Open AccessBehaviour of nanocrystalline tricalcium silicate-based cements at early stages of hydration
Author(s) -
América Yazmín Torres-Moreno,
Irma Araceli Belío-Reyes,
Sandra García-Medina,
Perla Y. López-Camacho,
Beatriz M. Millán-Malo,
Eric M. Rivera-Muñoz,
L. Bucio
Publication year - 2021
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abece9
Subject(s) - materials science , cement , hardening (computing) , nanocrystalline material , calcium silicate , silicate , compressive strength , composite material , chemical engineering , nuclear chemistry , chemistry , nanotechnology , engineering , layer (electronics)
Tricalcium silicate-based cements (TCS-BC) have reached great relevance in modern dentistry, where they are used in root-end filling or perforation repair treatments, and also for restoring deep and/or voluminous coronary carious lesions, among other applications. In some TCS-BC such as Biodentine TM , the physical and chemical properties, e.g. high compressive strength, have led to consider this cement as a dentine substitute. One of the drawbacks of Biodentine TM is its very high washout; which refers to the tendency of disintegrate at initial stage of hydration upon early contact with blood or other fluids, just at the moment after it is still as a freshly prepared paste. The present research was focused to compare properties related to workability and hardening at early stages of hydration of experimentally synthetized nano-sized tricalcium silicate (nTCS) and Biodentine TM (BIOD). Both pastes were tested for hardening at 0, 1, 2 and 3 h of hydration, using a penetration test adapted from standards D3441-79 and D1558-84. The hydrated products were evaluated by X-ray diffraction (XRD), thermogravimetry (TG) and 29 Si NMR spectroscopy; pH measurements were taken along 28 days of hydration. The set cement pastes were evaluated for sealing ability and microleakage. Following literature reports, the CSH phase as a hydration product, was identified and modeled in both cements as defective clinotobermorite Ca 11 Si 9 O 28 (OH) 2 ·8.5H 2 O. The CSH phases obtained differ from each other by its microstructural arrangement and packing densities, which depend on the w/c ratio of nTCS and BIOD pastes, which were 0.5 and 0.36 respectively. The hardening of BIOD is significantly influenced by its w/c ratio with a hydration fluid that presumably contains about 0.05% of polycarboxylate-based superplasticizer, which was identified by Raman spectroscopy. The washout and hardening properties were pictured by and scheme for flocculation, w/c ratio, and packing density of the CSH particles characterizing the cement pastes.