A dental filling is not a permanent fix, but it is not a temporary one either. How long a filling lasts depends on the material it is made from, where it is placed in your mouth, and how well you care for it. Most fillings last a decade or more, and some outlast the expectations of patients who got them years ago.
Understanding filling lifespan by material gives you a realistic sense of what to expect and helps you make sense of what your dentist is telling you when they mention replacing an older restoration.
How Long Do Fillings Last by Material?
Composite Resin (Tooth-Colored) Fillings: 7 to 10 Years
Composite resin is currently the most common filling material used in dental offices across Canada. It is made from a mixture of plastic resin and fine glass particles that can be shaded to match your tooth color almost exactly. The result is a restoration that is essentially invisible in normal conversation.
Composite is excellent for front teeth and smaller cavities on back teeth. Its limitation is durability under sustained heavy chewing force. Back molars absorb the most pressure in the mouth, and composite does not withstand this as long as harder materials.
The typical dental filling lifespan for composite is 7 to 10 years, though many last longer with good oral hygiene and in lower-stress locations. Composite fillings placed on back molars in patients who grind their teeth tend toward the shorter end of that range.
Amalgam (Silver) Fillings: 10 to 15 Years
Amalgam fillings are made from a combination of metals including silver, copper, tin, and a small amount of mercury. They were the standard filling material for most of the 20th century and are still used in some clinical situations today.
Amalgam is significantly harder and more durable than composite, making it well-suited for back molars. However, it expands and contracts with temperature changes over time, which can eventually create fine cracks in the surrounding tooth structure. It is also more visible than composite.
Many patients who had amalgam fillings placed 20 or 30 years ago still have them intact. The typical dental filling lifespan for amalgam ranges from 10 to 15 years, though older amalgam fillings that are still functioning and showing no signs of marginal breakdown may simply be monitored rather than replaced proactively.
Gold Fillings: 15 to 30 Years
Gold restorations, which include gold inlays and onlays, are the most durable filling option available. Gold wears at a rate very similar to natural enamel, does not fracture under force, and seals exceptionally well against the tooth surface. Clinically, gold restorations have the longest documented tooth filling durability of any material.
Their obvious limitation is appearance. Gold fillings are used almost exclusively on back teeth where they are not visible during normal conversation or smiling. They are also the most expensive filling option upfront, though their longevity often makes them cost-effective over time.
Ceramic (Porcelain) Fillings: 10 to 15 Years
Ceramic restorations, often called porcelain inlays or onlays, offer an aesthetically pleasing alternative to amalgam on back teeth where composite may not provide enough strength for larger cavities. They match tooth color closely and are more resistant to staining than composite.
Ceramic is strong but can be brittle if subjected to very high impact forces, which makes it less ideal for patients who grind their teeth heavily. The lifespan is typically 10 to 15 years.
What Affects How Long a Filling Lasts?
Location in the Mouth
Back teeth bear the majority of chewing force. Fillings on molars, particularly large ones, wear faster and are more likely to fracture or develop secondary decay around their margins than fillings on front teeth or smaller cavities.
Grinding and Clenching
Bruxism puts sustained, abnormal force on every tooth surface in the mouth, including fillings. Patients who grind their teeth at night often see fillings wear faster and may chip or crack their restorations. A custom night guard is one of the most effective ways to extend the life of dental work for patients who grind.
Oral Hygiene
A filling cannot develop a cavity, but the tooth around it can. If plaque accumulates at the margins where the filling meets the natural tooth structure, bacteria can work their way underneath and cause recurrent decay. This secondary cavity can undermine the filling without being visible to you until it is advanced enough to cause symptoms.
Brushing twice daily and flossing once daily, paying particular attention to the edges of fillings, is the most effective way to prevent this.
Diet and Habits
Frequent consumption of acidic beverages, sticky foods, and ice chewing all accelerate filling wear and can dislodge or chip restorations. Tooth filling durability is partially in your control through what you eat and drink.
Quality of the Original Placement
A filling that was placed with precise marginal adaptation to the tooth surface will last longer than one with even small gaps or overhangs. This is one reason that the skill and technique of the dentist placing the restoration matters, not just the material chosen.
Signs a Filling Needs to Be Replaced
Fillings do not always fail dramatically. Many times, your dentist identifies a failing restoration at a routine checkup before it causes symptoms. Signs that a filling may need replacement include:
Sensitivity to cold or sweets that has developed in a previously comfortable tooth. This may indicate recurrent decay forming around the filling’s margins, allowing bacteria to approach the nerve.
Visible cracks in or around the filling. Composite can chip and crack, particularly under heavy bite force. Small chips in low-stress areas may be monitored, while larger fractures need attention.
A filling that feels rough or different to your tongue. A smooth filling that has become rough may indicate surface wear or the beginning of marginal breakdown.
Pain when biting. Discomfort specifically triggered by biting on a filled tooth may signal a crack in the underlying tooth structure or in the filling itself.
A filling that falls out. This occasionally happens and is rarely a dental emergency. Keep the filling if possible and see your dentist within a day or two. The exposed tooth structure is vulnerable and should not be left unprotected for long.
At Destiny Dental, we examine the condition of existing restorations during every dental cleaning and exam and use X-rays to detect secondary decay that is not visible clinically. Catching a failing filling early means a simpler repair, usually just a new filling rather than a crown or root canal.
Do Older Amalgam Fillings Need to Be Replaced?
A question that comes up often is whether old amalgam fillings should be proactively replaced, particularly with composite. The answer is that a functional amalgam filling with intact margins and no evidence of cracking or secondary decay does not need to be replaced on a schedule. Replacing a structurally sound filling introduces the risk of weakening the tooth unnecessarily.
However, when an old amalgam filling shows signs of failing, cracking, or secondary decay, replacing it with composite or another material is completely appropriate and in many cases preferred given composite’s more conservative preparation requirements.
What Happens When a Filling Is Replaced?
When a filling is replaced, your dentist removes the old material, assesses the underlying tooth for decay, prepares the surface, and places a new restoration. If decay has progressed significantly beneath the old filling, a larger restoration may be needed, or in more advanced cases, a crown if the remaining tooth structure is too compromised to support a filling.
This is why consistent monitoring through regular checkups matters. Fillings that are caught failing early are simpler and less expensive to address than those that have been quietly deteriorating for years before symptoms appear.
Frequently Asked Questions
How long does a filling last on average?
Composite fillings typically last 7 to 10 years. Amalgam fillings last 10 to 15 years. Gold lasts 15 to 30 years. Actual lifespan varies based on location, habits, and oral hygiene.
Can a filling last 20 years?
Yes, particularly gold and well-placed amalgam restorations. Some patients have composite fillings that last well beyond 10 years with good care and low occlusal stress.
Does how long do fillings last depend on how often I see my dentist?
Yes, significantly. Regular checkups allow your dentist to identify fillings that are beginning to fail before they cause bigger problems. A failing filling caught early is usually a straightforward fix.
Is it normal for a new filling to be sensitive?
Mild sensitivity in a newly placed composite filling is normal for a few days to a few weeks as the tooth adjusts. Sensitivity that is worsening or persists beyond a month should be evaluated.
Can I get a tooth-colored filling on a back tooth?
Yes. Composite resin is suitable for most cavities on back teeth. For very large cavities on molars or in patients with heavy bite forces, your dentist may recommend a stronger material like ceramic or gold for better tooth filling durability.
Summary
How long do fillings last depends primarily on material, location, and patient habits. Composite typically lasts 7 to 10 years, amalgam 10 to 15, and gold up to 30 or more. Regular dental checkups are the most effective way to catch a failing filling before it leads to a more complex and expensive problem. Most fillings give years of reliable service when placed well and maintained properly.
If you have older fillings you want assessed, or you need a new filling placed, visit our dental fillings page or contact us at Destiny Dental to book an appointment.