Daily Care
Are white fillings as strong as metal ones?
22 July 2026 · The Dentist, Al Qusais, Dubai
The short answer
For small to medium cavities, modern white composite fillings are strong enough to last just as long as metal amalgam ones, often 7 to 10 years or more with good care. Amalgam still has a slight edge in very large fillings on back molars that take heavy chewing force, because it doesn't rely on a bonded seal to stay put. The right choice depends on the size and location of the cavity, not just which material sounds stronger, so it's genuinely a case-by-case decision your dentist should walk you through.
What each material actually does under pressure
Metal amalgam is a mix of mercury, silver, tin and copper that sets rock hard and has been used for over a century. It doesn't bond to the tooth, it's held in place by the shape of the cavity itself, a bit like a plug wedged into a hole. That makes it very good at resisting the crushing force of chewing, especially in molars where you generate the most bite pressure.
Composite resin, the white filling material, is a blend of plastic and fine glass or ceramic particles. It's bonded directly to the tooth using an adhesive and cured with a light. Bonding means it can support thinner sections of remaining tooth structure that amalgam can't, because it's chemically fused rather than just wedged in. The trade-off is that composite is more sensitive to technique. If moisture gets into the site during placement, or the bond isn't done carefully, it can fail sooner than it should.
Where the size of the filling matters more than the material
For small to medium cavities, the strength difference between the two materials is not something you'd notice day to day. Composite fillings placed correctly on a molar with a moderate cavity routinely last 7 to 10 years, similar to amalgam, and many patients get well beyond that. Wear patterns, grinding habits and how well you keep up with checkups affect the lifespan far more than the material choice at this scale.
The picture changes with very large fillings, particularly ones that replace most of the chewing surface on a back tooth. Here amalgam has a genuine mechanical advantage, since it doesn't depend on a bonded interface holding under repeated heavy load. In these bigger cases, a lot of dentists now reach for a ceramic or composite inlay, or a crown, rather than either plain filling material, because once a cavity is that large, the tooth itself needs more support than a filling of any kind can give it.
One more practical point: composite fillings shrink very slightly as they cure, which can occasionally create a tiny gap at the edge if the cavity is deep. This is a known and manageable issue, not a reason to avoid composite, but it's part of why placement technique matters as much as the material.
What this means for your next filling
If you're mainly asking because you want fillings that match your tooth colour, the honest answer is that composite is the right call for the vast majority of cavities, front or back, and you won't be trading away meaningful strength to get it. If you have an old, large amalgam filling that's cracked or leaking, that's a different conversation, and it usually needs an exam with an x-ray to see how much sound tooth is left underneath before deciding between a new filling, an inlay or a crown.
At The Dentist in Al Qusais, the first checkup is free for new patients, which is a good time to get a straight opinion on whether a cavity needs a simple composite filling or something more structural. Dr. Faris Alkhanafseh and Dr. Mohammad Nour will look at the size and position of the cavity and give you a written recommendation and price before anything is done. If a filling has been bothering you or you can see a crack forming around an old one, book a visit rather than waiting for it to get worse, call or WhatsApp 056 349 8888.
This article is general information, not a diagnosis. If you are in Dubai, the free first checkup at our Al Qusais clinic is the fastest way to get an answer about your own teeth.