Effect of preheating on cytotoxicity and physicochemical properties of light-cured calcium-based cements.

Abstract

The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.

Light-curing of calcium hydroxide-based liners: pH analysis and calcium ion release

“…However, their high solubility, poor mechanical properties, and lack of adhesion to dentinal tissue make them unviable. As a solution to the problem, some calcium hydroxidebased materials that allow photoactivation have appeared in the market [5,6]. The addition of polymerizable methacrylates allowed their physical properties, chemical stability and solubility to be improved [7][8][9], making their clinical use more favorable and practical.…”

“…Although photoactivation replaces the deficiencies that calcium hydroxide cements had, its use may prevent or reduce the release of calcium and hydroxyl ions into the tooth tissue, besides not achieving a good pH stability, thus affecting dentin remineralization [3]. However, there are controversies about this change in pH and ion release using light-cured calcium hydroxide-based materials [6]. Therefore, it is of interest to evaluate whether light-curing interferes with the beneficial properties of calcium hydroxide-based materials.…”