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

[BACKGROUND] Helicobacter 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 METHODS] Bacterial 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.

[RESULTS] A 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).

[CONCLUSIONS] H. 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.