For most cavities today, tooth-coloured (composite) fillings are the better choice. They match your teeth, bond to the enamel, and need less healthy tooth removed, while silver (amalgam) fillings are still strong and long-lasting in large back-tooth cavities. Both are safe and approved for use in Canada. Cavities are common and very treatable when caught early, and at Richmond Hill Smile Centre we pick the material based on the size, location and bite force of each tooth.
People usually ask this question for 2 reasons. Either an old silver filling is cracked or looks dark, or a new cavity just showed up on an X-ray during a dental hygiene visit. In both cases, the answer depends on the tooth, not just the material.
Large cavities change the conversation. When more than half of a tooth is gone, neither filling type is ideal, and crowns and bridges protect what’s left far better.
If decay has already reached the nerve, the filling question becomes secondary. A root canal clears the infection first. For children, tooth-coloured fillings and sealants are the standard in children’s dentistry, since kids’ teeth are smaller and look better with natural shades.
Quick answer: Tooth-coloured composite fillings look natural, bond to the tooth, and preserve more healthy structure, which makes them the first choice for most small and medium cavities. Silver amalgam fillings are durable and still useful for large back-tooth fillings. Both materials are considered safe by Health Canada for most people.
What are the 2 main types of fillings?
Composite (tooth-coloured) fillings
A composite filling is a mix of plastic resin and fine glass or ceramic particles. It’s placed soft, shaped to the tooth, and hardened with a blue curing light. Because it bonds to enamel and dentin, it seals the edges and supports the tooth.
Amalgam (silver) fillings
Amalgam is a blend of silver, tin and copper bound with mercury. It’s been used for over 150 years. It’s packed into the cavity and hardens on its own. Amalgam doesn’t bond to the tooth, so the dentist shapes the cavity with undercuts to lock the filling in place.
Side-by-side comparison
| Factor | Composite (tooth-coloured) | Amalgam (silver) |
|---|---|---|
| Appearance | Matches natural teeth | Silver, darkens over time |
| How it attaches | Bonds chemically to the tooth | Held in mechanically |
| Tooth removed | Less, mostly just the decay | More, to create retention |
| Strength on back teeth | Good for small to medium fillings | Excellent for large fillings |
| Typical lifespan | About 7 to 10 years, often longer | About 10 to 15 years, often longer |
| Sensitivity after placement | Mild sensitivity for a few days is possible | Can be sensitive to cold at first |
| Placement in a wet area | Needs a dry field | More forgiving with moisture |
| Expansion and cracking | Very little | Can expand slightly and contribute to cracks over decades |
| Repairable | Yes, can be patched | Usually replaced |
Are silver fillings safe?
This is the biggest worry people bring in. Amalgam contains mercury, but it’s bound in a stable alloy. Health Canada’s position is that amalgam fillings don’t pose a health risk for the general population, though it recommends avoiding new amalgam for pregnant people, children and those with kidney problems when another material is suitable.
The more practical point is this: removing healthy amalgam fillings that aren’t broken or leaking is usually unnecessary. Drilling them out releases more vapour than leaving them alone, and it removes extra tooth structure.
When old silver fillings should be replaced
- The filling is cracked or chipped
- Decay is forming under or around the edge
- The tooth has a crack line running from the filling
- The filling is large and the tooth is weakening
- There’s ongoing sensitivity or pain
When it’s fine to leave them
- The filling is intact with tight edges
- X-rays show no decay underneath
- The tooth has no cracks or symptoms
Myths about fillings and pain
“Getting a filling always hurts”
Local anesthetic numbs the tooth completely. Most people feel pressure and vibration rather than pain. Topical gel before the injection makes even that part more comfortable.
“Tooth-coloured fillings don’t last”
Modern composites are much stronger than early versions. With good home care and a balanced bite, they often last well beyond 10 years.
“Replacing all silver fillings will improve my health”
There’s no good evidence that replacing intact amalgam fillings improves general health. Replacement makes sense when a filling is failing or for cosmetic reasons you choose with your dentist.
“If a cavity doesn’t hurt, it can wait”
Most cavities don’t hurt until they’re deep. Waiting turns a small filling into a large one, a crown, or a root canal.
Safety note: If you have a known mercury allergy, kidney disease, or you’re pregnant or breastfeeding, tell your dentist before any filling work. If you have swelling, a throbbing tooth or a bad taste, see a dentist promptly, as these can point to infection. This article is general information and doesn’t replace an exam.
What happens during a filling appointment?
Here’s what to expect with a tooth-coloured filling.
- Exam and X-ray. Your dentist confirms the size and depth of the cavity.
- Numbing. Topical gel, then local anesthetic.
- Isolation. The tooth is kept dry with cotton rolls or a thin rubber sheet called a dental dam.
- Removing decay. Only the soft, damaged structure is removed.
- Bonding. A mild conditioner and bonding agent prepare the tooth surface.
- Layering the composite. The material goes in in thin layers, each hardened with a curing light.
- Shaping and polishing. The filling is shaped to your bite and polished smooth.
- Bite check. You bite on thin paper so any high spots can be adjusted.
Most single fillings take 30 to 60 minutes. You can eat once the numbness wears off.
Fillings vs inlays, onlays and crowns
Fillings work best when a cavity is small to medium. When a lot of tooth is missing, other restorations protect it better.
| Restoration | When it’s used | Coverage |
|---|---|---|
| Filling | Small to medium cavities | Fills the hole only |
| Inlay | Larger cavity inside the cusps | Custom piece made outside the mouth |
| Onlay | Damage that includes one or more cusps | Covers part of the chewing surface |
| Crown | Very large damage, cracks, after root canal on back teeth | Covers the whole tooth |
A cosmetic dentist in Richmond Hill will often suggest an onlay instead of a giant filling. It’s stronger and preserves more of the tooth than a full crown.
How long do fillings last, and how to make them last longer?
Lifespan depends more on habits than on material. These steps make a big difference:
- Brush twice a day with fluoride toothpaste
- Floss daily, since many fillings fail at the contact between teeth
- Cut back on frequent snacking and sweet drinks
- Wear a night guard if you grind or clench
- Avoid chewing ice, pens or hard candy
- Keep regular cleanings and checkups so small problems are caught early
Choosing a dentist for fillings
Good fillings depend on careful technique: proper isolation, precise layering and a well-checked bite. Look for a clinic that shows you your X-rays, explains the options, and doesn’t push replacing fillings that are working fine.
Richmond Hill Smile Centre is one of the best dental clinics in Richmond Hill for patients who want honest, conservative care. The team is made up of licensed dental professionals who follow Ontario’s standards for diagnosis, materials and infection control.
The office is at 10157 Yonge St Unit 101, Richmond Hill, ON L4C 1T6. You can email info@richmondhillsmilecentre.ca to ask about replacing old fillings or to book a checkup. If you’re looking for a top dentist in Richmond Hill who explains choices clearly, a quick exam and a set of bitewing X-rays is the best first step.
A real example
A patient in her 50s wanted all 6 of her old silver fillings replaced for cosmetic reasons. X-rays showed 4 were sound and 2 had decay at the edges. She replaced the 2 failing ones with tooth-coloured fillings first, then chose to replace the visible upper ones later for appearance. The 2 lower back fillings, hidden and healthy, stayed. It was a slower plan, but it kept more of her natural tooth.
What about other filling materials?
Composite and amalgam cover most fillings, but they aren’t the only options. Here’s a quick look at the others you might hear about.
Glass ionomer
Glass ionomer is a tooth-coloured material that releases fluoride over time. It’s softer than composite, so it’s used mostly for small fillings near the gumline, root surfaces in older adults, and baby teeth. It’s also handy when keeping a tooth completely dry is hard.
Ceramic (porcelain) inlays and onlays
These are made in a lab or with in-office milling, then bonded into the tooth. They’re very strong, resist stain well, and can last 15 years or more. They take 2 visits in many offices, or 1 with same-day milling.
Gold
Gold inlays and onlays are rarely used today, mostly because of appearance. They are still among the longest-lasting restorations and are very gentle on opposing teeth.
| Material | Look | Durability | Common use |
|---|---|---|---|
| Composite | Natural | Good | Most fillings, front and back |
| Amalgam | Silver | Very good | Large back fillings |
| Glass ionomer | Tooth-coloured, less glossy | Moderate | Gumline, root surfaces, baby teeth |
| Ceramic | Natural, very glossy | Excellent | Larger back-tooth restorations |
| Gold | Gold | Excellent | Heavy-bite areas, rare today |
How to spot a cavity early
Early cavities rarely hurt, so it helps to know the quieter signs. Book a checkup if you notice any of these:
- A brief zing with cold, sweet or sour foods
- Floss that shreds or catches in the same spot
- Food getting packed between 2 teeth after every meal
- A chalky white or brown spot on the tooth surface
- A rough edge you can feel with your tongue
- A dark line around an old filling
Why X-rays matter
Many cavities start between teeth where nobody can see them, not even your dentist with a mirror. Bitewing X-rays catch these early, when a small filling is enough. Most adults need them every 1 to 2 years, depending on cavity risk.
Who’s at higher risk?
- People with dry mouth from medications
- Frequent snackers and sippers of sweet or acidic drinks
- People with gum recession and exposed roots
- Anyone wearing braces or aligners who isn’t cleaning carefully
- Children and teens, whose enamel is still maturing
If you fall in one of these groups, ask about fluoride varnish and prescription-strength fluoride toothpaste. Both reduce new cavities.
Do insurance plans cover tooth-coloured fillings?
Coverage varies. Some plans pay for tooth-coloured fillings on all teeth. Others only cover the cost of an amalgam on back teeth and leave the difference to you. The CDCP and private plans each have their own rules, so it’s worth asking the front desk to check your coverage before treatment.
Frequently asked questions
Are tooth-coloured fillings as strong as silver fillings?
For small and medium cavities, yes. For very large fillings on heavy-chewing back teeth, amalgam or an onlay or crown may last longer.
Should I replace my silver fillings with white ones?
Only if they’re cracked, leaking, decayed underneath, or you want to change them for appearance. Healthy amalgam fillings can usually stay.
Do composite fillings stain?
The surface can pick up some stain from coffee, tea or red wine over time. Regular polishing at cleanings keeps them looking fresh.
Is it normal for a new filling to feel sensitive?
Mild sensitivity to cold or biting for a few days to 2 weeks is common. If it lasts longer or gets worse, see your dentist for a bite check.
Can children get tooth-coloured fillings?
Yes. Composite fillings are commonly used for children because they bond well, look natural and need less drilling.
Conclusion
Tooth-coloured fillings are the first choice for most small and medium cavities today.
Silver fillings are still safe and strong, and intact ones usually don’t need replacing.
The best filling depends on the tooth, so an exam and X-rays guide the right decision.
