Prolia (also known as Denosumab) is a drug used in the treatment of osteoporosis. It is described as an “anti-resorptive agent”, meaning that it stops the normal breakdown of bone that occurs in the normal turnover of bone in our bodies, while allowing the continued production of new bone leading to an increase in the bone density. Normally Prolia is provided as an injection every 6 months to help increase a patient’s bone density and thereby reduce their risk of suffering from bone fractures.
The drug is not incorporated into the new bone as it is with Bisphosphonate drugs but is an antibody that blocks the activity of the cells that take away bone (osteoclasts). The drug Prolia lasts 6 months and then must be given again to ensure that bone density does not start to reduce.
Dental side effect of receiving Prolia
Prolia has a side effect in patients who have to have tooth extractions performed. The trauma of the extraction on the bone surrounding the tooth may lead to a condition where the bone dies off, and following the extraction fragments of dead bone are lost from the extraction site. This wound can be painless or painful, varying from one patient to another. There is no effective treatment that can reliably prevent this condition developing. The condition is known as Medication-related osteo-necrosis of the jaw (MRONJ).
The optimal time for any dental extractions is therefore when the effect of the Prolia is at its lowest, in other words 6 months after the last injection and before the next one. It is always best to try and not delay the next injection as it has been found in UK studies of osteoporosis patients on Prolia that as soon as the time for the next injection passes, the bone density immediately starts to decline. In view of the rapid return to osteoporosis-related bone resorption after the Prolia-due-date has passed, and due to the rapid decline in bone density, bone fractures are likely if Prolia is withheld.
Recent UK data (2020) concerning over 2500 patients over 45 years of age, investigated patients receiving Prolia “on-time” (at 6 months after their last injection), after a “short-delay” (1-4 months later receiving their Prolia) and those with a “prolonged-delay” (4-6 months later receiving Prolia). It was found that there were 27 fractures per thousand patients in the on time group, 32/1000 in the short delay group and 42/1000 in the prolonged delay group. This clearly demonstrates that the Prolia injection should not be unduly delayed after extractions as the likelihood of fractures is worse the longer the drug is withheld. The extractions for Prolia patients should therefore take place near the end of the 6 months after Prolia was last administered and ideally 2-3 weeks before the 6 month point so that adequate healing may take place before the next Prolia is given.