Effect of mobile phone use on metal ion release from fixed orthodontic appliances

• Radiofrequencies from mobile phones and nickel concentrations in saliva were examined.
• Mobile phone radiation is positively correlated with nickel concentration in saliva.
• Nickel concentrations in saliva were different in men and women.

IntroductionThe 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.MethodsFifty 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.ResultsThe 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; R2 = 0.577).ConclusionsMobile phone usage has a time-dependent influence on the concentration of nickel in the saliva of patients with orthodontic appliances.