Biomonitorization of chromium, copper, iron, manganese and nickel in scalp hair from orthodontic patients by atomic absorption spectrometry

• Hair Cr, Cu, Fe, Mn and Ni were analyzed in orthodontic patients.
• Mn hair content was significantly increased when compared to the control group.
• Metal levels in orthodontic patients were comparable to control populations.
• Orthodontic appliances do not pose any health risk related to metals for the patients.
• The study provides values that may be useful for future comparative purposes.

The study was aimed to assess Cu, Cr, Fe, Mn and Ni levels in human scalp hair from a broad population group treated with orthodontic appliances (n = 70) to determine, whether the concentration of a given metal was significantly influenced by the orthodontic treatment in comparison to control group (n = 56). Levels of metal compounds were determined by atomic absorption spectrometry. The mean, ranges, median and 5th and 95th percentiles of metals analyzed in hair that were hypothesized to be systemically absorbed from stainless steel, are provided. The influence of individual factors on metal concentrations was considered (gender, age), and inter-element interactions were studied by evaluation of correlation coefficients between elements, as well as by multiple regression analysis. Differences in the content of metals in hair were only significantly increased for Mn when compared to the control group, but their levels were of the same magnitude to other control populations, and consequently, no risks linked to the treatment have been found. The orthodontic treatment increased significantly Mn levels in young patients (<20 years old) when compared with control group. Scalp hair analysis is a good method to investigate the release of the elements from fixed orthodontic appliances.