Pulp liner materials in selective caries removal: study protocol for a randomised controlled trial

IntroductionThe literature shows that selective carious tissue removal (SCTR) decreases the number and diversity of bacteria, stops the caries process and reduces the risk of pulp exposure. However, no consensus exists on which pulp liner would be suitable for teeth undergoing SCTR. So, this study will verify the in vivo response of dentine–pulp complex after SCTR in primary teeth with or without pulp liner material.Methods and analysisA randomised clinical trial, double-blinded, parallel-group and allocation concealment will be conducted with the enrolment of 384 patients from 5 to 9 years, with one maxillary/mandibular first/second primary molars with deep occlusal/occlusoproximal cavities. The remaining dentine will be lined with calcium hydroxide cement—group 1; mineral trioxide aggregate—group 2 and without liner—group 3. The primary outcome will be success of the of dentine–pulp complex evaluated clinically and radiographically at 6, 12 and 24 months, while the secondary outcomes will be the measurement of the dentine barrier on periapical radiographs. During all study, two trained and calibrated examiners will evaluate the treated teeth clinically and radiographically. Interexaminer and intraexaminer reliability will be verified by casual and systematic error. The Kolmogorov–Smirnov test will be adopted to test the normality of continuous variables. Comparisons among groups will be performed by using the χ2 test and anaylsis of variance, followed by Tukey test (p