Studies of microbiological contamination of water from dental units in rural dental practices
Keywords:
dental units, bacteria, water contamination, health hazardAbstract
Introduction. Scientific studies show that the water used in dental practices, which comes from the dental unit is contaminated with microorganisms – bacteria, fungi and protozoa – and may be the potential source of infections in patients and dental staff.
Aim. The objective of the study was the determination of the concentration and species composition of mesophilic bacteria present in the water from dental units in rural dental practices, from the aspect of potential health risk for patients and dental staff.
Material and methods. The material for the study was the water sampled from 20 dental unit reservoirs placed in rural dental practices in the Lublin Region. Mesophilic bacteria Gram-positive and Gram-negative were cultured on plating medium enriched with 5% sheep blood. Gram-negative rods were isolated and identified with the use of the selective-differential Eosin-Methylene Blue Agar. The identification of the isolated microorganisms was performed by means of the API 20E and API 20NE test technique, and the BIOLOG system.
Results. In all water samples the presence of mesophilic Gram-positive and Gram-negative bacteria was observed. The most abundant group were Gram-negative rods of the species Ralstonia pickettii and Sphingomonas paucimobilis, with the frequency of 35% each. In the group of Gram-positive bacteria, Gram-negative rods of the species Cellulomonas cellasea and genus Staphylococcus spp. were most frequently isolated. The total mean concentration of total microorganisms isolated from the water examined was 84,450.75 cfu/ml.
Conclusions. The common character of bacteriological contamination and the presence of opportunistic microorganisms in the water used in dental treatment may constitute a potential risk for the health of patients and dental team. It seems necessary to monitor the microbiological contamination of water in dental units – the application of the recommended methods and chemical agents available for the purpose of decontamination.
References
1. Szymańska J, Sitkowska J, Dutkiewicz J. Microbial contamination of dental unit waterlines. Ann Agric Environ Med 2008;15:173-9.
2. Szymańska J. Risk of exposure to Legionella in dental practice. Ann Agric Environ Med 2004;11:9-12.
3. Walker JT, Bradshaw DJ, Bennett AM, Fulford MR, Martin MV, Marsh PD. Microbial biofilm formation and contamination of dental- unit water systems in general dental practice. Appl Environ Microbiol 2000;66:3363-7.
4. Yabune T, Imazato S, Ebisu S. Assessment of inhibitory effects of fluoride-coated tubes on biofilm formation by using the in vitro dental unit waterline biofilm model. Appl Environ Microbiol 2008;74:5958-64.
5. Katoch VM. Infections due to non-tuberculosus mycobacteria (NTM). Indian J Med Res 2004;120:290-304.
6. Bzdęga W, Trykowski J, Bzdęga J. Dezynfekcja układów wodnych i sprężonego powietrza unitu stomatologicznego. Now Lek 2007;76: 436-9.
7. Tambekar DH, Gulhane PB, Goyal KS, Gulhane SR. Prevalence of Pseudomonas aeruginosa in dental unit water-lines. Res J Microbiol 2007;2:983-7.
8. Ma’ayeh SY, AL-Hiyasat AS, Hindiyeh MY, Khadera YS. Legionella pneumophila contamination of dental unit water line system in a dental teaching centre. Int J Dent Hyg 2008;6:48-55.
9. De Paola LG, Mangan D, Mills SE, Costerton W, Barbeau J, Shearer B, Bartlett J. A review of the science regarding dental waterlines. J Am Dent Assoc 2002;133: 1199-206.
10. Szymańska J. Dental bioaerosol as an occupational hazard in a dentist’s workplace. Ann Agric Environ Med 2007;14:203-7.
11. Prokopowicz D (ed.). Zagrożenia oportunistyczne. Białystok: Ekonomia i Środowisko; 2005.
12. Veronesi L, Capobianco E, Affanni P, Pizzi S, Vitali P, Tanzi ML. Legionella contamination in the water system of hospital dental settings. Acta Biomed 2007;78:117-22. Rowland BM. Bacterial contamination of dental unit waterlines: what is your dentist spraying into your mouth? Clin Microbiol News 2003;25:73-7.
13. Wagner D, Young LS. Nontuberculosus mycobacterial infections: a clinical review. Infection 2004;32:257-70.
14. Pawlikowska M, Deptuła W. Choroby u ludzi spowodowane chlamydiami i chlamydofilami. Postępy Hyg Med Dośw 2007;61:708-17.
15. Barbeau J. Lawsuit against a dentist related to serious ocular infection possibly linked to water from a dental handpiece. J Can Dent Assoc 2007;73:618-22.
16. Marciano-Cabral FG, Cabral G. Acanthamoeba spp. as agents of disease in humans. Clin Microbiol Rev 2003;16:273-307.
17. Matuszewska R, Krogulska B. Występowanie bakterii z rodzaju Legionella w wodzie z turbin dentystycznych. Mag Stomatol 2000;10:10-3.
18. Al-Saif KM, Assery M, Nahas MA. Microbial contamination of dental unit water systems in Saudi Arabia. Saudi Dent J 2007;19:110-4.
19. Uzel A, Cogulu D, Oncag O. Microbiological evaluation and antibiotic susceptibility of dental unit water systems in general dental practice. Int J Dent Hyg. 2008;6:43–7.
20. Shepherd PA, Shojaei MA, Eleazer PD, Van Stewart A, Staat RH. Clearance of biofilms from dental unit waterlines through the use of hydroperoxide ion-phase transfer catalysts. Quintessence Int 2001;32:755-61.
21. Göksay D, Cotuk A, Zeybek Z. Microbial contamination of dental unit waterlines in Istanbul, Turkey. Environ Monit Assess. 2008, Jan 22. Available from: www. ncbi. nlm.nih.gov/pubmed18210208 (accessed 15 May 2008).
