Objective: the aim of this study was to compare bacterial plaque accumulation on coated and uncoated orthodontic wires.
Method: Eighteen (9 upper&9 lower) epoxy resin-coated 16×22 nickel-titanium wires(Spectra, GAC) and eighteen(9 upper&9 lower)non-coated 16×22nickel-titanium wires(Sentalloy,GAC) with isolated package were selected and sterilized before application. Samples divided randomly between upper and lower arch in 18 patients so that every patient received one coated and one uncoated wire at the same time. Samples were removed and cutted in equal length after 3 weeks and placed in PBS buffer . After separation of bacteria in trip sin and EDTA solution, Diluted solution were cultured in blood agar and colony forming unit (CFU) and streptococcal colonies were counted .Paired t-test were used to analyze results.
Result: mean of CFU on uncoated wires was more than mean of CFU on coated wires (p<0.001). Mean of streptococcal colonies on uncoated wires was more than coated wires (p=0.003)
Conclusion: bacterial plaque accumulation on epoxy resin- coated nickel – titanium orthodontic wires is significantly lower than uncoated nickel – titanium wires.