White (composite) fillings: how they differ from amalgam and how long they last
A white filling is made from tooth-coloured composite resin and bonded to the tooth. Compared with amalgam (silver) fillings it looks better and allows less healthy tooth to be removed; done well, it lasts for many years.
When is a filling needed?
- When decay has reached the dentine beneath the enamel
- For small chips and cracks
- To replace old fillings with broken margins or decay underneath
- For wear at the neck of the tooth due to gum recession
Early enamel decay can sometimes be halted without a filling, with fluoride and good care. That's why early diagnosis matters.
White fillings versus amalgam
| Feature | Composite (white) filling | Amalgam filling |
|---|---|---|
| Appearance | Tooth-coloured | Silver-grey |
| Attachment | Bonded (adhesive) | Mechanical retention; more tooth removed |
| Preserving healthy tooth | Better | Less |
| Technique sensitivity | Needs a dry field and precision | More forgiving |
| Current use | Widely preferred | Use is declining |
Should I replace my old amalgam fillings?
Sound amalgam fillings with intact margins and no decay underneath don't always need replacing simply because they're amalgam; removing them can also remove healthy tooth. Replacement is planned if there's a fracture, crack, leaking margin or decay, or for cosmetic reasons.
What if the cavity is large?
If much of the tooth is lost, a direct filling may not support it well enough. A laboratory-made inlay or onlay, or a full crown, is then considered. If decay has reached the nerve, root canal treatment may be needed first. See types of dental crowns for options.
Sensitivity and care after a filling
Especially after deep fillings, sensitivity to cold can last a few days to a few weeks. If the tooth hits first when you bite, the filling may be high; a quick adjustment fixes it. Spontaneous, lingering pain may mean the nerve is affected and needs checking.
- You can eat straight after a composite filling (once the numbness wears off).
- Flossing matters to stop decay at the filling margins.
- Six-monthly check-ups catch small problems early.
Frequently asked questions
How long do white fillings last?
Depending on size, position and oral hygiene, they usually last many years. Large fillings and grinding can shorten their life.
Will I feel pain during a filling?
Local anaesthetic is used when needed, so no pain is expected. Small, shallow cavities may not need anaesthetic.
Do white fillings change colour?
Slight surface staining can occur over time and is mostly removed by polishing. Darkening at the margins can signal leakage and should be checked.
When can I eat after a filling?
Composite is hardened with a light, so you can eat straight away. If you had anaesthetic, wait for the numbness to wear off so you don't bite your tongue or cheek.
