White Fillings vs Amalgam: Why Amalgam Is Being Phased Out

This is not really a comparison any more

Search for “white fillings vs amalgam” and you will find a lot of pages weighing the two options as though you had a choice to make. In practice, in 2026, you mostly do not. Amalgam is in structured global decline, the great majority of clinics have stopped placing it, and a patient walking in with a cavity today will be offered composite.

So the useful question is not which is better. It is: why did the profession move away from a material that lasted a long time, what replaced it, and what should you do about the amalgam fillings already in your mouth?

Why amalgam is disappearing

The mercury question

Amalgam is roughly half mercury by weight, bound into an alloy with silver, tin and copper. The principal driver of the phase-out is not patient safety in the mouth — major health authorities have repeatedly found amalgam fillings safe for the general population — but environmental mercury.

Mercury from dental practices enters wastewater during placement and removal, and enters the air through cremation. An international treaty on mercury, to which Malaysia is a party, has committed countries to phasing down and progressively phasing out dental amalgam as part of a broader reduction in mercury use. That is a policy trajectory, and it is the main reason the material is going away.

There are precautionary restrictions on top of this. Amalgam is generally avoided in children, in pregnancy, and while breastfeeding.

The dentistry moved on independently

Even without the treaty, amalgam was losing ground on technical grounds. It has one fundamental limitation: it does not bond to the tooth. It is held in place mechanically, which means the cavity has to be cut with undercuts and a specific shape to lock the filling in.

The practical consequence is that healthy tooth structure had to be removed purely to retain the filling. On a small cavity, a surprising proportion of what was drilled away was sound tooth sacrificed to geometry rather than to decay.

What composite does that amalgam could not

• It bonds to the tooth. An adhesive layer locks the resin to enamel and dentine, so retention comes from the bond rather than from the shape of the cavity.
• It preserves healthy tooth. We remove the decay and very little else. Over a lifetime of restorations and replacements, that conservation compounds.
• It seals the margin. A well-bonded restoration resists bacteria re-entering at the join, provided it was placed in a dry field.
• It matches the tooth. Shaded to the surrounding enamel and effectively invisible.
• It reinforces rather than wedges. Amalgam expands and contracts with temperature and, over many years, can act like a wedge splitting the remaining walls of the tooth apart. Bonded composite does not work that way.

The trade-off is that composite is far more technique-sensitive. Amalgam was forgiving of a damp field; composite is not. This is precisely why we place every filling under rubber dam isolation, as explained in our guide to dental fillings in Puchong. A composite placed in a contaminated field will not perform as it should, and a great deal of the reputation composite once had for “not lasting” traces back to moisture control rather than to the material.

Should you replace the amalgam fillings you already have?

This is the question patients most often want answered, and the honest answer is usually no.

A sound amalgam filling that is not decayed underneath, has no gap at its margin, and is not causing symptoms should generally be left alone. Removing it means drilling away the filling and inevitably some tooth structure with it, and the replacement restoration will itself need replacing one day. Every replacement cycle costs tooth. There is no health benefit to routinely removing intact amalgam fillings, and the point of highest mercury exposure is during removal, not while it sits in place.

There are genuine reasons to replace one:

• Decay has restarted underneath or at the margin.
• The filling is fractured, or a cusp of the tooth around it has cracked.
• There is a visible gap between filling and tooth.
• The tooth is symptomatic — sensitive to biting, or to cold in a way that lingers.
• You want it changed for appearance, and you understand the trade-off.

That last one is a legitimate reason. But it should be a decision you make knowingly, not one presented to you as clinically necessary when it is not.

What replacement actually involves

If a specific amalgam does need replacing, the appointment runs like any other filling: local anaesthesia, rubber dam isolation — which here also serves to contain the old material as it is sectioned out — high-volume suction, then removal of any decay found underneath.

What is found underneath is the part that varies. Sometimes the tooth is sound and a straightforward composite goes in. Sometimes the decay is deeper than the X-ray suggested, and occasionally there is too little tooth left for a filling at all, in which case an onlay or crown is the right answer. We will tell you the possibilities before starting rather than surprising you halfway through.

Where this leaves you

If you need a new filling, it will be composite, and the thing that determines how long it lasts is how carefully it is placed. If you have old amalgams, have them monitored at your check-ups and replaced when there is a clinical reason — not on a schedule and not on principle. Our guide to protecting teeth from decay covers keeping the ones you have out of trouble in the first place.

This article is for general information and does not replace an in-person dental examination. Treatment options and costs depend on your individual condition and can only be confirmed after a clinical assessment.