Bisphosphonates inhibit oral and possible dental implant healing
Many patients seeking oral surgical care or dental implant placement may be using or have used bisphosphonate (BP) drugs. Agents such as Zometa, Boniva or Actonel are useful in the control of osteoporosis in postmenopausal women. Intravenous forms of these drugs are also used to retard cancer metastasis in chemotherapy.
Since 2003, there have been numerous reports in the scientific literature of osteonecrosis of the jaws (ONJ) associated with BP treatment. ONJ is breakdown or decay of the jawbone that can lead to chronic pain and at times permanent disfigurement. The disease can occur spontaneously or be caused by a dental infection or dental procedure.
The incidence of ONJ was found to be 0.8% in a retrospective study of 4,000 cancer patients reported in 2006. Since that time, millions of patients have been also been placed on these drugs, not for cancer but for the treatment, and at times, the prevention of osteoporosis.
Osteoporosis can lead to significant disability later in life, and short term use of these drugs has been shown to stabilize this disease. Oral surgeons however are reporting ONJ in patients that have used BP's for osteoporosis. There is concern about risks of oral surgery or dental implants in patients on these drugs. The current opinion is that patients using oral BP's for 3 years or more, especially in combination with steroid medications like prednisone, are at some risk of ONJ.
Researchers have identified the incidence and risk factors for ONJ, but little is known about how BP's are related to or cause the disease. What is known is how BP's effect bone by slowing down or stopping the turnover or remodeling of bone. This is how osteoporotic bone can become stronger over time but also how it may not heal properly after surgery. BP's also are known to effect soft tissues by decreasing angiogenesis (growth of new blood vessels). This is useful in controlling or preventing cancer metastasis or spread. It is not known if prevention of angiogenesis is directly linked to ONJ.
Researchers at Columbia University in New York published the results of a laboratory study of the effects of BP's on oral cell wound healing in 2008. Mouse oral mucosal cell cultures were exposed to the BP pamidronate at a range of clinically relevant doses. The findings show that BP treatment inhibits cell growth and wound healing at these doses and that the inhibition is not due to cell death.
This research is important because little is known about the pathobiology of ONJ and how best to treat it. It is known that the risk of ONJ can be minimized by having excellent dental health before starting these drugs. This can be accomplished by having a comprehensive dental exam including full mouth xrays and carrying out a complete dental treatment plan to address tooth decay (dental caries) and gum (periodontal) disease.
Further research is necessary to identify the specific mechanism of injury by BP's and allow the development of rational treatment protocols for ONJ. If you have taken BP's and require oral surgery or dental implants, please contact us to schedule a consultation.
Inhibition of Oral Mucosal Cell Wound Healing by Bisphosphonates, Landesberg et al, J Oral Maxillofac Surg 66:839-847, 2008