Should You Replace Old Silver Fillings?
No, you don’t need to replace silver fillings just because they’re old, as long as they’re intact and the tooth around them is healthy. Health Canada and the Canadian Dental Association don’t recommend removing sound amalgam fillings, since drilling them out removes healthy tooth structure and briefly releases more mercury vapour. Replacement makes sense when a filling is cracked, leaking, has decay underneath, or the tooth itself is fracturing, and our restorative care team can check each one at your next exam.
If you’ve read worrying things online about mercury, you’re not alone. It’s one of the most common questions we get, especially from people in their 40s, 50s, and 60s with a mouth full of fillings from childhood. The honest answer is reassuring for most people, with a few exceptions I’ll explain below. If you’d like your fillings looked at, you can book an appointment online.
Old fillings do fail eventually, though. When a large amalgam cracks the tooth around it, you may suddenly feel sharp pain or lose a chunk of tooth while eating. That’s a situation for our dental emergency in Tillsonburg care, ideally the same day.
Replacement options range from white composite fillings to porcelain onlays and crowns, and you can see the full list on our all dentistry services page. Want to know who’ll be looking after you? You can meet our doctors before your visit, and the team will walk you through what they see on your X-rays in plain language.
Replace a silver filling when
- It’s cracked, chipped, or has a gap at the edge
- There’s new decay around or under it
- The tooth next to it has a crack line or broken cusp
- It’s causing pain or sensitivity when you bite
- You have a confirmed allergy to amalgam components (rare)
What are silver fillings made of?
“Silver” fillings are dental amalgam, a mix of about 50% liquid mercury bound with a powder of silver, tin, and copper. Once mixed, the mercury is chemically locked into a hard, stable alloy.
Amalgam has been used for more than 150 years. It’s strong, long-lasting, and tolerates moisture well, which is why it was the standard filling material for most of the 20th century. Many amalgam fillings last 15 to 25 years or longer.
Are silver fillings dangerous?
For most people, no. Amalgam releases very small amounts of mercury vapour, mostly when chewing or grinding. Health Canada, the World Health Organization, and the US Food and Drug Administration have all reviewed the research and concluded that amalgam fillings aren’t harmful for the general population.
Regulators have become more cautious with certain groups, though. In 2020, the FDA recommended avoiding new amalgam fillings, when other materials are suitable, for people at higher risk:
- Pregnant women and people planning pregnancy
- Nursing mothers
- Children under 6
- People with kidney problems or certain neurological conditions
- People with a known mercury allergy
The same guidance said people with existing amalgam fillings in good condition should not have them removed, because removal itself can raise exposure. Health Canada has given similar advice for years.
Many countries are also phasing down amalgam for environmental reasons, since dental mercury can end up in wastewater. The European Union stopped most amalgam use in 2025. That decision was about protecting waterways and soil.
What are the signs an old filling is failing?
- Sensitivity to cold, hot, or sweets in a filled tooth
- Pain when you bite down or release your bite
- A dark line or shadow around the filling’s edge
- Food catching next to the filling
- A rough or sharp edge your tongue keeps finding
- Visible crack lines in the tooth around the filling
- A piece of tooth breaking off
Some failing fillings cause no symptoms at all, which is why checkups and bitewing X-rays matter. Decay under a filling often shows up on an X-ray long before it hurts.
Why do old amalgam fillings crack teeth?
Amalgam expands and contracts with temperature a bit differently from tooth enamel. Over decades of hot coffee and cold drinks, that small movement, plus the wedge-like shape of large fillings, can create cracks in the surrounding tooth.
Large amalgams placed in the 1970s and 1980s often needed more tooth removal than modern fillings. That leaves thin walls of tooth that are more likely to break.
How does a dentist decide which fillings to replace?
A careful dentist looks at each filling individually, the way a mechanic checks each tire instead of replacing all 4 because the car is old.
- Visual check: are the edges smooth and sealed, or ditched and stained?
- Explorer check: does a fine instrument catch at the margin?
- X-rays: is there a dark shadow under or beside the filling?
- Crack check: a light shone through the tooth and a bite test on a special tool can reveal cracks.
- Symptoms: sensitivity, biting pain, or food trapping.
- Your history: grinding, frequent cavities, or a past broken tooth nearby.
Fillings that pass these checks are usually left alone and watched. Those that don’t are replaced, often starting with the ones causing symptoms.
What does cracked tooth pain feel like?
Teeth with large old fillings are prone to a pattern called cracked tooth syndrome. Common signs:
- A sharp, quick pain when you bite on something specific, like a seed
- Pain when you release your bite, more than when you bite down
- Sensitivity to cold that fades quickly
- Trouble pinpointing which tooth hurts
Cracks can spread over time. Catching them early often means a crown or onlay can save the tooth, while a crack that reaches the root may mean extraction.
What can replace a silver filling?
| Option | Best for | Lifespan | Notes |
|---|---|---|---|
| Composite (white) filling | Small to medium fillings | About 7 to 12 years | Tooth-coloured, bonds to tooth, needs less drilling |
| Porcelain inlay or onlay | Large fillings, weak cusps | About 10 to 20 years | Made in a lab, very strong, saves more tooth than a crown |
| Crown | Cracked or heavily filled teeth | About 10 to 15+ years | Covers and protects the whole tooth |
| Glass ionomer | Root surfaces, kids, high cavity risk | Shorter | Releases fluoride, less durable for chewing surfaces |
| New amalgam | Specific situations where moisture control is hard | 15+ years | Used much less often today |
What happens when a silver filling is replaced?
- Exam and X-rays to confirm the filling needs replacing and to check for decay or cracks.
- Freezing with local anaesthetic.
- Isolation. A rubber dam or isolation device keeps the tooth dry and helps reduce particles reaching the mouth and throat.
- High-volume suction and water spray while the old amalgam is removed.
- Decay removal and inspection for cracks.
- New restoration. A composite filling the same day, or a temporary while an onlay or crown is made.
- Bite adjustment and polish.
Some clinics follow extra safety protocols for amalgam removal. Ask what precautions are used if this matters to you.
Common myths about silver fillings
“Removing all my amalgam will cure fatigue or other symptoms.”
Controlled studies haven’t shown that removing sound amalgam fillings improves general health symptoms in people without a specific allergy. Removal can raise mercury exposure briefly and weakens healthy teeth. If you have unexplained symptoms, talk with your doctor.
“White fillings are always better.”
Composite looks better and needs less drilling, but very large composites on back teeth may wear faster. Sometimes an onlay or crown is stronger.
“Old fillings last forever if they don’t hurt.”
Fillings can leak and develop decay underneath without pain. X-rays catch these early.
“Sedation is risky, so I’ll put off this work.”
Many filling replacements need only local freezing. For anxious patients, sedation options are available, chosen carefully and monitored by trained professionals.
Patient examples
The healthy 30-year-old filling. A 58-year-old asked to remove all 6 of her amalgams. 5 were intact with no decay. One had a crack beside it. We replaced only that one with an onlay and monitored the others.
The sudden break. A man bit into a sandwich and lost the inner wall of a molar with a large amalgam. He came in the same day. A crown restored the tooth.
The pregnancy question. An expectant mother had a small cavity. Her dentist used a composite filling and suggested waiting until after delivery to look at an old amalgam that was still in good shape.
How can you make fillings last longer?
- Brush twice a day with fluoride toothpaste and floss daily.
- Wear a night guard if you grind.
- Avoid chewing ice and very hard foods.
- Limit sugary snacks and drinks between meals.
- Keep regular checkups with X-rays at intervals your dentist recommends.
Finding a family dentist in Tillsonburg you can trust
Look for a clinic that replaces fillings when there’s a clear reason, explains the evidence honestly, and uses licensed dental professionals registered with the Royal College of Dental Surgeons of Ontario (RCDSO).
Family Dentistry on Brock is one of the most trusted clinics for anyone searching for a family dentist in Tillsonburg, with a 5.0 Google rating and 252+ patient reviews. Services include dental implants, clear aligners, restorative care, dental veneers, laser treatment, teeth whitening, dental emergency care, sedation dentistry, dental surgery, and orthodontics.
The clinic welcomes new patients and CDCP (Canadian Dental Care Plan) patients. Weekday hours run late on Mondays, until 7:00 PM, and Saturday visits are available by appointment.
Stop by 49 Brock St E, Tillsonburg, ON N4G 1Z7, call +1 519-900-5640, or email info@familydentistryonbrock.com. If a filling has cracked or the tooth is hurting, mention it when you call so this emergency dental clinic in Tillsonburg can see you quickly.
Frequently asked questions
How long do silver fillings last?
Many last 15 to 25 years or more. Lifespan depends on the size of the filling, your bite, grinding habits, and how well you clean around it.
Is it safe to have amalgam fillings removed while pregnant?
Most dentists recommend avoiding elective amalgam removal during pregnancy. If a filling is broken or causing pain, your dentist will choose the safest approach.
Do white fillings last as long as silver ones?
Modern composites often last 7 to 12 years, sometimes longer. Amalgam usually lasts longer, but composite needs less tooth removal and looks natural.
Will my insurance or CDCP cover replacing old fillings?
Coverage usually depends on whether replacement is needed for a health reason, like decay or fracture, rather than cosmetic preference. The front desk can check your specific plan.
Can I replace all my silver fillings in one visit?
It’s possible but often not ideal. Many dentists replace fillings by area over a few visits, which is easier on your jaw and allows careful work on each tooth.
Conclusion
Intact silver fillings usually don’t need replacing just because of their age.
Cracks, leaks, decay, or a weakened tooth are the real reasons to swap them out.
Regular checkups and X-rays help you replace the right fillings at the right time.
