When the tooth has a cavity (decay or caries) or fractured, the dentist will anesthetize it then remove the decay, or prepare the fracture margin, then restore the tooth to its original shape using bonded white filling (composite restoration). These restorations are tooth-colored, strong and provide pleasing aesthetics. Early detection of tooth decay is paramount to keeping your teeth healthy, strong and functional. If decay progresses it will cause sensitivity (specially to sweets and cold), and may invade the pulp of the tooth leading to constant toothache and possible swelling and infection requiring more extensive treatment. Composite restorations can also be used to close gaps between teeth and to build worn-out teeth.