title: Efficiency of different protocols for enamel clean-up after bracket debonding: an in vitro study.
abstract: OBJECTIVE
  This study aimed to assess the efficiency of six protocols for cleaning-up tooth enamel after bracket debonding.
  
  
  METHODS
  A total of 60 premolars were divided into six groups, according to the tools used for clean-up: 12-blade bur at low speed (G12L), 12-blade bur at high speed (G12H), 30-blade bur at low speed (G30L), DU10CO ORTHO polisher (GDU), Renew System (GR) and Diagloss polisher (GD). Mean roughness (Ra) and mean roughness depth (Rz) of enamel surface were analyzed with a profilometer. Paired t-test was used to assess Ra and Rz before and after enamel clean-up. ANOVA/Tukey tests were used for intergroup comparison. The duration of removal procedures was recorded. The association between time and variation in enamel roughness (∆Ra, ∆Rz) were evaluated by Pearson's correlation test. Enamel topography was assessed by scanning electron microscopy (SEM).
  
  
  RESULTS
  In Groups G12L and G12H, original enamel roughness did not change significantly. In Groups G30L, GDU, GR and GD, a smoother surface (p < 0.05) was found after clean-up. In Groups G30L and GD, the protocols used were more time-consuming than those used in the other groups. Negative and moderate correlation was observed between time and (∆Ra, ∆Rz); Ra and (∆Ra, ∆Rz); Rz (r = - 0.445, r = - 0.475, p < 0.01).
  
  
  CONCLUSIONS
  All enamel clean-up protocols were efficient because they did not result in increased surface roughness. The longer the time spent performing the protocol, the lower the surface roughness.
authors.affiliation: Brazilian Navy, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Lara Carvalho Freitas
authors.initials: LC
authors.lastname: Sigilião
authors.affiliation: Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Mariana
authors.initials: M
authors.lastname: Marquezan
authors.affiliation: Instituto Militar de Engenharia, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Carlos Nelson
authors.initials: CN
authors.lastname: Elias
authors.affiliation: Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: Ruellas
authors.affiliation: Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Eduardo Franzotti
authors.initials: EF
authors.lastname: Sant'Anna
mesh_terms: D001641:Bicuspid / Q000033:anatomy & histology*; D017005:Dental Debonding / Q000295:instrumentation* / Q000379:methods*; D003743:Dental Enamel / Q000293:injuries; D018130:Diamond; D006801:Humans; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D012117:Resins, Synthetic; D013499:Surface Properties; D013997:Time Factors; D017973:Tungsten Compounds
chemical_list: D012117:Resins, Synthetic; D017973:Tungsten Compounds; C002802:tungsten carbide; D018130:Diamond