Effect of Coronal Barrier Thickness on Fracture Strength of Immature Teeth

Abstract

Objectives: Secondary trauma is one of the main causes of root fracture in regenerative endodontic cases. The aim of this study was to compare the influence of placing Biodentine as a barrier material at different thicknesses on the fracture strength of simulated immature teeth. Materials and Methods: The root canals of 65 human maxillary central incisors were instrumented using Peeso reamers to simulate immature teeth. Ten teeth were assigned to the negative control group and received no access cavity preparation. The access cavities of the remaining 55 teeth were prepared. Among them, the root canals of 10 teeth were filled with calcium hydroxide to serve as the positive control. Forty-five teeth were randomly distributed into 3 groups (n=15); Group 1: 2-3 mm thick coronal plug, Group 2: 5-6 mm thick coronal plug, Group 3: complete obturation. After the storage period, fracture testing was performed using a universal testing machine. One-way analysis of variance and Tukey tests were used to analyze the data. Results: No significant difference was found among the positive control, group 1 and group 2 (P > 0.05). The negative control and group 3 presented the highest fracture strength values (P < 0.05), while there was no significant difference between them (P > 0.05). All fractures occurred through the cervical region of the root horizontally or obliquely. Conclusions: No significant reinforcement effect was obtained when Biodentine was used as a coronal plug. The complete root canal obturation of simulated immature teeth using Biodentine provided the best reinforcement effect. The coronal plug thickness had no influence on the fracture strength of immature teeth.