Bond Strength of Experimental Root Canal Sealers Based on MTA and Butyl Ethylene Glycol Disalicylate

Abstract

This study investigated the bond strength of two experimental root canal sealers based on MTA and butyl ethylene glycol disalicylate: MTAe and MTAe-HA. The reference materials used for comparison were AH Plus and MTA Fillapex. Twenty human upper incisors were selected and one 1 mm slice was obtained from the cervical third of each root. On the coronal surface of each slice, four 0.9 mm wide holes were drilled through the dentine. Standardized irrigation was performed and holes were filled with one of the four tested sealers: AH Plus, MTA Fillapex, MTAe, and MTAe-HA. The filled slices were stored in a PBS solution (pH 7.2) for 7 days at 37 °C. A push-out assessment was performed with a 0.7 mm plunger tip. Load was applied at a crosshead speed of 0.5 mm/min until sealer displacement. The results were expressed in MPa. The Kruskal-Wallis test was applied to assess the effect of each sealer on the push-out bond strength. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05. Significant differences among medians values obtained by materials were observed (p<0.001). AH Plus displayed the highest value of bond strength (p<0.001). In contrast, MTA Fillapex presented the lowest bond strength among all tested sealers (p<0.001). Experimental sealers showed intermediary bond strength values, with no statistical differences between them (p>0.05). In conclusion, experimental root canal sealers presented suitable bond strength outcomes when compared to MTA Fillapex.

Bovine teeth can reliably substitute human dentine in an intra‐tooth push‐out bond strength model?

“…, Prado et al . ). Consequently, the use of gutta‐percha may have the potential to randomly influence the behaviour of endodontic sealers, yielding erroneous conclusions regarding the performance of the sealers (Scelza et al .…”

“…As previously stated, in this push-out design, the load is applied only to the endodontic sealers that completely filled the standard holes. Therefore, this method represents a reliable and more direct result between the sealer and dentine interface and, at the same time, provides better control over the type of failure mode, because the test is not influenced by the resilience of gutta-percha (Silva et al 2016, Carvalho et al 2017, Prado et al 2018. Consequently, the use of gutta-percha may have the potential to randomly influence the behaviour of endodontic sealers, yielding erroneous conclusions regarding the performance of the sealers (Scelza et al 2015).…”

“…Bovine teeth are also easier to handle due to their size (Almeida et al 2009), mainly in the present push-out design. As a result, this method produces standardization and good reproducibility for bond strength tests of filling materials, being used in several recent publications (Scelza et al 2015, Silva et al 2016, Carvalho et al 2017, Prado et al 2018.…”

“…, Prado et al . ). The clear advantage of this novel design is to provide the same baseline substrate for all materials that are tested, as all groups are distributed in the holes within the same root slice, to reflect the intra‐tooth design of this model.…”

“…Although this is the most common method, it underscores a substantial drawback of creating a reliable baseline as a result of the variable morphology of the dentinal substrate and the intricate anatomy that challenge the standardization of human teeth samples (Scelza et al 2015, Silva et al 2016, Carvalho et al 2017. For this reason, a recent standard-hole method that increases the internal validity of push-out models has been proposed (Scelza et al 2015, Silva et al 2016, Carvalho et al 2017, Prado et al 2018. The clear advantage of this novel design is to provide the same baseline substrate for all materials that are tested, as all groups are distributed in the holes within the same root slice, to reflect the intra-tooth design of this model.…”