Composite (white) vs amalgam (silver) fillings: which is better?

If you need a filling today, you will almost certainly be offered a tooth-coloured composite (حشو تجميلي / حشو أبيض). Many people still have older silver amalgam fillings and wonder whether they are harmful or should be swapped. This page compares the two honestly, explains the mercury question, and describes when a filling is not enough.

What each filling is made of

Composite resin is a mixture of plastic resin and fine glass or ceramic particles. It is placed in layers, shaped, and hardened with a blue curing light. It bonds to the tooth using an adhesive.

Amalgam is an alloy of silver, tin, copper and liquid mercury. Once mixed and set, the mercury is bound in a stable alloy. Amalgam does not bond to the tooth; the dentist shapes the cavity so the filling locks in mechanically.

Side-by-side comparison

Are amalgam fillings dangerous?

Amalgam releases very small amounts of mercury vapour, especially when chewing or grinding. For most adults, major health authorities have found no clear evidence that intact amalgam fillings cause illness. However, the US Food and Drug Administration recommends that certain higher-risk groups avoid new amalgam fillings where appropriate, including pregnant and breastfeeding women, young children, people with kidney problems and people with a known mercury allergy (FDA: dental amalgam fillings).

Separately, the international Minamata Convention on Mercury has led many countries to phase down amalgam use, mainly to reduce mercury pollution in the environment. That is a major reason white fillings have become the default in modern practice.

Should I replace my old silver fillings?

Not automatically. Removing a sound amalgam filling means drilling, which releases more vapour during removal and removes some healthy tooth too. Replacement is reasonable when:

• There is decay under or around the filling.
• The filling is cracked, leaking or breaking down.
• The tooth next to it is cracked, or the cusps look weakened.
• You have a confirmed allergy to a component.
• You want a cosmetic change for a visible tooth, and understand the trade-off.

When old fillings are replaced, we use suction and isolation to limit exposure, and we check whether the remaining tooth is strong enough for a filling or would be better protected by an onlay or crown.

When a filling is not enough

Fillings work well for small and medium cavities. When a large part of a tooth is missing, especially in back teeth, a big filling can flex and the tooth can crack. In those cases an onlay or crown may last longer and protect the tooth better. See zirconia vs E.max crowns or our crowns and bridges page. If decay has reached the nerve, root canal treatment may be needed first.

How long do fillings last?

Both materials can last many years. Composite fillings commonly last around 7 to 10 years or more, and amalgam often lasts longer in large back fillings. Lifespan depends far more on your risk of decay, the size of the filling, grinding habits and hygiene than on the material alone. Small composite fillings in low-risk patients can last a very long time.

Who may not be ideal for composite fillings

• Very deep cavities below the gum line where the area cannot be kept dry; other materials such as glass ionomer may be used, at least temporarily.
• Very large restorations in heavy grinders, where an onlay or crown may be wiser.
• Patients at very high decay risk, who may benefit first from fluoride-releasing materials while the cause is brought under control.

Other filling materials you may hear about

Glass ionomer fillings release fluoride and tolerate moisture, which makes them useful near the gum line, in baby teeth and as temporary or intermediate fillings, though they are less wear-resistant. Ceramic inlays and onlays are made in a laboratory or milled digitally and bonded in place; they suit larger cavities where a direct filling would be weak. Your dentist should explain why a particular material is suggested for each tooth.

What happens at El Nabi

At our clinic in Maadi, we use tooth-coloured fillings for routine treatment. We examine the tooth, take an X-ray where needed to see the depth of decay, numb the area, remove decay conservatively, and build the filling in layers to match your tooth shape and shade. We then check your bite so the filling does not feel high. If a tooth is too weak for a filling, we will explain why and discuss the options. Fillings are part of our general dentistry services.

Fillings during pregnancy

Treating decay during pregnancy is generally considered safe and often advisable, typically in the second trimester. New amalgam fillings are usually avoided in pregnancy where a suitable alternative exists. See dental treatment during pregnancy.

Preventing the next filling

• Brush twice daily with fluoride toothpaste and clean between teeth.
• Reduce how often you snack on sugar or sip sweet drinks.
• Keep regular check-ups so small cavities are found early.

When to see a dentist

See a dentist if you notice a dark spot or hole, food catching between teeth, sensitivity to sweet or cold, a broken or rough filling, or pain when biting. Early decay is usually simpler to treat. You can message us on WhatsApp to book an examination.