| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3170582 | Orthodontic Waves | 2011 | 12 Pages |
PurposeThis study evaluated the effect of three resin removal methods on the rebond shear bond strength (RBS) of orthodontic brackets and on enamel surface (under stereo and electron microscopy), when using two types of brackets.MethodsSeventy freshly extracted human premolars were randomly distributed among three experimental groups (n = 20) and one control (n = 10). Metal brackets in experimental groups were debonded and the adhesive remnant index (ARI) was scored under 10× magnification. The residual adhesives were removed by three different methods: (1) tungsten carbide bur (TCB) at high and (2) low speed, and (3) sandblasting. Experimental premolars were bonded with new and sandblasted recycled brackets (50 μm Al2O3, 90 PSI). All specimens were subjected to thermocycling (3000 cycles, 5–55 °C, dwell time = 30 s, and transfer time = 15 s); and were debonded using a universal testing machine with crosshead speed of 1 mm/min, and the RBS and SBS were, respectively, measured in experimental and control groups. The ARI was re-scored.ResultsOne-way ANOVA did not observe a significant difference in the bond strength of all 7 groups (P = .411). The RBS was not significantly different from the SBS (P > .05) according to independent-samples Student t-test, apart from the group high-speed TCB with new brackets. No significant difference was found between resin removal methods (P = .400), bracket types (P = .713), and the interaction of both (P = .224), according to two-way ANOVA. Kruskal–Wallis test failed to observe significant differences between groups, both in ARI1 and ARI2 (P > .05).ConclusionUsing TCB might be comparatively superior. Enamel sandblasting was time-consuming and frequently damaged the enamel in all SEM figures. Using recycled-sandblasted brackets may provide sufficient RBS rates.
