Published March 2026

Suboxone Makers Knew About Dental Risks for Years

Last updated: May 2026

At the heart of the Suboxone dental injury litigation is a question of knowledge: when did Indivior PLC and Aquestive Therapeutics know that their film was destroying patients' teeth? Evidence gathered in litigation, public FDA adverse event databases, and the basic chemistry of the product all point to the same answer: long before the June 2022 warning.

What Manufacturers Know From Day One: The pH Issue

The acidic pH of Suboxone film (~3.4) is not a surprise. It is a measurable, documented property of the film's formulation — the polymer matrix, preservatives, and solubilizers that make the film dissolve in the mouth. Pharmaceutical manufacturers measure pH of oral drug products as a matter of standard protocol. Indivior and Aquestive knew the pH of their film from the development and testing stage.

The potential for dental harm from an acidic product that contacts tooth surfaces for 5–15 minutes, multiple times daily, is not a difficult inference. Dental enamel begins dissolving at pH 5.5. A pH of 3.4 is devastating to enamel. This is basic dental chemistry, well-established in the literature, knowable by any pharmaceutical scientist reviewing the formulation.

FDA Adverse Event Reports: A Paper Trail

The FDA's MedWatch adverse event reporting system (FAERS) contains thousands of reports of dental injuries associated with buprenorphine sublingual products. Under FDA regulations, manufacturers are required to monitor FAERS, review adverse event reports, and update their labeling when new safety signals emerge.

Reports of dental decay, tooth fracture, and tooth loss associated with Suboxone film appear in FAERS dating back years before the 2022 warning. Physicians, dentists, pharmacists, and patients filed these reports. Under the manufacturer's legal obligations, these reports were required to be reviewed and assessed. The allegation in the litigation is that these signals were not acted upon — that Indivior and Aquestive failed to update their label when they should have.

The 2017 Literature: Science Was Telling the Story

Beginning around 2017, peer-reviewed dental and medical literature began publishing case reports and observational studies describing unusual dental injury patterns in buprenorphine film patients — widespread decay in patients with no prior dental history, a pattern consistent with the film's acid exposure mechanism.

Pharmaceutical manufacturers are required by FDA regulations to monitor published scientific literature for safety signals. Published case reports of dental injury in their patient population are a known safety signal that triggers label review obligations. The argument in the litigation is that by 2017 at the latest, the manufacturers had both the adverse event reports and the published literature establishing a safety signal — and still failed to act.

The FDA's Pre-Warning Communication

The FDA does not issue Drug Safety Communications on its own initiative without prior communication with the manufacturer. Before the June 2022 public warning, the FDA contacted Indivior and other manufacturers and requested label changes addressing dental safety. This process takes months of back-and-forth — meaning the FDA was raising the issue with Indivior well before June 2022.

The pre-warning FDA communications are among the documents being sought in discovery in the Suboxone MDL. They are expected to establish the timeline of when the FDA raised the dental issue with the manufacturer — and what Indivior's response was.

Why "We Didn't Know" Is a Difficult Defense

In product liability litigation, a manufacturer's knowledge of a risk — and failure to warn — is a central issue in both negligence and strict liability claims. For Suboxone dental injury cases, the manufacturers face a difficult position on the knowledge question because:

• The film's pH (~3.4) was a known, documented product property from day one
• The dental damage potential of that pH to enamel (threshold pH 5.5) is established chemistry
• Adverse event reports were accumulating for years in a database the manufacturer was required to monitor
• Published literature documented the injury pattern by 2017
• The FDA communicated with manufacturers before issuing the 2022 public warning

This timeline is why the Suboxone dental injury litigation is proceeding — and why plaintiffs' attorneys believe these cases have merit.