Bond strength of resin composite to light activated bleached enamel.
OBJECTIVE
This study evaluated the microtensile bond strength (μTBS) of a resin composite bonded to bleached enamel as a function of bleaching conditions.


METHODS
The whiteness hydrogen peroxide (HP) bleaching agent containing 35% HP was applied to the central incisors' facial enamel surface and irradiated as follows: No treatment (G1; control); no light (G2); light-emitting diode, the 40s (G3); diode laser, the 20s (G4); and neodymium:yttrium aluminum garnet laser, 20s (G5). A Variolink II resin composite structure was then built up incrementally on the surface. The teeth were sectioned into three 1.2 mm × 1.2 mm wide "I"-shaped sections. The specimens were then subjected to microtensile testing at a crosshead speed of 1 mm/min. Data were analyzed using one-way ANOVA (α =0.05) followed by the Tukey Honestly Significant Difference post-hoc test. The fractured surfaces were observed with a stereomicroscope at × 100 magnification.


RESULTS
One-way ANOVA revealed no statistical differences among the groups (P > 0.05). No differences appeared between the groups bonded 14 days after bleaching (P > 0.05). Mean μTBS values (MPa) were as follows: 22.05 ± 5.01 (G1); 19.6 ± 5.6 (G2); 19.3 ± 5.4 (G3); 20.08 ± 2.08 (G4); and 18.1 ± 4.8 (G5). Many adhesive failures occurred at the bleached and irradiated enamel surfaces.


CONCLUSIONS
The various irradiation treatments following the application of the whiteness HP bleaching agent to enamel did not significantly reduce the μTBS within a 14-day period.
Department of Prosthodontics, Faculty of Dentistry, Abant Izzet Baysal University, Bolu, Turkey.
T
T
Yavuz
Department of Prosthodontics, Faculty of Dentistry, Medipol University, Istanbul, Turkey.
O Y
OY
Ozyilmaz
Department of Prosthodontics, Faculty of Dentistry, Selcuk University, Konya, Turkey.
A N
AN
Ozturk
Department of Prosthodontics, Faculty of Dentistry, Selcuk University, Konya, Turkey.
F
F
Aykent
D003188:Composite Resins; D001840:Dental Bonding; D003743:Dental Enamel / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D053844:Lasers, Solid-State; D008422:Materials Testing; D019279:Resin Cements; D013718:Tensile Strength; D014073:Tooth Bleaching / Q000379:methods*
D003188:Composite Resins; D019279:Resin Cements; C103502:Variolink; D006861:Hydrogen Peroxide