Acidic and alkaline chemicals' influence on a tricalcium silicate-based dental biomaterial

Bioactive hydraulic tricalcium silicate materials are commonly used in several dental procedures. Mineral Trioxide Aggregate (MTA) is one such material, which is used in a variety of clinical applications, the most recent of which is root canal sealing material, during which, the MTA potentially comes in contact with remnants of the chemical agents used for disinfecting root canals. The effects of commonly used root canal irrigating solutions on MTA have not been investigated in depth, thus far. The aim of this study was to determine the effect of five common chemical agents used in root canal preparation (sodium hypochlorite/NaOCl, ethylene diaminetetraacetic acid/EDTA, mixture of sodium hypochlorite and etidronic acid/NaOCl + EA, mixture of EDTA and Chlorhexidine/QMix, or saline) on a commercial tricalcium silicate (MTA Plus). Samples were analyzed using scanning electron microscopy with energy dispersive spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy and Inductively coupled plasma techniques to see effects of phases formed and calcium ion release. Specimens immersed in NaOCl and NaOCl + EA had strong peaks for calcium hydroxide, but materials exposed to EDTA and QMix had lesser XRD peaks for calcium hydroxide. The calcium hydroxide peak in the XRD indicates hydration of tricalcium silicate and formation of amorphous calcium silicate hydrate. Calcium released from samples immersed in EDTA and NaOCl was less than in NaOCl + EA and QMix solutions. Fewer calcium phosphate crystals and less calcium hydroxide were observed with the samples in NaOCl, EDTA and QMix, which could have an important impact as it negatively influences the bioactivity. (c) 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 377-387, 2019.