In vitro evaluation of ion releases from brackets and wires, used during orthodontic treatment, in artificial saliva with different PH values

This study aims in vitro measurement and evaluation of ion releases from brackets and wires, used in oral cavity during orthodontic treatment, in artificial saliva with different pH values. In this study to evaluate the ion releases at different pH values, 5 different bracket systems from various manufacturers (.022" slot MBT bracket system without a metal cap 18 unit from each brand) and .012", .014", .016", .018" or (.020"), .014"x.025" or (.016"x.022"), .017"x.025", .019"x.025" Ni-Ti arch wires (18 from each wire size which is used during orthodontic treatment, a total of 630) from same manufacturers is used. Brackets and wires from different manufacturers is placed in 250-ml glass laboratory flasks containing 100 ml artificial saliva, with a total of 180 samples. After the immersion periods of 1 day and 42 days (6 weeks), to measure the amounts of ion released in different acidities samples are analyzed by using ICP-MS (Inductively Coupled Plasma – Mass Spectrometer, Thermo Scientific, X Series 2, USA) for metal components. According to the study results; the elements with a statistically significant increase in the majority of the groups in the amount of ion release by decreasing pH are Co and Sr for the bracket group and Co, Ni and Sr for the wire group. For the bracket groups, the pH value changed from 6,7 to 4, indicating a statistically significant increase in the level of ion release throughout the elements. Maximum ion release from brackets and wires occurred on day 1. The UA group is a bracket group in which the elements release maximum ions at all pH values. The data obtained support the finding that different brands exhibit different ion release properties at different pHs, that the ion release level increases with decreasing pH in general, and that the corrosion behavior of the elements may vary depending on the construction and manufacturing styles of the devices. In line with this information, information has been obtained that can guide the clinician to assess whether the orthodontic treatment of inter-brand ion release differences is an important factor in exposure to toxic trace elements.