Dental fillings are used to treat a small hole or cavity in a tooth. Dentists remove the decayed tooth tissue and fill the space with a filling material. Fillings are also used to repair cracked or broken teeth and teeth that have been worn down from misuse. There are several types of filling materials used to repair cavities, including tooth-colored (composite) fillings, silver-colored (amalgam) fillings, gold, porcelain, and glass ionomer cement. Composite resin materials are increasingly used by dentists to fill teeth because many people prefer tooth-colored fillings and because composites continue to improve. The exact material used to create a dental filling depends on the type, location, and size of the cavity or damage being filled.

The steps involved in filling a tooth include removing the decayed portion of the tooth, cleaning the cavity of bacteria and debris, and preparing the space for the filling. If the decay is near the root, a liner made of glass ionomer, composite resin, or other material may be put in to protect the nerve. Tooth-colored fillings require several additional steps, including applying the tooth-colored material in layers and using a special light that "cures" or hardens each layer. After the filling is in, the dentist will finish and polish it.

To maintain fillings, good oral hygiene is important, including visiting the dentist regularly for cleanings, brushing with a fluoride toothpaste, flossing, and using an antibacterial mouthwash. Dental fillings and crowns do not last a lifetime and may need to be replaced.