Influence of Bioceramic Clinker particle size, radiopacifier, and liquids on their physicochemical properties

This study evaluated the addition of calcium tungstate (CaWO4) as a radiopacifier and the manipulation with distilled water (DW) or liquid with additives (LA) on the physicochemical properties of Clinker (CL; Angelus) with different particle sizes (2 to 30 µm and <2 µm), compared to White MTA and MTA Repair HP. Initial and final setting times (ST) were evaluated according to ISO 6876:2012 and ASTM C266-03 standards. Radiopacity was assessed following ISO guidelines, and solubility was evaluated after immersion in distilled water or phosphate-buffered saline for 7 days. The pH was measured using a digital pH meter in 1, 3, 7, 14, 21, and 28 days. ANOVA and Tukey and unpaired t-tests were performed (α=0.05). CL 2 to 30 µm showed shorter initial ST and higher final ST when manipulated with LA (p<0.05). The addition of CaWO4 increased the CL radiopacity for both particle sizes (p<0.05) but did not influence ST, solubility, and pH (p>0.05). All materials presented alkaline pH (p>0.05), especially in 24 hours and 7 days. Regarding the solubility, all groups exhibited mass gain, while White MTA in distilled water demonstrated mass loss (p<0.05). CL 2 to 30 µm + CaWO4 showed greater mass gain and higher radiopacity when manipulated with LA than DW (p<0.05). CL <2 µm manipulated with LA provides a shorter final ST. Both particle sizes positively influence the alkalization capacity of CL, especially in the initial periods. The addition of calcium tungstate and manipulation using LA showed adequate physicochemical properties for clinical application.