Opportunistic bacteria in dental unit waterlines: assessment and characteristics
Related Experiment Video
Updated: May 11, 2026

Oral Biofilm Analysis of Palatal Expanders by Fluorescence In-Situ Hybridization and Confocal Laser Scanning Microscopy
Published on: October 20, 2011
Jolanta Szymańska1, Jolanta Sitkowska
1Department of Paedodontics, Medical University of Lublin, Karmelicka 7, 20-018 Lublin, Poland. szymanska.polska@gmail.com
Aim:
The study aimed to determine qualitative and quantitative contamination of dental unit reservoir water with aerobic and facultative anaerobic bacteria, with regards to health risk to dental staff and patients.
Materials & Methods:
The study material included water samples from 107 unit reservoirs. Conventional microbiological methods were used. The isolated bacteria were divided into three groups according to pathogenic mechanisms.
Results:
Dental unit water contamination was widespread. The isolated bacteria average concentration was 1.1 × 10(5) CFU/ml, with Ralstonia pickettii as the prevailing species (49.33%). The total potentially pathogenic bacteria were 54.54% of all the isolated bacteria. Bacteria causing infectious and invasive diseases constituted over one-half of this group, while allergizing and immunotoxic bacteria occurred in smaller quantities.
Conclusion:
The presence of over 50% potentially pathogenic microorganisms among the isolated bacteria and their very high concentrations call for the daily use of effective methods to reduce dental unit water contamination and health risk.
Related Concept Videos
The Oral Microbiota
Biofilms
Atypical Pneumonia
Healthcare Associated Infections I: Iatrogenic, Exogenic and Endogenic
HAIs significantly increase the cost of health care. Extended stays in healthcare institutions, increased disability, increased costs of medications, including specialized antibiotics, and prolonged recovery times add to the patient's expenses and the healthcare institution and funding bodies. Common...
Cholera
Automated Microbial Diagnostics

