【摘要】 目的 通过扫描电镜观察根尖手术切除的根管治疗失败患牙样本，探究根尖外生物膜的检出率、形态特征及其与根尖表面形态的关系，分析根尖外生物膜存在的影响因素。方法 收集57例因根管治疗失败需行根尖手术的患牙根尖样本，采用扫描电镜观察根尖外表面，记录生物膜的检出率和形态结构。去除根面非矿化有机成分后，再次在扫描电镜下观察根尖表面的形态学特征。结果 在57例样本中，50例观察到根外细菌生物膜，检出率为87.72%。有生物膜组的根尖病变体积和根尖孔直径均显著大于无生物膜组（P<0.05）。生物膜主要由球菌、杆菌及丝状菌构成，呈团状、簇状或网状分布，也可见到典型的“玉米棒芯”样结构，所有样本均存在不同程度的根外吸收。结论 根管治疗失败的持续性根尖周炎患牙大多存在根尖外生物膜，其检出率与根尖病变大小及根尖孔尺寸呈正相关。更多还原

【Abstract】 Objective This study aims to explore the detection rate, morphological characteristics, and relationship between the extraradicular biofilm and the apical surface morphology by scanning electron microscopy in samples of teeth that underwent apical surgery due to root canal treatment failure. Additionally, the factors influencing the presence of extraradicular biofilm were analyzed. Methods A total of 57 apical samples from teeth requiring apical surgery due to root canal treatment failure were collected. The apical surface was examined using scanning electron microscopy, and the detection rate and morphological structure of the biofilm were recorded. After removing the non-mineralized organic components, the morphological characteristics of the apical surface were re-examined under scanning electron microscopy. Results Among the 57 samples, extraradicular bacterial biofilms were observed in 50 cases, yielding a detection rate of 87.72%. Both the volume of the apical lesion and the diameter of the apical foramen were significantly greater in the biofilm-positive group than in the biofilm-negative group(P < 0.05). The biofilm mainly consisted of cocci, bacilli, and filaments, displaying a clustered, aggregated, or network-like distribution, with typical “corncob-like” structures also observed. Varying degrees of extraradicular resorption were present in all specimens. Conclusion The majority of teeth with persistent periapical periodontitis due to failed root canal treatment harbor extraradicular biofilms. The detection rate positively correlates with both periapical lesion size and apical foramen diameter, and the biofilms display considerable morphological complexity.更多还原