Influence of composition on setting kinetics of new injectable and/or fast setting tricalcium silicate cements

摘要

Objectives. New commercial tricalcium silicate based cements were elaborated to improve handling properties and setting time. The goals of the present work were: (ⅰ) to determine the composition of the new injectable and/or fast setting calcium silicate based cements, and (ⅱ) to investigate the impact of the differences in composition on their setting kinetics. Methods. The materials considered were Angelus MTA™, Biodentine™, MM-MTA™, MTA-Caps™, and ProRoot MTA™ as control. Elemental composition of materials was studied by Inductively Coupled Plasma-Atomic Emission Spectroscopy and X-ray Energy Dispersive analysis, whereas phases in presence were analyzed by Micro-Raman spectroscopy and X-ray Diffraction analysis and cement surface by Scanning Electron Microscope. Setting kinetics was evaluated using rheometry. Results. Elemental analysis revealed, for all cements, the presence of three major components: calcium, silicon and oxygen. Chlorine was detected in MM-MTA, MTA-Caps and Biodentine. Different radio-opacifiers were identified: bismuth oxide in ProRoot MTA, Angelus MTA and MM-MTA, zirconium oxide in Biodentine and calcium tungstate (CaWO_4) in MTA-Caps. All cements were composed of di- and tri-calcium silicate, except Biodentine for which only the latter was detected. Major differences in setting kinetics were observed: a modulus of 8 × 10~8 Pa is reached after 12 min for Biodentine, 150 min for MM-MTA, 230 min for Angelus MTA and 320 min for ProRoot MTA. The maximum modulus reached by MTA-Caps was 7 × 10~8 Pa after 150 min. Significance. Even if these cements possess some common compounds, major differences in their composition were observed between them, which directly influence their setting kinetics.