A dental filling is not permanent. Every filling has a lifespan, and knowing what to expect helps you plan financially and avoid surprises at your next check-up.
The answer to "how long do fillings last" depends on the material, the size of the filling, where it is in your mouth, and how you look after your teeth. This guide covers the practical details.
Average lifespan by filling type
Different filling materials have different expected lifespans. These are general ranges based on clinical research. Individual results vary depending on the factors covered below.
Filling material | Typical lifespan | Notes |
|---|---|---|
Composite resin (tooth-coloured) | 5 to 10 years | Most common for visible teeth. Bonds directly to tooth structure. |
Amalgam (silver) | 10 to 15 years | Durable under heavy chewing force. Less commonly placed now due to aesthetics. |
Glass ionomer | 3 to 5 years | Releases fluoride. Often used for baby teeth or low-stress areas. |
Ceramic inlay/onlay | 10 to 20 years | Lab-made. Stronger and more stain-resistant than composite. Higher cost. |
Gold inlay/onlay | 15 to 25+ years | Extremely durable. Rarely chosen now due to appearance and cost. |
These numbers represent typical ranges. A well-placed composite filling in a small cavity with good oral hygiene may last well beyond 10 years. A large filling under heavy bite force may fail sooner.
What affects how long a filling lasts
Several factors determine whether your filling sits closer to the short end or the long end of its expected lifespan.
Size of the filling. Larger fillings are under more stress and have more surface area where the seal between filling and tooth can break down. A small filling replacing a minor cavity will generally outlast a large filling that replaces a significant portion of the tooth.
Location in the mouth. Back teeth (molars and premolars) handle the majority of chewing force. Fillings on these teeth take more punishment than fillings on front teeth. Composite fillings on molars tend to have shorter lifespans than the same material on incisors.
Your bite and grinding habits. If you grind your teeth at night, fillings wear down faster. The repeated force can crack composite or loosen the bond between filling and tooth. A night guard can protect both your teeth and your restorations.
Oral hygiene. Fillings do not get cavities, but the tooth around them can. If bacteria reach the margin where filling meets tooth, new decay can develop underneath. This is one of the most common reasons fillings need replacing. Consistent brushing, flossing, and regular professional cleaning protect the tooth structure around your fillings.
Diet. Frequent consumption of sugary or acidic foods increases the risk of decay around filling margins. Hard foods like ice, unpopped popcorn kernels, and hard lollies can chip or crack fillings.
How fillings fail
Fillings do not just fall out one day without warning. Failure usually develops gradually. Understanding how fillings fail helps you recognise problems early.
Marginal breakdown. Over time, the seal between filling and tooth can deteriorate. Bacteria and saliva seep into the gap, causing decay underneath the filling. This is called secondary or recurrent caries. You may not feel it until it becomes significant.
Fracture. Composite and amalgam can crack under repeated stress. A cracked filling may still feel fine initially but allows bacteria access to the tooth underneath.
Wear. Chewing gradually wears down filling material, changing the shape of the biting surface. This can alter your bite and put uneven pressure on adjacent teeth.
Debonding. Composite fillings rely on a chemical bond to the tooth. If that bond weakens, the filling can loosen or detach. This is more common with larger composite restorations.
Your dentist checks for all of these at your routine dental check-up. Catching a failing filling early often means a simpler, less expensive replacement.
When should you replace a filling
Not every old filling needs replacing. Age alone is not a reason to remove a well-functioning restoration. The key indicators are:
- Visible crack or chip in the filling material
- New decay detected on an x-ray around the filling margin
- Sensitivity that was not there before, particularly to sweet, hot, or cold
- Rough or catching edge that was not present previously
- Discolouration or dark line around the filling border (may indicate leakage)
- Food trapping around the filling that did not occur before
If your dentist recommends replacing a filling, ask what the findings are and what will happen if you wait. In most cases, earlier replacement means a smaller restoration. Waiting can mean the cavity grows and a crown becomes necessary instead.
Protecting your fillings to make them last
You cannot make a filling last forever. But you can push it toward the longer end of its expected lifespan.
Brush twice daily with fluoride toothpaste. Pay attention to the gum line around filled teeth.
Floss daily. Fillings between teeth are particularly vulnerable to decay at the margins. Flossing removes the plaque that brushing misses.
Attend regular check-ups. Six-monthly examinations allow your dentist to monitor filling integrity and catch early signs of failure.
Wear a night guard if you grind. Bruxism is one of the common causes of premature filling failure. A custom-fitted guard protects both your fillings and your natural teeth.
Watch what you bite. Avoid chewing ice, hard sweets, pens, and other objects that put sudden force on filled teeth.
At Ivy Dental in Everton Park and Nundah, we monitor your existing fillings at every check-up and will let you know if anything needs attention. We use high-resolution digital x-rays and intraoral photography so you can see exactly what we see.
If you have old fillings that have not been checked in a while, book a check-up at Ivy Dental. Call (07) 3266 7120 or visit us at Everton Park or Nundah. Open 7 days.
