Influence of bioceramic intracanal medication on the bond strength of bioceramic root canal sealer

To investigate the influence of the remaining volume of a new intracanal medication based on bioceramic compounds on the bond strength (BS) and formation of an adhesive interface between calcium silicate-based and epoxy resin-based root canal sealers. For this purpose, the specimens were distributed according to the intracanal medication (n = 26): Bio-C Temp (BCT) and Ultracal XS (UXS). The roots were scanned in microCT, and after 7 days, the medication was removed. Then a new scan was performed to evaluate the volume of medication remaining. Subsequently, 40 specimens were redistributed into 2 subgroups (n = 10) and filled according to the sealer used: AH Plus (AHP) and Bio-C Sealer (BCS), to assess the bond strength by using the push-out test, and the adhesive interface by confocal laser fluorescence microscopy (CLSM) and scanning electron microscopy (SEM). The t test showed a smaller remainder of BCT (1.77 +/- 0.86) compared with UXS (10.47 +/- 5.78), irrespective of the root third evaluated. The BS showed that teeth with BCT + BCS had higher bond strength values (3.70 +/- 1.22) when compared to the other groups: BCT + AHP (2.15 +/- 1.07), UXS + BCS (3.18 +/- 1.09) and UXS + AHP (2.11 +/- 1.02) (p<0.001). The cervical third had higher BS when compared with the middle and apical thirds (p < 0.001), and higher number of adhesive failures. The adhesive interface in SEM and CLSM images showed better adaptation for the association between BCT + BCS. Intracanal medication and silicate-based endodontic sealer appeared to interact chemically by forming a biomineralizing layer, allowing for an increase in the bond strength and forming an adhesive interface between the materials, with no or less gap formation.

Automated summary

This study investigated the impact of the remaining volume of a new intracanal medication on the bond strength and adhesive interface formation between calcium silicate-based and epoxy resin-based root canal sealers. The results showed that Bio-C Temp had a smaller remaining volume compared to Ultracal XS. The bond strength test revealed that the combination of Bio-C Temp and Bio-C Sealer had higher bond strength, with the cervical region exhibiting higher bond strength compared to the middle and apical thirds.