title: Bond strength of ceramic brackets under shear stress: an in vitro report.
abstract: The shear bond strength and the potential enamel damage on debonding of various currently available ceramic and stainless steel brackets were examined in vitro using extracted premolar teeth. The brackets were divided into two groups, one bonded with a new light-cured orthodontic adhesive and the other with a conventional chemically cured system. An Instron Universal testing machine was used to apply the shear stress. Mean, standard deviation, and extreme values were calculated for each group. Statistical analysis showed that the mean shear bond strength of the silane chemical bond provided by some ceramic brackets is significantly higher (p less than 0.05) than the mean of the mechanical bond of other ceramic and stainless steel brackets. There was no statistically significant difference between the mean shear bond strength of the two adhesives used. Mechanical bonds failed primarily within the adhesive itself, whereas chemical bonds failed predominantly at the adhesive-bracket interface. Single-crystal ceramic brackets tend to be more brittle than the polycrystalline ones. Strong chemical bonds can potentially lead to enamel failure on debonding.
authors: Department of Orthodontics, School of Dentistry, University of Minnesota, Minn.
authors: A D
authors: AD
authors: Viazis
authors: G
authors: G
authors: Cavanaugh
authors: R R
authors: RR
authors: Bevis
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D002516:Ceramics; D055598:Chemical Phenomena; D002621:Chemistry; D001840:Dental Bonding; D003738:Dental Cements; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D009967:Orthodontic Appliances; D013193:Stainless Steel; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; D003738:Dental Cements; D013193:Stainless Steel; C065742:Transbond; D017438:Bisphenol A-Glycidyl Methacrylate