The use of a setting accelerator and its effect on pH and calcium ion release of mineral trioxide aggregate and white Portland cement.

The aim of this study was to evaluate the influence of adding 10% calcium chloride (CaCl2) indicated as setting accelerator on pH and release of calcium ions of commercially available materials: ProRoot MTA (tooth-colored formula), MTA Branco, and White Portland cement. The products were mixed for 30 seconds in previously established ratios. To estimate the values of pH and release of calcium ion, polyethylene tubes were filled with the materials and immersed in containers with 10 ml of deionized water. The analyses were performed baseline, 30 minutes, 60 minutes, and 24 hours after the mixing process. A pHmeter (MicroNal B 371, Sao Paulo, SP, Brazil) and an atomic absorption spectrophotometer (Model GBC 904; CG Corp, Melbourne, Australia) equipped with a hollow cathode lamp were used to determine the data. According to the Student's t-test, the comparison between the pure and the CaCl2-added products indicated that the presence of this substance increased immediately the pH, although the results were very similar when they were analyzed in the other intervals. In addition, products with CaCl2 released more calcium ions than pure materials in the 24-hour period (p<0.05). The results revealed that the addition of CaCl2 to MTA enhanced the physicochemical properties of this product. Thus, materials mixed with CaCl2 became easier to handle and needed lower amounts of water in the mixing process.