Enhancing pH Modulation and Calcium Ions Release in External Resorption Artificial Defects: A Comparative Analysis of Ultrasonic Activation Effects on Ca(OH)2, MTA, and CEM Cement.

Abstract

Background and Objectives: Diffusion of hydroxide (OH)^- and calcium (Ca)⁺⁺ ions through dentin may cease external root resorption. Calcium hydroxide (Ca(OH)₂), mineral trioxide aggregate (MTA), and calcium-enriched mixture (CEM) cement are the choices for this purpose due to their optimal properties. This study sought to analyze the effects of ultrasonic activation (UA) on pH and the release of calcium ions from Ca(OH)₂, MTA, and CEM cement in external root resorption artificial defects. Materials and Methods: This in vitro research involved the instrumentation and shaping of the root canals of 150 single-rooted teeth (#F4). External defects were intentionally made on the middle one-third of the root surface. Teeth were randomly assigned to a negative control group (n = 10), one positive control group (n = 20), and six experimental groups (each n = 20) according to the root canal filling material (Ca(OH)₂ paste, MTA, CEM, gutta-percha, Ca(OH)₂ paste+ultrasonic, MTA + ultrasonic, and CEM + ultrasonic). Ultrasonic energy was transferred to the test materials using a #25 spreader. Ca⁺⁺ concentration and pH were measured after 1, 7, 15, and 30 days in all groups. Statistical analysis involved the use of repeated measure analysis of variance (ANOVA) and paired-sample T-test (P ≤ 0.05). Results: The levels of calcium ions and pH increased significantly over time in all groups (P < 0.001). There were significant differences between the experimental groups in terms of pH and the concentration of released calcium ions at different times (P < 0.001). The Ca(OH)₂ plus ultrasonic energy group ranked first, while the gutta-percha group ranked last in terms of release of calcium ions and pH. Conclusion: The Ca(OH)₂, MTA, and CEM cement groups showed an increase in pH and the release of calcium ions at the external root resorption defects. Additionally, the application of ultrasonic energy increased the release of calcium ions at these sites.