Dental fillings are a common method of repairing and restoring teeth back to their normal shape and function after damage from cavities, cracks, grinding, and fractures. There are several different types of filling materials each with their strengths and weaknesses.
Composite (White) tooth-colored fillings are a very popular choice of material because their color can be matched to your natural tooth color. Placing composite fillings takes more steps, but they can "bond" to the tooth which other filling materials cannot do so. Composite fillings are may chip over time and generally don't last quite as long as other types of fillings.
Amalgam (Silver) fillings are strong, long-lasting, and inexpensive. However, they are dark in color and are avoided in visible areas, such as the front teeth.
The most common need for a filling is to repair the tooth after a cavity has been removed. A cavity is an infection of bacteria inside the tooth. The bacteria secrete acid that destroys tooth structure creating a hole in the tooth. Cavities start in the tooth, but if left un-treated, the bacterial infection can spread and infect the surrounding areas. Bacteria from cavities can infect the nerve & blood supply to your teeth, spread into & destroy bone, and damage your gum tissue. Even if nothing is hurting, there can still be a cavity in a tooth.