Effects of L-ascorbic acid as an additive for improving the physical properties and setting behavior of fabricated...

Calcium silicate (CS) cement presents significant drawbacks, including prolonged setting time, handling difficulty, and susceptibility to washout during early setting stages. Given the molecular structure of l-ascorbic acid (AscA), we hypothesized that it could influence the setting characteristics of CS cement. AscA is an effective antioxidant and possesses wide therapeutic properties. This study investigated the effects of AscA addition on the properties of CS cement.

CS cement clinkers were synthesized and pulverized by jet milling. After characterization of the synthesized CS cement, the composition having high percentage of tricalcium silicate phase and low free CaO content (lime saturation factor 98.19) was selected. Addition of ZrO₂ (20 wt%) to the jet-milled CS powder followed by CaSO₄·½H₂O (5 wt%) addition, was done to fabricate CS cement. AscA was incorporated into the mixing solution at various concentrations. Setting time, flow, penetration resistance, compressive strength, washout resistance, and MTT cytocompatibility were evaluated.

Adding AscA up to 0.05 % enhanced the cement's flowability compared to the AscA-free control. AscA concentration negatively correlated with both setting time (P < 0.01, r = -0.963) and washout volume (P < 0.01, r = -0.957); setting time positively correlated with washout volume (P < 0.01, r = 0.889). Higher AscA correlated with increased early compressive strengths. The AscA-containing groups showed enhanced cell viability compared to the AscA-free group.

Incorporating AscA into CS cement resulted in faster setting, greater washout resistance, and higher compressive strength. Incorporating AscA into CS cement formulations is a promising approach for developing advanced CS cement.