Method: 60 crowns of molars were embedded in acrylic resin and mechanically ground to expose a flat enamel surface, polished and etched with 37% phosphoric acid gel for 15 s. The specimens were randomly assigned to four groups (n=15), according to the surface treatment. Group 1 (control) had no saliva/blood contamination. The other groups were saliva/blood-contaminated and subjected to different post-contamination protocols: in Group 2, the surfaces were contaminated and applied sealant Fluroshield; in Group 3, the surfaces were contaminated, after Single Bond adhesive system was applied and sealant Fluroshield; in Group 4, the surfaces were contaminated, after Prime&BondNT adhesive system was applied and sealant Fluroshield. In all groups, a 3-mm enamel bonding site was demarcated and the contaminated groups were done with 0.01 mL of fresh saliva/blood for 20s. After 24 hours in distilled water, shear bond strength was tested at a crosshead speed of 0.5 mm/minute.
Result: Means (in MPa) were: Group 1: 12.61 (0.77); Group 2: 2.28(0.90); Group 3: 7.07 (0.55) and Group 4: 7.79(0.78). Data were analysed statistically by the ANOVA and Duncan test at 5% significance level. Groups 3 and 4 were similar to each other (P > 0.05). These groups (1, 3 and 4) had statistically significantly higher bond strengths than Groups 2.
Conclusion: Saliva/blood contamination negatively affected the shear bond strength to permanent tooth enamel. Among the saliva/blood-contaminated groups, no difference was observed between the adhesive systems.
Keywords: Adhesion, Blood, Enamel, Saliva and Sealants
See more of: Dental Materials 1: Adhesion - Bond Strength Testing and Mechanisms