Tooth decay and implants,dental model. Close-up of four teeth in the left lower jaw of a human. This model has transparent gums,showing the roots of the teeth. From far right,the teeth and their conditions are: first molar (cracked; tooth decay,black; infected root and inflamed nerve pulp,red),second pre-molar (filled with a dental metallic-looking filling),first pre-molar (has been replaced with a screw-based implant),canine (healthy). Tooth decay is caused by acid-secreting bacteria feeding on food debris in the mouth. The infected area can be drilled out and filled,or the tooth can be replaced completely |