International endodontic journal | 2021
Methodological proposal for evaluation of adhesion of root canal sealers to gutta-percha.
Abstract
AIM\nTo compare the bond strength of an epoxy resin-based sealer and two calcium silicate-based sealers (CSS) to gutta-percha disks using a new method.\n\n\nMETHODOLOGY\nRound disks of gutta-percha (n = 60), measuring 10 mm in diameter and 2 mm in thickness, were placed on a glass plate and a drop of each sealer (AH Plus, EndoSequence BC Sealer and EndoSeal MTA) was placed on their surface. Another identical disk was placed onto the first one and a standardized weight (0.0981 N) applied over them using a special developed apparatus. Ten samples prepared for each sealer were submitted to a microshear bond strength test accomplished by a specially designed setup coupled to a universal testing machine. The Kruskal-Wallis test followed by a post hoc procedure was used to compare groups considering the preliminary analysis of the raw data that indicated the non-adherence to a Gaussian distribution (Shapiro-Wilk, p < 0.05). Alpha-error was set at 5%.\n\n\nRESULTS\nOverall, no premature failure occurred. All sealers had some degree of adhesiveness to gutta-percha disks but with a significant difference among them (Kruskal-Wallis, p = 0.019). The epoxy resin-based sealer (AH Plus) had significantly higher median shear bond strength values (1.43 MPa; 1.40-1.83) compared to Endoseal MTA (0.53 MPa; 0.46-0.73) (p = 0.021) and Endosequence BC Sealer (0.45 MPa; 0.34-0.46) (p = 0.023) while the lowest median value was observed with Endosequence BC Sealer (0.45 MPa; 0.34-0.46) (p < 0.05).\n\n\nCONCLUSIONS\nCSS sealers had weaker bonding to gutta-percha when compared to the epoxy resin-based AH Plus sealer. The proposed methodology is an innovative and reproducible method for testing the bond strength of root canal sealers to gutta-percha.