Indian Journal of Dental Research (Jan 2012)
The effect of air abrasion on the retention of metallic brackets bonded to fluorosed enamel surface
Abstract
Background: Bonding brackets to fluorosed enamel remains a clinical challenge and bracket failure at the compromised enamel interface is common. Objective: To check the effect of air abrasion on the retention of metallic brackets bonded to fluorosed enamel surface. Materials and Methods: Sixty freshly extracted human premolar teeth having moderate to severe dental fluorosis as per Dean′s criteria were collected and divided into three groups of 20 each. The groups were treated as follows: In group I, acid etching was followed by bonding with Transbond XT® ; in group II, sandblasting and acid etching was followed by bonding with Transbond XT® ; and in group III, sandblasting and acid etching was followed by bonding with Enlight LC® . An Instron™ universal testing machine was used for determining the debonding force, and from this the shear bond strength was computed. The sample with highest shear bond strength from each group was selected for the scanning electron microscopy (SEM) study. The prepared specimens were examined under a JSM-840A scanning electron microscope (JEOL Ltd, Tokyo, Japan) operated at 20 kV. Photographs were taken at progressively higher magnifications of ×50, ×100, ×500, and ×1000 to view the enamel surface and the adhesive remaining on the enamel surface after debonding. The shear bond strengths of the groups were compared using the one-way ANOVA (analysis of variance) and Tukey post hoc test. The distribution of adhesive remnant index (ARI) score was compared using the Chi-square test. Results: The mean shear bond strength in group I was 10.36 MPa, with a standard deviation of 0.225. The corresponding values in group II and group III were 11.41±0.237 MPa and 11.39±0.201 Mpa, respectively. There was a statistically significant difference between the three groups in the mean shear bond strength values. Conclusion: Sandblasting followed by acid etching provides significantly higher bond strength values compared to acid etching alone, irrespective of the bonding material employed.
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