Purpose: To compare and evaluate the effectiveness of the two fruit vinegar pretreatments, apple vinegar and grape vinegar, on micro-tensile dentin bond strength at different universal adhesive modes.
Material and Methods: Sixty premolars were divided into two groups according to universal adhesive modes (30 teeth for self-etch and 30 teeth for etch and rinse groups). Three subgroups of ten teeth each were created from each group: no pretreatment of the dentin, pretreatment with apple vinegar, and pretreatment with grape vinegar. Mid-coronal dentin was exposed using an automated diamond saw with copious water coolant. Vinegar was applied for 60 seconds, followed by 10 seconds of rinsing, and adhesive layers were applied according to manufacturer instructions. After resin composite build-up, teeth were sectioned to obtain 0.9±0.1 mm rods. Micro-tensile bond strength and mode of failure were measured. ANOVA and the Mann-Whitney U test were used to analyze the data statistically.
Results: No significant difference was found between etch and rinse and self-etch modes in no pretreatment subgroup. For apple and grape vinegar, self-etch recorded significantly higher values than etch rinse mode. Regarding the mode of failure, the predominant failure in both pretreated vinegar etch and rinse modes was adhesive failure. The majority mode of failure in the pretreated vinegar self-etch mode was a cohesive and mixed failure.
Conclusion: Apple and grape vinegar pretreatment positively impacts dentin micro-tensile bond strength, specifically with self-etch universal adhesive mode. Cohesive failure was more represented in both types of vinegar pretreatment.