DEAR DR. ROACH: I’m a 79-year-old female who’s in good health. I am 5 feet tall and weigh 95 pounds, and I’m very active. I’ve been taking Prolia for the past two to three years for osteoporosis, which has since improved to osteopenia. Right after this past Prolia shot, I developed discomfort in my mouth and was told that I have a cracked root in a molar. I previously had a root canal on this molar and was told that this tooth should be extracted.

I realized that it would be best to wait five more months to do this to be safe, out of concern of getting osteonecrosis of the jaw (ONJ). My question is, what do I do in case of an emergency, especially if the tooth becomes infected and needs to be extracted sooner? Also, since I have a history of dental problems, how can I get off Prolia in the future and still protect my bones? — L.L.

ANSWER: Denosumab (Prolia) is a treatment for osteoporosis that is normally given as an injection every six months. Among its side effects is an increase in the risk of ONJ, which is a serious condition that consists of poor blood supply to the bone, causing death in part of the bone of the jaw. The lower jaw (mandible) is much more commonly affected than the upper jaw (maxilla).

Osteoporosis medicines that slow down the action of the osteoclasts, which are the cells that break down bone so that it can be rebuilt, put people at a higher risk of ONJ. These medicines include the bisphosphonate class, like oral alendronate (Fosamax) and risendronate (Actonel), as well as the intravenous drug zoledronic acid (Reclast), in addition to Prolia. Prolia has the highest risk of ONJ, followed by IV bisphosphonates and oral bisphosphonates.

A tooth extraction is a high-risk procedure for developing ONJ. For people on Prolia, the risk of ONJ is about 2.3%, which is much higher than the approximately 0.3% risk for people on oral bisphosphonates.

You are right that your best bet is waiting to get the extraction until just before the time you would have taken your next dose of Prolia. In one study, not a single person out of 76 people developed ONJ if they waited five to seven months after their previous dose. However, you don’t want to wait too long as the osteoporosis will start to progress, and a person can develop a fracture. The timing needs to be critical, and the medication should be restarted as soon as the extraction site has healed.

Your dentist can minimize the risk of ONJ by using an antibiotic and a very careful extraction technique. Some evidence supports the use of platelet-rich fibrin in the extraction socket, but other studies haven’t found a benefit. Your dentist should do this even if you can wait the additional five months, and they should certainly do it if the tooth requires extraction sooner. Your doctor who’s prescribing Prolia should be discussing the plans with your dentist at this time.

As mentioned before, oral bisphosphonates have a lower risk of ONJ. But there are other classes of medication for osteoporosis that carry little to no risk of ONJ, such as the parathyroid hormone analog teriparatide (Forteo); the selective estrogen receptor modulator raloxifene (Evista); and the sclerostin inhibitor romosozumab (Evenity).

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu.