An Examination of Bacterial Colonisation on Nickel-Titanium Arch-wires with Different Surface Properties

Introduction: Microbial dental plaque accumulation during fixed orthodontic treatment, leads to iatrogenic decalcification of the enamel and to development of the white spot lesions. The surface charcteristics of orthodontic wires can affect this situation. Aim: To comparatively assess the uncoated nickel-titanium archwires (A-NiTi) and epoxy resin-coated nickel-titanium archwires (A-NiTVER) in vivo, regarding the periodontal status, Streptococcus mutans (SM) and Lactobacillus (LB) colony numbers on wires and in saliva samples. Materials and Methods: In this cross sectional study, 31 individuals (20 females, 11 males) with a mean age of 15.5 +/- 1.84 years were included. A-NiTi and A-NiTi/ER were applied randomly and in sequential order. Saliva and archwire samples were obtained, to assess the amount of SM and LB colony numbers before archwire application, and after archwire applications (A-NiTi and A-NiTi/ER). Periodontal parameter that was assessed was gingival bleeding index. Factorial design repeated measures ANOVA and Bonferroni methods were used for statistical analysis. Results: The SM count in saliva before archwire application was statistically lower than A-NiTi and A-NiTi/ER application (p<0.001) statistically significant differences were found between A-NiTi and A-NiTi/ER archwires for LB colony numbers (p<0.001). The LB counts between saliva and archwires for A-NiTiand A-NiTi/ER, were in a moderate positive relationship with each other. No significant difference in the GBI percentage was observed (p>0.05). Conclusion: Increased LB colony numbers were obtained on A-NiTi/ER compared to A-NiTi. The increase in LB colony numbers between saliva and archwires for A-NiTi, and similarly for A-NiTi/ER were correlated with each other.