Aim:To make a comparative evaluation of the effect of different post space irrigation procedures on the push-out bond strength of prefabricated fiber posts luted with self-adhesive resin cement in different root thirds (coronal, middle, and apical). Materials and methods:Sixty freshly extracted single-rooted teeth were selected, and after root canal preparation and obturation, standardized post spaces were prepared. Teeth were then randomly divided into four groups (n = 15), according to the different post space irrigants used: group I-distilled water (control); group II-17% ethylenediaminetetracetic acid (EDTA) + 2.5% sodium hypochlorite (NaOCl); group III-99% ethanol; group IV-SmearOFF. All solutions were maintained in the root canals for 60 seconds and dried with paper points. Prefabricated fiber posts were luted using the self-adhesive resin cement. The push-out test was carried out by applying a load using Instron Universal Testing Machine. Results:The results of the analysis of variance (ANOVA) and the post hoc Bonferroni tests revealed that the push-out bond strength was significantly affected by the different post space irrigants (p < 0.001). However, no significant difference in push-out bond strength was attained with reference to the different locations inside the canal (i.e., coronal, middle, and apical) (p > 0.05). Conclusion:Pretreatment of the post space using 99% ethanol resulted in highest bond strength with respect to prefabricated fiber posts luted with self-adhesive resin cement. The push-out bond strengths exhibited by both, the newly launched irrigant: SmearOFF and the combination of EDTA + NaOCl, were comparable.Clinical significance: Irrigation of post space after mechanical post space preparation is the central key to remove smear layer, open dentinal tubules along with achieving superior bond strength of fiber posts cemented with a self-adhesive resin cement to root dentin.

Aim:Comparative evaluation of the fracture resistance of maxillary premolar teeth restored with two high-viscosity bulk-fill composites and incrementally placed composite.Materials and Methods:Seventy-five freshly extracted maxillary premolar teeth were selected. Fifteen specimens served as positive control (Group 1). Mesio-occluso-distal cavity preparation was prepared on the rest of the specimens. These specimens were further divided into four groups: unrestored teeth (Group 2), teeth restored with incrementally placed nanocomposite (Group 3), teeth restored with high-viscosity bulk-fill giomer (Group 4), and teeth restored with high-viscosity bulk-fill nanocomposite (Group 5). The specimens were then subjected to compressive axial load using Instron universal testing machine. Data were analyzed using data were analyzed using Statistical package for social sciences software (SPSS v 20.0, IBM Corp.).Results:The positive control group exhibited highest fracture resistance (1104.70 ± 122.2 N). There was no statistically significant difference seen in between the incrementally placed nanocomposite and high-viscosity nanocomposite (P > 0.05). The fracture resistance values displayed by the high-viscosity bulk-fill giomer were found to be statistically lower than the other two groups.Conclusion:High-viscosity bulk-fill nanocomposite may substitute incrementally placed nanocomposite with respect to fracture resistance.