The impact of thermocycling process on the dislodgement force of different endodontic cements.
To evaluate the effects of thermocycling (500 cycles, 5°C/55°C) on the push-out bond strength of calcium silicate based cements including WMTA, Nano-WMTA, and Bioaggregate to root dentin. Forty-eight dentin slices were prepared and divided into 3 groups (n = 16) and filled with Angelus WMTA, Nano-WMTA, or Bioaggregate. After incubation, half of the samples were thermocycled while the other half remained untreated. Push-out bond strength was calculated, and the modes of the bond failures were determined by SEM. The highest bond strength was seen in nonthermocycled Nano-WMTA samples and the lowest in thermocycled Bioaggregate samples. The significant differences between nonthermocycled and thermocycled samples were only noticed in WMTA and Nano-WMTA groups (P < 0.001). The mode of failure for thermocycled samples of all three cements was mostly cohesive. Thermocycling process can drastically affect the push-out bond strength of calcium silicate based cements. The intrastructural damages occurred due to the thermal stresses, causing cohesive failures in set materials. Sealing property of endodontic cements which have experienced the thermal stresses can be jeopardized due to occlusal forces happening in furcation cites.
Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
Mohammad Ali
MA
Saghiri
Armen
A
Asatourian
Franklin
F
Garcia-Godoy
James L
JL
Gutmann
Nader
N
Sheibani
D017607:Aluminum Compounds / Q000737:chemistry; D001696:Biomechanical Phenomena; D017610:Calcium Compounds / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry; D004338:Drug Combinations; D006801:Humans; D008422:Materials Testing / Q000379:methods*; D053758:Nanoparticles; D010087:Oxides / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D013696:Temperature
D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D017640:Silicates; C086631:mineral trioxide aggregate