of this study is to investigate the presence of BPs in bone sequestra (surgically removed or naturally exfoliated) in patients with osteonecrosis of the jaw caused byBPs (BRONJ), followed by the Oral Pathology Unit of the San Paolo Hospital, University of Milan, and in Dental Unit of Papa Giovanni Paolo XXIII Hospital of Bergamo.