Next, a drill, air abrasion instrument or laser will be used to remove the decayed area. Your dentist will probe the area to determine if all the decay has been removed and then will prepare the space for the filling by cleaning the cavity of bacteria and debris. If the decay is near the root, your dentist may first put in a liner made of glass ionomer, composite resin, or other material to protect the nerve. Generally, after the filling is in, your dentist will finish and polish it. The tooth-colored material is applied in layers and a special light that “cures” or hardens each layer is applied. When the multilayering process is completed, the dentist will shape the composite material to the desired result, trim off any excess material, and polish the final restoration.