Cavities happen. Whether it’s from a sweet tooth or missed brushings, most of us will need a filling at some point. But when the time comes, you might hear your dentist ask: Composite or amalgam?
If that question leaves you confused, don’t worry. You’re not alone. Let’s break it down and help you make the best choice for your smile.
What Are Cavity Fillings?
Fillings are used to fix small holes in your teeth caused by decay. The dentist removes the damaged part, then fills the space to stop the problem from getting worse.
Fillings do more than just stop pain—they also help protect the tooth and keep your bite in line.
But when it comes to the material used, there are usually two main options: composite or amalgam.
Composite or Amalgam: What’s the Difference?
Composite Fillings
These are made from a tooth-coloured resin that blends with your natural teeth. Dentists often use them for front teeth or places where looks matter most.
Pros of Composite:
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Natural look – Matches your tooth colour.
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Good for small or mid-size cavities.
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Bonds directly to the tooth, which can help keep more of the healthy tooth in place.
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Quick setting time – usually done in one visit.
Cons of Composite:
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Can be less durable on back teeth under strong pressure.
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May cost more than amalgam.
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Can stain over time, like natural teeth.
Amalgam Fillings
These are made from a mix of metals, including silver, tin, copper, and a small amount of mercury. They’ve been used for over 150 years.
Pros of Amalgam:
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Very strong and long-lasting – great for molars.
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Usually cheaper than composite.
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Can handle heavy chewing forces.
Cons of Amalgam:
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Silver colour stands out, especially on visible teeth.
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Requires more tooth removal in some cases.
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Small amounts of mercury, which raises health concerns for some people.
Is Amalgam Safe?
You may have heard about the mercury in amalgam fillings. Mercury is a toxic metal, so it’s fair to question it.
But here’s what science says:
Amalgam fillings release very small amounts of mercury vapour. Most research shows that, for most people, this amount is too low to cause harm.
However, some groups—like pregnant women, people with mercury allergies, or those with kidney problems—may prefer to avoid it.
If you’re unsure, speak with your dentist. They can help you decide whether composite or amalgam is safer for you.
Cost Comparison: Composite or Amalgam?
Amalgam is often the cheaper option. It’s fast to place and less technique-sensitive.
Composite costs more, but many people feel the natural look is worth the price—especially for teeth that show when you smile.
Prices vary by location, tooth size, and whether you’re treated privately or on the NHS. Some NHS treatments only offer amalgam on back teeth. It’s worth checking your plan before deciding.
Durability: Which Lasts Longer?
Amalgam fillings usually last longer, sometimes up to 15 years or more. They’re tough and wear-resistant.
Composite fillings may last 5–10 years, depending on where they are and how well you look after them.
That said, improvements in dental materials mean newer composites are lasting longer than before—especially when placed by skilled dentists.
When Should You Choose Composite?
Choose composite fillings if:
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The filling is on a visible tooth (like front or side teeth).
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You want a natural, tooth-coloured look.
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You have a metal allergy or mercury concern.
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You’re happy to pay a bit more for appearance.
When Might Amalgam Be Better?
Opt for amalgam fillings if:
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The filling is on a back tooth that does most of the chewing.
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You need a long-lasting, strong option.
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You want a lower-cost solution.
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You’re not concerned about the silver colour.
What If You Already Have Fillings?
If you have existing amalgam fillings that are in good shape, there’s no need to remove them. Taking out a filling can weaken the tooth unless there’s decay or damage.
But if your filling is old, worn, or cracked, you might consider switching to composite—especially on visible teeth.
Always ask your dentist before making a change.
Choosing What’s Right for You
There’s no one-size-fits-all answer. The right filling depends on where the cavity is, how big it is, your budget, and your personal preferences.
When your dentist asks, Composite or amalgam?, you’ll now know what they mean—and how to answer with confidence.
Remember: the best filling is one that restores your tooth, prevents further damage, and fits your lifestyle. Talk it through with your dentist and make an informed choice.