title: The effect of different surface treatments of demineralised enamel on microleakage under metal orthodontic brackets.
abstract: BACKGROUND
  The aim of this investigation was to assess the effects of different treatments of demineralised enamel on microleakage under orthodontic brackets.
  
  
  METHODS
  Seventy-five intact premolars were randomly assigned to five groups. The teeth in groups 2 through 5 were immersed in a demineralising solution for 16 weeks. In groups 1 (control) and 2 (demineralised/control), conventional acid etching was used. In group 3, sodium hypochlorite (NaOCl) was applied on the enamel surface for 1 min after acid etching, and in group 4, Transbond Plus (3M Unitek, Monrovia, CA, USA) self-etching primer (SEP) was used. The teeth in group 5 were treated with 2% sodium fluoride (NaF) for 4 min before etching. After bracket bonding, the specimens were thermocycled, sealed with nail varnish, immersed in 0.5% basic fuchsine solution for 24 h and sectioned. Microleakage was measured under a stereomicroscope for the enamel-adhesive and adhesive-bracket interfaces of both occlusal and gingival sides.
  
  
  RESULTS
  Demineralised teeth showed more microleakage at the enamel-adhesive interface on both occlusal and gingival sides compared to sound teeth, but the difference was not significant (P>0.005). Treating the demineralised enamel with 5% NaOCl or Transbond Plus SEP was not effective in reducing microleakage. NaF treatment followed by acid etching of demineralised enamel resulted in significantly lower microleakage in most comparisons (P<0.005).
  
  
  CONCLUSIONS
  The use of 2% NaF on hypomineralised enamel before the bracket bonding procedure is an effective way to decrease microleakage.
authors: Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. AhrariF@mums.ac.ir.
authors: Horieh
authors: H
authors: Moosavi
authors: Farzaneh
authors: F
authors: Ahrari
authors: Hamideh
authors: H
authors: Mohamadipour
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D002327:Cariostatic Agents / Q000737:chemistry; D004396:Coloring Agents; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D003743:Dental Enamel / Q000648:ultrastructure*; D003763:Dental Leakage / Q000145:classification*; D006801:Humans; D016910:Orthodontic Brackets; D016877:Oxidants / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012394:Rosaniline Dyes; D012969:Sodium Fluoride / Q000737:chemistry; D012973:Sodium Hypochlorite / Q000737:chemistry; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D017001:Tooth Demineralization / Q000473:pathology*
chemical_list: D002327:Cariostatic Agents; D004396:Coloring Agents; D003722:Dental Alloys; D016877:Oxidants; D010756:Phosphoric Acids; D019279:Resin Cements; D012394:Rosaniline Dyes; C429625:Transbond Plus Self-Etching Primer; C477790:Transbond XT; D013193:Stainless Steel; C025485:basic fuchsin; D012969:Sodium Fluoride; D012973:Sodium Hypochlorite; C030242:phosphoric acid