

In this article
Tooth-colored composite fillings are one of the most common treatments for cavities today. If you’re comparing them with “metal” options like amalgam, you’re not alone—many people want a restoration that’s safe, strong, and nearly invisible.

Still, it’s normal to have questions about how long composites last, whether they release chemicals like BPA, and how much they’ll cost out of pocket. Let’s walk through what makes composite fillings different and when they’re the right choice.
What are Composite Fillings?
Composite fillings are tooth-colored restorations used to treat cavities. They’re made of a soft resin-based material that contains tiny glass or ceramic particles for added strength.
Your dentist sculpts this mixture into the prepared area of your tooth, then hardens it using a curing light. Unlike metal fillings, composites bond directly to your tooth.
This bonding process helps preserve more of your natural enamel, giving the finished result a natural appearance. Over time, improvements in the material’s composition have made composite fillings more durable and widely used for front and back teeth alike.
Composite is often chosen for its:
Ask your dentist to confirm whether bonding is appropriate for your specific tooth.
Composite is a good choice for many, but not all, dental restorations. Whether it’s the best fit depends on the size of the cavity, where the tooth sits in your mouth, and how well your dentist can keep the area dry during the procedure.
Here are common factors that support choosing composite:
In cases where the cavity is large or you have habits such as grinding your teeth, your dentist may recommend alternative restorations, like onlays or full crowns.
Composite resin is one of several materials used to repair teeth. Each type has pros and cons depending on your needs, budget, and the tooth being restored.
Here’s how composite compares to other common options:
Recent guidelines support composite as one of several recommended options for many routine fillings. Still, for large back teeth or in people who grind their teeth, alternatives like crowns or inlays may last longer.
Composite fillings are generally considered safe, and concerns about BPA or chemical leaching are often based on outdated or misunderstood information.
Evidence shows BPA exposure from resin-based materials is small and short-lived (typically 24–48 hours), and proper placement steps (full cure plus wiping/rinsing or surface sealing) further minimize exposure.
Composite resins contain monomers (liquid building blocks like UDMA and Bis-GMA) that harden when exposed to light. BPA isn’t a main ingredient, but trace amounts can appear as a byproduct or from surface layers. These amounts are very small and typically decrease to negligible levels within 24 hours.
To reduce exposure even further, dentists may:
If you need reassurance, you can ask your dentist which steps they use to minimize monomer exposure during curing and finishing.
Composite fillings are built to last several years, especially when placed in small- to medium-sized cavities on low-stress teeth. Their lifespan is influenced by factors such as oral hygiene, cavity size, bite force, and the quality of the filling placement.
Many failures aren’t due to the material breaking but to new decay at the filling's edges. That’s why brushing, flossing, and regular dental checkups are so important.
Some data suggest that composites can last 7 to 10 years or more in low-risk cases, while others show higher replacement rates when risk factors, such as poor diet or bruxism, are present.
Composite fillings often cost more than metal ones, typically ranging from $90 to $450 depending on the tooth, number of surfaces, and local rates. Amalgam fillings, by contrast, typically cost between $50 and $300.
Some dental insurance plans partially cover composites, but only up to the cost of amalgam. This is called a "posterior composite downgrade." In those cases, you pay the difference.
Here are some questions to ask your insurance before treatment:
We suggest calling your plan about “posterior composite downgrades” before treatment and requesting a pre-estimate.
Getting a composite filling is a straightforward process that usually takes 30–60 minutes. It’s more technique-sensitive than placing amalgam but has the benefit of bonding directly to your tooth.
Here’s what typically happens at your appointment:
Plan to avoid chewing while numb and test your bite gently the evening after your procedure.
It’s common to have mild sensitivity to temperature or pressure for a few days. That should fade as the tooth settles. If you feel a sharp pain when biting down, the filling may need a quick adjustment.
To help your filling last:
Brush and floss normally and call your dentist if pain persists or worsens.
Before your filling appointment, it helps to share relevant health info and ask the right questions.
Here are some questions you can ask your dentist:
Bring your medication list and habits so your dentist can tailor a plan that suits you.
In this article