RESUMO
Background: Cavity preparation often causes gingival bleeding which can be controlled by hemostatic agents (HAs). These along with blood act as contaminants and hamper the bonding mechanism. Collagen cross-linkers (CCLs) are agents known to increase the bond strength (BS) to dentin. Hence, the purpose of this in vitro study was to determine the effect of two different CCLs, proanthocyanidin (grape seed extract [GSE]) and hesperidin on the microtensile BS (µTBS) of a self-etch adhesive (SEA) system to dentin which was contaminated with blood and a HA. Materials and Methods: Thirty-six extracted human molars were collected, and their occlusal surfaces were sectioned to expose the dentin. The teeth were randomly divided into four groups: Group I - Control, Group II - Contamination with blood and HA, Group III - Application of GSE after contamination, and Group IV - Application of hesperidin extract after contamination. The SEA was applied, followed by the use of a nanocomposite. Dentin-composite rods were obtained from each group, and µTBS testing was done. The fracture pattern was visually classified as an adhesive failure at the interface, cohesive failure in composite, or dentin. The scanning electron microscope (SEM) analysis was done for two samples from each group. Statistical analysis was done using the Student's unpaired "t" and ANOVA test. Results: Group II showed a statistically significant reduction in µTBS in comparison to Group I. This was overcome in Groups III and IV. Hesperidin showed marginally better results than GSE. Conclusions: The use of GSE and hesperidin increases the µTBS of composite resin to dentin postcontamination with blood and ViscoStat Clear with Single Bond Universal Adhesive.