Dental drilling. Drill being used in a patient's mouth. The drill is being used to remove areas of decayed tooth (black). The space will then either be filled in with a dental filling, or the tooth will be drilled down even further so a cap (an artificial tooth) can be fitted. The drill head is seen next to one of the pre-molars. Next to it is a canine, and at the front of the mouth are the incisors. Tooth decay (dental caries) is caused by bacteria feeding on food debris in the mouth, producing acids that lead to erosion of the tooth enamel.
Ceramic dental crowns. Close-up of the mouth of a 72-year-old female patient with custom-made ceramic crowns in place in order to repair and replace decayed upper incisors and canines. The crowns are fixed to a metal support that is attached to fixtures surgically embedded into holes drilled in the patient's jawbone. Here, all the but the patient's front two teeth have been repaired or replaced.