title: Porcelain surface conditioning protocols and shear bond strength of orthodontic brackets.
abstract: OBJECTIVE
  The objective of the present study was to determine which of six bonding protocols yielded a clinically acceptable shear bond strength (SBS) of metal orthodontic brackets to CAD/CAM lithium disilicate porcelain restorations. A secondary aim was to determine which bonding protocol produced the least surface damage at debond.
  
  
  METHODS
  Sixty lithium disilicate samples were fabricated to replicate the facial surface of a mandibular first molar using a CEREC CAD/CAM machine. The samples were split into six test groups, each of which received different mechanical/chemical pretreatment protocols to roughen the porcelain surface prior to bonding a molar orthodontic attachment. Shear bond strength testing was conducted using an Instron machine. The mean, maximum, minimal, and standard deviation SBS values for each sample group including an enamel control were calculated. A t-test was used to evaluate the statistical significance between the groups.
  
  
  RESULTS
  No significant differences were found in SBS values, with the exception of surface roughening with a green stone prior to HFA and silane treatment. This protocol yielded slightly higher bond strength which was statistically significant.
  
  
  CONCLUSIONS
  Chemical treatment alone with HFA/silane yielded SBS values within an acceptable clinical range to withstand forces applied by orthodontic treatment and potentially eliminates the need to mechanically roughen the ceramic surface.
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Lestrade
authors.forename: Richard W
authors.initials: RW
authors.lastname: Ballard
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Xu
authors.forename: Qingzhao
authors.initials: Q
authors.lastname: Yu
authors.forename: Edwin L
authors.initials: EL
authors.lastname: Kee
authors.forename: Paul C
authors.initials: PC
authors.lastname: Armbruster
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000537:Aluminum Oxide / Q000737:chemistry; D017076:Computer-Aided Design; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D017005:Dental Debonding / Q000379:methods; D003743:Dental Enamel / Q000033:anatomy & histology; D045662:Dental Etching / Q000295:instrumentation / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis / Q000295:instrumentation; D018130:Diamond / Q000737:chemistry; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D008422:Materials Testing; D016910:Orthodontic Brackets; D033081:Shear Strength; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D003722:Dental Alloys; D012821:Silanes; C493120:lithia disilicate; D003776:Dental Porcelain; D012822:Silicon Dioxide; D018130:Diamond; D000537:Aluminum Oxide; D006858:Hydrofluoric Acid