Research

Which lasts longer: composite (tooth-colored) or amalgam fillings?

What was studied

Systematic reviews and meta-analyses comparing how long amalgam and composite resin fillings last in back teeth before needing replacement, and what typically causes each to fail.

Main findings

Pooled data generally shows amalgam fillings lasting somewhat longer than composite in back teeth — one systematic review reported median survival exceeding 16 years for amalgam versus about 11 years for composite, with composite showing a meaningfully higher failure rate driven mainly by decay at the filling's edges. Amalgam failures, when they happen, are more often due to fracture. Other data suggests the longevity gap has narrowed as composite materials have improved.

Limitations

Findings vary noticeably between studies depending on the specific composite material, filling size, and patient risk factors like grinding or oral hygiene — this isn't a fixed rule for every situation.

What this means for patients

If pure longevity is your top priority and appearance isn't a concern, amalgam has a longevity edge in the evidence. If aesthetics matter to you, composite is a reasonable, well-established choice — just understand it may need replacement somewhat sooner on average.