title: Shear bond strength of brackets bonded with two light-curing orthodontic adhesives.
abstract: OBJECTIVE
  To compare the shear bond strength of stainless steel brackets bonded with two orthodontic adhesive systems, Transbond XT (3M Unitek) and Orthobond (Morelli Dental Products).
  
  
  METHODS
  Forty bovine teeth were randomly divided in two groups of 20 each: group 1 (control): Transbond XT primer + Transbond XT Adhesive paste (3M Unitek); group 2: Orthoprimer (Morelli Dental Products) + Orthobond. In each group all teeth were etched with 37% phosphoric acid, and all products were used according to manufacturers instructions. After 30 min, a universal testing machine was used to apply an occlusal shear force directly to the enamel/bracket interface at a speed of 0.5 mm/min. The groups were compared using Student's t-test.
  
  
  RESULTS
  Mean results and standard deviations for the groups were: group 1= 11.22 Mpa (1.68), group 2= 4.88 Mpa (1.18). A significant difference was observed in the bond strengths of the two groups evaluated (p < 0.0001).
  
  
  CONCLUSIONS
  Under the conditions of this study, Orthobond system presented lower shear bond strength when compared to Transbond XT.
authors.affiliation: School of Dentistry, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Rowan V
authors.initials: RV
authors.lastname: Vilar
authors.forename: Nathaly F
authors.initials: NF
authors.lastname: Souza
authors.forename: Julio P
authors.initials: JP
authors.lastname: Cal-Neto
authors.forename: Myrela
authors.initials: M
authors.lastname: Galvão
authors.forename: Hélio
authors.initials: H
authors.lastname: Sampaio-Filho
authors.forename: Alvaro de Moraes
authors.initials: Ade M
authors.lastname: Mendes
mesh_terms: D000134:Acid Etching, Dental; D000818:Animals; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D055117:Curing Lights, Dental; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D008422:Materials Testing; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D003188:Composite Resins; D010756:Phosphoric Acids; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer; C477790:Transbond XT; C516047:Transbond XT Light Cure Adhesive Primer; D013193:Stainless Steel; C030242:phosphoric acid