If you have had dental work done before the mid-2000s, there is a good chance you have at least one amalgam (silver) filling. These metallic restorations were the standard for decades. They are strong, durable, and many are still in service 20 or 30 years later.
But times have changed. Composite (tooth-coloured) fillings are now the default material in most Australian practices, including Ivy Dental. And if you are looking at your old silver fillings and wondering whether they should be replaced, you are asking a reasonable question.
Here is an honest comparison to help you decide.
What is amalgam?
Dental amalgam is a mixture of metals: silver, tin, copper, and mercury. The mercury binds the other metals into a hard, stable alloy. Amalgam has been used in dentistry for over 150 years.
Its main advantages are strength and longevity. Large amalgam fillings in back teeth can withstand heavy chewing forces for decades. Cost is another factor. Amalgam is less expensive than composite, though the price gap has narrowed.
Its main disadvantages are aesthetic (silver-grey colour is visible) and the fact that amalgam does not bond to tooth structure. The dentist creates mechanical retention by shaping the cavity, which sometimes requires removing more healthy tooth than a bonded composite would.
What is composite?
Composite resin is a tooth-coloured filling material made from a mixture of plastic and glass particles. It bonds directly to enamel and dentine, which means less healthy tooth needs to be removed during preparation.
Composite is matched to your tooth colour, so it is virtually invisible once placed. It is the standard material for front teeth and increasingly for back teeth as well.
The trade-off: composite fillings in high-stress areas (large cavities in back teeth) may not last as long as amalgam under heavy biting forces. Research suggests composite fillings in posterior teeth last an average of 7 to 10 years, while amalgam averages 10 to 15 years. Individual variation is significant in both cases.
When replacement makes clinical sense
Not every amalgam filling needs replacing. A filling that is intact, well-sealed, and symptom-free may serve you well for years to come. Replacing a sound filling means removing it, which removes some additional tooth structure in the process.
Replacement is recommended when:
The filling is cracked or fractured. Amalgam can develop cracks over time, particularly in large fillings. Cracks allow bacteria and saliva underneath the filling, which can lead to decay.
Decay is present underneath. Detected on X-rays at a routine check-up. The filling may look fine on the surface, but decay can develop at the margins where the filling meets the tooth.
The tooth has fractured. Large amalgam fillings do not flex with the tooth. Over years of chewing and temperature changes, the tooth can crack around the filling. A fractured cusp often means the tooth needs a crown or onlay rather than another filling.
The filling is corroding. Old amalgam can corrode and expand slightly over time, putting pressure on the surrounding tooth walls.
Aesthetic reasons. Visible amalgam fillings, particularly in the smile zone, are a valid reason for replacement if the appearance bothers you.
When replacement is not necessary
If your amalgam filling is sound, well-adapted, and the tooth is healthy on X-ray, there is no clinical urgency to replace it. The Australian Dental Association's position is that routine replacement of sound amalgam fillings is not recommended on health grounds.
Replacing a filling always carries a small risk of complications: sensitivity, the need for a larger restoration, or in rare cases, the need for root canal treatment if the tooth's nerve is affected during preparation.
Your dentist can assess each filling at your regular check-up and advise which ones are ageing and which are still serving you well.
The replacement process
Replacing an amalgam filling with composite takes one appointment, typically 30 to 60 minutes depending on the size.
Isolation. We place a rubber dam (a thin sheet that isolates the tooth) during amalgam removal. This keeps amalgam debris out of your mouth and provides a dry field for the composite bonding process. High-volume suction removes particles and vapour.
Removal. The amalgam is sectioned and removed in chunks rather than ground to powder. This is a deliberate technique to minimise aerosolised mercury.
Decay check. Once the old filling is out, the tooth is inspected for decay. Any soft or compromised tooth structure is removed.
Bonding and placement. The composite is applied in layers, each cured with a blue light. The material is sculpted to match the tooth's anatomy, then polished.
Bite check. The filling is adjusted so it meets the opposing teeth evenly.
For larger cavities where much of the tooth structure is missing, your dentist may recommend a ceramic inlay, onlay, or crown instead of a direct composite filling. These lab-made restorations are stronger for large restorations and tend to last longer.
Cost comparison in Brisbane
At Ivy Dental, composite fillings start from $200 for a small, single-surface filling. Larger fillings cost more depending on the number of surfaces involved and the complexity.
Amalgam fillings are still available but are rarely requested. The cost difference between the two materials is modest for most filling sizes.
If you are replacing multiple fillings, we can stage the work over several appointments to spread the cost. Most major health funds cover a portion of filling replacement under general dental. We process claims with HICAPS at our Everton Park and Nundah locations.
Payment plans may be available to approved applicants.
Indicative pricing. Your quote may differ based on clinical assessment.
Making the decision
The choice to replace amalgam fillings is personal. Here is a simple framework:
Replace now if your dentist identifies cracks, decay, or marginal breakdown at your check-up.
Consider replacing if the fillings are visible when you smile and the aesthetics bother you, or if you have a personal preference to avoid amalgam.
Leave alone if the fillings are sound, symptom-free, and your dentist confirms they are intact on X-ray.
Your dentist can assess every filling and give you specific advice at your next dental check-up.
Book a filling assessment
If you have old amalgam fillings and want to know where they stand, book a check-up at Ivy Dental. We will X-ray, assess each filling, and give you clear options. No pressure to replace anything that does not need it.
Call (07) 3266 7120 or book online at our Everton Park and Nundah practices. Open 7 days. Your general dentistry check-up is the ideal time to have old fillings assessed.
