title: AnEx-vivoShear and tensile bond strengths of orthodontic molar tubes bonded using different techniques.
abstract: BACKGROUND
  Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands.
  
  
  METHODS
  The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated into five groups of 40 teeth as follows: group 1: molar tubes bonded to etched teeth (37% phosphoric acid gel; control group); group 2: molar tubes bonded to etched teeth (37% phosphoric acid) with the addition of silane to the base of molar tubes; group 3: molar tubes bonded to teeth pre-treated with 18% hydrochloric acid and pumice (micro-abrasion); group 4: molar tubes bonded to teeth pre-treated with microabrasion with the addition of silane to the base of molar tubes; group 5: molar tubes bonded to teeth pre-treated with microabrasion before conventional acid etching combined with the addition of silane to the base of molar tubes. The bond strength testing was performed using a computer control electromechanical universal testing machine.
  
  
  RESULTS
  The highest mean shear and tensile bond strengths were recorded in group 5 (13.81±2.54MPa and 13.97±2.29 MPa, respectively). Micro-abrasion alone (group 3) and the combination of enamel micro-abrasion and the addition of silane (group 4) produced bond strength values comparable to the control.
  
  
  CONCLUSIONS
  Enamel surface pre-treatment (micro abrasion) before conventional acid etching combined with the addition of silane to the base of the molar tube produced the highest bond strengths among all tested groups.Key words:Molar, shear strength, tensile strength, orthodontic appliances.
authors.affiliation: Professor, Department of Preventive Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, Irbid-Jordan.
authors.forename: Elham
authors.initials: E
authors.lastname: Abu-Alhaija
authors.affiliation: Master student, Department of Preventive Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, Irbid-Jordan.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Jaradat
authors.affiliation: Professor, Department of Prosthodontics, Faculty of Dentistry, Jordan University of Science and Technology, Irbid-Jordan.
authors.forename: Ahed
authors.initials: A
authors.lastname: Alwahadni