RESUMO
As for other dental treatments, root canal therapy may lead to failure. Correction of these conditions will be faced with problems and complexities, particulary if any periapical lesion is peresent. The aim of this study was to evaluate the success rate of retreament in teeth with apical lesions. In this descriptive study 60 teeth with failed root canal therapy which had been retreated by an endodontist were reevaluated clinically and radiographically between 6 to 12 monthis after retreatment. Clinical examinations were performed by a clinician and comparison with the primary symptoms, recorded in patiants file, was obtained. Periapical radiographs were prepared by parallel technique and E speed film with the same proccessing conditions. Periapicel lesion size was evaluated and comparison was made before and 6-12 month after retreament, using photoshop software [version7] .The data were analyzed by chi-square test and agreemental tables. Statistically, there was no correlation between variables and success rate. The success and failure percentage of retreatment was 81.7% and 5%, respectively and 13.3% of cases were uncertain. The most success rate was observed in group of 31-40 years old [95%], keeping in mind that most patients were in this age group. The least success was in group over 50 years old. According to this study, the high success rate could be expected in retreatment of teeth with periapical lesion