Proroot mineral trioxide aggregate cement used as a retrograde filling without addition of water: an in vitro evaluation of its microleakage.

The aim of this in vitro study was to compare at different times the microleakage of roots filled with Proroot mineral trioxide aggregate (MTA) mixed with water as recommended by the manufacturer or filled only with powder without any previous hydration. Forty-four extracted single-rooted human teeth had their crown removed, and their roots were instrumented, filled with gutta-percha without cement, resected at 3 mm from the apex, and ultrasonically prepared with CK5 retrotips. The roots were randomly divided into 2 groups, group 1 (n = 20) and group 2 (n = 20) with 2 positive and 2 negative control roots. Teeth in group 1 were filled with white Proroot MTA prepared as suggested by the manufacturer, whereas in group 2, teeth were filled with white Proroot MTA by using only powder without any hydration. Microleakage of each root was measured at 24 hours and 1, 2, 4, and 12 weeks after filling with a fluid filtration device. No statistically significant difference (P > .05) in microleakage between groups 1 and 2 was detected at any time except the 1-week period. The lack of water addition during the preparation of the cement in this study did not affect the in vitro sealing ability of Proroot MTA.