Tehran University of Medical Sciences
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Mohammad Hossein Nekoofar

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

Authors: Shokouhinejad, N. - Yazdi, K. A. - Nekoofar, M. H. - Matmir, S. - Khoshkhounejad, M. -
Keywords: Acid , Endosequence Root Repair Material , Mineral Trioxide Aggregate , pH, Dislocation ,
J Dent (Tehran), Vol.11, No.2, 2014,Page:161-6
OBJECTIVE: 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). MATERIALS AND METHODS: 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 degrees 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 x40 magnification. The data for dislocation resistance were analyzed using the t-test and one-way analysis of variance. RESULTS: 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. CONCLUSION: 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.