Pulp oxygen saturation and clinical outcomes after direct pulp capping with MTA or 45S5 bioactive glass in mature permanent teeth: a pragmatic randomized clinical trial

To evaluate pulp oxygen saturation and clinical outcomes after direct pulp capping with mineral trioxide aggregate (MTA) or 45S5 bioactive glass in mature permanent teeth with carious pulp exposure. This pragmatic randomized clinical trial included 44 mature permanent teeth from patients aged 15–40 years presenting deep carious lesions with a clinical diagnosis compatible with reversible pulpitis or early pulpal inflammation. Teeth were randomly allocated (1:1) to direct pulp capping with MTA (n = 22) or 45S5 bioactive glass (n = 22). Pulp oxygen saturation, cold sensitivity, and radiographic findings were assessed at baseline and after 1, 3, 6, 12, and 18 months. Pulp oxygen saturation values were measured using pulse oximetry and analyzed over time using the Friedman test. Clinical survival was estimated using Kaplan–Meier analysis and compared between groups using the log-rank, Breslow, and Tarone–Ware tests. No significant changes in pulp oxygen saturation were observed over time in either group (MTA, p = 0.665; 45S5, p = 0.723). Kaplan–Meier analysis demonstrated a significantly higher clinical survival probability for teeth treated with MTA than for those treated with 45S5 bioactive glass (log-rank, p = 0.002). Cox regression analysis showed that the pulp-capping material was the only variable significantly associated with treatment failure (HR = 9.51; p = 0.012). Pulp oxygen saturation remained stable after treatment but did not discriminate between successful and failed cases. MTA demonstrated more favorable clinical outcomes than 45S5 bioactive glass for direct pulp capping in mature permanent teeth.