Variation in surface topography of different NiTi orthodontic archwires in various commercial fluoride-containing environments.
OBJECTIVE
The surface topography can affect the friction behavior between an orthodontic wire and brackets during clinical applications. The purpose of this study was to investigate the influence of a fluoride-containing environment on the surface topography variations of different nickel-titanium (NiTi) orthodontic archwires.


METHODS
Four different NiTi commercial orthodontic archwires were immersed in fluoride mouthwashes and in artificial saliva with the addition of commercial fluoride toothpastes or prophylactic gels for a 28-day period. Atomic force microscopy (AFM) was used to measure the three-dimensional surface topography of NiTi archwires before and after the immersion tests. Two-way analysis of variance (ANOVA) was used to analyze the surface roughness variance (including DeltaR(a), DeltaR(ms), and DeltaR(z)) with the archwire manufacturer and immersion test environment as the factors.


RESULTS
Both the archwire manufacturer and immersion environment had a significant influence on DeltaR(a), DeltaR(ms), and DeltaR(z) (manufacturer: P<0.05; environment: P<0.0001). Regardless of the archwire manufacturer, no statistically significant difference in DeltaR(a) (<70 nm), DeltaR(ms) (<90 nm), and DeltaR(z) (<450 nm) was observed on the tested NiTi archwires in lower fluoride-containing (<2500 ppm) environments, including the various fluoride mouthwashes and the artificial saliva added with fluoride toothpastes. In artificial saliva added with high fluoride prophylactic gel (around 17,000 ppm), a significant increase in DeltaR(a) (around 120-250 nm), DeltaR(ms) (around 140-320 nm), and DeltaR(z) (around 770-1410 nm), i.e. increasing the surface roughness, was observed on the tested NiTi archwires.


CONCLUSIONS
The variation in the surface topography of the NiTi orthodontic archwires in the commercial fluoride-containing environments should be taken into consideration when the friction between the archwire and bracket is a clinical concern.
Huang
Her-Hsiung
HH
Faculty of Dentistry, School of Dentistry, National Yang-Ming University, Taipei 112, Taiwan.
D000149:Acidulated Phosphate Fluoride / Q000737:chemistry; D002327:Cariostatic Agents / Q000737:chemistry*; D045424:Complex Mixtures / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D017276:Friction; D005782:Gels; D006801:Humans; D021621:Imaging, Three-Dimensional; D007101:Immersion; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D009067:Mouthwashes / Q000737:chemistry; D009532:Nickel / Q000737:chemistry*; D009969:Orthodontic Wires; D012464:Saliva, Artificial / Q000737:chemistry; D012824:Silicic Acid; D012822:Silicon Dioxide / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014100:Toothpastes / Q000737:chemistry; D014260:Triclosan / Q000737:chemistry
D002327:Cariostatic Agents; D045424:Complex Mixtures; D003722:Dental Alloys; D005782:Gels; D009067:Mouthwashes; D012464:Saliva, Artificial; D014100:Toothpastes; C546060:hydrated silica gel-based toothpaste; C040654:titanium nickelide; D012824:Silicic Acid; D000149:Acidulated Phosphate Fluoride; D014260:Triclosan; D012822:Silicon Dioxide; D009532:Nickel; D012969:Sodium Fluoride; D014025:Titanium; D005459:Fluorides