Effect of acidic environment on dislocation resistance of endosequence root repair material and mineral trioxide aggregate

• Published in: Journal of dentistry (Tehran, Iran) Vol. 11; no. 2; pp. 161 - 166
• Main Authors: Shokouhinejad, Noushin, Yazdi, Kazem Ashofteh, Nekoofar, Mohammad Hossein, Matmir, Shakiba, Khoshkhounejad, Mehrfam
• Format: Journal Article
• Language: English
• Published: Iran Tehran University of Medical Sciences 01-03-2014
• Subjects: Original; Acid; pH, Dislocation; Endosequence Root Repair Material; Mineral Trioxide Aggregate
• ISSN: 1735-2150; 2008-2185

The aim of this study was to compare the effect of an acidic environment on dislocation resistance (push-out bond strength) of EndoSequence Root Repair Material (ERRM putty and ERRM paste), a new bioceramic-based material, to that of mineral tri-oxide aggregate (MTA).
One-hundred twenty root dentin slices with standardized canal spaces were divided into 6 groups (n = 20 each) and filled with tooth-colored ProRoot MTA (groups 1 and 2), ERRM putty (groups 3 and 4), or ERRM paste (groups 5 and 6). The specimens of groups 1, 3, and 5 were exposed to phosphate buffered saline (PBS) solution (pH=7.4) and those of groups 2, 4, and 6 were exposed to butyric acid (pH= 4.4). The specimens were then incubated for 4 days at 37°C. The push-out bond strength was then measured using a universal testing machine. Failure modes after the push-out test were examined under a light microscope at ×40 magnification. The data for dislocation resistance were analyzed using the t-test and one-way analysis of variance.
In PBS environment (pH=7.4), there were no significant differences among materials (P=0.30); but the mean push-out bond strength of ERRM putty was significantly higher than that of other materials in an acidic environment (P<0.001). Push-out bond strength of MTA and ERRM paste decreased after exposure to an acidic environment; whereas ERRM putty was not affected by acidic pH. The bond failure mode was predominantly cohesive for all groups except for MTA in an acidic environment; which showed mixed bond failure in most of the specimens.
The force needed for dislocation of MTA and ERRM paste was significantly lower in samples stored in acidic pH; however, push-out bond strength of ERRM putty was not influenced by acidity.