Dental Sciences Research Center, Department of Orthodontics, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.
Department of Orthodontics, School of Dentistry, Iran University of Medical Sciences, Tehran, Iran.
Int Orthod. 2024 Dec;22(4):100901. doi: 10.1016/j.ortho.2024.100901. Epub 2024 Aug 21.
The aim of this study was to evaluate the physico-mechanical, anti-bacterial, and anti-demineralization properties of orthodontic resin composite containing photoactivated zinc oxide nanoparticles (ZnONPs) on Streptococcus mutans biofilm around ceramic and metal brackets.
Following the minimum inhibitory concentration (MIC) determination for ZnONPs, shear bond strength (SBS) was tested for composites containing different concentrations of ZnONPs. The chosen concentration was used to evaluate the microleakage, anti-bacterial, and anti-demineralization properties.
Adding 50μg/mL of ZnONPs to the orthodontic composite did not negatively affect its physico-mechanical properties. ZnONPs (50μg/mL)-mediated aPDT and 0.2% chlorhexidine significantly (P=0.000) reduced S. mutans biofilms compared to the phosphate-buffered saline (PBS) groups (metal/PBS=7.47±0.7×10, and ceramic/PBS=7.47±0.7×10), with the lowest colony count observed in these groups (metal/chlorhexidine=1.06±0.4×10, ceramic/chlorhexidine=1±0.2×10, metal/ZnONPs-mediated aPDT=1.33±0.3×10, and ceramic/ZnONPs-mediated aPDT=1.2±0.3×10). Sodium fluoride varnish and ZnONPs-mediated aPDT showed the highest efficacy in anti-demineralization and significantly improving the enamel surface microhardness compared to the artificial saliva, especially in ceramic bracket groups (524.17±42.78N and 441.00±29.48N, 394.17±46.83N, P=0.000, and P=0.003, respectively).
ZnONPs (50μg/mL)-mediated aPDT effectively inhibited S. mutans biofilm and promoted anti-demineralization without adverse effects on the physico-mechanical properties of the composite resin. These results suggest the potential of this method in preventing white spot lesions during orthodontic treatment.
本研究旨在评估正畸复合树脂中光激活氧化锌纳米颗粒（ZnONPs）对陶瓷和金属托槽周围变形链球菌生物膜的物理力学、抗菌和抗脱矿性能。
在确定 ZnONPs 的最小抑菌浓度（MIC）后，测试了含有不同浓度 ZnONPs 的复合材料的剪切粘结强度（SBS）。选择的浓度用于评估微渗漏、抗菌和抗脱矿性能。
将 50μg/mL 的 ZnONPs 添加到正畸复合材料中不会对其物理力学性能产生负面影响。ZnONPs（50μg/mL）介导的光动力疗法和 0.2%洗必泰与磷酸盐缓冲盐水（PBS）组相比，显著降低了 S. mutans 生物膜（金属/PBS=7.47±0.7×10，陶瓷/PBS=7.47±0.7×10），这些组中观察到的菌落计数最低（金属/洗必泰=1.06±0.4×10，陶瓷/洗必泰=1.0±0.2×10，金属/ZnONPs 介导的光动力疗法=1.33±0.3×10，陶瓷/ZnONPs 介导的光动力疗法=1.2±0.3×10）。与人工唾液相比，氟化钠涂料和 ZnONPs 介导的光动力疗法在抗脱矿方面表现出最高的疗效，并显著提高了牙釉质表面的显微硬度，尤其是在陶瓷托槽组中（524.17±42.78N 和 441.00±29.48N，394.17±46.83N，P=0.000 和 P=0.003）。
ZnONPs（50μg/mL）介导的光动力疗法有效抑制了 S. mutans 生物膜的形成，并促进了抗脱矿作用，而对复合树脂的物理力学性能没有不良影响。这些结果表明，这种方法在预防正畸治疗期间的白垩斑病变方面具有潜力。
