Nickel and chromium levels in the saliva and serum of patients with fixed orthodontic appliances

The aim of this study was to evaluate the concentrations of nickel and chro mium ions in salivary and serum samples from patients treated with fixed or thodontic appliances. A second aim of this study was to determine any signi ficant changes in these concentrations during any period of the treatment t ime. Saliva and blood samples were collected from 100 patients ranging in a ge from 12 to 33 years. Twenty samples from each group were obtained. The g roups were as follows: In the first group, saliva and blood samples were co llected before insertion of the fixed appliances. In the second, third, fou rth, and fifth groups, samples were collected at 1 week, 1 month, 1 year, a nd 2 years after appliance insertion. The serum was prepared by centrifugin g the blood sam les at 3000 rpm for 10 minutes. The fixed appliances consis ted of an average of 4 bands and 20 bonded brackets. No palatal or lingual appliances welded to bands or extraoral auxiliary appliances were used. The spectrophotometric determinations were carried out using electrothermal at omic absorption spectrophotometry. The results indicated certain difference s in the amounts of nickel and chromium released from fixed orthodontic app liances during different periods of treatment. The Mann-Whitney U-test from the SPSS statistics program was used to analyze the significance of the di fferences between no-appliance samples and those obtained with the applianc es present. In the serum, there were statistically significant increases in ion concentration in the second-year groups. In saliva samples, nickel and chromium reached their highest levels in the first month and decreased to their initial level in the rest of the groups. It can be concluded that fix ed orthodontic appliances release measurable amount of nickel and chromium when placed in the mouth, but this increase doesn't reach toxic levels for nickel and chromium in the saliva and serum.