An evaluation of corrosion on nickel-titanium archwires after clinical use of different commercial mouthwashes

The object of this in-vivo study is to compare the amount of corrosion occured on the surface of NiTi wires within various mouthwashes. A total of 80 patients with selected criteria were split into 4 equal groups of 20 patients. These patients were arranged as to use mouthwash containing %0,05 of (225ppm Fˉ) sodium fluoride (NaF) (Colgate Plax®), mouthwash containing %21,6 of alcohol (Listerine Cool Mint®), mouthwash containing %0,2 of clorhexidine (CHX) (Klorhex®) and the control group used drinking water as mouthwash with melt menthol. Besides to that, as-received wires were observed to compare. Before starting the application of mouthwashes to standardize the oral environment, the participants were told to brush their teeth with aloe vera based toothpaste and the toothbrush with thin and soft bristles for 3 days. After 30 days of using mouthwashes, as-retrieved wire samples were examined with Atomic Force Microscopy (AFM) and surface roughness values' were calculated. Acquired data was statistically analyzed with SPSS ((Statistical Package for Social Sciences, ABD) for Windows 21.0. The results have been assessed at 95% confidence interval and a significance level p<0.05. The results of the study indicated that mouthwashes including neutral fluoride, essential oil and CHX created higher surface roughness than control group and as-received wire groups. AFM images show supportive data with the results of clinical study. In our study, we claim that the mouthwashes included in this study cause considerable corrosion on NiTi wires. In order to eliminate this, increasing the efficiency of tooth brushing would be appropriate instead of using those mouthwashes. Key words: Corrosion, surface roughness, mouthwash, atomic force microscopy, NiTi wires