Periapical film is one of important method for odontiasis diagnose. The periapical film can reflect some changes in root tip or periapical tissue found under human observation hardly. Those changes take great effect in diagnose of intractable odontopathy. The various kinds of appearance in periapical film, such as anatomy mutation of root canal, vertical fracture, tooth trauma, root absorption, expanding file broken down in root canal should be made a special effort and the mutation of normal anatomy tissue should be done too. Computerized tomography or panorama film could be used when questionable problem show up on the periapical film of intractable case.
