Assessment of root dentin pH changes in primary and permanent molars with different types of calcium hydroxide intracanal medication

Abstract

© 2018 Japanese Society of Pediatric Dentistry Purpose: To evaluate root dentin pH changes using different calcium hydroxide medications in primary and permanent molar root canals. Methods: Sixty primary and 60 permanent molar roots were prepared with Twisted files and assigned in two subgroups: Group1, nonsetting calcium hydroxide (n = 30); group 2, viscous vehicle-based material (ApexCal ® ) (n = 30). The assigned materials were delivered in root canals and then stored for 24 h, 7 days and 14 days. All specimens were transversely cut in three sections and pH change was determined by Expandable Ion Analyzer cooperating with Flat Membrane pH Electrode and Reference Half-Cell Electrode at sample root surfaces. Two-way ANOVA was used for statistical analysis. Results: No significant difference was observed in primary teeth at all test periods. The mean pH values of the nonsetting calcium hydroxide group (pH10.39–10.90) were greater than those in viscous vehicle-based group (pH 9.84–10.12), but significant difference was observed only at 24 h. Among permanent teeth, the highest pH values of both materials were observed at 7 days. The pH values of the nonsetting calcium hydroxide group (pH 10.40–11.10) were greater than those in the viscous vehicle-based group (pH 9.80–10.41); however, no significant difference was observed at any test period. Conclusion: The peak pH of nonsetting calcium hydroxide group was at 24 h in primary teeth and 7 days in permanent teeth. The nonsetting calcium hydroxide group showed higher pH values than those in the viscous group in both primary and permanent teeth.