title: Evaluation of Antibacterial Effects of Silver-Coated Stainless Steel Orthodontic Brackets.
abstract: OBJECTIVE
  White spots and enamel demineralization around orthodontic brackets are among the most important complications resulting from orthodontic treatments. Since the antibacterial properties of metals and metallic particles have been well documented, the aim of this study was to assess the antibacterial effect of stainless steel orthodontic brackets coated with silver (Ag) particles.
  
  
  METHODS
  In this study, 40 standard metal brackets were divided into two groups of 20 cases and 20 controls. The brackets in the case group were coated with Ag particles using an electroplating method. Atomic force microscopy and scanning electron microscopy were used to assess the adequacy of the coating process. In addition, antibacterial tests, i.e., disk diffusion and direct contact tests were performed at three, six, 24, and 48 hours, and 15 and 30 days using a Streptococcus mutans strain. The results were analyzed using Student's t-test and repeated measures ANOVA.
  
  
  RESULTS
  Analyses via SEM and AFM confirmed that excellent coatings were obtained by using an electroplating method. The groups exhibited similar behavior when subjected to the disk diffusion test in the agar medium. However, the bacterial counts of the Ag-coated brackets were, in general, significantly lower (P<0.001) than those of their non-coated counterparts.
  
  
  CONCLUSIONS
  Brackets coated with Ag, via an electroplating method, exhibited antibacterial properties when placed in direct contact with Streptococcus mutans. This antibacterial effect persisted for 30 days after contact with the bacteria.
authors.affiliation: Associate Professor, Department of Orthodontics, Dental Material Research Center, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Valiollah
authors.initials: V
authors.lastname: Arash
authors.affiliation: Assistant Professor, Department of Orthodontics, Faculty of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Keikhaee
authors.affiliation: Associate Professor, Department of Material Engineering, Babol University of Technology, Babol, Iran.
authors.forename: Sayed Mahmood
authors.initials: SM
authors.lastname: Rabiee
authors.affiliation: Associate Professor, Department of Microbiology, Infectious Diseases and Tropical Medicine Research Center, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Ramazan
authors.initials: R
authors.lastname: Rajabnia
authors.affiliation: Assistant Professor, Department of Social Medicine, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Soraya
authors.initials: S
authors.lastname: Khafri
authors.affiliation: General Dental Practitioner, Private Practice, Shiraz, Iran.
authors.forename: Saeid
authors.initials: S
authors.lastname: Tavanafar
keywords: Electroplating; Orthodontic Brackets; Silver; Stainless Steel; Streptococcus mutans