title: An in vitro evaluation of the tensile and shear strengths of four adhesives used in orthodontics.
abstract: The in vitro shear and tensile strength of four enamel adhesives was investigated. The materials examined were System 1+, Vitrebond, C & B Metabond and Panavia-Ex (original version). The mode of failure of each material was also investigated under a scanning electron microscope. Edgewise mesh-backed brackets were bonded to the buccal surface of extracted premolar teeth and forces applied with an Instron 1011 testing machine. Results indicated that Panavia-Ex (with sandblasted brackets) had the highest tensile strength when compared to the other materials (P < 0.01). Panavia-Ex had the highest shear strength when compared to C & B Metabond (P < 0.05) and to the other materials (P < 0.01). C & B Metabond had the highest shear and tensile strength of the other adhesives (P < 0.01). No significant differences were found for System 1+ when compared to Vitrebond for tensile strength, but System 1+ was stronger for shear strength (P < 0.01). Analysis of failure shows that 50% of the samples failed at the adhesive-enamel interface, 25% failed in a combined mode and the remaining 25% failed either adhesively to metal or cohesively.
authors.affiliation: Department of Child Dental Health, School of Dental Science, University of Dublin, Eire.
authors.forename: P F
authors.initials: PF
authors.lastname: McSherry
mesh_terms: D000180:Acrylic Resins; D001896:Boron Compounds; D003738:Dental Cements; D005899:Glass Ionomer Cements; D008422:Materials Testing; D019563:Mechanics; D008689:Methacrylates; D008768:Methylmethacrylates; D016910:Orthodontic Brackets; D010710:Phosphates; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; D001896:Boron Compounds; D003738:Dental Cements; D005899:Glass Ionomer Cements; D008689:Methacrylates; D008768:Methylmethacrylates; D010710:Phosphates; D019279:Resin Cements; C045637:System 1 plus; C067790:Vitrabond; C052304:Panavia EX; C049495:Super-bond