title: Quantitative analysis of S. mutans and S. sobrinus cultivated independently and adhered to polished orthodontic composite resins.
abstract: In orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms.
  
  
  OBJECTIVE
  The purpose of this study was to quantitatively determine the independent bacterial colonization of S. mutans and S. sobrinus in orthodontic composite resins.
  
  
  METHODS
  Seven orthodontic composite adhesives for bonding brackets were selected and classified into 14 groups; (GIm, GIs) Enlight, (GIIm, GIIs) Grengloo, (GIIIm, GIIIs) Kurasper F, (GIVm, GIVs) BeautyOrtho Bond, (GVm, GVs) Transbond CC, (GVIm, GVIs) Turbo Bond II, (GVIIm, GVIIs) Blugloo. 60 blocks of 4x4x1 mm of each orthodontic composite resin were made (total 420 blocks), and gently polished with sand-paper and ultrasonically cleaned. S. mutans and S. sobrinus were independently cultivated. For the quantitative analysis, a radioactive marker was used to codify the bacteria (³H) adhered to the surface of the materials. The blocks were submerged in a solution with microorganisms previously radiolabeled and separated (210 blocks for S. mutans and 210 blocks for S. sobrinus) for 2 hours at 37 ºC. Next, the blocks were placed in a combustion system, to capture the residues and measure the radiation. The statistical analysis was calculated with the ANOVA test (Sheffè post-hoc).
  
  
  RESULTS
  Significant differences of bacterial adhesion were found amongst the groups. In the GIm and GIs the significant lowest scores for both microorganisms were shown; in contrast, the values of GVII for both bacteria were significantly the highest.
  
  
  CONCLUSIONS
  This study showed that the orthodontic composite resin evaluated in the GIm and GIs, obtained the lowest adherence of S. mutans and S. sobrinus, which may reduce the enamel demineralization and the risk of white spot lesion formation.
authors.affiliation: Health Sciences, School of Medicine, Autonomous University of State of Mexico, Toluca City, Mexico.
authors.forename: Ulises
authors.initials: U
authors.lastname: Velazquez-Enriquez
authors.forename: Rogelio Jose
authors.initials: RJ
authors.lastname: Scougall-Vilchis
authors.forename: Rosalia
authors.initials: R
authors.lastname: Contreras-Bulnes
authors.forename: Jaime
authors.initials: J
authors.lastname: Flores-Estrada
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Uematsu
authors.forename: Ryozo
authors.initials: R
authors.lastname: Yamaguchi
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D001422:Bacterial Adhesion / Q000502:physiology*; D058491:Bacterial Load; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D003738:Dental Cements; D003775:Dental Polishing; D016910:Orthodontic Brackets / Q000382:microbiology*; D010756:Phosphoric Acids; D019279:Resin Cements; D013295:Streptococcus mutans / Q000254:growth & development*; D016986:Streptococcus sobrinus / Q000254:growth & development*; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; C519484:Beauty Ortho Bond; C522883:Blugloo; D003188:Composite Resins; D003738:Dental Cements; C418867:Enlight; C472990:Kurasper F; D010756:Phosphoric Acids; D019279:Resin Cements; C065742:Transbond; D017438:Bisphenol A-Glycidyl Methacrylate