How Long Do Dental Fillings Last? Lifespan by Material and Signs a Filling Is Failing
Quick answer: Many dental fillings remain serviceable for years, and some last decades, but there is no dependable expiration date for an individual filling. A practical overview is roughly 5–15 years for many direct fillings, with results varying widely by material, size, tooth and patient. Amalgam restorations in back teeth have shown longer median survival than composite in some studies, while other comparisons—especially for large, complex restorations—remain uncertain. These figures summarize group results and offer context rather than a promise or replacement schedule. A filling does not need replacement simply because it is old. Dentists assess the filling and the remaining tooth for decay, cracks, wear, symptoms and whether a smaller repair can work. New pain, a crack, a loose or lost filling, or swelling should be assessed promptly.
A filling restores part of a tooth, but both the material and the tooth around it continue to face chewing forces, temperature changes and new decay risk. The best estimate depends on what was placed, where it sits and how much sound tooth remains.
Typical lifespan by filling material
Published estimates differ because studies follow different patients, teeth and definitions of “failure.” A restoration may be repaired or monitored rather than fully replaced. Use the ranges below as orientation only, not as a countdown.
| Material / restoration | Broad estimate | What changes the outlook |
|---|---|---|
| Composite resin | Often about 5–10 years; some last longer | Size, number of tooth surfaces, bite load, bonding and moisture control during placement |
| Dental amalgam | Often 10–15 years or longer; some remain useful for decades | Tooth condition, restoration size, fracture risk and new decay at its edges |
| Glass ionomer | Often shorter, around 5 years in broad patient guidance; sometimes less under heavy chewing forces | Use and location matter; it may suit selected low-load, gumline or pediatric situations |
| Gold or ceramic inlay/onlay | Can serve for 10–20 years or more | These are indirect restorations made to fit the tooth; material, design, tooth support and bite all matter |
These ranges combine broad clinical guidance and research, and they should not be read as head-to-head rankings. For example, a 2025 systematic review of adult permanent back teeth reported median survival above 16 years for amalgam and 11 years for composite across the included studies. Those results describe the studies reviewed—not a forecast for one person. A separate review of complex, multi-surface back-tooth restorations found too little high-quality direct evidence to establish that one material always performs better.
Composite is tooth-coloured and bonds to the tooth. Amalgam is a metal alloy used for many years. Glass ionomer has different handling and strength characteristics. Gold and ceramic inlays or onlays are made outside the mouth and fit into or over part of the tooth; they are not the same as a direct filling. A dentist selects among suitable options based on the tooth, cavity, patient needs and local availability.
Why fillings last longer in some teeth
- Size and surfaces: a larger restoration replaces more tooth and may leave less natural structure to resist cracking. A filling spanning several surfaces has different demands from a small one-surface repair.
- Location and bite force: back teeth take substantial chewing loads. A concentrated or uneven bite can stress the filling and the tooth.
- Grinding or clenching: repeated high forces can contribute to wear, chips or fractures. Ask a dentist whether a bite assessment or protective appliance is appropriate.
- New decay risk: decay can develop beside an existing restoration. Frequent sugar exposure, plaque control, dry mouth and individual cavity risk influence the surrounding tooth.
- Placement conditions: some materials, particularly bonded composite, depend on careful technique and moisture control. The dentist also checks the bite and finish.
- Tooth condition: cracks, prior treatment, the amount of remaining tooth and the restoration’s shape can change the plan and outlook.
Good daily cleaning, fluoride toothpaste, limiting frequent sugary snacks and regular dental examinations can help manage new decay risk. They cannot guarantee a particular filling lifespan or prevent every crack.
Signs a filling may need attention
A filling can develop a problem without an obvious symptom, so routine examinations matter. Contact a dental professional for new or persistent sensitivity, pain when biting, a chipped or cracked edge, a filling that feels loose or has fallen out, food repeatedly catching around it, or a change in the tooth. A dentist may examine the area and use imaging when appropriate to check the restoration and nearby tooth. Symptoms alone cannot show whether the filling needs polishing, repair, replacement or a different treatment.
Arrange prompt dental assessment for pain, a crack, a loose or lost filling, suspected decay, or swelling. Severe or rapidly worsening symptoms need urgent dental advice. Do not wait for a lifespan estimate to act on a new problem.
Does an old filling need to be replaced?
Age alone is not a reason to replace a filling. If it is intact and the tooth is healthy, a dentist may simply monitor it during routine care. This is especially important for intact amalgam: the FDA advises against removing it solely because it is old when there is no decay beneath it. Unnecessary removal can sacrifice healthy tooth structure and briefly increase mercury-vapor exposure during the procedure.
When a defect is found, replacement is not the only possible response. The dentist considers the size and position of the problem, decay, symptoms, remaining tooth and whether the restoration can be retained safely. Depending on those findings, options may include:
| Finding | Possible next step | Why an exam matters |
|---|---|---|
| No concerning change | Review or monitor | Frequency is individualized to the tooth and cavity risk |
| Minor roughness or a small surface defect | Polish, reshape or seal a localized area | A dentist checks whether the margin is sound and the defect is limited |
| Localized chip or defect with sound restoration remaining | Consider a repair | Repair may preserve more healthy tooth than replacing the whole restoration |
| Extensive failure, significant decay or fracture | Discuss replacement or another restoration | The amount of remaining tooth may call for an inlay, onlay or crown rather than another small filling |
This is a discussion guide, not a self-diagnosis tool. A dentist decides what is appropriate after assessing the tooth. International FDI criteria likewise describe a range from monitoring and refurbishment to resealing, repair and replacement; replacement is reserved for defects too extensive to reasonably repair.
Frequently asked questions
Can a filling last a lifetime?
Some restorations remain functional for many decades, while others fail earlier. No material or care routine guarantees lifetime service. A dentist can assess whether a particular filling remains sound.
Which filling material lasts the longest?
Gold and amalgam have long track records, and some comparisons find longer survival for amalgam in adult back teeth. But the evidence does not establish one universal winner for every tooth and situation. Size, site, technique and remaining tooth structure matter.
Should I replace a silver filling because it is old?
Not just because of its age or colour. FDA guidance says an intact amalgam without decay beneath it should not be removed solely because it is old. Discuss a specific concern with a dentist.
Can a filling be repaired instead of replaced?
Sometimes. A small, accessible defect may be polished, sealed or repaired while retaining sound parts. Extensive decay, fracture or damage may make replacement more appropriate. The decision requires an examination.
When should I call a dentist?
Contact a dentist promptly for new or persistent pain, a cracked tooth or filling, a loose or lost filling, swelling, or suspected decay around a filling. Seek urgent advice for severe or rapidly worsening symptoms.
Sources and further reading
- Cleveland Clinic: Dental Fillings
- American Dental Association: Materials for Direct Restorations
- Bhagwat et al. (2025): Systematic review of amalgam versus composite in permanent posterior teeth
- Santos et al. (2025): Complex direct posterior composite and amalgam restorations
- FDI revised criteria for evaluating dental restorations
- FDA: Information for Patients About Dental Amalgam Fillings
- NHS: Chipped, broken or cracked tooth
This article provides general information and is not a diagnosis or substitute for dental care. Your dentist can assess your tooth, filling and treatment options.