Bond strengths of new simplified dentin-enamel adhesives

Purpose: To compare the in vitro shear bond strengths (SBS) of five simplif ied dentin adhesives. The tested hypothesis was that the recently introduce d simplified adhesive systems would have similar or higher SBS than an exis ting simplified acetone-based adhesive used as a control. Materials and Met hods: 100 flat bonding sites were polished to 600-grit on the labial surfac e of bovine incisors mounted in acrylic resin. 50 teeth were ground to expo se enamel, while the remaining 50 specimens were prepared to expose middle dentin. The specimens were randomly divided into five equal groups to be tr eated with simplified dentin adhesives: Dentastic Uno, EasyBond, Gluma One Bond, One Coat Bond, and One-Step (control). A composite post was bonded to each treatment area. After thermocycling, enamel and dentin shear bond str engths were determined using an Instron testing machine and the data were s ubmitted to statistical analyses. Results: Mean enamel bond strengths range d from 14.6-28.4 MPa. One Coat Bond had the highest mean enamel SBS, but it was not significantly higher than those of Gluma One Bond and Dentastic Un o. EasyBond and One-Step had statistically similar mean enamel SBS and thes e were significantly lower than the mean enamel SBS of the other three adhe sives. For dentin, mean SBS ranged from 14.8-21.7 MPa. Dentastic Uno had th e highest mean dentin SBS, but it was not significantly greater than those of One Coat Bond and Gluma One Bond. Although One Step had the lowest mean dentin SBS, it was not significantly different from those of either EasyBon d or Gluma One Bond.