Objective:To evaluate the clinical efficacy and influence factors of direct pulp capping using a bioactive ceramic in mature permanent teeth with carious pulp exposure, in order to explore the feasibility and indications of vital pulp therapy for such teeth.Methods:From January 2016 to September 2017, 57 patients (57 teeth) with carious pulp exposure in mature permanent teeth were selected from the Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology. All the teeth were preoperatively diagnosed as deep caries with normal pulp or reversible pulpitis. After rubber dam isolation, all the carious dentin was removed and the exposed pulp tissue was observed under microscope. Hemostasis should be achieved within 3 min by using 2.5% sodium hypochlorite cotton pellets with a gently press. A resin composite restoration was performed immediately or 2 weeks later after direct pulp capping by using a bioceramic material (iRoot BP Plus). The patients were re-examined 12 to 50 months after operation (average 30 months) and the outcomes were evaluated by symptoms, clinical examination and X-ray. Kaplan-Meier survival analysis was used to calculate the success rate and influence factors were analyzed by Log-Rank test.Results:Totally 50 patients [age (32±13) years old (13-68 years old), 12 males and 38 females] received the follow-up examination more than one year. The overall success rate was 90% (45/50) and the success rates at 1 year, 2 years, 3 years and more were 98%, 89% and 81%, respectively. Age, gender, symptom, tooth and cavity type, pulpal exposure size and coronal restoration material had no significant correlations with the treatment outcome ( P>0.05). Conclusions:Direct pulp capping of mature permanent teeth with carious pulp exposure by using iRoot BP Plus might have high success rate. There′s no significant correlations between the major clinical factors and the treatment outcome.