Do tooth-colored dental fillings release BPA into your mouth?

What's actually in it

Tooth-colored dental fillings (called resin-based composites) replaced silver amalgam fillings in most dental practices. They look better, but they're made from plastic resins. The base ingredient in many of these resins is Bis-GMA, which is made from bisphenol A (BPA). BPA can also be present as an impurity or breakdown product.

BPA is an endocrine disruptor that mimics estrogen. Even small amounts can interfere with hormone signaling. Your mouth is warm, wet, and acidic, all conditions that help chemicals leach out of plastics.

What the research says

A 2026 study in Polymers measured BPA release from modern resin-based dental composites over time. The researchers tested how much BPA came out of the fillings in a lab setup that mimicked mouth conditions.

The fillings did release BPA. The highest levels came out in the first 24 to 72 hours after the filling was placed. After that, the release rate dropped steadily. But it didn't stop completely. Low levels of BPA continued to leach out over weeks.

The good news: the total amount released was small. For a single filling, the BPA exposure is well below the tolerable daily intake set by most regulatory agencies. But if you have multiple fillings, the cumulative exposure goes up. And the "safe" limits for BPA have been shrinking as more research comes in. The EU cut its tolerable daily intake for BPA by a factor of 20,000 in 2023.

Children are a bigger concern. Their bodies are smaller, their hormone systems are still developing, and they may be getting BPA from multiple sources: food containers, receipts, and now dental work.

If you're getting new fillings, ask your dentist about BPA-free composite options. They exist. Some newer formulations use alternative resins that don't contain or release BPA. For existing fillings, the leaching rate has likely dropped to very low levels if they've been in place for more than a few weeks.