Do you have metal fillings and want a more natural-looking smile? Amalgam or 'silver' fillings have been used by dentists to repair decayed or damaged teeth for over 150 years, but they have become considerably less popular in recent years as tooth-coloured 'white' fillings have become widely available.
In New Zealand, a study conducted by the University of Otago Faculty of Dentistry found that amalgam use declined from 52.3% of fillings in 1998 to just 7.1% in 2017, indicating a general phasing out of the material.
Metal fillings are considered safe as long as they're still intact, and you don't need to replace them if you don't want to. But if you would prefer a whiter and more natural-looking smile, you can ask your dentist about amalgam replacement.
What are the risks of amalgam fillings?
Metal amalgam fillings contain a small amount of mercury, which makes some people worried about their health risks if the filling gets damaged, especially as this leads to metal fillings being classified as hazardous waste.
The level of free mercury in these fillings is low and not considered to pose a risk to human health, but health authorities still recommend that some people avoid these fillings. This includes children, pregnant and breastfeeding women and people with kidney disease who may be at higher risk of complications.
What are the alternatives to metal fillings?
If you choose to have a metal filling replaced, a different type of filling will need to be put in its place. These can be made from different materials, depending on how much of the natural tooth remains and your price range.
- Composite resin is the most common material used in fillings today. Your dentist can choose a shade of resin that matches your natural tooth colour, so the filling will be difficult to distinguish.
- Glass-ionomer cement (GIC) is less durable than composite resin, so it's often used for teeth that are put under less pressure. This is commonly used for children's fillings, as it has properties that can help to prevent tooth decay.
- Porcelain (ceramic) fillings are a more expensive option, but they offer the greatest aesthetic benefit as the material has a very similar appearance to natural tooth enamel. Porcelain fillings, inlays and onlays need to be custom-made, which may require multiple visits or only one visit if your dental clinic uses the CEREC system.
Dental crowns are an alternative to fillings that may be needed if a tooth has been more severely damaged or needs support. Crowns are porcelain caps placed over a tooth to restore its original appearance and function.
How is amalgam removed?
Your dentist will make sure you understand the possible risks before you agree to amalgam filling removal and replacement. Dentists who offer this treatment need to follow strict protocols to ensure the safety of patients and the environment by removing and disposing of toxic mercury safely.
A rubber dam is placed in the patient's mouth to prevent inhalation or ingestion of harmful substances during the procedure. Dentists use tungsten carbide dental burs to remove the filling, which reduces heat and vapours produced. After the tooth is cleaned and disinfected, the new filling can be placed.