ABSTRACTBackground:Bioactivity refers to the ability of a material to interact with living organisms or biological systems in a way that elicits a specific response. In the context of materials science and medicine, bioactivity is particularly important because it can determine the suitability of material for various applications.Objective:To evaluate and compare different commercially available calcium silicate-based materials regarding: 1. Morphological and elemental analysis at the dentin/material interface. 2. Calcium and silicon release and uptake by adjacent root canal dentine by evaluating the calcium and silicon incorporation depth in adjacent root canal dentin.Materials and Methods:This study examined four calcium silicate-based cements: Biodentine, MTA Angelus, BioAggregate, and MTA Plus. One hundred extracted human teeth with intact apices and no cavities were selected. Root sections measuring 3 mm in length were created at the mid-root level using low-speed diamond discs. Bioactivity was evaluated at 1, 7, 30, and 90 days, respectively.Results:The principal composition of the interfacial dentine layer and incorporation of calcium and silicon into dentine was measured at 1, 7, 30, and 90 days. Statistical analysis was performed by multiple comparisons using post hoc Tukey HSD.Conclusion:All the materials have shown bioactivity, i.e. release of calcium, silicon, and their uptake in the adjacent dentin in the presence of phosphate-buffered saline.