AbstractThis study aimed to investigate the factors affecting the success rate of full pulpotomy in permanent posterior teeth with pulpitis. The study included 105 permanent posterior teeth clinically diagnosed as reversible or irreversible pulpitis in 92 patients aged 18–82 years. All teeth underwent a full pulpotomy using mineral trioxide aggregate as a capping material and were recalled for clinical and radiographic evaluation at 3, 6, 12, and 24 months postoperatively. The overall success rate after the 12-month review was above 90%, and failed cases mainly occurred during the first 12 months after treatment. In this study, the treatment outcome of pulpotomy was not related to sex, or tooth position and the cause of pulpitis. To analyze the influence of age on the treatment outcome, all the teeth were allocated to three groups: group 1 (18–39 years); group 2 (40–59 years); and group 3 (≥ 60 years). A significant difference in success rate was found between groups 1 and 3 (P = 0.014). These results suggest that pulpotomy can be used as an alternative treatment for permanent mature teeth diagnosed with pulpitis and that aging is one factor affecting the treatment outcome.