Colonization of Dental Unit Waterlines by <i>Helicobacter pylori</i>: Risk of Exposure in Dental Practices

• Main Authors: Monica Giacomuzzi, Carla M. Zotti, Savina Ditommaso
• Format: Article
• Language: English
• Published: MDPI AG 2019-08-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: dentistry; dental unit; infection control; cross-infection contamination; <i>Helicobacter pylori</i>; streptococci
• Online Access: https://www.mdpi.com/1660-4601/16/16/2981

Dental unit waterlines (DUWLs) can be considered one of the possible routes of <i>H. pylori</i> transmission, although its presence in DUWLs has not yet been investigated thoroughly. The present study aimed to discover the prevalence of <i>H. pylori</i> and oral streptococci (<i>S. oralis</i> and <i>S. mutans</i>) in DUWLs to evaluate the risk of exposure to human pathogens in dental practices. We collected the output water from 60 dental chair units (DCUs) in 26 private dentistry settings in Turin, searching for <i>H. pylori</i> and oral streptococci (OS) DNA, with a polymerase chain reaction (PCR) technique. At the same time, dentists completed a questionnaire about their DCUs, their main activities, the presence of anti-retraction devices, their attitudes about disinfection, etc. No dental chair unit tested was contaminated with <i>H. pylori</i> or <i>S. mutans</i>; only one dental chair was contaminated with <i>S. oralis</i> (1.7%). Considering the results, we can state that: (i) the lack of <i>H. pylori</i> DNA in water samples analyzed, suggests that municipal water is presumably treated with a sufficient chlorine level to inactivate DNA over time; (ii) the aspiration of oral fluids is limited by anti-retraction valves fitted distally to hand pieces; (iii) propidium monoazide qPCR (PMA-qPCR) could be a good technique to investigate and monitor potential environmental sources of infections such as DUWLs.