Also known as dental caries, tooth decay is the gradual erosion of the outer enamel of a tooth and sometimes also the inner dentin. Initial decay usually occurs on the grinding surfaces of the back teeth and areas around the gum line.
The main cause of decay is the acid produced by bacteria in plaque (a sticky deposit of food particles, dead cells, saliva, and bacteria on the surface of teeth). Early- stage decay often causes no symptoms.
Later, there may be toothache; sensitivity of the tooth to heat, cold, or sugary foods; and bad breath. Superficial decay may be treated by applying fluoride to the decayed area.
More advanced decay may need a filling or root canal treatment (removing the tooth’s inner tissues, then sealing the tooth).
With very advanced decay, the tooth may need to be extracted