Composite fillings are tooth-colored materials used to restore decayed areas of teeth. The dental composite quartz resin s very strong and similar to the color of the natural tooth. The tooth is prepared by removing all the decay and preparing an etched surface for bonding. A thin resin is applied, which bonds to the surface. The composite material is place into the tooth and velvet blue light is directed at it, causing it to harden immediately. Your dentist will then smooth and polish the filling so that it feels natural in your mouth.