Evidence map›Paper›PMID 41167175›Full record

ArticleInternational dental journal2026

Distribution of Helicobacter pylori in the Oral Cavity of Patients With Tooth Extractions at Various Locations and Ages.

Masakazu Hamada, Ryota Nomura, Yuko Ogaya, Kyoko Nishiyama, Tamami Kadota, Kazuhiko Nakano

Abstract read
In one paragraph

Article in International dental journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Masakazu HamadaDepartment of Oral & Maxillofacial Oncology and Surgery, Graduate School of Dentistry, The University of Osaka, Suita, Osaka, Japan. Electronic address: hamada.masakazu.dent@osaka-u.ac.jp.
Ryota NomuraDepartment of Pediatric Dentistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Yuko OgayaDepartment of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka, Suita, Osaka, Japan.
Kyoko NishiyamaDepartment of Oral & Maxillofacial Oncology and Surgery, Graduate School of Dentistry, The University of Osaka, Suita, Osaka, Japan.
Tamami KadotaDepartment of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka, Suita, Osaka, Japan.
Kazuhiko NakanoDepartment of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka, Suita, Osaka, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundHelicobacter pylori is well known to cause gastric cancer, gastric ulcers and duodenal ulcers. The oral cavity has been implicated as a reservoir of H. pylori in adulthood. However, there are currently no detailed studies focused on the tooth type colonised by H. pylori and/or the age of subjects. Therefore, we examined the distribution of H. pylori in oral specimens collected from 163 Japanese adults who underwent tooth extraction. MATERIALS AND

methodsBacterial DNA was extracted from 163 Japanese adults, and H. pylori was detected using PCR. Surface deposits on the occlusal surface were observed using an electron microscope.

resultsA PCR analysis revealed H. pylori in 17 saliva samples (10.4%), 27 tooth samples (16.6%) and 19 pulp samples (11.7%). We also confirmed surface deposits on the occlusal surface of deeply impacted and obviously stained third molars using electron microscopic images, and H. pylori was detected in 11 out of 33 (33.3%) extracted impacted third molars. We then categorised tooth extraction sites into 3 patterns: teeth other than the third molars, erupted third molars and impacted third molars, and compared the ages of subjects who tested positive and negative for H. pylori. Among impacted third molars, H. pylori-positive subjects were significantly older than H. pylori-negative subjects for all oral samples tested (P < .05). We then examined these subjects based on the localisation of H. pylori in saliva, teeth and dental pulp, and found that subjects with teeth that were positive for H. pylori were significantly older than those with teeth that were negative for H. pylori (P < .05).

conclusionsH. pylori may colonise not only erupted teeth, but also impacted teeth, particularly in the elderly. Impacted third molars left for a long period may be a reservoir for H. pylori.

Indexed as

Helicobacter pyloriMouthTooth ExtractionAdolescentAdultAgedAge FactorsDental PulpDNA, BacterialFemaleHelicobacter InfectionsHumansJapanMaleMiddle AgedMolar, ThirdDNA, BacterialExtracted toothHelicobacter pyloriMolecular biological analysisOral specimens

Identifiers

PMID41167175
PMCPMC12641215

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.