Structure and functional potential of intracanal microbiome: Bioinformatics for endodontic therapy

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K11698
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Conservative dentistry
• Research Institution: Tohoku University
• Principal Investigator: Yamaki Keiko 東北大学, 歯学研究科, 非常勤講師 (90182419)
• Co-Investigator(Kenkyū-buntansha): 佐藤 拓一 新潟大学, 医歯学系, 教授 (10303132) ; 鷲尾 純平 東北大学, 歯学研究科, 准教授 (20400260)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: 根尖性歯周炎 / 根管内細菌叢 / 16S rRNA遺伝子 / メタ16S解析

Outline of Final Research Achievements

Microbial composition of infected root canals varies consistently among reports. To determine the characteristics of the endodontic microbiome, the intracanal flora of apical periodontitis in 13 patients were profiled and compared with the profiles of their saliva and plaque. Infected root canal wall dentin was harvested from the involved teeth and their saliva and plaque were collected. Bacterial DNA was extracted from the samples and 16S rRNA gene analysis targeting the V3-V4 region was conducted on the Illumina MiSeq platform using QIIME2. The functional potential of the microbiomes was inferred using PICRUSt2. The endodontic microbiomes were more anaerobic, rich in Firmicutes, and scarce in Actinobacteriota and Proteobacteria, compared with saliva and plaque microbiomes. Despite their difference in structure and membership, the nine most abundant metabolic pathways were common among them. The intra-individual variance in endodontic microbiome was also found.

Free Research Field

歯内治療学

Academic Significance and Societal Importance of the Research Achievements

根尖性歯周炎は歯科臨床現場において高頻度で遭遇する歯内疾患であり、その原因は根管に侵入定着した口腔細菌である。約1000種とされるヒト口腔細菌のうち一人が保有するのは100-200種のため、感染根管から検出される細菌はレポートにより大きく異なる。現在、根尖性歯周炎の病因は特定の菌ではなく、細菌叢すなわち多種多様な細菌の集合体と考えられており、次世代シーケンサー（NGS）を利用した細菌叢の解析が進行中である。本研究を通じて明らかとなった感染根管内の細菌叢の特徴を踏まえ、従来の標準治療法より普遍的かつ効率的な根管治療法が開発され、国民の健康増進に資するることが期待される。