In Vitro Comparison of the Setting of Dry ProRoot MTA by Moisture Absorbed through the Root

J Endod 34(6):3 (2008) PMID 18498896

This study explored the potential of dry ProRoot mineral trioxide aggregate (MTA) (Dentsply Tulsa Dental, Tulsa, OK) powder to set solely by moisture absorbed through the root. Thirty-three single-rooted extracted teeth were decoronated and instrumented. The canal was packed with dry powder, and the coronal and apical 4 to 5 mm was sealed with nail varnish. Teeth were grouped and submerged in physiologic saline as follows: group A, 12 hours; group B, 36 hours; and group C, 72 hours. After submersion, the teeth were sectioned, and a 5-lb pound weight was placed on the Proroot MTA for 1 minute. The surface was evaluated for any evidence of penetration or fracture at 15x magnification. Nine of 10 samples were set at 72 hours versus 4 of 10 at 36 hours and 1 of 10 at 12 hours. Statistical analysis using a McNemar test with a significance of p < 0.05 found the number of roots in which dry MTA powder set at 72 hours versus 12 hours was statistically significantly different (p = 0.0133).