Endodontic treatment failure consecutive to unsystematic radiographic examination.

This case report describes the endodontic therapy on a three-rooted mandibular first molar. The initial endodontic treatment was carried out after misreading preoperative periapical radiograph. Moreover, the working length was determined only with the apex locator. So, the additional disto-lingual root left unidentified and remained untreated, failing the treatment. A thorough radiographic examination in the initial therapy would have allowed the identification of the supernumerary root and its canal. Although the apex locators determine accurately the working length, it does not inform about the root canal morphology. It can be concluded and remarked that a systematic radiographic examination, including preoperative radiographs, is essential for success in endodontic therapy.