Why Replace Old Amalgam

This is a common and completely plausible question that gets asked frequently and there is no hard and fast answer. Why have a filling replaced when it has been there for years and years and never caused you any problems?? The answer is usually that, just because you don’t have pain, doesn’t mean that you do not have a problem. A lot of problems with your teeth and gums will cause you absolutely no pain until it is too late.

What is amalgam?

Amalgam is a metal alloy consisting of mercury, silver, tin and copper, it has been used in dentistry for over 150yrs and has been a very successful filling material for a long time. It is silver in colour, which often tarnishes to black with time. As a metal it is capable of thermal expansion, contraction and galvanic action. It is not bonded to teeth like todays filling materials, but more packed, locked and wedged into cavities.

Does amalgam leach mercury?

Amalgam fillings do give off a component of mercury vapour during their lifespan in a tooth.  Whether or not the volume of this is enough to cause health problems has been debated for decades and there are multiple contradictory studies to prove both sides quite convincingly.

Problems with Amalgam

X-rays can’t see through amalgam.

We use x-rays to see a cross-sectional view through your teeth, showing us in between, underneath fillings, the roots under the gum and into the grooves. Amalgam fillings show up bright white and do not allow us to see through them. This allows decay to exist that is blocked by the amalgam filling. It is difficult to diagnose decay underneath amalgam fillings until it is quite extensive, which is often the difference between having another filling or a root canal on the tooth.

Amalgam contributes to cracks.

When you bit on a tooth with an amalgam filling, the forces are distributed throughout the remaining tooth and cracks form.

This is due to a combination of things:

Horizontal vs Vertical Cracks.

Horizontal cracks make their way from the inner tooth to the gum-line and will generally result in a corner or wall of healthy tooth fracturing off, requiring a restoration. Vertical cracks propagate towards the root and nerve of the tooth and when untreated, result in root canal therapy or complete splitting of the tooth requiring extraction. Once a crack is visible in an at risk tooth, it is definitely a problem, even if it does not cause you pain.

Porcelain Fillings

Inlays & Onlays


I recommend for all medium-large amalgam fillings to be replaced in porcelain.

This is why:


So, to answer the question, you need to decide which approach you would like to take when it comes to your mouth. If you would prefer to wait until there is a problem, then wait. If you would like to be proactive in preventing problems, then replace them.

Make An Appointment


If you are not sure about your old amalgam fillings, contact Sydney Boutique Dentistry in Waterloo, Sydney on 02 9699 5199 or book online.