title: Effect of fluoride application on shear bond strength of brackets bonded with a resin-modified glass-ionomer.
abstract: OBJECTIVE
  The purpose of this study was to assess the effect of fluoride application at 3 different steps of the bonding process on the shear bond strength and bond failure site of a resin-modified glass ionomer cement.
  
  
  METHODS
  Sixty stainless steel brackets were bonded to bovine incisors with Fuji Ortho LC (GC Europe, Leuven, Belgium) under 4 different enamel conditions: (1) uncontaminated enamel, (2) enamel precleaned with fluoride-containing prophylaxis paste, (3) 1.1% acidulated phosphate fluoride (APF) gel applied immediately before conditioning, and (4) 1.1% APF gel applied immediately before bonding. After bonding, all samples were stored in distilled water for 24 hours and subsequently tested in shear mode on a universal testing machine.
  
  
  RESULTS
  No significant differences were found between groups 1 (uncontaminated enamel) and 2 (fluoride application during prophylaxis). Both groups showed significantly greater shear bond strength values than groups 3 (fluoride application before conditioning) and 4 (fluoride application before bonding). Groups 3 and 4 did not differ significantly. Moreover, no significant differences in debond locations were found among the 4 groups.
  
  
  CONCLUSIONS
  Fluoride application during initial prophylaxis does not affect the bond strength values of Fuji Ortho LC, whereas it significantly lowers bond strength values when applied before both conditioning and bonding.
authors.affiliation: Department of Orthodontics, University of Pavia, Italy. vcacciafesta@hotmail.com
authors.forename: Vittorio
authors.initials: V
authors.lastname: Cacciafesta
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Sfondrini
authors.forename: Debora
authors.initials: D
authors.lastname: Calvi
authors.forename: Andrea
authors.initials: A
authors.lastname: Scribante
mesh_terms: D000134:Acid Etching, Dental; D000149:Acidulated Phosphate Fluoride / Q000008:administration & dosage; D000180:Acrylic Resins; D000538:Aluminum Silicates; D000704:Analysis of Variance; D000818:Animals; D002327:Cariostatic Agents / Q000008:administration & dosage*; D002417:Cattle; D016009:Chi-Square Distribution; D003722:Dental Alloys; D001840:Dental Bonding / Q000379:methods*; D003777:Dental Prophylaxis; D003799:Dental Stress Analysis; D005459:Fluorides / Q000008:administration & dosage*; D005899:Glass Ionomer Cements; D016910:Orthodontic Brackets; D011897:Random Allocation; D033081:Shear Strength; D013193:Stainless Steel
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D002327:Cariostatic Agents; D003722:Dental Alloys; C095451:Fuji Ortho LC; D005899:Glass Ionomer Cements; D013193:Stainless Steel; D000149:Acidulated Phosphate Fluoride; D005459:Fluorides