Sidhu HK. Dent Update 2015; 42: 436–440

Correspondence in the Letters section of this Journal (eg Br Dent J 2014; 217: 258–259) have reported that new drugs, such as denosumab (Prolia®, XGEVA®), and the antiangiogenic agents bevacizumab (Avastin®) and sunitinib (Sutent®), of course in addition to bisphosphonates, are associated with osteonecrosis of the jaw (ONJ). This review describes the mechanisms of action and therapeutics of denosumab and bisphosphonates. Denosumab is a monoclonal human antibody that has bone antiresorptive properties. It is used to prevent osteoporotic fractures in postmenopausal women who cannot take bisphosphonates, and prevention of skeletal-related events in adults with bone metastases. In the above cited correspondence, it was stated the 'risk of ONJ is about 1% for cancer patients receiving intravenous BPs (zole(n)dronate), and there is a comparable figure for cancer patients exposed to denosumab'. A key difference between denosumab and zoledronic acid, is that the effects of denosumab are reversed after six months. Although controversial, drug-holidays for those on denosumab (and sunitinib) for whom dental surgery is indicated are not discussed.