Endodontic Management of a Tooth with Severe External Root Resorption using Injected Non-setting Calcium Hydroxide Paste: A Case Report

External Root Resorption (ERR) is a pathological condition that can lead to tooth loss if not diagnosed and treated correctly. Calcium Hydroxide Ca(OH)(2) is an intracanal medicament, which is used in cases of teeth with pulp necrosis, peri-radicular lesions and ERR. This paper describes the endodontic management of a tooth with severe ERR using injected non-setting Ca(OH)(2) paste. A 28-year-old patient was referred for endodontic evaluation of tooth 47, which presented an extensive composite resin restoration and was negative to cold test. Panoramic and periapical radiographs revealed the presence of a filled pulp chamber, calcified root canals, ERR on the mesial and distal roots, and apical periodontitis in the mesial and distal roots. The diagnosis of asymptomatic apical periodontitis and severe ERR was established, and conventional root canal treatment combined with non-setting Ca(OH)(2) dressing was chosen. After five months, no more discharge from the root canal was observed, and a decrease in the size of the periapical lesion and arrest of ERR was detected. The root canal was filled, and the patient was referred for restoration. At the 6-months follow-up, radiographic examination evidenced periapical repair and containment of the ERR process. Chemomechanical root preparation in association with a non-setting Ca(OH)(2) dressing protocol allows positive outcomes during the management of severe ERR associated with pulp necrosis and periapical inflammation.