title: Occurrence and severity of enamel decalcification adjacent to bracket bases and sub-bracket lesions during orthodontic treatment with two different lingual appliances.
abstract: Using lingual enamel surfaces for bracket placement not only has esthetic advantages, but may also be suitable in terms of reducing frequencies of enamel decalcifications.
  
  
  
  To test the null-hypothesis that there is no significant difference in enamel decalcification or cavitation incidence adjacent to and beneath bracket bases between two lingual multi-bracket (MB) appliances that are different in terms of design, material composition, and manufacturing technology (group A: WIN, DW-LingualSystems; group B: Incognito, 3M-Unitek), taking into account patient- and treatment-related variables on white spot lesion (WSL) formation.
  
  
  
  Standardized, digital, top-view photographs of 630 consecutive subjects (16214 teeth; n Incognito = 237/6076 teeth; n WIN = 393/10138 teeth; mean age: 17.47±7.8; m/f 43.2/56.8%) with completed lingual MB treatment of the upper and lower permanent teeth 1-7 were screened for decalcification or cavitation adjacent to and beneath the bracket bases before and after treatment, scored from 0 to 7. Non-parametric ANOVA was used for main effects 'appliance type', 'gender', 'treatment complexity', 'grouped age' (≤16/>16 years), and 'treatment duration' as covariable, at an α-level of 5%.
  
  
  
  About 2.57% [5.94%] of all teeth in group A [B] developed decalcifications. Subject-related incidence was 9.59% [16.17%] for upper incisors in group A [B], and 12.98% [25.74%] for all teeth 16-46. There were significant effects by gender, age, and treatment duration.
  
  
  
  The null-hypothesis was rejected: sub-bracket lesions were significantly less frequent in group A, while frequencies of WSL adjacent to brackets were not significantly affected by appliance type. In view of the overall low incidences of lingual post-orthodontic white-spot lesions, the use of lingual appliances is advocated as a valid strategy for a reduction of enamel decalcifications during orthodontic treatment.
authors.affiliation: *Department of Orthodontics, University Medical Center Göttingen, Germany, **Department of Orthodontics, Universidad de La Frontera (UFRO), Temuco, Chile, mknoesel@yahoo.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Knösel
authors.affiliation: ***Private Practice, Bad Essen.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Klang
authors.affiliation: ****Department of Medical Statistics, University Medical Center Göttingen, and.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Helms
authors.affiliation: ***Private Practice, Bad Essen, *****Department of Orthodontics, Hannover Medical School (MHH), Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Wiechmann
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D001840:Dental Bonding / Q000379:methods; D003743:Dental Enamel / Q000473:pathology; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D007180:Incisor / Q000473:pathology; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets / Q000009:adverse effects*; D014059:Tongue; D017001:Tooth Demineralization / Q000209:etiology*; D014087:Tooth Movement Techniques / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D055815:Young Adult