title: [Increased susceptibility for white spot lesions by surplus orthodontic etching exceeding bracket base area].
abstract: BACKGROUND
  There is a paucity of information with regard to the susceptibility of iatrogenic white spot lesion formation after inattentive, surplus orthodontic etching with 30% phosphoric acid and the subsequent provision or absence of adequate oral hygiene.
  
  
  METHODS
  Ninety sound enamel specimens were randomly allocated to 6 trial groups (N = 15 each) for etching with 30% phosphoric acid for either 15 seconds and standardized daily enamel brushing or no brushing, etching for 30 seconds with daily brushing or no brushing, or nonetched controls with brushing or no brushing. Nutritive acidic assaults were simulated by demineralization cycles 3 times per day for 1 hour with interim storage in artificial saliva. Lesion depths in terms of percentage of fluorescence loss (delta F, delta Q) and lesion extension compared with the baseline were assessed by using quantitative light-induced fluorescence after 2, 7, 14, 21, and 42 days. Etching duration, trial time elapse, and oral hygiene, as well as the significance of factor interactions, were analyzed with 3-way analysis of variance (α=5%).
  
  
  RESULTS
  The impact of the factors of enamel brushing, trial time elapse, and etching each had a comparably significant effect on lesion progression. The effect of surplus etching on white spot lesion formation was significantly enhanced by the simultaneous absence of enamel brushing and also the progression of trial time. The combination of 30 seconds of surplus etching with inadequate oral hygiene was especially detrimental.
  
  
  CONCLUSIONS
  Excessive surplus orthodontic etching of the complete labial enamel surface, instead of the bracket bases only, must be avoided to prevent iatrogenic white spot lesions. Etching times not exceeding 15 seconds are favorable.
authors.affiliation: Private Orthodontic Practice, Kirchröder Street 77, 30625 Hannover, Allemagne.
authors.forename: Michael
authors.initials: M
authors.lastname: Knösel
authors.affiliation: Universitätsmedizin Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Allemagne.
authors.forename: Mariana
authors.initials: M
authors.lastname: Bojes
authors.affiliation: Department of Medical Statistics, Universitätsmedizin Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Allemagne.
authors.forename: Klaus
authors.initials: K
authors.lastname: Jung
authors.affiliation: Dentistry Center, Department of Preventive Dentistry, Periodontology and Cariology, Universitätsmedizin Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Allemagne.
authors.forename: Dirk
authors.initials: D
authors.lastname: Ziebolz
authors.forename: Stéphane
authors.initials: S
authors.lastname: Renger
mesh_terms: D000134:Acid Etching, Dental / Q000009:adverse effects*; D001840:Dental Bonding; D003731:Dental Caries / Q000139:chemically induced*; D003743:Dental Enamel / Q000187:drug effects; D004198:Disease Susceptibility; D005453:Fluorescence; D006801:Humans; D007049:Iatrogenic Disease; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000009:adverse effects*; D011897:Random Allocation; D012464:Saliva, Artificial / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D017001:Tooth Demineralization / Q000139:chemically induced; D014089:Tooth Remineralization; D014099:Toothbrushing / Q000379:methods
chemical_list: D010756:Phosphoric Acids; D012464:Saliva, Artificial; C030242:phosphoric acid