1 Associate professor Department of Orthodontics, Islamic Azad Dental College, Tehran

2 Dentist

3 Assistant professor Department of Orthodontics, Islamic Azad Dental College, Tehran



Objective: The aim of this study was to determine salivary concentrations of Nickel , Chromium and Cobalt ions in patients with fixed orthodontic appliances. 
Materials and Methods: This study was performed on salivary samples of 60 subjects including 30 subjects (20 females and 10 males) who were under orthodontic treatment with fixed orthodontic appliance for average of 1.5 to 2 years as study group and 30 individuals(20 females and 10 males) without any appliance therapy as control group. The chemical analyses of saliva was done with an electrothermal atomic absorption spectrophotometry to detect the metal ion content of the saliva. The Mann-Whitney u-test was used to analyze significance of the differences between two groups. 
Results: Examining the content of Nickel in the saliva of orthodontic patients and controls, the Nickel content of saliva in study group was significantly higher than the controls (p < 0.01). The mean salivary Chromium content was 13.60 ± 7.30 ng ⁄ ml, and 1.40 ± 4.80 ng/ml in subjects with and without orthodontic appliances respectively. Statistically significant differences were found between the groups (P < 0.002).
Conclusion: fixed orthodontic appliances release measurable amount of Nickel and Cobalt when placed in the mouth however; this increase doesn’t reach toxic levels in saliva.