Orthodontic bracket bond strength and resin composite adhesive degree of conversion associated with type of curing unit and total energy

Abstract

Title from PDF of title page, viewed on March 27, 2014Thesis advisor: Mary P. WalkerVitaIncludes bibliographical references (pages 45-51)Thesis (M. S.)--School of Dentistry. University of Missouri--Kansas City, 2013This study examined the effect of light curing sources on shear bond strength and degree of conversion of orthodontic resin composite adhesive as function of type of curing unit and total energy, as well as evaluated the correlation between shear bond strength and degree of conversion. Curing units included in the study were plasma arc (PA), light emitting diode (LED) and quartz tungsten halogen (QTH) with 5k, 10k, or 15k mJ/cm2 of total energy delivered to the orthodontic adhesive by each unit type. Based on an analysis of variance (α=.05), there was no significant effect of type of curing source on shear bond strength; however, there was a significant effect of total energy, with shear bond strength encreasing as energy increased across curing units. For degree of conversion there was a significant effect of curing unit with PA producing higher degree of conversion than LED or QTH, which were not significantly different from each other. There was also a significant effect of total energy on degree of conversion with a significant increase between 5k to 10k mJ/cm2. There was a positive moderate overall correlation between shear bond strength and degree of conversion. Results of this study suggest that the PA curing unit is more efficient at polymerization (degree of conversion) of orthodontic resin composite adhesive. However, there is no difference in shear bond strength produced when using PA, LED or QTH curing sources for orthodontic bracket bonding procedures when equal total energy is delivered to the adhesiveAbstract -- List of illustrations -- List of tables -- Acknowledgments -- Introduction -- Materials and methods -- Results -- Discussion -- Conclusions -- Literature cite