The FDA stated last week that transmucosal buprenorphine has been associated with dental problems, including tooth loss. The statement was based on 305 reports to the FDA Adverse Event Reporting System (FAERS) database since buprenorphine was approved 20- years ago.
Many of my patients on buprenorphine medications have had dental problems, and the topic was often-described at SuboxForum over the years. It isn’t clear what spurred the FDA to release the warning now. There have been two case series describing tooth damage in patients on buprenorphine but the most-recent report was published almost 10 years ago.
Confounding variables make it difficult to determine whether buprenorphine can harm teeth. Most of the patients who benefit from buprenorphine treatment have histories of addiction, during which they may not have kept up with daily dental care or annual dental visits. Modern preventive dentistry includes flouride treatment and regular x-rays to detect early decay. Early treatment of caries, for example, can prevent severe decay and tooth loss. Use of other drugs, particularly methamphetamine, can cause tooth decay and loss. Opioid use disorder increases acid regurgitation by loosening the gastro-esophageal junction. Reduced frequency of brushing, combined with some dietary factors, also impact dental health.
But the FDA warning states that some people experienced dental problems as soon as two weeks after starting buprenorphine, and that some patients had healthy teeth when buprenorphine was initiated. The average time to diagnosis of tooth decay was about 2 yeasr. Interestingly, the FDA notes that almost 10% of the patients who reported decay were using buprenorphine for pain treatment rather than treatment of opioid use disorder.
The FDA suggests that patients reduce the potential for damage by rinsing their teeth and gums with water after their dose of medication has dissolved, and to brush their teeth an hour later. Many patients hold the dissolved dose of buprenorphine in their mouths for 20 minutes or longer out of concern that they won’t absorb it sufficiently to avoid withdrawal. On average, patients absorb about 30% of an 8 mg dose of Suboxone Film according to the manufacturer. The time required to obtain that degree of absorption is not clear.
The mechanism for dental decay from buprenorphine is not known. Teeth hold up to nighttime grinding and gnashing, acidic and basic foods, and hot or cold liquids. Why would 20 minutes of exposure to buprenorphine cause problems? In a case series, Suzuki suggests that the low pH of buprenorphine/naloxone (3.4) combined with low buffering capacity alters oral flora and increases growth of streptococcus mutans, similar to a process in methamphetamine users. I also remember a letter to the editor of an unknown jounal years ago that questioned possible tooth decay from buprenorphine, suggesting that the opioid effects of the medication negatively influenced immune function in teeth. I don’t know enough about dentistry to say whether that hypothesis is reasonable.
Curiously, most of my 270 patients — many of whom have been on buprenorphine for many years — have had no dental problems. That suggests that rather than a universal effect, damage depends on the presence of multiple factors, such as varied habits or genetic differences between patients. Dry mouth or xerostomia can be caused by medications and health conditions, and has long been associated with dental caries.
In short, the FDA is changing package labelling to add risk of dental decay to orally-dissolving buprenorphine medications. The addition appears to be due to reports of dental decay by some patients and doctors and not the result of a formal study. Hopefully further research will determine whether buprenorphine directly impacts dental health, or if instead it is one part of a contellation of variables.