title: Comparison of shear bond strength of plastic and ceramic brackets.
abstract: OBJECTIVE
  The purpose of this in vitro study is to compare the shear bond strength of various esthetic brackets used in conjunction with two different adhesive systems.
  
  
  METHODS
  Five non-silanized ceramic brackets (Aspire Gold/Forestadent, Clarity™/3M Unitek, CLEAR/Adenta, Contour Twin/ODS, QuicKlear/Forestadent) and four plastic brackets (Aesthetik-Line®/Forestadent, Brillant®/Forestadent, Composite Clear®/ODS, Elegance®/Dentaurum) were bonded either with Transbond™ XT (3M Unitek, Monrovia, CA, USA) or with ConTec SE (Dentaurum, Ispringen, Germany) to bovine permanent mandibular incisors. Twelve specimens were tested in each group, thus, bonding 60 ceramic and 48 plastic brackets with either adhesive to a total of 216 teeth. Shear bond strength was measured in accordance with the DIN 13990-2 standard governing test methods for the entire attachment-adhesive-enamel system. The fracture surfaces resulting from shear-induced debonding were analyzed via light microscopy.
  
  
  RESULTS
  The combinations Clarity™ + Transbond™ XT, CLEAR® + Transbond™ XT, and Contour Twin + Transbond™ XT exhibited shear bond strengths of over 10 MPa. The Adhesive Remnant Index scores of the various bracket types varied widely according to the different bracket-base designs. No enamel fractures were observed.
  
  
  CONCLUSIONS
  Some bracket-adhesive combinations in this study attained shear bond strengths approaching those of metal brackets. The risk of debonding-related enamel defects is comparable with different esthetic bracket combinations. Manufacturers' recommendations for the adhesive systems to be used with their brackets should be strictly adhered to.
authors.affiliation: Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Zielinski
authors.forename: S
authors.initials: S
authors.lastname: Reimann
authors.forename: A
authors.initials: A
authors.lastname: Jäger
authors.forename: C
authors.initials: C
authors.lastname: Bourauel
mesh_terms: D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D002516:Ceramics / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D019544:Equipment Failure Analysis; D066298:In Vitro Techniques; D007180:Incisor / Q000737:chemistry*; D008422:Materials Testing; D016910:Orthodontic Brackets; D010969:Plastics / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D003738:Dental Cements; D003764:Dental Materials; D010969:Plastics