What are fillings?

Fillings are special materials that your dentist places in or on your teeth to repair tooth decay (cavities) or defects on the tooth surface. Fillings are also called restorations. They restore the tooth to form and function. Advances in dental materials and methods provide new, effective ways to restore teeth.

There are 2 types of restorations. They are called direct and indirect restorations.

Direct restorations

These need a single office visit to place a filling into a prepared cavity. Materials used for these filings include:

• Dental amalgam. These are also known as silver fillings. Amalgam fillings have been used for decades. They have been tested for safety and resistance to wear. Dentists have found amalgams to be safe, reliable, and effective.

• Composite (resin). Composite fillings are tooth-colored restorations. They are made from acrylic resin filled with tiny glass or quartz particles. They are strong, safe, and reliable. They are not quite as strong or wear resistant as amalgam. But they are stronger and more durable than glass ionomers. They can be used on biting surfaces. They are bonded to the tooth.

• Glass ionomers. Glass ionomers are tooth-colored materials made from fine glass powders and acrylic acids. These are used in small fillings that do not have to withstand heavy pressure from chewing.

• Resin ionomers. Resin ionomers are made from glass with acrylic acids and acrylic resin. Both of these types of glass ionomers chemically bond to the mineral in the tooth.

Indirect restorations

These need 2 or more office visits to put on the teeth. They include:

• Inlays

• Onlays

• Porcelain and resin veneers

• Crowns

• Bridges

These restorations are made with 1 or more of these:

• Ceramic. These are all-porcelain material. This material looks like natural tooth enamel in color and translucency.

• Porcelain fused to metal. This gives additional strength.

• Composite resin. Indirect composites are like to those used for fillings. They are tooth-colored, but they are not as strong or hardy as ceramic or metal.

• Gold. Gold alloys are used often for crowns, foundations for porcelain fused to metal crowns, or inlays and onlays.

• Base metal alloys. Less expensive metal alloys may be used as alternatives to gold for all-metal crowns and porcelain fused to metal crowns.

At the first visit, a dentist will prepare the tooth. They will make an impression of the area that will be restored. At the second visit, the dentist will cement the new restoration into the prepared area. Some dentists use CAD/CAM (computer-aided design/manufacturing) software. This lets them make the indirect restoration in the office and apply it at the same appointment. This saves you a return visit.