Effect of soft drinks on the physical and chemical features of nickel-titanium-based orthodontic wires.

Department of Orthodontics, School of Dentistry, University of Bologna, Italy.
Acta odontologica Scandinavica (Impact Factor: 1.41). 04/2011; 70(1):49-55. DOI: 10.3109/00016357.2011.575083
Source: PubMed

ABSTRACT The purpose of this study was to evaluate the effect of three popular soft drinks on the Young's modulus, hardness, surface topography and chemical composition of widely used nickel-titanium-based orthodontic wires.
Thirty-two specimens (20 mm in length) were cut from the straight portion of pre-formed 0.019 × 0.025 inch Nitinol Heat-Activated archwires and randomly divided into four groups of eight specimens each: Group A1 (Coca Cola(®) regular); Group A2 (Santal(®) orange juice); Group A3 (Gatorade(®)); Group B (distilled, deionized water; dH(2)O). Each specimen was immersed in 10 ml of one of the soft drinks or dH(2)O, control, for 60 min, at 37°C. At the end of the soaking time, the Young's modulus and hardness were determined using a nanoindenter. Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) was used to characterize the effects on the topography and chemical composition of the wires.
No statistically significant differences were found between the groups either in the Young's modulus or in hardness after the selected soaking protocol. Besides some surface colour changes, the topography and the chemical composition of the wires were not affected by the immersion in any of the chosen soft drinks.
These in-vitro results suggest that the consumption of soft drinks cannot be acknowledged as one possible reason for the degradation of the physical and chemical properties of heat activated nickel titanium orthodontic wires in patients undergoing fixed orthodontic treatment.

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    ABSTRACT: The effects of carbamide peroxide, hydrogen peroxide and cola soft drink on the topographic modifications of commercially-pure titanium (CP-Ti) and Ti-6Al-4V were investigated. Ti discs were divided into 18 groups (n = 4) based on the solution treatment and Ti type. Specimens were immersed in 3 mL of each solution for 4 h per day (for the remaining 20 h, discs were left dry or immersed in artificial saliva) for 15 days. For control, specimens were immersed in only artificial saliva. Ti surfaces were examined using scanning electron (SEM) and atomic force (AFM) microscopes and their surface roughness (in µm) and surface chemical modifications were investigated. Data were analyzed by ANOVA and Tukey's test (α = 0.05). Groups immersed in 35% hydrogen peroxide showed the highest roughness (Ra) (171.65 ± 4.04 for CP-Ti and 145.91 ± 14.71 for Ti-6Al-4V) (p < 0.05), followed by groups treated with carbamide peroxide 16% (110.91 ± 0.8 for CP-Ti and 49.28 ± 0.36 for Ti-6Al-4V) and 35% (65.67 ± 1.6 for CP-Ti and 53.87 ± 1.98 for Ti-6Al-4V); treatment with artificial saliva did not affect the results. These values were statistically superior to those observed prior to the treatment and to those of the control group (31.0 ± 0.99 for CP-Ti and 29.95 ± 0.58 for Ti-6Al-4V). Cola soft drink did not alter the surface roughness of either Ti type (p > 0.05). SEM and AFM revealed dramatic changes in the specimens surfaces immersed in the 35% hydrogen peroxide, mainly for CP-Ti. No detectable chemical modifications on the Ti surface were observed. Bleaching agents promoted significant changes in Ti topography, which could affect the longevity of implants treatments. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
    Journal of Biomedical Materials Research Part B Applied Biomaterials 05/2013; · 2.31 Impact Factor


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