Assessment of Friction Among Nickel Free Orthodontic Brackets and Archwires Combinations in Wet Condition (An In-vitro Comparative Study)
Background: Exposure to nickel-containing orthodontic appliances may cause intraoral or extraoral allergic reactions in patient with nickel-allergy. It is important to select a bracket and archwire combination that are nickel free and efficient during orthodontic treatment. Objective: to evaluate the static and kinetic frictional force generated by two types of nickel free metal brackets and three types of nickel free archwires in wet condition. Materials and Method: two types of brackets (cobalt chromium and nickel free stainless steel), coupled with three archwires (nickel free stainless steel, rhodium coated stainless steel, and titanium molybdenum) were used, ligated with conventional figure “O” elastomeric ligatures. Friction of 6 bracket/archwire combinations was measured by (Instron) machine with presence of artificial saliva. Each bracket/ wire was tested only once to eliminate the influence of wear. A new elastomeric ligature on each trial was used to minimize the influence of elastic deformation. Independent t-test and ANOVA test, were used to statistically analyze the results at a 0.05 level of significant. Results: there are a statistically significant difference in friction generation between the brackets and among the archwires. Conclusion: the best bracket/archwire combination for the patients with nickel hypersensitivity are nickel free stainless-steel brackets with nickel free stainless steel archwire.