To solve the high instances of failure caused by endodontic reinfection, herein, an improved root filling material was produced to meet the multi-functional demand of sealers for root canal therapy. In this study, polyurethane (PU)-based nanocomposites were prepared by loading bismuth oxide, hydroxyapatite and antibacterial agents, namely Ag₃PO₄ and ZnO nanoparticles, which were named CP-Ag and CP-Zn sealers, respectively. A parallel biological evaluation at bacterial and cellular levels was performed to determine the fate of the different components of the PU-based sealers. Furthermore, the composition of sealers was quantified by screening their antibacterial activity and apoptotic factors, considering the potential toxicity of the nanoparticles and high dosage of metals. The in vitro optimization investigation was conducted systematically against Streptococcus mutans and Staphylococcus aureus, including bacteriostatic and dynamic tests, and the expression of the B-cell lymphoma-2 gene family and caspase proteases in the mitochondria-mediated apoptotic pathway was evaluated using the commercial AH Plus® and Apexit® Plus sealers for comparison. Additionally, the physical properties and sealing ability of sealers were assessed. The results showed that all PU-based sealers could meet the requirements of ISO 6876:2012 for root canal sealing materials. Based on the evaluation system, CP-Zn sealers expressed longer lasting antibacterial activity and lower toxic effect on cells compared to CP-Ag sealers. Especially, the CP-Zn5 sealer exhibited selective antimicrobial efficacy and hypo-toxicity, which were better than that of the two commercial sealers. According to the two-dimensional and three-dimensional methods, the good sealing ability of the CP-Zn5 sealer is the same as the excellent filling characters of AH Plus, which adapts to irregular root canals.

中文翻译：

---

多功能聚氨酯封闭剂在根管治疗中通过细胞凋亡优化抗菌效果的体外评价

为了解决由牙髓再感染引起的高失败率的实例，在此，生产了改良的根填充材料，以满足对根管治疗的密封剂的多功能需求。在这项研究中，通过加载氧化铋，羟基磷灰石和抗菌剂Ag ₃ PO ₄和ZnO纳米颗粒（分别称为CP-Ag和CP-Zn密封剂）来制备聚氨酯（PU）基纳米复合材料。进行了细菌和细胞水平的平行生物学评估，以确定基于PU的封闭剂不同成分的命运。此外，考虑到纳米粒子的潜在毒性和高剂量的金属，通过筛选它们的抗菌活性和凋亡因子来量化封闭剂的组成。的系统地对变形链球菌和金黄色葡萄球菌进行了体外优化研究使用商业AHPlus®和Apexit®Plus封闭剂评估了细菌（包括抑菌和动态测试）以及线粒体介导的凋亡途径中B细胞淋巴瘤2基因家族和caspase蛋白酶的表达，以进行比较。另外，评估了密封剂的物理性质和密封能力。结果表明，所有聚氨酯基密封剂都可以满足ISO 6876：2012对根管密封材料的要求。基于评估系统，与CP-Ag封闭剂相比，CP-Zn封闭剂表现出更长的持久抗菌活性和更低的对细胞的毒性作用。特别是，CP-Zn5封闭剂表现出选择性的抗菌功效和低毒性，优于两种商业封闭剂。根据二维和三维方法，