In vitro evaluation of the impact of a bioceramic root canal sealer on the mechanical properties of tooth roots

• Published in: Journal of dental sciences Vol. 19; no. 3; pp. 1734 - 1740
• Main Authors: Wang, Ya-Hui, Liu, Si-Yi, Dong, Yan-Mei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-2024; Association for Dental Sciences of the Republic of China; Elsevier
• Subjects: Bioceramic sealer; Compressive strength; Drying method; Elastic modulus and hardness; Mineralization; Original; Compressive strength; Bioceramic sealer; Drying method; Mineralization; Elastic modulus and hardness
• ISSN: 1991-7902; 2213-8862
• DOI: 10.1016/j.jds.2023.10.013

Endodontically treated teeth are more prone to vertical root fracture with the mechanical property changes to some extent during root canal treatment. This study aimed to investigate the effects of a bioceramic sealer on the mechanical properties of tooth roots.
Dentin discs were dried by two different methods (ethanol drying and paper points drying) and then filled with a BC sealer named iRoot SP. SEM and EDS were used to analyze the newly formed minerals in dentin tubules. Elastic modulus and hardness of the secondary dentin in areas proximal to the primary dentin (PD-SD) and areas proximal to canal or iRoot SP (SD-C/SD-iRoot SP) were measured using nanoindentation technique. The compressive strength of roots filled with iRoot SP were tested by compressive loading test.
(1) Penetration and mineralization: Paper points drying was more conducive to iRoot SP adhesion, spreading and penetration into the dentin tubules than 95% ethanol drying. (2) Micromechanical properties: After filling root canal with iRoot SP, the elastic modulus and hardness of SD-iRoot SP were higher than those of PD-SD (P = 0.001 and P = 0.000). (3) Fracture resistance: The compressive strength of the roots filled with iRoot SP was not significantly different from that of the roots unprepared and unfilled (P = 0.957), but was higher than that of the roots prepared and unfilled (P = 0.009).
Excessive drying (95% ethanol drying method) is not conducive to the penetration and mineralization of the BC sealer iRoot SP into dentin tubules. The good bioactivity of iRoot SP was responsible for increasing the elastic modulus and hardness of dentin, which strengthened the prepared roots.