Effect of saliva and blood contamination on the shear bond strength of fifth-, seventh-, and eighth-generation bonding agents: An in vitro study

AIM: To evaluate the bond strength of different adhesives after contamination with saliva and blood at various steps of application. MATERIALS AND METHODS: Buccal surfaces of 180 human premolars were sliced to expose dentin. The specimens were randomly divided into six groups (n = 30), in which saliva and blood were used as contaminants in three groups each. The groups were further divided according to the generation (fifth – OptiBond Solo Plus Kerr, USA; seventh – OptiBond All-In-One Kerr, USA; eighth – Futurabond DC, Voco, Germany) of the adhesive used. Effect of contaminant application both before and after polymerization of the adhesive was evaluated. Composite cylinders were fabricated on exposed dentinal surfaces and were subjected to shear bond strength test. The results were subjected to one-way analysis of variance and t-test. RESULTS: The eighth-generation adhesive showed the highest mean shear bond strength, followed by fifth- and seventh-generation adhesive. Salivary contamination resulted in greater decrease of bond strength when contaminated before polymerization. However, the results were vice versa when blood contamination was done, except in the case of fifth-generation adhesive. Blood contamination produced the lowest shear bond strength in all conditions. CONCLUSION: The eighth-generation adhesives showed the highest and blood contamination the lowest bond strength in all conditions.