Suboxone Tooth Decay Developments

One attorney for the plaintiffs points out that a settlement becomes more likely when they establish causation with expert evidence during discovery, a critical process before “meaningful” negotiations can occur. As well, bellwether discovery and trial preparations must be completed in advance of a global settlement. As for the MDL status throughout 2025, plaintiffs are also waiting on decisions on motions to dismiss.

Indivior, the Suboxone manufacturer, is no stranger to settlements.

• 2019: The U.S. Justice Department reached a $1.4 billion settlement from Reckitt Benckiser (Indivior’s former parent company) over alleged false marketing and safety misrepresentation.
• 2021: Nearly $60 million was returned by the FTC to consumers allegedly overcharged for Suboxone due to anti-competitive conduct.
• 2023: Indivior paid $102.5 million to 42 states over inflated costs linked to blocking generic alternatives.
• 2023: Indivior paid $385 million to resolve monopoly lawsuits alleging unlawful practices to restrict competition.

Motion to Dismiss

If dismissals are denied, settlement talks seem more likely. (Lawyers typically see settlements as likely eventually, but only when the evidence phase—especially around causation—is better developed.) If motion to dismiss is denied by the judge, lawsuits are allowed to move forward into the discovery phase, which includes expert testimony, exchange of evidence, and depositions. And Suboxone plaintiffs have the opportunity to prove their claims in court. Defendant Indivior faces an expensive discovery and possibly the risk of jury trials. With this increased pressure, companies like the Suboxone manufacturer often consider settlement talks.  

Scientific Evidence

Scientific evidence is gaining momentum, which could mean another nudge at Indivior to settle. The Journal of the American Medical Association published a study in 2020 that found, after examining over 33,000 patients, suboxone users had significantly higher rates of dental problems compared to other opioid addiction treatments. The study determined that sublingual buprenorphine/naloxone users had a 42% higher risk of dental adverse events compared to transdermal buprenorphine users and a 67% higher risk compared to oral naltrexone users. According to NIH, buprenorphine/naloxone has a pH of 3.4 when dissolved in water, which makes it highly acidic. Suboxone patients are instructed to hold the tablet under the tongue for 5-10 minutes to maximize absorption, creating prolonged acidic exposure that can directly damage tooth enamel. And it’s a double whammy: Suboxone also causes dry mouth, reducing the protective saliva that would normally neutralize acids and protect teeth. So, direct acid exposure plus reduced saliva protection can lead to rapid tooth decay.

In 2018 the FDA classified 131 out of 305 cases of adverse dental events as serious. Of those serious cases, 26 involved patients with no prior history of dental problems, which undermined Individor’s arguments that pre-existing conditions were the sole cause. And in another study in 2022, the FDA required a label change, warning about possible oral health problems associated with transmucosal (sublingual, buccal) buprenorphine formulations commonly used to treat opioid use disorder.

Based on the above, legal experts believe it provides enough evidence for plaintiffs’ claims that Indivior knew about the acidic nature of sublingual Suboxone and its potential to destroy tooth enamel. However, patient-level proof is still required (dental records, timing of onset relative to Suboxone start, other risk factors, adherence to oral-care guidance, etc.). And courts will also hear counterarguments. To be continued…