Tooth Fillings

Tooth fillings, also known as dental fillings, are used to replace natural tooth structure when it becomes fractured, broken or damaged by tooth decay. If you need a filling, your dentist can use a range of filling materials. Dental fillings will fix your tooth so it looks and works at its best.

Dental filling material options

When a dental filling is needed, there are different material options that your dentist can choose from to fix the tooth. Each dental filling material has advantages and disadvantages and there are different factors that can influence which one is used. Some factors include where the tooth is located in the mouth, how the teeth bite together, and how big or small the filling will be.

Your dentist will give you advice on dental filling options and what kind of dental filling is best for you. This could be different for each tooth.

Amalgam

Dental amalgam is a silver-coloured filling material. It is made of mercury, silver, copper, zinc and tin. It has been used as a filling material to fix teeth for over 150 years and has one of the longest life expectancies of dental filling materials. Dentists and scientists have done a lot of research on dental amalgam.

Amalgam was commonly used in dental fillings by dentists in the 1990s. These days it is less commonly used, with some dental practices choosing not to use it at all. Amalgam is strong and long-lasting, but more tooth structure needs to be cut away to fix the tooth with an amalgam filling. This is because the amalgam is held in place by the shape of the cavity that is cut into the tooth. Amalgam does not stick to the tooth surface like white filling materials do.

This filling material is silver in colour and can appear darker over time.

Amalgam safety

Some people claim that mercury in dental amalgam can cause health issues. There is no quality research that has shown that this is true. Scientific research has shown that the mercury in amalgam fillings is not absorbed well by the body. Small amounts of mercury from amalgam do get into the blood but are removed by the kidneys and passed out of the body in urine.

There are only two proven side-effects of amalgam:

• Lichen planus – a condition involving small sores on the gum or inside of the cheek.
• An allergic reaction affecting the soft tissues near the filling. Signs of an allergic reaction can include swelling, redness, and itching, but these are rare.

Dental amalgam has been used less and less for dental fillings over the years. This is not due to concerns directly related to human health, but due to concerns about the environment. Mercury from dental clinics can potentially get into the environment. To prevent this, dentists have created policies and installed equipment to help them safely get rid of amalgam waste to limit the amount released into the environment.

A dental amalgam filling in a molar tooth.

Should I remove my amalgam fillings?

Dental amalgam is a safe and very useful filling material. There is no need to remove and replace your amalgam fillings for no specific reason. There is no evidence that changing healthy amalgam fillings with a different material option, without a specific reason, will produce a better health outcome for patients.

If you choose to have your amalgam fillings removed, make sure you understand the effects of this decision. Each time a dental filling is cut out of a tooth, more tooth structure is cut away. There is also no guarantee that the new filling or material will be better than the amalgam filling already in place. All dentists are trained in how to remove and replace amalgam fillings. Dentists do not need specialist training to do this.

Even though dental amalgam is not commonly used for dental fillings anymore, your dentist may still recommend it as the filling material of choice for certain dental fillings.

Composite resin

Composite resin is a tooth-coloured or white filling material. It can be used for fillings in both the front and back teeth. It is commonly used to fix broken or decayed teeth and for cosmetic dental treatments, such as veneers.

Composite fillings are glued to the surface of the tooth, which is called bonding. Because composite resin is bonded to the tooth’s surface, less tooth structure needs to be cut away for composite fillings to be placed. This means more natural tooth structure can be kept with composite resin fillings.

The colour of the material can be matched to the colour of the tooth being fixed. When the colour is well matched, the filling may not be able to be seen by other people looking at your teeth.

Before and after a composite resin filling in a molar tooth.

Left Cavity cut into the tooth after removing tooth decay.

Right Cavity filled with a tooth-coloured composite resin filling.

This filling was completed using a rubber dam to isolate the tooth from the rest of the mouth.

Glass-ionomer cement (GIC) is also a white or tooth-coloured filling material. It is not as strong as composite resin. Fluoride is an ingredient in this dental filling material. It has many uses, but common uses include fissure sealants and temporary fillings.

Gold and porcelain

Fillings can be made of gold and porcelain. Gold fillings and porcelain fillings are created outside of the mouth and then glued into the tooth’s cavity. This type of filling is called an inlay.

Gold and porcelain fillings are very strong and can last a long time. One advantage of a porcelain inlay is that they can be matched to the colour of the tooth. Both gold and porcelain fillings take time as they need to be made at a dental laboratory. It often takes at least two appointments.