Direct Restoration

Glass ionomers are tooth-coloured materials made of a mixture of acrylic acids with fine glass powders that are used to fill cavities, particularly those on the root surfaces of teeth. They are primarily used for small fillings in areas that need not withstand heavy chewing pressure. Glass ionomers also are used to cement dental crowns. Some glass ionomers are resin reinforced.

Advantages:

• Tooth-coloured so the filling looks more natural.
• Can contain fluoride that may help prevent further decay.
• A minimal amount of tooth structure removed.
• Low incidence of a localised allergic reaction.
• Usually completed in a single visit.

Direct Restoration

The word “amalgam” when referring to dental fillings means a mixture of two or more metals in which mercury is a component. Dental amalgam is a mix of approximately 43% to 54% mercury with other metals, including silver, copper and tin. Dental amalgams have commonly been called “silver fillings” because of their silver colour when they are first placed.

Today, amalgam is used most commonly in the back teeth. It is one of the oldest filling materials and has been used (and improved) for more than 150 years. Dental amalgam is the most thoroughly researched and tested filling material.

Advantages:

• Strong, durable and stands up to biting force.
• Can be placed in one visit.
• Normally the least expensive filling material.
• Self-sealing with minimal-to-no shrinkage and it resists leakage (leakage occurs when a filling does not completely seal, permitting food and bacteria to "leak in" and promote new decay behind or beneath the filling).
• Resistance to further decay is high.
• Frequency of repair and replacement is low.
• Amalgam is the only material that can be used in a wet environment, especially important when treating small children or special needs patients.