PUSH OUT BOND STRENGTH OF ROOT CANAL FILLING WITH EPOXY RESIN-BASED, MTA-BASED AND BIOCERAMIC-BASED ENDODONTIC SEALERS

Abstract

Aim: to compare the push out bond strength of the root canal filling with epoxy resin-based (Adseal), MTA-based (MTA Fillapex) and Bioceramic-based (Endosequance BC) sealers. Materials and Methods: Forty five extracted mandibular human first premolars with straight fully formed roots were selected for this study and were de-coronated at 17 mm from the apex. All root canals were prepared by using the ProTaper Universal Ni Ti rotary system in a crown down manner up to F4 according to manufacturer's instruction to the their working length. The canals were irrigated with 17% EDTA to remove the smear layer and the final rinse was performed with 5 mL 5.25% sodium hypochlorite. The roots were randomly assigned to three groups, fifteen for each (n=15). Adseal, MTA Fillapex and Endosequence BC sealers were used with gutta percha size F4 by lateral condensation technique for groups I, II and III respectively. All roots stored in 100% humidity at 37ºC for one week for completing setting of sealers. The roots were embedded in self cure acrylic resin, and transversely sectioned perpendicular to the long axis of the root 2 mm thickness slices. Apical diameter of 0.88 ± 0.02 mm in all slices were selected for the push-out test by universal testing machine. The dislodging force was measured in Newton for all slice samples and tabulated. Push out bond strength (MPa) for every slice sample is calculated and the three groups were compared. The slices were then examined under stereomicroscope and categorized into adhesive, cohesive or mixed type of bond failure mode. The data were tabulated and statistically analyzed. Results: Endosequence bioceramic represented the highest bond strength followed by Adseal then MTA Fillapex which represented the lowest bond strength with a significant difference between them at P≤0.05. Comparison between Adseal and Endosequence bioceramic groups and between MTA Fillapex and Endosequence bioceramic groups showed a significant difference between them at P≤0.05 with higher bond strength of Endosequence bioceramic sealer. Adseal represented higher bond strength than MTA Fillapex with no significant difference between them at P≤0.05. Comparison between the three tested groups of sealers regarding the bond failure categories showed no significant difference between them at P≤0.05.