Micro Tensile Bond Strength of an Universal Dentin Adhesive System

Objectives: The aim of the present investigation was to evaluate microtensile bond strength (MTBS) of a recently introduced universal dentin adhesive systems (Futurabond U, Voco, Cuxhaven, Germany) on enamel and dentin in self-etch and etch&rinse mode in vitro compared to established bonding agents.
Methods: 120 freshly extracted third molars were included. All teeth were specially prepared allowing the simulation of dentin perfusion. Dentin specimens with a total thickness of 1.5 mm were obtained under standardized conditions. The specimens were randomly assigned to eight experimental groups: group A/B: Futurabond U etch&rinse on enamel and dentin; group C/D: Futurabond U self-etch on enamel and dentin; group E/F: Futurabond DC self-etch on enamel and dentin; group G/H: Solobond M etch&rinse on enamel and dentin. All materials were applied as recommended by the manufacturer. MTBS was measured 15 minutes after light curing of the composite material (GrandioSo, Voco, Germany) using an universal testing machine.
Results: For the eight groups following values were evaluated (in MPa): A: 21.44 (+/- 5.85), B: 18.42 MPa(+/- 5.01), C: 16.09 (+/- 4.31), D: 14.83 (+/- 4.72), E: 20.61 (+/- 6.20), F: 13.10 (+/-1.79), G: 21.10 (+/-3.19) and H: 16.66 (+/- 2.94).Statistical analysis showed a significant influence of the used dentin bonding mode and substrate (p< 0.001, ANOVA). Bond strengths of Futurabond U used on enamel in etch&rinse mode (group A) was significantly increased compared to self-etch mode (group C) (p< 0.05, Tukeys test). Regarding the dentin (group B and D) no significant differences could be detected between the different modes (p> 0.05, Tukeys test).
Conclusions: Regarding the limitations of an in vitro study it can be concluded that the universal dentin adhesives system showed promising results. Therefore, the clinical use of this universal adhesive system might be a good alternative to the established systems on enamel and dentin.