White Fillings vs Amalgam Fillings — What You Should Know
Confused about the difference between white composite fillings and traditional silver amalgam? This guide explains both options honestly — including durability, appearance, safety, and cost.
When a tooth has a cavity (decay) or a broken area that needs restoring, your dentist places a filling to repair it. There are two main materials in common use:
White (composite resin) fillings — tooth-coloured, made from a mixture of plastic and glass particles
Silver amalgam fillings — a durable alloy of mercury combined with silver, tin, and copper
Both materials have been used safely in dentistry for many years. White fillings have become the standard for most cavities, but amalgam has been widely used for over 150 years and remains in many mouths around the world.
Important note: From 1 January 2025, the use of dental amalgam in the UK is restricted to specific clinical circumstances only, following the UK's commitment under the Minamata Convention on Mercury. In most situations, your dentist will now place a white composite filling as standard. This leaflet provides background so you understand what is in your existing fillings and what your options are if any need replacing.
Option 1 — White (composite resin) fillings
Composite resin is a tooth-coloured material made from fine glass particles embedded in a plastic (resin) matrix. It is placed directly into the cavity, shaped, and then hardened using a bright blue curing light. Modern composites can closely match your natural tooth shade.
Benefits:
Natural-looking — closely matches the colour of surrounding tooth enamel
Bonds directly to the tooth surface, which can mean less healthy tooth removal in some cases
Suitable for front and back teeth
Can be repaired if they chip or wear — amalgam fillings cannot
No mercury content
Now the standard filling material in UK practice for most situations
Drawbacks and risks:
Can be more technique-sensitive — moisture control is critical during placement, especially in back teeth
More prone to wear than amalgam in very large cavities under heavy biting pressure
May show slight colour change (staining) over many years, especially with tea, coffee, and red wine
Lifespan of a large composite filling is typically 5–10 years, though smaller fillings often last longer
Placement takes slightly longer than amalgam
Some patients experience temporary sensitivity after placement
Cost: NHS Band 2 (£75.30) covers composite fillings for most teeth. Privately: typically £120–£300 per filling depending on size and tooth location. The exact cost will be confirmed on your individual treatment plan. Fees vary between practices and depend on the complexity of your case.
Option 2 — Amalgam fillings
Dental amalgam is an alloy containing approximately 50% mercury bound with silver, tin, and copper. When mixed and placed, a chemical reaction renders the mercury stable. Amalgam has been used in dentistry since the 1800s.
Benefits:
Extremely durable — well-placed amalgam fillings can last 15–25 years or more
Very strong under heavy biting forces — historically preferred for large cavities in back teeth
Less technique-sensitive — can be placed in slightly moister conditions
Historically less expensive than composite
Drawbacks and risks:
Visible silver colour — not tooth-coloured
Requires slightly more tooth removal to create mechanical retention, as it does not bond to the tooth
Contains mercury — although the mercury in set amalgam is stable and the safety record is well-established, it is now being phased out across the UK and EU for environmental reasons
Cannot be used in children under 15, pregnant women, breastfeeding mothers, or people with kidney problems (per current UK restrictions)
Amalgam can cause a grey discolouration of the surrounding tooth over time
Removal of old amalgam fillings releases mercury vapour — this should only be done with appropriate precautions if clinically necessary, not for cosmetic reasons alone
Cost: Amalgam is no longer routinely available in most UK practices due to the 2025 restrictions. Where it is still placed in specific circumstances, NHS Band 2 pricing applies.
Is amalgam safe? — The facts
This is one of the most common questions patients ask. Here is what the evidence says:
Dental amalgam has a long and well-documented safety record. The small amount of mercury vapour released from set amalgam fillings is generally below levels considered harmful for most healthy adults.
The MHRA (Medicines and Healthcare products Regulatory Agency) and the European Commission have reviewed the evidence extensively. There is no proven link between amalgam fillings and systemic diseases in the general population.
Amalgam is being phased out globally — including in the UK from 2025 — primarily for environmental reasons (mercury is a persistent environmental pollutant), not primarily because of patient safety concerns.
You should not have existing amalgam fillings removed for health reasons unless specifically advised by a clinician. Removing them unnecessarily causes more mercury vapour exposure and destroys tooth structure.
If you have specific concerns about amalgam or a condition that means it should be avoided, discuss this with your dentist.
What if I want to replace my old amalgam fillings?
Many patients want to replace old silver amalgam fillings with tooth-coloured composite for cosmetic reasons. This is possible, but there are important points to consider:
Removing a functioning amalgam filling removes healthy tooth structure and is not recommended purely for cosmetic reasons by most professional guidelines
The procedure exposes you to more mercury vapour during removal than leaving the filling alone — though precautions can minimise this
When amalgam is replaced, the resulting composite filling may not last as long as the amalgam did
If an old amalgam filling is genuinely failing, cracked, leaking, or causing decay — replacing it with composite is entirely appropriate
Some patients choose to replace amalgam fillings gradually as they naturally fail over time, rather than replacing them all at once
If cosmetic improvement is a priority, discuss the options with your dentist. They will give you an honest assessment of which fillings are functioning well and which are genuinely due for replacement.
Questions to ask your dentist
If you are unsure about your existing fillings or are about to have a new filling placed, ask:
What material will you use for my filling, and why?
Are any of my old amalgam fillings failing or due for replacement?
What is the risk of replacing a filling that is currently working well?
How long should a composite filling last for my particular tooth?
If I want to replace an amalgam filling for cosmetic reasons, what would that involve?
Is there anything about my diet or habits that might reduce the lifespan of my fillings?
NHS charges are set nationally and reviewed annually. Private fees are a guide — your dentist will confirm the exact cost on your treatment plan before you agree to proceed. NHS availability varies by area and not all treatments are available on the NHS. Your dentist will discuss the best option for your specific case.
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. Your dentist will confirm what is suitable for your specific circumstances before you agree to any treatment.
References
Aligned with guidance from: FGDP(UK), SDCEP, MHRA, Minamata Convention on Mercury.