Push-out bond strength of mineral trioxide aggregate in the presence of alkaline pH.
BACKGROUND
The aim of this study was to evaluate the effect of a range of alkaline pH values on the push-out strength of white mineral trioxide aggregate (WMTA).


METHODS
The standardized lumens of root slices prepared from extracted single-rooted human teeth were filled with white ProRoot MTA. The specimens were then randomly divided into 4 groups (n = 20) and wrapped in pieces of gauze soaked in synthetic tissue fluid (STF) (pH, 7.4) and STF buffered in potassium hydroxide at pH values of 8.4, 9.4, or 10.4. The samples were incubated for 3 days at 37 °C. The push-out bond strengths were then measured by using a universal testing machine. Failure modes after the push-out test were examined under a light microscope at ×40 magnification. The data were analyzed by using one-way analysis of variance and Tukey post hoc tests.


RESULTS
The greatest (9.46 ± 0.63 MPa) and lowest (5.68 ± 0.83 MPa) mean push-out bond strengths were observed after exposure to pH values of 8.4 and 10.4, respectively. There were significant differences between the groups (P = .001). The bond failure was adhesive for all experimental groups.


CONCLUSIONS
Push-out bond strength of WMTA could be influenced by different alkaline pH values.
Department of Dental Material, School of Dentistry, Tehran Branch, Islamic Azad University, Tehran, Iran. saghiri@gmail.com
Mohammad Ali
MA
Saghiri
Noushin
N
Shokouhinejad
Mehrdad
M
Lotfi
Mohsen
M
Aminsobhani
Ali Mohammad
AM
Saghiri
D000468:Alkalies / Q000737:chemistry*; D017607:Aluminum Compounds / Q000737:chemistry*; D002021:Buffers; D017610:Calcium Compounds / Q000737:chemistry*; D001840:Dental Bonding; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D004338:Drug Combinations; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D008422:Materials Testing; D010087:Oxides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D011189:Potassium Chloride / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000468:Alkalies; D017607:Aluminum Compounds; D002021:Buffers; D017610:Calcium Compounds; D004338:Drug Combinations; D006878:Hydroxides; D010087:Oxides; D010710:Phosphates; D017680:Potassium Compounds; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D014867:Water; D012965:Sodium Chloride; D011189:Potassium Chloride; C013216:potassium phosphate; C018279:sodium phosphate; C029943:potassium hydroxide