Comparison of Some Dietary Habits on Corrosion Behavior of Stainless Steel Brackets: An in vitro Study

Background and Objective: Resistance to corrosion is an advantageous property of orthodontic brackets; however, due to low levels of pH found in the mouth of a patient, localized corrosion may occur. This can affect tooth movement by increasing friction between the arch wire and bracket slot and initiate enamel discoloration. Additionally, corrosion causes the release of elements that may lead to cytotoxic and biological side effects. The aim of this study was to compare the amount of corrosion caused by lemon juice, vinegar and Coca-Cola® on orthodontic brackets in vitro and then to recommend the most suitable diet during orthodontic treatment. Method: Sixty orthodontic brackets in three groups of twenty were immersed in a test solution (Fusamaya-Meyer artificial saliva plus lemon juice, vinegar or Coca-Cola) at a temperature of 37°C±1. Moreover, a negative control consisting of twenty brackets were put in pure artificial saliva. After 6 weeks the amount of corrosion was determined by measuring ΔW of mean weights of brackets and the results were analyzed by general linear models (repeated measurement). Results: Significant differences were seen during different weeks of the study (P<0.001) and different solutions (P<0.001). This study showed the amount of corrosion in orthodontic brackets was the most for cola followed by vinegar and then lemon juice. In addition, mean differences for cola versus lemon juice was - 0.010 (sig. <0.001), vinegar versus lemon juice was -0.006 (sig. =0.001) and cola versus vinegar was - 0.004 (sig. =0.013). Conclusion: Acidic effervescent soft drinks such as cola have to be eliminated or minimized in the nutritional diet of orthodontic patients because of their harmful effects on their brackets.

Orthodontic Bracket, corrosion, lemon juice, vinegar, Coca-Cola®

1. Brantley WA, Eliades T. Orthodontic materials. 1st ed. New York: Thieme, pp. 288–9, 2001.

2. Eliades T. Orthodontic maternal research and applications: Part 2. Current status and projected. Future developments in materials and biocompatibility. Am J Orthod Dentofacial Orthop, 131(2): 253–62. 2007.

3. Mockers O, Deroze D, Camps J. Cytotoxicity of orthodontic band, brackets and arch wires in vitro. Dent Mater, 18(4): 311–7, 2002.

4. Wataha JC. Biocompatibility of dental casting alloys: A review. J Prosthet Dent, 83(2): 223–34, 2000.

5. ES-Souni M, ES-Souni M, Fischer-Brandies H. Assessing the biocompatibility of NiTi shape memory alloys used for medical applications. Anal Bioanal Chem, 381(3): 557–67, 2005.

6. Savolainen H. Biochemical and clinical aspects of nickel toxicity. Rev Environ Health, 11(4): 167–73, 1996.

7. Messer RL, Bishop S, Lucas LC. Effects of metallic ion toxicity on human gingival fibroblasts morphology. Biomaterials, 20(18): 1647–57, 1999.

8. Lindsten R, Kurol J. Orthodontic appliances in relation to nickel hypersensitivity: A review. J Orofac Orthop, 58(2): 100–8, 1997.

9. Oh KT, Kim KN. Ion release and cytotoxicity of stainless steel wires. Eur J Orthod, 27(6): 533–40, 2005.

10. Gwinnett AJ. Corrosion of resin-bonded orthodontic brackets. Am J Orthod, 81(6): 441–6, 1982.

11. Shin JS, Oh KT, Hwang CJ. In vitro surface corrosion of stainless steel and NiTi orthodontic appliances. Aust Orthod J, 19(1): 13–8, 2003.

12. Lin MC, Lin SC, Lee TH, Huang HH. Surface analysis and corrosion resistance of different stainless steel orthodontic brackets in artificial saliva. Angle Orthod, 76(2): 322–9, 2006.

13. Siargos B, Bradley TG, Darabara M, Papadimitriou G, Zinelis S. Galvanic corrosion of metal injection molded (MIM)and conventional brackets with nickel-titanium and copper-nickel-titanium arch wires. Angle Orthod; 77(2): 355–60, 2007.

14. Matasa CG. Attachment corrosion and its testing. J Clin Orthod, 29(1): 16–23, 1995.

15. Chaturvedi TP, Upadhayay SN. An overview of orthodontic material degradation in oral cavity. Indian J Dent Res, 21(2): 275–84, 2010.

16. Veien NK, Borchorst E, Hattel T, Laurberg G. Stomatitis or systemically-induced contact dermatitis from metal wire in orthodontic materials. Contact Dermatitis, 30(4): 210–213, 1994.

17. Al-Waheidi EM. Allergic reaction to nickel orthodontic wire: A case report. Quintessence Int, 26(6): 385–387, 1995.

18. Dunlap CL, Vincent SK, Barker BF. Allergic reaction to orthodontic wire: Report of a case. J Am Dent Assoc, 118: 449–50, 1989.

19. Huang HH. Surface characterizations and corrosion resistance of nickel titanium orthodontic archwires in artificial saliva of various degrees of acidity. J Biomed Mater Res A, 15; 74(4): 629–39, 2005.

20. Haung HH. Corrosion resistance streesed Niti and stainless steel wires in acid artificial saliva. J Biomed Mater Res, 66(4): 829–839, 2003.

21. Huang HH, Chiu YH, Lee TH,Wu SC, Yang HW, Su KH et al. Ion release from NiTi orthodontic wires in artificial saliva with various acidities. J Biomed Mater Res A, 15; 66(4): 829–39, 2003.

22. Es-Souni M, Es-Souni M, Fischer-Brandies H. On the properties of two binary NiTi shape memory alloys. Effects of surface finish on the corrosion behaviour and invitro bicompatibility. Biomatrials, 23(14): 2887–94, 2002.

23. Lin MC, Lin SC, Lee TH, Huang HH. Surface analysis and corrosion resistance of different stainless steel orthodontic brackets in artificial saliva. Angle Orthod, 76(2): 322–9, 2006.

24. Staffolani N, Damiani F, Lilli C, Guerra M, Staffolani NJ, Belcastro S et al. Ion release from orthodontic appliance. J Dent, 27(6): 449–54, 1999.

25. Grosgogeat B, Pernier C, Schiff N, Comte V, Huet A. Biocompatibility and resistance to corrosion of orthodontic wires. Orthod Fr, 74(1): 115–21, 2003.