Fillings wear out and need replacement, usually after 5 to 30 years depending on the material and how hard you chew

Dental fillings are not permanent. The material breaks down over time from chewing, temperature changes in your mouth, and natural wear. A filling that lasts 15 years in one person's mouth might last only 8 years in another's, depending on the type of filling, where it sits in your mouth, and how much force you put on it when you eat.

Your dentist checks fillings during regular exams by looking for cracks, gaps, and decay underneath. If a filling is failing, your dentist will recommend replacement before the tooth underneath starts to break down. Waiting until a filling falls out or causes pain usually means more expensive work later — sometimes a root canal or crown instead of a straightforward replacement.

Key Takeaways

  • Composite (tooth-colored) fillings typically last 5 to 10 years, while amalgam (silver) fillings often last 10 to 30 years.
  • Your dentist can spot a failing filling during a regular exam before you feel pain or notice a problem.
  • Fillings fail because of cracks, gaps that let bacteria in, or decay starting underneath the filling material.
  • Replacing a filling costs less than treating decay that spreads under an old filling, so replacement is usually worth doing when recommended.

How long different filling materials last

Amalgam fillings (the silver-colored ones) are the most durable. They typically last 10 to 30 years, sometimes longer. They expand and contract with temperature changes, which can eventually cause cracks in the tooth around them, but the filling material itself holds up well. Many people have amalgam fillings that have lasted 20+ years without problems.

Composite fillings (tooth-colored plastic resin) last 5 to 10 years on average. They bond to the tooth differently than amalgam and wear down faster, especially on back teeth where you chew hardest. Composite fillings are popular because they look natural, but they need replacement more often. If you grind your teeth at night or chew ice, composite fillings may fail sooner.

Glass ionomer fillings (a cement-like material) last about 5 to 7 years and are used mainly on baby teeth or below the gum line. They release fluoride, which helps prevent decay, but they are not strong enough for chewing surfaces on permanent teeth.

The location of the filling matters too. A filling on a back molar takes much more force than one on a front tooth, so back fillings wear out faster regardless of material.

Signs a filling is failing and needs replacement

You may not notice a failing filling until your dentist points it out. During an exam, your dentist looks for visible cracks, gaps between the filling and the tooth edge, or dark spots that suggest decay underneath. Some fillings fail silently — bacteria slip in through a tiny gap and start eating away at the tooth structure you cannot see.

If you do notice symptoms, they include sensitivity to hot or cold (especially if it lingers after you stop eating), pain when chewing on that tooth, or a visible crack or chip in the filling. A filling that falls out completely is obviously a sign it needs replacement. Sometimes you will taste something metallic or notice a rough edge where the filling used to be smooth.

Decay under a filling often does not hurt until it reaches the nerve. By then, you may need a root canal instead of a straightforward replacement. This is why catching a failing filling early matters — your dentist can replace it before decay spreads.

What happens during a filling replacement

Replacing a filling is similar to placing a new one. Your dentist removes the old filling material, cleans out any decay underneath, and fills the space with fresh material. If decay has spread into the tooth, your dentist may need to remove more tooth structure, which can mean a larger filling or a crown instead.

The procedure usually takes 20 to 45 minutes depending on the filling size and location. Your dentist will numb the area first, so you should not feel pain, though you may feel pressure and hear the drill. After replacement, the tooth should feel normal within a few hours. Avoid chewing on that side until the filling hardens completely — your dentist will tell you how long to wait based on the material used.

Cost and insurance coverage for filling replacement

Replacement fillings usually cost between $100 and $300 per tooth, depending on the size, material, and your location. Composite fillings cost more than amalgam because they take longer to place and look better. Most dental insurance plans cover filling replacement at 80% to 100% if the filling is failing for reasons other than cosmetic preference.

Insurance companies sometimes deny replacement claims if the filling is less than a certain age (often 5 years) and shows no sign of failure. If your dentist recommends replacement but insurance denies it, ask your dentist to document the reason — decay underneath, a crack, or a gap — so you can appeal or understand why they are recommending it.

How to extend the life of your fillings

You cannot stop fillings from aging, but you can slow the process. Brush twice daily with fluoride toothpaste and floss once a day, especially around the edges of fillings where decay starts. Avoid chewing on hard objects like ice, hard candy, or pen caps, which crack fillings faster. If you grind your teeth at night, ask your dentist about a night guard — grinding puts extra stress on fillings and can cause them to fail years earlier.

See your dentist every six months for a checkup. Regular exams catch failing fillings before they cause problems. If you notice sensitivity or pain around an old filling, call your dentist rather than waiting for your next scheduled visit — early treatment is usually simpler and cheaper.

Frequently Asked Questions

Can a filling last forever?

No. Even the most durable amalgam fillings eventually wear down or develop gaps. Most fillings last 5 to 30 years depending on material and use, but none are permanent. Your dentist will monitor them and recommend replacement when they start to fail.

Is it safe to leave an old filling in place if it is not bothering me?

Not always. A filling can fail silently — bacteria slip in through a crack or gap you cannot see and decay spreads underneath. By the time you feel pain, the decay may be large enough to need a root canal or crown. If your dentist sees a problem during an exam, replacement is usually worth doing before decay spreads.

Why do composite fillings need replacement more often than amalgam?

Composite material is softer and wears down faster under chewing pressure. It also shrinks slightly as it hardens, which can create tiny gaps where bacteria enter. Amalgam is harder and does not shrink, so it lasts longer — though it is less popular now because of appearance and other concerns.

What if I cannot afford to replace a filling my dentist recommended?

Talk to your dentist about the risk. If decay is already present, waiting usually makes the problem bigger and more expensive. If the filling is just starting to fail with no decay yet, your dentist may recommend monitoring it more closely instead of replacing it right away. Some dental offices offer payment plans or can refer you to low-cost clinics.

Do I have to replace a filling with the same material?

No. You can switch from amalgam to composite or vice versa. Composite looks better but needs replacement sooner. Amalgam lasts longer but is visible. Discuss the trade-offs with your dentist based on the tooth location and how long you want the filling to last.