TITLE:
Cross Contamination in Oral Health Care: A Potential Public Health Risk—The Phenomenon of Biological Fluid Backflow: An Experimental Study
AUTHORS:
Houda Habibi Alaoui, Amina Gharibi, Mohammed Timinouni, Nadia Zaim
KEYWORDS:
Cross Contamination, Aerosols, Dental Unit Waterline(s), Back-Contamination
JOURNAL NAME:
Advances in Infectious Diseases,
Vol.14 No.4,
December
25,
2024
ABSTRACT: In oral health care, the spread of harmful infectious agents from the oral cavity is a constant concern. The aim of this study was to evaluate the possibility of cross-contamination between patients due to the backflow of biological fluids and contaminated aerosols into the water tubes of rotating instruments (high-speed turbines). A second aim was to assess the dispersion of the aerosols generated in the medical environment and the risk of contamination for the dentist. Materials and methods: For safety reasons, we carried out an experimental study on two sheep heads purchased from a butcher to simulate periodontal treatment in the two oral cavities. The first cavity was artificially contaminated with the reference strain of Staphylococcus aureus to assess the transfer of this bacteria from one cavity to the other through the waterlines of the high-speed turbine used. Results: The study revealed a worrying risk of cross-contamination from contaminated aerosols flowing back through the dental turbine into the dental unit waterlines (33.33%) [p S. aureus and total heterotrophic bacteria (THB) were dispersed at varying distances from the oral cavity. In particular, the highest contamination levels were found within 0.3 m of the patient for S. aureus (M = 43.66, SD = 1) and THB (M = 45.59, SD = 5), with contamination levels decreasing at a distance of 1.5 m, respectively (M = 5.63, SD = 3.61; M = 8.09, SD = 7.01) [p ≤ 0.05]. Conclusions: Procedures should be implemented to limit the risk of cross-contamination during dental treatment. This can be achieved by strict adherence to hygiene and asepsis measures in the dental unit and medical devices, compliance with regulatory standards (e.g., ISO 15883 1-2), and the installation of anti-retraction valves in dental turbines, dental chair unit and suction systems to prevent backflow of contaminated biological fluids and aerosols.