RESUMO
INTRODUCTION: Transient apical breakdown (TAB) caused by orthodontic treatment is a reversible resorptive process in which the apex of a tooth shows some radiographic evidence of resorption and the crown may display some discoloration. It usually requires no treatment other than monitoring and elimination of the orthodontic forces applied to the tooth. METHODS: This report describes the case of a 48-year-old man patient who was referred to the department of endodontics for evaluation of some discoloration of his upper right central incisor, which was undergoing orthodontic treatment. The tooth was nonresponsive to sensitivity tests, it was sensitive to percussion, and, radiographically, there was some evidence of root resorption and apical radiolucency. RESULTS: Because TAB was the suspected cause of the signs and symptoms, no treatment was performed on the tooth except for periodic recalls, and lightening and eventual removal of the orthodontic appliances was indicated. CONCLUSIONS: Ten weeks after the initial appointment and removal of the applied orthodontic forces, color improvement was observed, accompanied by a return of tooth sensitivity to cold tests.