assessment of bond strength between metal brackets and non-glazed ceramic in different surface treatment methods

objective:   the aim of this study was to evaluate the bond strength between metal brackets and non-glazed ceramic with three different surface treatment methods. materials and methods: forty-two non-glazed ceramic disks were assigned into three groups. group i and ii specimens were etched with 9.5% hydrofluoric acid. subsequently in group i, silane and adhesive were applied and in group ii, bonding agent was used only. in group iii, specimens were treated with 35% phosphoric acid and then silane and adhesive were applied. brackets were bonded with light-cured composites. the specimens were stored in water in room temperature for 24 hours and then thermocycled 500 times between 5°c and 55°c. results: the difference of tensile bond strength between groups i and iii was not significant (p=0.999). however, the tensile bond strength of group ii was significantly lower than groups i, and iii (p<0.001). the adhesive remnant index scores between the three groups had statistically significant differences (p<0.001). conclusion: with the application of scotch bond multi-purpose plus adhesive, we can use phosphoric acid instead of hydrofluoric acid for bonding brackets to non-glazed ceramic restorations.