¬Influence of novel dry bonding approaches on the shear bond strength of a universal adhesive: An in vitro study

Context: Aims: To determine the effect of novel dry bonding approaches on the shear bond strength of universal adhesive.Settings and Design: Methods and Material: The occlusal surface of forty extracted human molars were sectioned to expose the superficial dentin. The samples were randomly divided into four groups with 10 samples in each. The bonding to composite resin was done by a universal adhesive in the first group by self etch approach, second group by etch and rinse approach, the third and fourth groups were bonded by etch and rinse approach but additionally they were treated with Grape seed extract (GSE) and Dimethyl Sulfoxide (DMSO) prior to the application of the bonding agent according to the novel dry bonding approaches. Then, resin composite was inserted into a plastic tube placed on the specimen and light polymerized as per manufacturer’s instructions. 5 samples in each group were stored in distilled water at 37°C for 24 hrs, the rest of the 5 samples in each group were thermocycled to mimic 1 year of aging. Then, shear bond strength analysis was done at a crosshead speed of 1.0 mm/min in a universal testing machine. Finally, the mode of failure was analysed under a stereomicroscope.Statistical analysis used: The statistical analysis for comparison of the mean bond strengths among the various groups was accomplished by Post-hoc Mann whiteney and Kruskal Wallis test. Results: Thermocycling significantly reduced the bond strength in etch and rinse group. The highest bond strength at 24 hrs and at one year was observed in DMSO treated group. Adhesive failure was seen more frequently in all the groups. Conclusions: DMSO treated group showed significantly higher bond strength and bond durability.