title: Effect of mobile phone use on metal ion release from fixed orthodontic appliances.
abstract: BACKGROUND
  The aim of this study was to evaluate the effect of exposure to radiofrequency electromagnetic fields emitted by mobile phones on the level of nickel in saliva.
  
  
  METHODS
  Fifty healthy patients with fixed orthodontic appliances were asked not to use their cell phones for a week, and their saliva samples were taken at the end of the week (control group). The patients recorded their time of mobile phone usage during the next week and returned for a second saliva collection (experimental group). Samples at both times were taken between 8:00 and 10:00 pm, and the nickel levels were measured. Two-tailed paired-samples t test, linear regression, independent t test, and 1-way analysis of variance were used for data analysis.
  
  
  RESULTS
  The 2-tailed paired-samples t test showed significant differences between the levels of nickel in the control and experimental groups (t [49] = 9.967; P <0.001). The linear regression test showed a significant relationship between mobile phone usage time and the nickel release (F [1, 48] = 60.263; P <0.001; R(2) = 0.577).
  
  
  CONCLUSIONS
  Mobile phone usage has a time-dependent influence on the concentration of nickel in the saliva of patients with orthodontic appliances.
authors.affiliation: Research associate, Departments of Ophthalmology & Visual Sciences and Biomedical Engineering, School of Medicine and Public Health, University of Wisconsin, Madison, Wis. Electronic address: saghiri@wisc.edu.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Saghiri
authors.affiliation: Researcher, Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran.
authors.forename: Jafar
authors.initials: J
authors.lastname: Orangi
authors.affiliation: Clinical instructor, Department of Dental Materials, Kamal Asgar Research Center, Shiraz, Iran.
authors.forename: Armen
authors.initials: A
authors.lastname: Asatourian
authors.affiliation: Resident of advance education in general dentistry (AEGD), Florida Institute for Advanced Dental Education, Miami, Fla.
authors.forename: Peiman
authors.initials: P
authors.lastname: Mehriar
authors.affiliation: Professor, Departments of Ophthalmology & Visual Sciences and Biomedical Engineering, School of Medicine and Public Health, University of Wisconsin, Madison, Wis.
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D040421:Cell Phone; D003722:Dental Alloys / Q000737:chemistry* / Q000528:radiation effects; D060733:Electromagnetic Radiation; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009532:Nickel / Q000032:analysis* / Q000528:radiation effects; D009967:Orthodontic Appliances; D011829:Radiation Dosage; D012463:Saliva / Q000737:chemistry*; D012737:Sex Factors; D013054:Spectrophotometry, Atomic / Q000379:methods; D013997:Time Factors; D055815:Young Adult
chemical_list: D003722:Dental Alloys; D009532:Nickel