Comparison of some dietary habits on corrosion behavior of stainless steel brackets: An in vitro study

Abstract

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.