In vivo examination of nickel and chromium release from different types of brackets

The objectives in this study are to examine different bracket types in terms of their impact on the nickel and chrome levels in saliva, blood and urine, and to track the changes of those ion releases at different times of treatment and assess their correlation. Saliva, blood and urine samples were taken from 51 individuals with ages ranging from 12 to 21. Three groups were constructed: conventional metal brackets, ceramic brackets and self-ligating brackets groups. Samples were taken from individuals at five different phases: Phase I and II were assessed as TControl, Phase III as T1, Phase IV as T2, and Phase V as T3. All patients fixed orthodontic treatments were planned as non-extraction treatment. In all fixed orthodontic treatments, 20 brackets and 4 molar single-tubes were used. Chemical analyses were done using the Atomic Absorption Spectrometer. SPSS 20.0 software was used for statistical analyses. For inter-group comparisons Kruskal-Wallis Test and for intra-group Wilcoxon Test were used. Correlation between variables were measured using Spearmen Correlation Test Nickel and chrome levels in saliva and urine rised in the metal and self-ligating groups, in the first 30 days of treatment (T1) compared to the TControl period. Ions release from conventional brackets group were more than that of the esthetic and self-ligating brackets groups in most of the cases. This finding was particularly apparent in chrome level rise in T1-T2 period for metal brackets groups. Mid-level positive correlation between saliva and urine chrome levels was found. Notable amount of nickel and chrome release from fixed orthodontic appliances can be observed. However, released amounts of nickel and chrome do not reach toxic levels in saliva, blood or urine. Key Words: Nickel Release, Chromium Release, Fixed Orthodontic Treatment