There are a number of different types of filling materials these include: amalgam (silver coloured), composite fillings (tooth coloured), glass ionomer (tooth coloured), gold inlays and onlays (gold coloured), porcelain inlays (tooth coloured).
Amalgam is a long lasting and hard wearing silver coloured material and has been used to restore back teeth in dentistry for at least 150 years. It is not unusual for an amalgam filling to last 15 to 20 years.
Composite fillings are strong, but may not be as hard wearing as amalgam fillings teeth. Their major advantage is they are tooth coloured. After the tooth is prepared, the filling is bonded onto the area with a light shone onto it to set. Composites are always used in front teeth and are increasingly used in back teeth. The dentist will choose an individual shade to match your existing teeth, although over time staining can happen.
Glass ionomer fillings form a chemical link with the tooth. They have the advantage of releasing fluoride, which helps to prevent further tooth decay and strengthen the enamel. This type of filling is fairly weak and, because of this, is usually limited to use on children’s teeth and non-biting surfaces eg around the neck of the teeth adjacent to the gum. Little preparation is needed as the filling bonds directly to the tooth.
Gold inlays or onlays can be used in most areas of the mouth. An inlay is small and within the biting surface of the tooth. An onlay can cover a larger area of the tooth. Gold is the most long lasting and hard wearing filling material and will last for many, many years. An advantage of gold is that it does not tarnish and has great strength. One of the differences between gold and other filling materials is that the gold filling is made in a laboratory by a technician and then cemented into the mouth in the surgery.