Physicochemical properties of MTA, CEM, hydroxyapatite and nano hydroxyapatite-chitosan dental cements.

Objective: Dental cements used as fillers in endodontics are in direct contact with the alveolar bone and bone regeneration by these cements is an important factor for their clinical success. The ability to form new hard tissue and its integration with the surrounding tissues are determined by the process of apatite deposits formation on bioactive ceramics. This study aims to evaluate the bioactivity of Mineral trioxide aggregates, Calcium enriched mixture, hydroxyapatite and nano hydroxyapatite-chitosan cements. Materials and methods: Samples disks of these cements immersed in Simulated Body Fluid (SBF) solution were evaluated on days 1, 7 and 14 through measuring pH as well as examining the cement surface morphology and calcium to phosphorus ratio via Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Analysis (EDXA) respectively and Fourier Transform Infrared Spectroscopy (FTIR) analysis of apatite deposited chemical groups. Results: The nano hydroxyapatite-chitosan and hydroxyapatite cements have neutral pH values, and CEM and MTA cements are "slightly basic" and "very basic" respectively. The SEM results revealed that apatite crystals would in time form on the surface of the cements. The EDXA results showed that calcium and phosphorus increased in all cements as time passed. Conclusion: All the tested cements demonstrated bioactivity. The CEM and the nano hydroxyapatite-chitosan cements demonstrated better bioactive features in terms of pH values.