Stiffness and stress fluctuations in dental cement paste: a continuum micromechanics approach

Abstract

Calcite-reinforced hydrates provide the superior mechanical properties of Biodentine, a cementitious material used in dentistry. Herein, a self-consistent micromechanics model links two nanoindentation-probed, lognormally distributed microstiffness distributions of infinitely many hydrate phases, to the material’s macrostiffness, quantified from longitudinal and transverse ultrasonic wave transmission experiments. Thereby, the model provides values for the Poisson’s ratio of the hydrates and for a microcrack density reflecting grain boundary defects. Moreover, the model-predicted hydrate microstresses turn out as beta-distributed, while the overall stiffness can be equally well upscaled from only two, piecewise uniform, hydrate phases exhibiting median microstiffness values.