A white filling (also called a composite or tooth-coloured filling) is a restoration used to repair a tooth damaged by decay, a crack, or a chip. The filling material is a mixture of resin and fine glass particles that can be closely matched to the natural colour of your tooth.
White fillings are the most commonly placed filling material in the UK today. They bond directly to the tooth, which means less healthy tooth structure needs to be removed compared to older metal (amalgam) fillings in many cases.
Why might I need a filling?
A filling is needed when:
Tooth decay (a cavity) has damaged part of the tooth and must be removed
A tooth has chipped or fractured
An existing filling has broken down or is leaking and needs replacing
There is surface wear from grinding or acid erosion that needs to be restored
If decay is not treated, it will grow larger over time. Eventually it may reach the nerve of the tooth, causing pain and requiring root canal treatment or extraction. Early treatment is nearly always simpler and less expensive.
What does the procedure involve?
Having a white filling is straightforward:
Anaesthetic — the tooth is numbed with a local anaesthetic injection. The area will feel numb for 1–3 hours afterwards.
Removing decay — the decayed or damaged tooth tissue is removed using a small drill. You will feel pressure and vibration but not pain.
Preparing the cavity — the remaining tooth is cleaned and conditioned to help the filling bond securely.
Placing the filling — composite resin is placed in layers and each layer is hardened with a curing light.
Shaping and polishing — the filling is trimmed to fit your bite precisely and polished for a smooth finish.
A routine filling appointment takes 30–60 minutes. Larger or more complex fillings may take longer.
Risks and possible complications
Common:
Sensitivity to hot, cold, and sweet for a few days to a few weeks after placement — this usually settles. Sensitivity toothpaste can help.
Slight discomfort when biting if the filling is a little high — this is easily corrected at a review visit
Uncommon:
If the decay was very deep and close to the nerve, the tooth may develop pulp inflammation that requires root canal treatment even after the filling is placed. Your dentist will discuss this risk before treatment if it applies to your tooth.
The filling may fracture or come loose over time, particularly in large fillings under heavy biting forces
Rare:
An allergic reaction to the filling materials (very uncommon)
White fillings in back teeth can be less durable than amalgam for very large restorations. Your dentist will advise on the most appropriate option for your specific situation.
How long do white fillings last?
With good care, white fillings typically last 7–10 years, though many last longer. Factors that affect lifespan include:
The size and location of the filling — large fillings in back teeth are under greater stress
Teeth grinding — places heavy force on fillings and can cause fractures
Diet and oral hygiene — sugar and plaque around the margins of a filling cause recurrent decay
Questions to ask your dentist
How large is the cavity, and how deep does the decay go?
Is there any risk this tooth might need root canal treatment?
Would an inlay or onlay be more suitable than a direct filling?
How can I prevent getting another cavity in this area?
This leaflet is for general information only and does not replace professional dental advice. It is intended to support — not replace — the discussion with your dentist about your individual options, risks, and treatment plan. Treatment outcomes vary between patients depending on individual circumstances. Your dentist will confirm exact fees and what is suitable for your specific circumstances before you agree to any treatment.
References
Aligned with guidance from: SDCEP, FGDP(UK), NICE.