Acidic and alkaline chemicals’ influence on a tricalcium silicate-based dental biomaterial Prasanna Neelakantan , 1 Todd Berger, 2 Carolyn Primus, 3 Hagay Shemesh, 4 Paul R. Wesselink 4 1 Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong 2 Dentsply International, Tulsa, Oklahoma 3 Consultant in Medical Devices, Sarasota, Florida 4 Division of Endodontology, Academic Centre for Dentistry Amsterdam, ACTA, Amsterdam, The Netherlands Received 3 January 2018; revised 8 March 2018; accepted 14 March 2018 Published online 00 Month 2018 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jbm.b.34129 Abstract: 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 vari- ety 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 disin- fecting 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 prepa- ration (sodium hypochlorite/NaOCl, ethylene diaminetetraacetic acid/EDTA, mixture of sodium hypochlorite and etidronic acid/ NaOCl 1 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 Trans- form Infrared Spectroscopy and Inductively coupled plasma techniques to see effects of phases formed and calcium ion release. Specimens immersed in NaOCl and NaOCl 1 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 1 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. V C 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000–000, 2018. Key Words: EDTA, etidronic acid, FTIR, hydration, scanning electron microscopy, sodium hypochlorite, tricalcium silicate, X-ray diffraction How to cite this article: Neelakantan P, Berger T, Primus C, Shemesh H, Wesselink PR. 2018. Acidic and alkaline chemicals’ influence on a tricalcium silicate-based dental biomaterial. J Biomed Mater Res Part B 2018:00B:000–000. INTRODUCTION Mineral trioxide aggregate (MTA) is a well-characterized, radiopaque, tricalcium silicate cement with a multitude of uses in dentistry, ranging from pulp capping, perforation repair, apexification, root end filling and as a root canal sealer. 1,2 When mixed with water, this material forms cal- cium silicate hydrates and calcium hydroxide. 3 The white form of the first MTA product, Tooth-Colored ProRoot MTA V R (Dentsply Maillefer, Ballaigues, Switzerland) is composed of tricalcium silicate, bismuth oxide, dicalcium silicate, with minor amounts of tricalcium aluminate and calcium sulfate. 4 The original MTA (US Patent 5,415,547) was composed of a mixture of tri/dicalcium silicate powder with bismite in the proportion 4:1 that sets in the presence of water. MTA Plus V R (compounded by Prevest Denpro, Jammu, India) is also a tri- calcium silicate-based material that is available as a powder- liquid formulation with a very similar formula to the tooth- colored ProRoot MTA; however, MTA Plus is available at a lower cost, bulk packaging in bottles, and has better handling and faster setting. 2 Newer products have varied amounts of alternative radiopaque components; however, the MTA Plus product contains bismite. MTA Plus powder has a fine particle size (50% of the particles finer than 1 mm), and is indicated for pulpal or periapical tissue contact, including root canal sealing, 5 which ProRoot MTA is not. The latter indication was why this material was selected for testing with root canal dis- infectants in this study. Newer products have varied amounts of other radiopaque components; however, the MTA Plus prod- uct contains bismite. Tricalcium silicate is susceptible to low pH which can interfere with setting. 6–8 The use of acids such as ethylene diamine tetra acetic acid (EDTA) has been shown to disrupt the formation of C–S–H gel during hydration of MTA. 7,9 A recent report suggested that sodium hypochlorite (NaOCl) interacted with MTA, which was characterized by diminution of the calcium hydroxide phase, in addition to discoloration of This manuscript was submitted as part of the doctoral thesis of Prasanna Neelakantan to the University of Amsterdam. Correspondence to: P. Neelakantan; e-mail: prasanna@hku.hk V C 2018 WILEY PERIODICALS, INC. 1