Karygianni L, Anderson A C, Tennert C, Kollmar K, Altenburger M J, Hellwig E, Al-Ahmad A
Department of Operative Dentistry and Periodontology, Center for Dental Medicine, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany.
Clin Oral Investig. 2015 Mar;19(2):319-27. doi: 10.1007/s00784-014-1231-4. Epub 2014 Mar 28.
Root canal treatment failures often correlate with persistent biomaterial-associated endodontic infections. The aim of the present study was to assess the impact of endodontic obturation material sampling from root canals with posttreatment apical periodontitis on improving standard study protocols.
Samples from previously filled root canals and their corresponding endodontic filling materials were obtained from five root-filled teeth with posttreatment periradicular lesions. After cultivation, the isolated microorganisms were quantified and biochemically identified. Moreover, clone libraries were constructed after the amplification of bacterial 16S ribosomal DNA (rDNA) from the same samples. DNA from selected clones was sequenced to identify microbial species. Transmission electron microscopy (TEM) aided visualization of the detected bacteria.
Overall, 22 taxa of the phyla Firmicutes, Actinobacteria, and Bacteroidetes were detected in both obturation and root canal samples by culture-dependent and culture-independent methods. Root canal fillings sheltered 17 species (3.30-7.50 × 10(3) CFU/ml). Of these, nine were detected solely in the retrieved obturation materials. The reinfected root canals harbored 13 taxa (3.48-7.36 × 10(3) CFU/ml). Obligate and facultative anaerobic bacteria prevailed. The number of different species ranged from 1 to 5 within a single sample. Fungi were not detected.
Bacteria can colonize both root canals and endodontic fillings in vivo.
Integrating the sampling of obturation materials with standard root canal sample collection offers a clearer insight into the actual microbial flora of reinfected root canals and improves the study protocols of secondary/persistent endodontic infections.
根管治疗失败常与持续性生物材料相关的牙髓感染有关。本研究的目的是评估从患有治疗后根尖周炎的根管中采集牙髓充填材料对改进标准研究方案的影响。
从五颗患有治疗后根尖周病变的根管充填牙中获取先前充填根管及其相应牙髓充填材料的样本。培养后，对分离出的微生物进行定量和生化鉴定。此外，从相同样本中扩增细菌16S核糖体DNA（rDNA）后构建克隆文库。对选定克隆的DNA进行测序以鉴定微生物种类。透射电子显微镜（TEM）辅助检测细菌的可视化。
总体而言，通过依赖培养和不依赖培养的方法在充填材料和根管样本中均检测到厚壁菌门、放线菌门和拟杆菌门的22个分类单元。根管充填物中含有17种细菌（3.30 - 7.50×10³CFU/ml）。其中，9种仅在取出的充填材料中检测到。再次感染的根管中含有13个分类单元（3.48 - 7.36×10³CFU/ml）。专性和兼性厌氧菌占优势。单个样本中不同物种的数量范围为1至5种。未检测到真菌。
细菌可在体内定殖于根管和牙髓充填物中。
将充填材料采样与标准根管样本采集相结合，能更清楚地了解再次感染根管的实际微生物菌群，并改进继发性/持续性牙髓感染的研究方案。
