Most dental fillings last between 7 and 15 years, though the range stretches from under 5 years to over 30 depending on the material, the size of the filling, and how well you care for your teeth. Composite resin, the tooth-colored material used in the majority of fillings today, averages about 7 years but can exceed 10 years when the filling is small and oral health is good. Gold and porcelain restorations routinely last 20 to 30 years.
Lifespan by Filling Material
The material your dentist uses is the single biggest factor in how long your filling will hold up. Composite resin is the most common choice because it matches your tooth color, but it wears faster than metal alternatives. A large review of over 30 long-term studies found that at least 60% of composite fillings survive more than 10 years when the right materials are applied correctly. The average, though, sits closer to 7 years, and larger fillings on chewing surfaces tend to fall on the shorter end of that range.
Amalgam (silver) fillings are less popular than they used to be, partly for cosmetic reasons and partly due to concerns about trace mercury content. But they’re durable, typically lasting 10 to 15 years and sometimes much longer. Gold inlays and onlays are the most long-lived option at 20 to 30 years, though they cost significantly more and require two visits. Porcelain and ceramic restorations fall in a similar range, often lasting 20 years or more, with the added benefit of blending in with natural tooth color.
Why Fillings Eventually Fail
Fillings don’t just dissolve or disappear. They fail in specific, predictable ways. The most common reason is new decay forming around the edges of the filling. Over time, the seal between the filling material and your tooth enamel can break down, creating a microscopic gap. Bacteria and food particles work their way into that gap, and decay develops underneath, sometimes without any visible sign on the surface.
The second major cause is fracture. Constant pressure from chewing, grinding, or clenching gradually wears fillings down, and eventually the material chips or cracks. This is especially common in back teeth, which absorb the full force of your bite. Fillings can also simply come loose and fall out. When this happens to a new filling, it usually points to a problem with how the filling was placed. When an older filling falls out, it’s more often because the remaining tooth structure around it has weakened or decayed.
Interestingly, your personal biology plays a role too. A study from the University of Pittsburgh found that a genetic variation affecting an enzyme naturally present in teeth can weaken the bond between the filling and the tooth surface, leading to earlier failure. The same study found that smoking increased the overall failure rate and that alcohol consumption was linked to more failures within the first two years. These aren’t small effects: they represent measurable differences in how long the same filling lasts in different people.
Factors That Shorten or Extend Filling Life
Beyond the material itself, several factors determine whether your filling lands at the short or long end of its expected range.
- Filling size: Smaller fillings last longer. A small filling on a front tooth might easily reach 15 years, while a large filling covering most of a molar’s chewing surface may fail in under 5. The more tooth structure that remains intact around the filling, the better it holds up.
- Tooth location: Back teeth (molars and premolars) take far more force during chewing than front teeth. Fillings in these locations wear faster and are more prone to cracking.
- Grinding and clenching: If you grind your teeth at night or clench during the day, you’re putting enormous extra pressure on your fillings. This accelerates wear on any material, but especially on composite resin. A night guard can make a real difference.
- Oral hygiene: Brushing, flossing, and regular dental cleanings slow the decay that forms around filling edges. Poor oral hygiene is probably the most controllable risk factor for early filling failure.
- Diet: Frequent exposure to acidic foods and drinks (citrus, soda, wine) erodes both tooth enamel and the margins where fillings meet teeth. Sticky and hard foods put mechanical stress on restorations.
How to Tell a Filling Needs Replacing
Some failing fillings announce themselves clearly. You might feel a sharp edge with your tongue, notice increased sensitivity to hot or cold, or feel pain when you bite down. A piece of filling material might chip off or the whole filling could fall out while you’re eating. These are obvious signs.
More often, though, a filling deteriorates gradually and you won’t notice. The seal breaks down, decay starts underneath, and the filling looks fine from the outside. This is one of the main reasons regular dental checkups matter even when nothing hurts. Your dentist can spot wear, marginal breakdown, and early decay around fillings using visual exams and X-rays well before you’d feel any symptoms. Catching a failing filling early usually means a simple replacement. Waiting until it hurts can mean a root canal or crown instead.
Getting the Most From Your Fillings
You can’t change your genetics, but the controllable factors add up to a meaningful difference. Keeping fillings clean is straightforward: brush twice a day with fluoride toothpaste, floss daily (especially around filled teeth), and don’t skip dental visits. Research consistently shows that patients with good oral health get significantly more years from their composite fillings, pushing past the 10-year mark rather than hitting the 7-year average.
If you grind your teeth, a custom night guard protects both your fillings and your natural tooth structure. Avoiding habits like chewing ice, biting pen caps, or using your teeth to open packaging eliminates unnecessary stress on restorations. And if you smoke, that’s one more reason to consider quitting: the data on increased filling failure rates in smokers is clear.
When a filling does need replacing, the replacement is usually larger than the original because some additional tooth structure has been lost. After two or three replacement cycles, there may not be enough tooth left to support another filling, and a crown becomes necessary. Getting the maximum life out of each filling isn’t just about comfort or cost in the moment. It’s about preserving the tooth for the long run.