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Introduction: The restoration of structurally compromised endodontically treated teeth pose most challenging adhesive restorative procedure and controversies still exist about which material or technique are best for their restoration. Aim: To evaluate the push-out bond strength of two fiber post systems luted with self-etch adhesive after phosphoric acid conditioning of the root dentin at two different storage periods. Materials and Methods: Eighty mandibular premolars with single straight canals, decoronated at cementoenamel junction were endodontically treated and post spaces of 8 mm were prepared. Root samples were randomly divided into two groups; Groups 1 and 2 (n=40 each) according to the storage period and four subgroups (n=10 each) depending on the type of fiber post (subgroups A and C: glass fiber posts, B and D: carbon fiber posts) cemented. In subgroups A and B, fiber posts were luted with self-adhesive (Rely X U200) cement. In C and D subgroups, 37% phosphoric acid etching of the root dentin was done prior to cementation of the posts. After one month and 12 months storage period, uniform root slices were obtained for all the specimens with the help of a diamond saw and the slices were subjected to push-out test. The results were analysed with twoway ANOVA and Tukey’s multiple post-hoc test. Results: The 37% phosphoric acid etching significantly improved the bond strength of fiber posts luted with self-adhesive resin (p

Background: To facilitate the easier placement of direct resin composite in deeper cavities, bulk fill composites have been introduced. The Mechanical stability of fillings in stress bearing areas restored with bulk-fill resin composites is still open to question, since long term clinical studies are not available so far. Thus, the objective of the study was to evaluate and compare the microtensile bond strength of three bulk-fill restorative composites with a nanohybrid composite., Material and Methods: Class I cavities were prepared on sixty extracted mandibular molars. Teeth were divided into 4 groups (n= 15 each) and in group I, the prepared cavities were restored with nanohybrid (Filtek Z250 XT) restorative composite in an incremental manner. In group II, III and IV, the bulk-fill composites (Filtek, Tetric EvoCeram, X-tra fil bulk-fill restoratives) were placed as a 4 mm single increment and light cured. The restored teeth were subjected to thermocycling and bond strength testing was done using instron testing machine. The mode of failure was assessed by scanning electron microscope (SEM). The bond strength values obtained in megapascals (MPa) were subjected to statistical analysis, using SPSS/PC version 20 software.One-way ANOVA was used for groupwise comparison of the bond strength. Tukey's Post Hoc test was used for pairwise comparisons among the groups., Results: The highest mean bond strength was achieved with Filtek bulk-fill restorative showing statistically significant difference with Tetric EvoCeram bulk-fill ( p < 0.003) and X-tra fil bulk-fill ( p <0.001) composites. Adhesive failures are mostly observed with X-tra fil bulk fill composites, whereas mixed failures are more common with other bulk fill composites., Conclusions: Bulk-fill composites exhibited adequate bond strength to dentin and can be considered as restorative material of choice in posterior stress bearing areas. Key words: Bond strength, Bulk-fill restoratives, Configuration factor, Polymerization shrinkage., Competing Interests: Conflict of interest statement:The authors have declared that no conflict of interest exist.