A permanent tooth filling is a restorative material bonded into a cleaned-out cavity to rebuild the tooth’s shape, stop decay, and restore normal biting — but despite the name, it doesn’t last forever.
“Permanent” only separates a lasting restoration from a temporary dressing placed while a tooth heals. It is not a lifetime guarantee; every filling can wear, chip, or pull away and need replacing.
When A Filling Is The Right Fix
A filling works when a cavity or minor chip leaves enough healthy tooth structure to hold it. Dentists remove decayed tissue, shape the cavity, and pack it with material that hardens into a functional surface.
Once damage runs deeper than the hard outer layers, a filling alone won’t work. Decay reaching the pulp (the nerve-containing tissue inside the tooth) requires more: throbbing pain that won’t quit, or sharp sensitivity to heat and cold that lingers after the stimulus is gone, points toward pulp damage and possibly root-canal therapy. Badly broken-down teeth often need a crown; cavities too large for a direct filling but not severe enough for a crown may call for an inlay or onlay.
The Procedure, Step By Step
Most direct fillings finish in one visit. The National Institute of Dental and Craniofacial Research outlines the sequence: the dentist numbs the tooth with local anesthesia, removes decayed tissue, fills the cavity, hardens composite resin with a curing light, polishes the surface, and adjusts the bite so the tooth meets its opposite evenly.
Composite resin is fussier because saliva contamination weakens the bond, so the dentist works to keep the area dry. Mild sensitivity or sore gums for roughly one to two weeks afterward is normal. Pain when biting down usually means the filling sits too high and needs quick reshaping.
Indirect restorations — inlays and onlays of gold, porcelain, or ceramic — are built outside the mouth, often in a lab, and typically need two visits: one for impressions, one for insertion. If you’d rather compare at-home repair kits for small chips before booking, see our tested at-home filling kit roundup.
Materials And What They Cost In The US
Composite resin is a tooth-colored mix of resin and powdered glass, chosen mainly for appearance. Dental amalgam is a silver-colored alloy of mercury, silver, tin, copper, and zinc that holds up well under heavy chewing. Glass ionomer cement suits small cavities but not large ones.
| Restoration | Typical Cash Price | Best For |
|---|---|---|
| Amalgam, two surfaces | $229 | Back teeth under heavy bite force |
| Composite, one surface, front tooth | $199 | Visible repairs where color matters |
| Composite, one surface, back tooth | $217 | Small rear cavities |
| Composite, two surfaces, back tooth | $274 | Moderate rear cavities |
| Composite, three surfaces, back tooth | $333 | Wide rear cavities |
| Two-surface posterior composite (2026 analysis) | $304 average | Mid-size rear cavities; state range $232–$500 |
Those are published averages, not fixed rates. Region, tooth location, surface count, insurance deductibles, and negotiated fees shift the final charge.
The American Dental Association’s amalgam guidance matters before you choose. It strongly recommends precapsulated amalgam alloy because the sealed capsule delivers a more consistent alloy-to-mercury ratio and cuts mercury-vapor leakage and waste. The ADA’s amalgam resource page also notes that existing amalgam in good condition generally should not be removed solely over mercury concerns, since removal itself raises exposure.
Safety Notes And The Mistakes That Cost You
Amalgam is considered safe for most people but releases low levels of mercury vapor during placement and removal. Pregnant or nursing people, young children, people with neurological disease or impaired kidney function, and anyone with a metal sensitivity should avoid new amalgam fillings when possible; composite resin or glass ionomer are the usual alternatives.
- Treating a filling as forever. All restorations can fail and need replacement.
- Ignoring worsening pain. Persistent throbbing or lingering temperature sensitivity can signal pulp injury.
- Skipping the health history. Pregnancy, nursing, kidney disease, neurological disease, and metal allergies belong on the form before material selection.
- Assuming every tooth qualifies. Extensive structural loss may push you toward an inlay, onlay, crown, or root canal.
Expect a follow-up if the bite feels off. A high filling is a common, easily fixed complaint — one adjustment visit usually resolves it.
Common Questions
How long does a permanent filling actually last?
There’s no fixed lifespan; “permanent” only distinguishes the restoration from a temporary dressing. Longevity depends on the material, tooth location, bite force, and oral hygiene. Fillings can wear, chip, or loosen, so regular exams matter more than any expected replacement date.
Is it normal for the tooth to hurt after a filling?
Mild sensitivity or sore gums for about one to two weeks is common and usually settles. Pain when biting down often means the filling sits slightly too high and needs reshaping. Throbbing pain or heat/cold sensitivity that lingers long after the trigger is gone deserves a call to your dentist.
Do I have to get amalgam, or can I choose composite?
Material choice is usually a conversation. Composite resin is tooth-colored and favored for visible teeth; amalgam is durable and often cheaper for back molars. If you’re pregnant or nursing, have impaired kidney function, neurological disease, or a metal sensitivity, tell your dentist so composite or glass ionomer can be considered first.
Sources
- National Institute of Dental and Craniofacial Research. “Dental Fillings” Supports the procedure steps and material descriptions.
- American Dental Association. “Amalgam” Source for amalgam safety guidance and precapsulated alloy recommendation.
- Cleveland Clinic. “Dental Fillings” Supports recovery expectations and when a crown or root canal is needed.