title: Influence of different orthodontic brackets on adherence of microorganisms in vitro.
abstract: OBJECTIVE
  To define the capacity of different bracket materials to modify the growth and adherence of microorganisms.
  
  
  METHODS
  Three types of brackets from the right upper central incisor were used: metallic, ceramic, and composite. Streptococcus mutans and Candida albicans were studied. The association of both species was also evaluated. The brackets were placed in flat-bottomed vials containing basal medium with 20% sucrose added; the flasks were inoculated with each of the microbial suspensions. The samples were incubated at 37 degrees C for 48 hours, after which the brackets were removed. The supernatant was removed from the flasks, the cells adhering to the glass were counted, and the brackets were studied with electron microscopy.
  
  
  RESULTS
  The adherence of Streptococcus mutans was not modified by the different brackets. The adherence of Candida albicans was increased by the composite bracket, whereas the use of metallic brackets decreased the number of colony-forming units (CFUs). By electron microscopy we demonstrated that the adherence of Streptococcus mutans plus Candida albicans together varied according to the bracket materials with composite > ceramic > metallic.
  
  
  CONCLUSIONS
  Orthodontic appliances serve as different impact zones and modify microbial adherence and colonization, acting as foreign reserves and possible sources of infection.
authors.affiliation: Microbiology Unit, School of Dentistry, University of Buenos Aires, Argentina. maria_brusca@hotmail.com
authors.forename: M I
authors.initials: MI
authors.lastname: Brusca
authors.forename: O
authors.initials: O
authors.lastname: Chara
authors.forename: L
authors.initials: L
authors.lastname: Sterin-Borda
authors.forename: A C
authors.initials: AC
authors.lastname: Rosa
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001422:Bacterial Adhesion; D002176:Candida albicans / Q000254:growth & development / Q000502:physiology*; D002448:Cell Adhesion; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets / Q000382:microbiology*; D011140:Polyurethanes / Q000737:chemistry; D013295:Streptococcus mutans / Q000254:growth & development / Q000502:physiology*
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D008670:Metals; D011140:Polyurethanes