الفهرس | Only 14 pages are availabe for public view |
Abstract The aim of this study was to compare the acid-etch technique with sandblasting surface preparation technique on the shear bond strength of orthodontic stainless steel bracket bonded to enamel surface. The sixty premolars were used in the shear bond strength experiment. Twenty premolars were randomly divided into three groups. The acid etching group I, the sandblasting (SB) group II, and sandblasting and acid etching group III. Sandblasting was done with 27 μm aluminum oxide with PrepStartTM Device at 80 psi for 5 seconds and acid etching was done with 37% ortho-phosphoric acid solution for 15 seconds in this study. The upper first premolars brackets were bonded to the specimens. Each specimen was mounted in an Instron Universal Machine and tested to failure in shear mode. After debonding, the teeth were examined using stereomicroscope to determine the percentage of adhesive remaining on the enamel after bracket removal (ARI). Shear bond strength determined in (MPa) at 1 mm/minute Collected data were statistically analyzed for descriptive statistical as well as significance of difference between different groups using one-way analysis of variance ANOVA test followed by multiple comparison post hoc test. In the enamel surface evaluation study, five specimens from each group was selected and scanned using Scanning Electron Microscope at 500x, 1000x, 1200 and 2000x magnification after different methods of surface treatment, to evaluate the effect of the different methods of treatment on the enamel surface. |