Influence of prophylactic fluoride agents on the color changes and surface roughness of polymer and rhodium coated nickel-titanium orthodontic archwires

Abstract

The effect of fluoride use on the color change and surface characteristics of coated nickel and titanium (NiTi) orthodontic archwires was investigated. Epoxy resin, PTFE or rhodium-coated archwires were exposed to acidulated phosphate fluoride (APF) or sodium fluoride (NaF) or artificial saliva (AS), simulating three-month clinical trials. Color changes (∆E) were assessed using a laboratory spectrophotometer in the three-dimensional CIELab color space. The roughness (Ra) and surface structure of the archwires were examined using a non-contact profilometer and scanning electron microscopy (SEM), respectively. Data were analyzed using two-way and one-way variance (ANOVA) and post-hoc Bonferroni test (α=0.05). The average values of ∆E and Ra were the highest for epoxy-APF archwires and the lowest for rhodium-AS archwires. A significant relationship was found between the archwires surface treatment method and the ∆E and Ra values. After three months, greater changes in color and roughness were observed with APF than with AS.