Increased tooth brushing frequency is associated with reduced gingival pocket bacterial diversity in patients with intracranial aneurysms

Mikko J Pyysalo; Pashupati P Mishra; Kati Sundström; Terho Lehtimäki; Pekka J Karhunen; Tanja Pessi

doi:10.7717/peerj.6316

Increased tooth brushing frequency is associated with reduced gingival pocket bacterial diversity in patients with intracranial aneurysms

PeerJ. 2019 Jan 25:7:e6316. doi: 10.7717/peerj.6316. eCollection 2019.

Authors

Mikko J Pyysalo^{1

2

3

4}, Pashupati P Mishra^{5

6}, Kati Sundström^{5

6}, Terho Lehtimäki^{5

6}, Pekka J Karhunen^{5

6}, Tanja Pessi⁴

Affiliations

¹ Department of Otorhinolaryngology, Faculty of Medicine and Health Technology, University of Tampere, Tampere, Finland.
² Department of Oral and Maxillofacial diseases, Tampere University Hospital, Tampere, Finland.
³ Oral Health Services, City of Tampere, Tampere, Finland.
⁴ Department of Molecule Microbiology, Faculty of Medicine and Health Technology, University of Tampere, Tampere, Finland.
⁵ Faculty of Medicine and Health Technology and Finnish Cardiovascular Research Center, University of Tampere, Tampere, Finland.
⁶ Fimlab Laboratories ltd, Tampere, Finland.

Abstract

Objectives: The objective of this study was to investigate the association of tooth brushing frequency and bacterial communities of gingival crevicular fluid in patients subjected to preoperative dental examination prior to operative treatment for unruptured intracranial aneurysms.

Methods: Gingival crevicular fluid samples were taken from their deepest gingival pocket from a series of hospitalized neurosurgical patients undergoing preoperative dental screening (n = 60). The patients were asked whether they brushed their teeth two times a day, once a day, or less than every day. Total bacterial DNA was isolated and the V3-V4 region of the 16S rRNA gene was amplificated. Sequencing was performed with Illumina's 16S metagenomic sequencing library preparation protocol and data were analyzed with QIIME (1.9.1) and R statistical software (3.3.2).

Results: Bacterial diversity (Chao1 index) in the crevicular fluid reduced along with reported tooth brushing frequency (p = 0.0002; R2 = 34%; p (adjusted with age and sex) = 0.09; R2 = 11%) showing that patients who reported brushing their teeth twice a day had the lowest bacterial diversity. According to the differential abundant analysis between the tooth brushing groups, tooth brushing associated with two phyla of fusobacteria [p = 0.0001; p = 0.0007], and one bacteroidetes (p = 0.004) by reducing their amounts.

Conclusions: Tooth brushing may reduce the gingival bacterial diversity and the abundance of periodontal bacteria maintaining oral health and preventing periodontitis, and thus it is highly recommended for neurosurgical patients.

Keywords: 16S rRNA amplification; Bacterial DNA; Biofilm(s); Cardiovascular disease(s); Fusobacteria; Gingivitis; Intracranial aneurysms; Oral microbiome; Preventive dentistry.

Grants and funding

The study has been financially supported by the Jane and Aatos Erkko Foundation (Tanja Pessi), the Competitive State Research Financing of the Expert Responsibility area of Tampere University Hospital (Terho Lehtimäki, Pekka Karhunen and Tanja Pessi), the Academy of Finland (Grant no. 286284 for Terho Lehtimäki), the Tampere Tuberculosis Foundation (Terho Lehtimäki, Pekka Karhunen,Tanja Pessi), the Academy of Finland (grant 286284 for Terho Lehtimäki), the Laboratory Medicine Foundation (Kati Sundström, Tanja Pessi), and the Finnish Clinical Chemistry Foundation (Tanja Pessi). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.