Nickel and chromium levels in the saliva of a Saudi sample treated with fixed orthodontic appliances

ABSTRACT

The aim of this study was to measure the amount of nickel [Ni] and chromium [Cr] released into the saliva of Saudi patients treated with fixed orthodontic appliances. Ninety salivary samples were collected in a cross-sectional manner. Forty samples were collected from patients [17 males, 23 females] with fixed orthodontic appliances after different periods of orthodontic treatment ranging from the first month and up to 32 months into treatment. The fixed orthodontic appliance consisted of 4 bands, 20 stainless steel brackets, and upper and lower nickel titanium or stainless-steel arch wires. The other 50 samples were collected from people without appliances [24 males, 26 females]. Samples were analyzed using Inductive Coupled Plasma/Mass Spectrometry and Inductively Coupled Plasma Optical Emission Spectroscopy to measure Ni and Cr levels, respectively. Student's t-test was used to compare Ni and Cr levels in the treated and untreated control groups. The mean Ni level was 4.197 microg/L in the experimental group and 2.3 ug/L in the control group [p < 0.05]. The mean Cr level was 2.9 microg/L in the experimental group and 3.3 microg/L in the control group [p < 0.05]. Fixed orthodontic appliances resulted in a non-toxic increase in salivary levels of Ni, but no change in Cr levels. Duration of orthodontic treatment did not affect Ni and Cr levels in the saliva