Comparative study of physico-chemical properties of MTA-based and Portland cements.

The purpose of this investigation was to evaluate the physicochemical properties of gray and white structural and nonstructural Portland cement, gray and white ProRoot MTA and MTA BIO. The water/powder ratio, setting time, solubility and pH (hydrogen-ion potential) changes of the materials were evaluated. Tests followed specification #57 from the American National Standard Institute/American Dental Association (2000) for endodontic sealing materials and pH was determined by a digital pH meter. The test results were statistically analyzed by variance analyses for global comparison and by the complementary Tukey's test for pairwise comparisons (5%). Considering the water/powder ratio, no significant difference (p > 0.05) was observed among the cements. MTA BIO (33.10 +/- 2.30) had the lowest setting time (p < 0.05), gray ProRoot MTA (10.10 +/- 2.70) had the highest (p < 0.05). White nonstructural Portland cement (2.55 +/- 0.08) had the highest solubility (p < 0.05), while gray ProRoot MTA (1.03 +/- 0.12) had the lowest (p < 0.05), although all materials showed solubility values in compliance to ANSI/ADA. No difference (p > 0.05) was observed among materials when considering pH evaluation. The pH levels were highly alkaline immediately after immersion in solution, remaining stable throughout the test period. The authors conclude that the cements had similar water/powder proportions. MTA BIO had the shortest setting time and gray ProRoot MTA had the lowest solubility. All cements had similar behavior in the pH analysis.