Comparing the chromium ion release rate from stainless steel orthodontic wires with and without surface abrasion in an artificial saliva solution: An in-vitro study

Introduction : Placing orthodontic wires in the oral cavity, exposing them to saliva, can cause corrosion and the release of metal ions, such as chromium. If this release of metal ions exceeds a certain amount, it could lead to cell toxicity and other complications. This study aimed to determine the chromium ion release rate from stainless steel orthodontic wires in an artificial saliva solution. Methods and Materials : In this laboratory study, we selected 24 sections of stainless-steel orthodontic wires from two brands: American Orthodontics and Ortho Organizer. The wires from each brand were then divided into two groups, one with scratches and one without. In each group, we placed three pairs of upper and lower jaw orthodontic wires into Falcon tubes filled with 50cc of artificial saliva solution. After ensuring complete sealing, we incubated the samples at 37 degrees Celsius. The concentration of chromium ions released in each sample was measured using an ICP-OES device at three intervals: 1, 14, and 28 days. We analyzed the obtained data using SPSS version 24 software. Results : The study results demonstrate a significant difference (P<0.001) in the amount of chromium ion released between wires without surface scratches and those with surface scratches for both brands. On average, the release of chromium ions was higher in wires with surface scratches. Additionally, a significant difference (P<0.001) in chromium ion release was observed between the two brands. In this case, the Ortho Organizer brand exhibited a higher average release of chromium ions, both in wires with surface scratches and those without. Conclusion: This study demonstrates that chromium ions are released at a faster rate from stainless steel (SS) orthodontic wires with surface scratches. Nevertheless, it's important to note that the maximum amount of chromium ion released remains below the toxic threshold for the human body.