How Long Do Dental Fillings Last? Lifespan by Material and Replacement Costs
Amalgam fillings last 10 to 15 years, composite 5 to 10 years, ceramic 15 to 20 years, and gold 20 to 30 years. But the real question is what it costs to maintain a filling over 30 years, including replacements. The cheapest filling upfront is not always the cheapest long-term.
Lifespan by Material
| Material | Average Lifespan | Shortens Lifespan | Signs of Failure |
|---|---|---|---|
| Amalgam | 10-15 years | Grinding, large size, poor seal | Dark edges, rough surface, sensitivity |
| Composite | 5-10 years | Grinding, staining, large size, moisture during placement | Discolouration, rough edges, gap around filling |
| Ceramic | 15-20 years | Fracture from heavy bite force, cement washout | Chipping, sensitivity, visible crack |
| Gold | 20-30 years | Very few. Gold rarely fails before the tooth does | Loose fit, sensitivity (rare) |
Signs Your Filling Needs Replacement
Sensitivity to hot or cold
New sensitivity around an old filling often means the seal has broken and bacteria are reaching the nerve.
Visible crack or chip
A crack in the filling or tooth around the filling means the restoration is no longer protecting the tooth.
Dark shadow underneath
A dark area visible around or under a filling (especially composite) may indicate decay underneath.
Rough or jagged edges
If the filling feels rough to your tongue or catches on floss, the edges have broken down.
Pain when biting
Pain localised to one tooth when chewing can indicate a filling that is too high, cracked, or has decay underneath.
Filling falls out
If a filling falls out, see your dentist within a few days. Keep the area clean and avoid chewing on that side.
Replacement Filling Costs
Replacing a filling costs about the same as a new filling in most cases. Your dentist removes the old filling, cleans out any new decay, and places a new restoration. However, if the cavity has grown since the original filling, the replacement will be larger (more surfaces, higher ADA code, higher cost).
Important: Each replacement cycle removes a small amount of additional tooth structure. After 2 to 3 replacement cycles, there may not be enough healthy tooth remaining for another filling. At that point, your dentist will recommend a crown ($800 to $3,000), which represents a significant cost escalation.
This replacement cycle is the key financial argument for choosing a longer-lasting material upfront. A gold inlay that lasts 25 years may be cheaper over a lifetime than a composite filling replaced 3 times, especially if the third replacement escalates to a crown.
30-Year Lifecycle Cost Model
How much does each material cost over 30 years, including replacements? This model assumes average lifespans and that each replacement is the same size and cost as the original.
| Material | Initial Cost | Replacements | 30-Year Total | Cost/Year |
|---|---|---|---|---|
| Amalgam | $100 | 2 (at years 12 and 24) | $250 | $8.33 |
| Composite | $200 | 3 (at years 8, 16, and 24) | $600 | $20.00 |
| Ceramic | $500 | 1 (at year 18) | $1,000 | $33.33 |
| Gold | $800 | 0 | $800 | $26.67 |
This model uses midpoint costs and does not account for inflation, the risk of escalation to a crown, or insurance contributions. Real-world costs may differ.
Replacing Amalgam with Composite
Many patients ask about replacing old amalgam (silver) fillings with composite for aesthetic reasons. The cost is $200 to $400 per tooth, depending on the size of the old filling and how many surfaces are involved.
Is it medically necessary? Usually no. If the amalgam filling is intact, well-sealed, and not causing symptoms, there is no medical reason to replace it. The ADA and FDA both state that dental amalgam is safe for most adults and children over 6.
Mercury exposure during removal: Removing amalgam releases a small amount of mercury vapour. Your dentist should use proper ventilation, suction, and a rubber dam to minimise exposure. The exposure is brief and well below safety thresholds, but it is worth knowing about.
Insurance coverage: Most plans do not cover elective amalgam replacement. If you choose to replace a functional amalgam filling with composite for cosmetic reasons, you will likely pay the full cost out of pocket. If the amalgam is damaged or has decay underneath, insurance should cover the replacement as a standard filling.
When a Replacement Filling Becomes a Crown
Each time a filling is replaced, the dentist removes the old filling plus any new decay, then places a larger restoration. After 2 to 3 replacement cycles, the remaining tooth structure may be too thin to support another filling. At this point, a crown is required.
This escalation path is important to understand when choosing your initial filling material. A filling that lasts longer means fewer replacement cycles and a lower risk of eventually needing a crown. The jump from a $200 composite filling to an $800 to $3,000 crown is significant.
Read the full filling vs crown decision guide