Trolić Ines Musa, Turco Gianluca, Contardo Luca, Serdarević Nikolina Leona, Otmačić Helena, Špalj Stjepan
PhD student, School of Dental Medicine University of Zagreb, Croatia.
Department of Medical, Surgical and Health Sciences, Laboratory for Dental Biomaterials, University of Trieste, Italy.
Acta Stomatol Croat. 2017 Dec;51(4):316-325. doi: 10.15644/asc51/4/6.
The aim of the study was to examine how probiotic supplements affect the corrosion stability of orthodontic archwires made of nickel-titanium alloy (NiTi).
NiTi archwires (0.508x0.508 and having the length of 2.5 cm) were tested. The archwires (composition Ni=50.4%, Ti=49.6%) were uncoated, nitrified and rhodium coated. Surface microgeometry was observed by using scanning electron microscope and surface roughness was measured by profilometer through these variables: roughness average, maximum height and maximum roughness depth. Corrosion was examined by electrochemical method of cyclic polarisation.
Rhodium coated alloy in saliva has significantly higher general corrosion in saliva than nitrified alloy and uncoated alloy, with large effect size (p=0.027; η2=0.700). In the presence of probiotics, the result was even more pronounced (p<0.001; η2=0.936). Probiotic supplement increases general and localised corrosion of rhodium coated archwire and slightly decreases general corrosion and increases localised corrosion in uncoated archwire, while in the case of nitrified archwire the probability of corrosion is very low. The differences in surface roughness between NiTi wires before corrosion are not significant. Exposure to saliva decreases roughness average in rhodium coated wire (p=0.015; η2=0.501). Media do not significantly influence surface microgeometry in nitrified and uncoated wires.
Probiotic supplement affects corrosion depending on the type of coating of the NiTi archwire. It increases general corrosion of rhodium coated wire and causes localised corrosion of uncoated and rhodium coated archwire. Probiotic supplement does not have greater influence on surface roughness compared to that of saliva.
本研究旨在探讨益生菌补充剂如何影响镍钛合金（NiTi）正畸弓丝的耐腐蚀稳定性。
对NiTi弓丝（尺寸为0.508x0.508，长度为2.5 cm）进行测试。弓丝（镍含量50.4%，钛含量49.6%）分为未涂层、氮化处理和镀铑处理三种。通过扫描电子显微镜观察表面微观几何形状，并使用轮廓仪测量表面粗糙度，测量变量包括平均粗糙度、最大高度和最大粗糙度深度。采用循环极化电化学方法检测腐蚀情况。
镀铑合金在唾液中的全面腐蚀明显高于氮化合金和未涂层合金，效应量较大（p = 0.027；η2 = 0.700）。在有益生菌存在的情况下，结果更为显著（p < 0.001；η2 = 0.936）。益生菌补充剂会增加镀铑弓丝的全面腐蚀和局部腐蚀，略微降低未涂层弓丝的全面腐蚀并增加局部腐蚀，而对于氮化弓丝，腐蚀概率非常低。腐蚀前NiTi弓丝之间的表面粗糙度差异不显著。暴露于唾液会降低镀铑弓丝的平均粗糙度（p = 0.015；η2 = 0.501）。培养基对氮化和未涂层弓丝的表面微观几何形状没有显著影响。
益生菌补充剂对腐蚀的影响取决于NiTi弓丝的涂层类型。它会增加镀铑弓丝的全面腐蚀，并导致未涂层和镀铑弓丝的局部腐蚀。与唾液相比，益生菌补充剂对表面粗糙度的影响不大。
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