Condò Roberta, Carli Elisabetta, Cioffi Alessandro, Cataldi Maria Elena, Quinzi Vincenzo, Casaglia Adriano, Giancotti Aldo, Pirelli Paola, Lucarini Ivano, Maita Francesco, Maiolo Luca, Mampieri Gianluca
Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy.
Department of Surgical Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, 56126 Pisa, Italy.
Materials (Basel). 2022 Jun 30;15(13):4612. doi: 10.3390/ma15134612.
Fluoride-based mouthwashes and gels are preventive measures in countering demineralization and caries but, modifying environmental acidity, can reduce the wet corrosion resistance of orthodontic alloys. To evaluate chemical stability, in vitro experiments were conducted on stainless steel and nickel-titanium wires, weighed before and after immersion in household fluorinated mouthwashes and gels, measuring weight variations and elution of metal ions from acid corrosion phenomena. Elution samples were analyzed by inductively coupled plasma mass spectrometry, detecting residual ion concentration, while surface changes were analyzed under scanning electron microscopy. Results showed stainless steel wires do not undergo significant erosion when exposed to most fluorinated mouthwashes but, at prolonged exposure, alloys elute gradually greater amounts of metals and Ni-Ti wires become more sensitive to some mouthwashes. Ions' elution varies considerably, especially for Ni-Ti wires, if exposed to household fluorinated gels, for which significant negative values were obtained. Changes, affecting wires' outer layer, negatively act on shiny appearance and luster, reducing corrosion resistance. Although examined orthodontic wires showed good chemical stability and low toxicity, surface corrosion from exposure to fluorinated agents was observed. Home use must be accompanied by clinician prescription and, for household dental gels, must follow manufacturers' recommendations, ensuring prophylactic action without damaging alloys surfaces.
含氟漱口水和凝胶是预防牙齿脱矿和龋齿的措施，但由于会改变环境酸度，可能会降低正畸合金的耐湿腐蚀性。为评估化学稳定性，对不锈钢丝和镍钛丝进行了体外实验，在将其浸入家用含氟漱口水和凝胶前后进行称重，测量重量变化以及酸腐蚀现象导致的金属离子洗脱情况。通过电感耦合等离子体质谱法分析洗脱样品，检测残留离子浓度，同时在扫描电子显微镜下分析表面变化。结果表明，不锈钢丝暴露于大多数含氟漱口水时不会发生明显腐蚀，但长时间暴露后，合金会逐渐洗脱更多金属，镍钛丝对某些漱口水变得更敏感。如果暴露于家用含氟凝胶，离子洗脱差异很大，尤其是镍钛丝，会得到显著的负值。影响金属丝外层的变化会对其光泽外观产生负面影响，降低耐腐蚀性。尽管所检测的正畸金属丝显示出良好的化学稳定性和低毒性，但仍观察到暴露于含氟剂导致的表面腐蚀。家庭使用必须有临床医生的处方，对于家用牙科凝胶，必须遵循制造商的建议，确保预防作用而不损坏合金表面。
