What Ingredients Are in Composite Fillings?

Composite fillings are a type of tooth filler used to close cavities, cracks and fractures in teeth. White composite fillings tend to be more aesthetically appealing than silver amalgam fillings because they discreetly blend in with the natural color of teeth. Composite fillings are made from several basic ingredients but they can vary from one dental practice to another depending on the desired strength of the filling.

Glass particles or powdered glass is a common ingredient in composite fillings. The glass particles are tightly packed and used to give the filling its white tooth color, which makes it look more natural inside the mouth. In most composite fillings, glass particles make up 60 to 80 percent of the filling. In some cases the glass powder is replaced by quartz or porcelain particles.

Synthetic resin is generally found in composite fillings. The resin functions as the base of the composite filling to which the glass particles are added to complete the filling. Synthetic resin comes in a variety of shades that a dentist matches to a patient's teeth to create the most natural-looking filling possible.

Acrylic is a common setting agent used in composite fillings. Acrylic is the plastic matrix that holds all the other ingredients together to form a durable, long-lasting filling. After the filling is placed, the dentist cures it with light, making it hard and setting it in place inside the mouth. Because acrylic is fluid until it is set with light, it allows the dentist to properly mold the filling to the patient's mouth for a more natural appearance.

Composite fillings are extremely durable. The glass and/or porcelain particles allow for a strong filling that can last for many years. Composite fillings are often chosen over silver or gold fillings for their natural look. They are molded to fit the appearance of your mouth and are virtually undetectable. Composite fillings are also mercury-free and less sensitive to hot and cold temperatures.