The impact of thermocycling process on the dislodgement force of different endodontic cements.

PubMed ID: 24063004

Author(s): Saghiri MA, Asatourian A, Garcia-Godoy F, Gutmann JL, Sheibani N. The impact of thermocycling process on the dislodgement force of different endodontic cements. Biomed Res Int. 2013;2013:317185. doi: 10.1155/2013/317185. Epub 2013 Aug 24. PMID 24063004

Journal: Bio Med Research International, Volume 2013, 2013

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.