| 3107 Evaluation of Orthodontic Bracket Bond Strengths Using LED Curing Units | ||
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K.G. SPILLANE, E. TUFEKCI, J.M. CARTER, P.C. MOON, and S.J. LINDAUER, Virginia Commonwealth University - VCU/MCV, Richmond, USA Evaluation of orthodontic bracket bond strengths using LED curing units. Recently, light emitting diode (LED) curing units have become popular for bonding orthodontic attachments. According to manufacturers, these high-speed light systems reduce curing time without compromising the bond strength of composite resins. Purpose: The aim of this study was to compare the shear bond strength and mode of bond failure of brackets bonded using 4 different light curing units. Materials and Methods: 100 extracted human molars were randomly assigned to 3 LED groups (OrtholuxTM LED, L.E. Demetron 1, and GC E-Light) and one conventional visible light-curing group (OrtholuxTM XT) (N=25). Edgewise brackets were bonded using each of the curing units following manufacturer's instructions. After 24 hours, brackets were debonded in an Instron universal testing machine. Shear bond strengths were calculated. The site of bond failure was scored according to the Adhesive Remnant Index (ARI). Statistics included one-way ANOVA, Kruskal-Wallis and Weibull survival analyses. Results: The mean shear strengths were 14.9 ± 7.9, 15.9 ± 6.3, 13.7 ± 5.9 and 15.6 ± 6.9 MPa for the OrtholuxTM LED, L.E. Demetron, GC E-Light and OrtholuxTM XT, respectively. There were no significant differences in mean shear bond strengths and ARI scores among the 4 groups (P>0.20). Weibull analysis indicated stress required for a 10% probability of failure was 4.4 and 5.9 MPa for GC E-Light and OrtholuxTMLED, respectively. This may be of clinical relevance because these values are below the suggested minimum bond strength value of 6-8 MPa. Conclusions: Based on the findings of this study, the LED curing units did not perform significantly different than the visible light-curing unit. This information supports the routine clinical use of light emitting diode-curing units for bonding of orthodontic brackets.
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| Seq #335 - Adhesion III 10:15 AM-11:30 AM, Saturday, 13 March 2004 Hawaii Convention Center Exhibit Hall 1-2 | ||
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