How Long Do Fillings Last? Lifespan by Material & Warning Signs

Editorially reviewed by the Dental.me Editorial Team · Updated July 2026

A dental filling is one of the most common repairs in dentistry, but almost no one is told the most important fact about it: no filling lasts forever. Every filling has a working life, and when it reaches the end of that life it needs to be replaced. How long you get depends heavily on the material, the size of the filling, where it sits in your mouth and how well you look after it. This guide walks through the realistic lifespan of each filling type, what shortens it, the warning signs that yours is failing, and the simple habits that stretch every filling as far as it will go.

How long should a filling last?

As a broad rule, most fillings last somewhere between 7 and 15 years, and many go longer than that with good care. But “a filling” is not one thing. A small tooth-colored filling on a front tooth and a large silver filling on a back molar are made of different materials, carry very different chewing loads, and wear out on completely different timelines.

It also helps to think in averages rather than guarantees. The numbers below are typical ranges seen across research and everyday practice, not promises. A well-placed filling in a low-stress spot on a careful patient can outlast the average by years, while a large filling on a grinder can fail early. If you want to understand why the repair was needed in the first place, our explainer on what a cavity actually is is a useful starting point.

Filling lifespan by material

Material is the single biggest predictor of how long a filling lasts. Here is how the common types compare.

Amalgam (silver) fillings — about 10 to 15 years

Amalgam is the traditional silver-colored filling. It is strong, hard-wearing and inexpensive, which is why it held up well on back teeth for generations. Many amalgams last 10 to 15 years, and some go well beyond 20. The trade-off is appearance and the fact that placing a large amalgam can require removing more tooth structure. If you are weighing your options, our side-by-side on composite versus amalgam fillings compares them in detail.

Composite (tooth-colored) fillings — about 7 to 10 years

Composite resin is the tooth-colored material most dentists now use. It bonds directly to the tooth and looks natural, which makes it the default for visible teeth. The average lifespan is a little shorter than amalgam, roughly 7 to 10 years, partly because composite can wear and stain over time. Materials and bonding techniques keep improving, so newer composites often outlast older estimates.

Gold inlays and onlays — about 15 to 30 years

Gold is the longest-lasting option by a wide margin. Cast gold inlays and onlays are made in a lab and cemented in, and they routinely last 15 to 30 years or more because gold is gentle on opposing teeth and resists wear and fracture. The downsides are cost and the gold color. If your dentist has mentioned a lab-made restoration, our guide to inlays versus onlays explains how they differ from a standard filling.

Ceramic and porcelain fillings — about 10 to 15 years

Ceramic and porcelain restorations are tooth-colored, highly stain-resistant and strong. Like gold, larger ones are usually made in a lab as inlays or onlays. A typical ceramic restoration lasts 10 to 15 years, and often longer, combining a natural look with good durability at a higher price than composite.

Glass ionomer fillings — about 5 years

Glass ionomer releases fluoride and bonds to the tooth, which makes it useful for children’s teeth, fillings below the gumline and temporary repairs. It is not as strong as the others and wears faster, so it typically lasts around 5 years and is rarely the first choice for a heavy-chewing back tooth.

What affects how long a filling lasts

Two people can get the same material and see very different results. These are the factors that decide the outcome.

• Size of the filling. Large fillings fail sooner than small ones. The more of the natural tooth that has been replaced, the less support the remaining tooth gives and the more stress the restoration takes.
• Location and bite forces. Molars do the heavy chewing, so back-tooth fillings wear faster than fillings on front teeth that mainly bite and tear.
• Recurrent decay. New decay forming at the edge of an existing filling, called recurrent or secondary decay, is the single most common reason fillings are replaced. Plaque collects at the margin, undermines the seal and lets bacteria back under the filling.
• Oral hygiene. Brushing twice a day and flossing keeps the margins clean and directly slows that recurrent decay.
• Grinding and clenching. Bruxism loads fillings with force far beyond normal chewing and is a frequent cause of chips, fractures and early failure.
• The dentist’s technique. How well the tooth was isolated, shaped, bonded and polished affects the seal and the lifespan from day one.

Signs your filling is failing

Fillings rarely fail without warning. Watch for these signs and book a check-up if any appear.

• New sensitivity to hot, cold or sweet foods around the tooth.
• A sharp pain when you bite down, which can signal a crack or a loose filling.
• A rough, chipped or worn edge you can feel with your tongue.
• A visible crack, line or gap between the filling and the tooth.
• A dark spot or shadow around the filling, which may be decay creeping underneath.
• Food consistently trapping in or beside the filling.
• The filling loosening or falling out entirely. If that happens, our guide on what to do about a lost filling covers the steps to protect the tooth until you can be seen.

No filling is permanent: the replacement cycle

This is the part patients are least often told. Because every filling eventually wears out, most teeth go through a replacement cycle over a lifetime. The catch is that each replacement usually removes a little more tooth structure, since the dentist has to clear the old material and any new decay before placing the new filling.

Over several cycles, a tooth can run out of enough healthy structure to hold a simple filling. At that point the treatment steps up to a crown, which caps the whole tooth, or in some cases a root canal if decay reaches the nerve. That progression is a strong reason to protect the fillings you have and to catch problems early, while the fix is still small. Cost climbs at each step too, and our overview of what a dental filling costs shows how a timely replacement is far cheaper than a crown or root canal later.

How to make your fillings last

You cannot make a filling permanent, but you can push it toward the top of its range with a few habits.

• Brush and floss daily. Clean margins are the best defense against recurrent decay, the number one killer of fillings.
• Wear a night guard if you grind. A custom guard absorbs the clenching forces that crack fillings, and it protects your natural teeth at the same time.
• Go easy on hard and sticky foods. Ice, hard candy and chewy sweets can chip a filling or pull it loose, especially an older one.
• Keep regular check-ups. Your dentist can spot a worn margin or early crack long before it hurts, so a quick polish or small repair replaces a bigger job.
• Do not ignore new sensitivity. A twinge that lingers is worth a call rather than a wait.

When to see a dentist, and does insurance cover replacement?

See a dentist promptly if a filling hurts when you bite, feels rough or loose, becomes sensitive, or has visibly cracked or fallen out. Even without symptoms, a routine exam every six months is the most reliable way to catch a failing filling early, because most problems are silent until they are advanced.

On insurance, most dental plans do cover replacement fillings, but usually only after a waiting period on the same tooth, often around two years from the last filling, and typically at a set percentage rather than the full cost. Plans also tend to reimburse based on the least expensive material that does the job, so a tooth-colored upgrade on a back tooth may leave you paying the difference. Check your specific plan for frequency limits, downgrade clauses and any annual maximum before treatment so there are no surprises.

The honest bottom line: fillings are a repair, not a cure. Expect to replace them over time, choose the material that fits the tooth and your budget, and protect them with good hygiene and regular visits so each one lasts as long as it possibly can.

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