Presently, the perception is that osteonecrosis has a very low incidence associated with oral bisphosphonates. However, most of the information that I find available includes relatively limited term usage of these drugs – approximately three years.
However, I frequently see patients who have taken bisphosphonates for five, ten, twelve or more years! To my knowledge, we are in uncharted territory regarding the risk of increased incidence of osteonecrosis for these patients. What we do know is that these drugs accumulate with a perhaps undefined or unknown half-life, and the percentage of vital bone likely diminishes with usage over time.  Â
Unfortunately, the incidence of very significant, untreated, periodontal disease is on the rise. I am seeing on a very regular basis, (as are periodontists across the country), patients presenting with increasingly advanced periodontal conditions. This dramatic increase in disease severity, along with the extended usage of bisphosphonate drugs, can be potentially dangerous.Â
It is also important to note that even advanced periodontal disease is most often completely without symptoms, and that fewer than 50% of general dentists today examine their patients for periodontal disease. Therefore, I am strongly encouraging physicians to refer their patients to a periodontist for dental clearance, prior to initiating bisphosphonate therapy. Â With this minimal effort, we could greatly reduce the risk of osteocrenosis for our patients.
 I welcome your input or questions regarding this subject.
 Sincerely,
Mark J. Weingarden, D.M.D.