Lukic Dejana, Karygianni Lamprini, Flury Manuela, Attin Thomas, Thurnheer Thomas
Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland.
Microorganisms. 2020 May 6;8(5):674. doi: 10.3390/microorganisms8050674.
Oral bacteria possess the ability to form biofilms on solid surfaces. After the penetration of oral bacteria into the pulp, the contact between biofilms and pulp tissue may result in pulpitis, pulp necrosis and/or periapical lesion. Depending on the environmental conditions and the availability of nutrients in the pulp chamber and root canals, mainly Gram-negative anaerobic microorganisms predominate and form the intracanal endodontic biofilm. The objective of the present study was to investigate the role of different substrates on biofilm formation as well as the separate and collective incorporation of six endodontic pathogens, namely and into a nine-species "basic biofilm". This biofilm was formed in vitro as a standard subgingival biofilm, comprising and The resulting endodontic-like biofilms were grown 64 h under the same conditions on hydroxyapatite and dentin discs. After harvesting the endodontic-like biofilms, the bacterial growth was determined using quantitative real-time PCR, were labeled using fluorescence in situ hybridization (FISH) and analyzed by confocal laser scanning microscopy (CLSM). The addition of six endodontic pathogens to the "basic biofilm" induced a decrease in the cell number of the "basic" species. Interestingly, counts increased in biofilms containing and respectively, both on hydroxyapatite and on dentin discs, whereas counts increased only on dentin discs by addition of . The growth of on hydroxyapatite discs and of and on dentin discs were significantly higher in the biofilm containing all species than in the "basic biofilm". Contrarily, the counts of , and on hydroxyapatite discs as well as counts of and on dentin discs decreased in the all-species biofilm. Overall, all bacterial species associated with endodontic infections were successfully incorporated into the standard multispecies biofilm model both on hydroxyapatite and dentin discs. Thus, future investigations on endodontic infections can rely on this newly established endodontic-like multispecies biofilm model.
口腔细菌具有在固体表面形成生物膜的能力。口腔细菌侵入牙髓后，生物膜与牙髓组织之间的接触可能导致牙髓炎、牙髓坏死和/或根尖周病变。根据牙髓腔和根管内的环境条件以及营养物质的可利用性，主要是革兰氏阴性厌氧微生物占主导并形成根管内牙髓生物膜。本研究的目的是调查不同底物对生物膜形成的作用，以及六种牙髓病原体，即[具体病原体名称未给出]分别和共同掺入九种“基础生物膜”的情况。这种生物膜在体外作为标准龈下生物膜形成，由[具体细菌名称未给出]组成。由此产生的类牙髓生物膜在相同条件下在羟基磷灰石和牙本质盘上生长64小时。收获类牙髓生物膜后，使用定量实时PCR测定细菌生长情况，使用荧光原位杂交（FISH）进行标记，并通过共聚焦激光扫描显微镜（CLSM）进行分析。向“基础生物膜”中添加六种牙髓病原体导致“基础”菌种的细胞数量减少。有趣的是，在羟基磷灰石和牙本质盘上，分别含有[具体细菌名称未给出]和[具体细菌名称未给出]的生物膜中[具体细菌名称未给出]数量增加，而仅在牙本质盘上添加[具体细菌名称未给出]时[具体细菌名称未给出]数量增加。在包含所有菌种的生物膜中，[具体细菌名称未给出]在羟基磷灰石盘上的生长以及[具体细菌名称未给出]和[具体细菌名称未给出]在牙本质盘上的生长明显高于“基础生物膜”。相反，在所有菌种生物膜中，羟基磷灰石盘上的[具体细菌名称未给出]、[具体细菌名称未给出]和[具体细菌名称未给出]数量以及牙本质盘上的[具体细菌名称未给出]和[具体细菌名称未给出]数量减少。总体而言，与牙髓感染相关的所有细菌菌种都成功掺入了羟基磷灰石和牙本质盘上的标准多菌种生物膜模型中。因此，未来对牙髓感染的研究可以依赖于这个新建立的类牙髓多菌种生物膜模型。
