title: Effects of two soft drinks on shear bond strength and adhesive remnant index of orthodontic metal brackets.
abstract: OBJECTIVE
  Bond failure of brackets during orthodontic treatment is a common problem; which results in treatment interference, increased treatment time and prolonged clinical time for rebonding of failed brackets. The purpose of this study was to evaluate the effects of Coca-Cola and a non-alcoholic beer on the shear bond strength and adhesive remnant index (ARI) of orthodontic metal brackets in vitro.
  
  
  METHODS
  Eighty intact human premolars were divided into two experimental groups of Coca-Cola and non-alcoholic beer (Istak), and a control group of artificial saliva. Over a period of thirty days, the test groups were immersed in the respective soft drinks for 5 minutes, twice a day. For the remainder of the time, they were kept in artificial saliva at 37°C. The control group was stored in artificial saliva during the experiment. All samples were subjected to shearing forces using Universal Testing Machine. ARI was determined with a stereomicroscope at ×12 magnification. The data of shear bond strength were statistically analyzed by one-way ANOVA and Tukey's Post-Hoc test and the data of ARI scores were analyzed by Kruskal-Wallis test.
  
  
  RESULTS
  No significant difference was observed in ARIs of the three groups (P≤ 0.552). The shear bond strength of Coke group was significantly lower than that of the two other groups (P≤ 0.035); but there was no significant difference between the shear bond strength of Istak and the control group (P≤ 0.999).
  
  
  CONCLUSIONS
  Coca-Cola decreased the shear bond strength of orthodontic brackets.
authors.affiliation: Assistant Professor, Department of Orthodontics, Arak University of medical science, Arak, Iran.
authors.forename: Soodabeh Sadat
authors.initials: SS
authors.lastname: Sajadi
authors.affiliation: Assistant Professor, Department of Orthodontics, Dental School, Shahed University, Tehran, Iran.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Eslami Amirabadi
authors.affiliation: Assistant Professor, Department of Endodontics, Arak University of medical science, Arak, Iran.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Sajadi
keywords: Index; Remnant; Shear strength, Adhesive; Soft drinks