Effects of Fluoride Treatment Agents on Dental Metallic Materials

Introduction: The administration of fluoride is recognized as an aid in the control and prevention of plaque and caries. It is also an important adjunct in orthodontic care. The more commonly used fluoride agent is acidulated phosphate fluoride, containing 1.23 w/o fluoride ion (pH 3.5); this media can be corrosive to metals.Objectives: The purpose of this study is to evaluate the effects of varying fluoride agents on orthodontic metallic brackets and identify if there are adverse effects on their integrity. Materials and Methods: Eight brackets (4 stainless steels, 4 CpTi) were treated in fluoride medium for 1-min and 4-min to evaluate their discoloration and changes in microstructures. Seven different fluoride agents and a control (artificial saliva) were used. Three dentists were assigned to evaluate the extent of discoloration on four wings of each 12-group sample. Further assessments were made by SEM. Results: No significant difference was found between 1-min and 4-min treatments. All brackets were discolored to some extent. CpTi exhibited more discolorations, but was removed by 100-stroke brushing. SEM of stainless steel brackets revealed typical intergranular attacks, which could potentially affect the material’s structural integrities. Conclusion: Special care is needed when subjecting a patient with orthodontic brackets to a fluoride medium. This is especially true for stainless steel brackets.