COMPARATIVE EVALUATION OF DENTIN MOISTURE EFFECT ON BOND STRENGTH AND ADHESIVE INTERFACE OF TWO EPOXY RESIN AND TWO CALCIUM SILICATE BASED ROOTCANAL SEALERS – AN IN-VITRO STUDY

Abstract

To compare and evaluate effect of three root canal drying protocols on push-out bond strength (PBS), failure modes and interfacial adaptation of epoxy resin (AH Plus, AD Seal) and calcium silicate-based (Bio-C, AH Plus Bioceramic) sealers. Materials and Methods: Ninety-six extracted single-rooted mandibular premolars were decoronated, prepared with ProTaper Next up to X3, irrigated and divided into four groups (n=24): Group A-AH Plus, B-AD Seal, C-Bio-C, D-AH Plus Bioceramic. Each group was further subdivided (n=8) by drying protocol: Dry (White Mac tip + flexible capillary tip + paper points), Slightly moist (White Mac tip + capillary tip only), Wet (White Mac tip + single paper point). Obturation was performed with single-cone technique using corresponding sealer, access sealed with GIC. Samples were stored at 37°C and 95% humidity for 3 months, then sectioned into 1-mm slices from cervical, middle and apical thirds. PBS was measured with universal testing machine, failure modes with stereomicroscope (adhesive/cohesive/mixed), and bond adaptation with scanning electron microscope. Statistics: One-way ANOVA with Tukey's post hoc for PBS; chi-square for failure modes and adaptation; significance p<0.05. Results: Epoxy resin sealers showed highest PBS in dry canals across all thirds (p<0.001), but decreased significantly in slightly moist and wet conditions. Calcium silicate sealers showed higher PBS in slightly moist canals (p<0.001) and lowest in dry and wet conditions. Adhesive failures predominated overall, especially epoxy resin sealers in dry canals. Wet canals showed more cohesive/mixed failures and Poor to No adaptation (p=0.005), while dry canals with epoxy resin sealers showed Good to Reasonable adaptation (p=0.04). Conclusion: Drying protocol significantly influences sealer-dentin bond. Dry canals favor epoxy resin sealers; controlled slightly moist canals favor calcium silicate sealers. Excessive moisture impairs bonding and adaptation for all sealers, emphasizing need for sealer-specific tailored drying protocol.