When a tooth is decayed, the diseased dental tissue is removed and a filling is placed to restore the normal tooth anatomy. The treatment is done under local anaesthesia. Tooth-coloured composite resin is used to repair teeth, filling holes or changing the shape and colour of teeth. It is often used to close unwanted gaps between teeth or to bring tooth into arch alignment. A white filling takes between 30 to 60 minutes to complete and can make your tooth look totally natural again.