Preparation, characterization and In vitro cytotoxicity assay of calcium silicate derived SiO₂ rice husk

Calcium silicate that is biocompatible may find application in the medical field, particularly in the replacement of bone grafts. One readily available and rich source of silica (SiO₂) for the production of silica-based compounds is rice husk waste. The three types of Indonesian rice husks that we use for our preparation and characterization of calcium silicate bioceramics are black (code: KS-H), red (code: KS-M), and white (code: KS-P). Additionally, we assess their cytocompatibility at various concentrations (0.5, 0.25, 0.1, and 0.01 mg/mL) using the methyl-thiazolyl-tetrazolium (MTT) assay on MG63 cell types. The triclinic anorthic phase of Wollastonite-1A, a kind of calcium silicate with the chemical formula CaSiO₃, with its rough, porous, uneven surface appearance, was present in all three samples. The 2-way ANOVA test's MTT assay findings revealeda significant differences between samples at groups (p value of 0,000). The Tuckey test results based on the sample group showed a significant difference (p < 0,05) in cell viability between the KS-H and Control group,however, the ISO 10993-5 considered no toxic properties based on the mean cell viability of all test materials at different concentrations (0.5; 0.25; 0.1; and 0.01 mg/mL) (78.72% - 123.51%). We may conclude that the three calcium silicates prepared in this study are not cytotoxic and have potential used in medical and dental application.