ObjectivesOn the basis of a large sample size and a long follow-up period, the objectives of this study were to evaluate the outcomes of direct pulp capping (DPC) in mature permanent teeth with carious pulp exposure using a kind of bioaggregate putty (BP) which commercially named iRoot BP Plus (Innovative Bioceramix, Inc., Vancouver, Canada) and to analyze the potential prognostic factors.Materials and methodsThe design of this research was retrospective regarding treatment procedures and prospective regarding the assessment of outcomes. The preoperative diagnosis of the teeth was either normal pulp or reversible pulpitis. Results were assessed based on clinical and radiographic examinations with at least 12 months of follow-up after DPC. No symptoms or signs, a positive response to electric pulp testing, a normal response to cold pulp testing and radiographs showing no abnormalities were considered to indicate success. Kaplan-Meier survival analysis was used to calculate the cumulative survival of teeth after DPC. Univariate and multivariate Cox proportional hazard regressions were used to analyze potential prognostic factors.ResultsThree hundred thirty-four patients, including a total of 354 teeth, were available for the final clinical examination. The follow-up period ranged from 12 to 85 months, with an average of 27.0 & PLUSMN; 0.8 months. The total success rate was 85% (302/354), and the cumulative survival rates at 1, 2, 3, 4, and 5 years were 92%, 87%, 83%, 76%, and 72%, respectively. Univariate analysis indicated a significantly increased risk of failure in patients aged above 40 years and those treated by resident operators (P & LE; 0.01), with hazard ratios of 2.18 and 2.27, respectively.ConclusionsUnder appropriate indication selection and treatment procedures, long-term success is possible in mature permanent teeth with carious pulp exposure by DPC using iRoot BP Plus. Patient age and operator experience are potential prognostic factors.