How Long Does a Cavity Filling Last?

A common estimate is 5–10 years for a tooth-colored composite filling and 10–15 years for an amalgam filling, commonly called a silver filling. Those are rough expectations, not expiration dates. Some fillings last much longer, while others need attention sooner because of new decay, fracture or problems with the surrounding tooth. Gentle Dental’s patient guide gives these ranges and identifies cavity size, bite forces and placement quality as important influences.

For an existing filling, the useful question is not simply “How old is it?” It is “Is the filling—and the tooth around it—still sound?”

Expected lifespan depends on the filling

Filling type	Useful expectation
Composite resin, or white filling	Often estimated at 5–10 years, but it can remain serviceable longer.
Amalgam, or silver-colored filling	Often estimated at 10–15 years; some last 20 years or more.
Temporary filling	A short-term repair, not a substitute for completing treatment. Keep the follow-up appointment your dentist gives you.

The permanent-filling estimates above come from Gentle Dental. Published patient guides differ: Bupa Dental Care says well-cared-for composite fillings can last around 12–15 years and explains that temporary fillings are not designed for long-term use.

That variation is a reason to avoid treating any range as a replacement schedule. A systematic review of 12 long-term studies found good survival for composite fillings in permanent back teeth, including studies following restorations beyond ten years. Your dentist can give a more relevant expectation after assessing the particular tooth.

Gold and porcelain repairs are often inlays or onlays—custom-made restorations fitted into or over part of the tooth—rather than the direct filling placed during an ordinary cavity appointment. Their lifespan is not a like-for-like comparison with a small composite filling. Cleveland Clinic explains the distinction.

What makes a filling fail sooner?

Two important factors are your risk of further cavities and how much of the tooth the filling covers. The review of composite fillings in permanent back teeth found higher failure risk in people at higher cavity risk and in fillings covering more tooth surfaces. New decay and fracture were the main reasons for failure. Systematic review

Grinding or clenching can add stress, and placement technique matters too. Composite needs a clean, dry working area while it is bonded to the tooth. That is why the best material for your tooth depends on more than its advertised lifespan. Gentle Dental; American Dental Association

When should an old filling be checked?

Arrange a dental assessment if a filling becomes loose, chipped or rough, starts trapping food, or the tooth develops new sensitivity or pain when chewing. These changes do not tell you the diagnosis, but they justify checking the filling and surrounding tooth. Gentle Dental

For a new filling, mild sensitivity can settle within a week or two. Pain on biting may mean the filling needs a bite adjustment rather than replacement. Contact the dentist if symptoms persist or worsen, particularly with lingering hot-or-cold pain. Call promptly for a broken filling, severe pain, facial or jaw swelling, or fever. Cleveland Clinic

Repair or replacement—not automatic replacement

A limited defect may be suitable for repair or smoothing rather than removing the whole filling. The FDI World Dental Federation recommends considering repair case by case because replacement removes additional tooth tissue.

For an intact amalgam filling with no decay underneath, the FDA does not recommend routine removal solely over mercury concerns. Removal sacrifices healthy tooth structure and temporarily increases mercury-vapor exposure. An exception is when a health professional considers removal medically necessary, such as for a documented allergy to the material.

Before agreeing to treatment, ask:

• “Can you show me the decay, crack or other defect that needs treatment?”
• “Could this be repaired or monitored instead of fully replaced?”
• “If you recommend a crown, which parts of the tooth need reinforcement?” See filling versus crown.
• “What is the written cost for each reasonable option?” Our filling cost guide explains how to compare a quote.

To help the tooth and filling last, brush twice daily with fluoride toothpaste, clean between teeth daily and keep dental checkups. If you grind or clench, ask whether a protective guard is appropriate. These steps address decay and excess stress; they cannot guarantee a particular number of years. ADA prevention guidance; Gentle Dental