Evaluation of Composite Resin Bonding to Coronal Dentin Contaminated by Endodontic Sealers

Background: Endodontically treated teeth lose their structure primarily as a result of trauma, decay, and during root canal therapy. Root canal sealers containing eugenol reduce the bond strength of resin cements, therefore present study investigates the shear bond strength of composite to dentin contaminated by endodontic sealers using three types of sealers. Materials and Methods: In this study, 60 human premolar teeth crowns were cross-sectioned to expose the coronal dentin. The samples were divided into 4 groups of 15. In the 3 groups, the dentin surface was contaminated by Endofill, AH26, and MTA Fill apex sealers respectively and group 4 was considered as a control group. The specimens' shear bond strength was measured by a universal testing machine with a loading speed of 1mm/min. The mean shear bond strength was analyzed using Kruskal-Wallis and U Mann-Whitney by SPSS 16. P<0.05 was considered significant. Results: The mean shear bond strength of the studied groups was significantly different (P=0.03). The highest shear bond strength was seen in the control group and the lowest one was related to the Endofill group. A significant difference was seen between the shear bond strength of the two groups (Endofill, AH 26) (P=0.02) and (Endofill, control) (P=0.01). Conclusion: The contamination of dentine with endodontic sealers significantly reduces the shear bond strength of composites to dentin. The shear bond strength was lowest in eugenol-based sealer.