| The objectives of this study were to compare in vitro long-term (30 month) fluoride release rates and re-release rates (following fluoride exposure) from three orthodontic bonding materials containing fluoride using a disc model, and to compare the fluoride release rates of two orthodontic bonding materials containing fluoride using an in vitro tooth-bracket model. For part I of the study, 10 samples of each material (Python(TM), Assure(TM), Fuji Ortho(TM) and Transbond(TM) XT) were fabricated and stored in de-ionized distilled water at 37°C. Five samples had fluoride release rates measured at days 546, 637, 730, 821 and 913 from time of initial fabrication, while 5 samples were exposed to fluoride for 4 minutes at day 535 and had measurements taken on days 546, 548, 552, 575, 637, 730, 821 and 913. To prevent cumulative measurements, the storage solutions were changed 24 hours prior to measurement. For part II of the study, 10 samples of each material were used to bond orthodontic brackets to extracted human premolars and stored as in part I. (Abstract shortened by UMI.). |
