When filling a cavity a dental dam is used. This is a rubber cloth, isolating the tooth to be treated from the rest of the mouth keeping it dry during the treatment. An additional advantage is that less water and dental materials can get into your mouth or throat. The use of local anaesthetics is possible but not always needed. The dentist will remove the decay using a drill. Next the cavity will be cleaned and the tooth coloured composite resin is placed in the area. This is then hardened by a cured light. The dentist will shape the material to the desired result and polish the restoration.