Effect of etching time and light sources on the shear bond strength of metal brackets to ceramic cylinders

OBJECTIVE: To evaluate the shear bond strength of brackets bonded to ceramic with Transbond XT resin, etching time intervals (1 and 2 minutes) and three Light sources (Xenon Plasma Arc, LED and Halogen Light ), with and without silane.METHODS: In total, 12 feldspathic ceramic cylinders (15 mm x 20 mm), etched with 10% hydrofluoric acid were used. For light activation, the brackets were divided according to the light source to be used (n-15): LED UltraLume 5 (L); Apollo 95E plasma arc (AP) and Halogen light XL 2500 (H). After 24 h the samples were submitted to shear bond strength testing at crosshead speed of 0.5 mm/minute.RESULTS: The data were submitted to the analysis of variance (ANOVA) and the Tukey test (5%). Bond Strength: UltraLume 5 (11.4 ± 3.56 MPa) was superior to XL 2500 (9.12 ± 2.83 MPa) and Plasma Arc (5.11 ± 2.93 MPa) (p