Abstract:

  Background and Aim: Different types of brackets are manufactured by various companies which are used in orthodontic treatment. The amounts of nickel, chromium and cobalt ions nreleased from these brackets are different and the side effects of these ions are clearly known. The purpose of this study is to assess the effect of time on the release of ions from various brackets that are manufactured by 4 companies.

  Materials and Methods : In this experimental study 160 orthodontic brackets from Biom,Organizer,American and Dentarum companies were evaluated for ion release. The samples were divided into 8 groups containing 20 brackets each. Four groups were immersed in artifact saliva and kept in an incubator for one week. The other four groups were immersed in artifact saliva for 6 months. Afterwards, 0.5 ml of each solution was analyzed by spectrophotometer for the the amount of released Cr,Co and Ni ions. Statistical analysis of the data was done using one way ANOVA, two way ANOVA, Tomhane and t test.

  Results : The level of Ni,Cr and Co ions released for different brackets after one week were as follows: Biom: 378±16.5, 0.4±0.74,0.4±0.1. Dentarum: 142±10.12, 2.61±0.22, 1.34±0.14. American: 58.5±2.06, 0.46±0.28, 0.65±0.04. Organizer: 57±3.53, 0.22±0.47, 8.9±0.3, the ions released after a period of 6 months reported to be as follows: Biom: 3000±91.4,2.4±0.12,4000±0.38.Dentarum:1200±87.23,3.40±0.21,2.40±0.08. American:55.1±2.21, 3.2±0.07,11.40±0.16 Organizer: 55.20±2.32,7.80±0.22, 6.50±0.11. The amount of released ions was found to be significantly different among the four groups. (p<0.001)

  Conclusion: The American brand released the least amount of ions in the long term. Therefore, it is a more suitable choice for long-term orthodontic treatments.