A 65-year-old male patient has been taking Zometa on and off for the last year f

There are concerns regarding dental treatment of this patient because intravenous bisphosphonates have been linked to the development of osteonecrosis of the jaw (ONJ) after certain dental procedures.

Bisphosphonates are drugs used orally and intravenously for the treatment and prevention of osteoporosis, hypercalcemia (high blood calcium that occurs in cancer), metastatic bone disease (to decrease bone pain), multiple myeloma (cancer of the body's plasma cells), and Paget's disease. Bone is a living tissue with a blood supply. Every year bone dies off and is replaced with new bone. Osteoclasts resorb the bone and osteoblasts lay down new bone. Bisphosphonates reduce this bone cell turnover by affecting the osteoclasts. Osteoclasts ingest the bisphosphonate and die within 2 days, thus supporting the buildup of new bone, even around the old bone that was not resorbed by the osteoclasts, which helps reduce fractures in the hip, spine, and other areas. Normally, osteoclasts live for 14 days. Also, bisphosphonates reduce high blood calcium levels caused by cancer. Thus, the most concerning adverse effect of bisphosphonates is the development of osteonecrosis of the jaw (ONJ) in patients having dental procedures. The underlying mechanism of action of ONJ is not clearly understood but as described above, if necrotic (old, diseased/dead) bone is inhibited from being resorbed by osteoclasts, then the necrotic bone will inhibit healing and affect blood supply to the area. Precipitating factors associated with ONJ include extractions, periodontal/implant surgery, and endodontics.

Since the patient is taking an intravenous bisphosphonate, it is probably best not to extract the tooth but an alternate procedure would be to perform root canal treatment for the meantime.