Material-dependent corrosion behavior of fixed lingual retainer wires following exposure to a Streptococcus mutans–containing cariogenic medium: an electrochemical and surface analysis

İngilizce (OpenAlex)

Abstract The aim of this study was to comparatively evaluate the corrosion behavior of six orthodontic lingual retainer wire materials following exposure to a Streptococcus mutans –containing cariogenic medium under simulated oral conditions. Sixty lingual retainer wire specimens, including six materials (3-strand stainless steel, 6-strand stainless steel, titanium Grade 1, titanium Grade 5, Bond-A-Braid, and gold), were divided into study and control groups. The study specimens were exposed to a S. mutans –containing cariogenic medium for 28 days, whereas control specimens were incubated under identical conditions in sterile artificial saliva. Potentiodynamic polarization tests were performed to determine corrosion current density, corrosion rate, and polarization resistance, and surface characteristics were evaluated by SEM. Statistical significance was set at p < 0.05. Exposure to a S. mutans –containing cariogenic medium was associated with material-dependent changes in corrosion behavior. Corrosion current density and corrosion rate increased significantly in the 6-strand stainless steel and Bond-A-Braid retainers following exposure. A significant reduction in polarization resistance was observed only for the 6-strand stainless steel retainer ( p < 0.05). In contrast, the gold retainer exhibited significantly lower corrosion current density and corrosion rate together with higher polarization resistance following exposure ( p < 0.05). SEM analysis revealed material-specific surface deposits and pitting patterns. The findings indicate that exposure to a S. mutans –containing cariogenic medium results in material-dependent electrochemical responses among fixed lingual retainer wires. Titanium Grade 1 demonstrated the most stable electrochemical performance under the tested conditions, whereas gold exhibited a distinct electrochemical response following exposure. Corrosion-related surface alterations following exposure to a S. mutans –containing cariogenic environment may compromise retainer surface integrity and longevity, potentially promoting plaque accumulation and adversely affecting long-term clinical performance. Therefore, particularly under cariogenic conditions, consideration of corrosion resistance alongside mechanical properties may be beneficial when selecting orthodontic lingual retainer materials.