A comparative study of surface hardness between two bioceramic materials in an experimental apexification model under wet and dry conditions

Background: The placement of a wet cotton pellet against Mineral Trioxide Aggregate (MTA) is often recommended to ensure the completion of its setting reaction. Objective: This study aimed to evaluate the setting behaviour of MTA Angelus and NeoMTA by comparing their hardness after placing them in dry and moist conditions. Methodology: A simulated open apex was created on 40 polyvinyl tubes. The apical 4 mm of the tubes was filled with the two materials, NeoMTA Plus (Avalon Biomed Inc. Bradenton, FL, USA) and MTA Angelus (Angelus, Londrina, PR, Brazil) (n=20 per group). Both groups were subdivided into two subgroups based on the dry and wet conditions (n=10 per group). A wet cotton pellet was placed above the two materials in the wet group, and the coronal segment was sealed using Type II Glass ionomer cement (GC corporation Tokyo, Japan). Gutta-percha was placed against the test materials in the dry group with the coronal segment sealed with amalgam. Samples were placed in an oasis soaked in phosphate-buffered saline for seven days in 100% humidity and at 37°C. Microhardness was measured independently at 4 and 2 mm from the apex. Hardness was compared between materials and conditions, applying analysis of variance (a = .05). Results: The presence of dry or wet conditions had no significant effect on material hardness. MTA Angelus showed significantly higher hardness values compared with NeoMTA Plus. Conclusion: The moisture of the periapical environment can compensate for the absence of a wet cotton pellet and is adequate for the setting of the materials.