The improvement of the self-setting property of the tricalcium silicate bone cement with acid and its mechanism

Tricalcium silicate (C3S) is a potential candidate as bone cement with excellent biological properties. However, the long setting time of C3S is not conducive to clinic applications. Simply considering hydration, it is possible to increase the consumption of the hydration products to accelerate hydration. Based on these considerations, phosphoric acid (PA), gluconic acid (GA) and citric acid (CA) were used as curing agents, which can consume calcium hydroxide and so accelerate hydration. A series of measures were used to characterize the influences of the acids on hydration: compressive strength, setting time, pH value, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and backscattered electron imaging. The results showed that the three acids shortened the setting time of C3S cement; however, CA and GA had an inhibiting effect on the hydration and PA accelerated hydration. Investigating the mechanism of action of these three acids on hydration of C3S cement may be beneficial to improve the practicality of C3S as bone cement.