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

Introduction 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 P 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.