Comparison of the Efficacies of Disinfectants To Control Microbial Contamination in Dental Unit Water Systems in General Dental Practices across the European Union

Abstract

Water delivered by dental unit water systems (DUWS) in general dental practices can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWS provide a reservoir for microorganisms and should be controlled. This study compared disinfection products for their ability to meet the American Dental Association's guideline of <200 CFU · ml ؊1 for DUWS water. Alpron, BioBlue, Dentosept, Oxygenal, Sanosil, Sterilex Ultra, and Ster4Spray were tested in DUWS (n ‫؍‬ 134) in Denmark, Germany, Greece, Ireland, The Netherlands, Spain, and the United Kingdom. Weekly water samples were tested for total viable counts (TVCs) on yeast extract agar, and, where possible, the effects of products on established biofilm (TVCs) were measured. A 4-to 5-week baseline measurement period was followed by 6 to 8 weeks of disinfection (intermittent or continuous product application). DUWS water TVCs before disinfection ranged from 0 to 5.41 log CFU · ml ؊1 . Disinfectants achieved reductions in the median water TVC ranging from 0.69 (Ster4Spray) to 3.11 (Dentosept) log CFU · ml ؊1 , although occasional high values (up to 4.88 log CFU · ml ؊1 ) occurred with all products. Before treatment, 64% of all baseline samples exceeded American Dental Association guidelines, compared to only 17% following commencement of treatment; where tested, biofilm TVCs were reduced to below detectable levels. The antimicrobial efficacies of products varied (e.g., 91% of water samples from DUWS treated with Dentosept or Oxygenal met American Dental Association guidelines, compared to 60% of those treated with Ster4Spray). Overall, the continuously applied products performed better than those applied intermittently. The most effective products were Dentosept and Oxygenal, although Dentosept gave the most consistent and sustained antimicrobial effect over time.

Antibacterial Effect of Sanosil 2% and 6% and Sodium Hypochlorite 0.5% on Impressions of Irreversible Hydrocolloid (Alginate) and Condensational Silicone (Speedex)

“…We found that total effectiveness of 0.5% sodium hypochlorite was higher than Sanosil 6% and 2%. This is similar to the results of Ghahramanloo, which showed a superior antibacterial effect of 0.525% sodium hypochlorite spray over Sanosil solution (13).According to one report, Sanosil was more effective to disinfect environment surface including dental seat and office cabinets (14).Effectiveness of this material in removal of water contamination in dental units is also shown (15) . Sanosil has been reported to be effective on Alginate materials (13).…”

A Comparison of Different Disinfectants on the Microbiological Quality of Water from the Dental Unit Waterlines of a Military Hospital

“…Currently, there is no evidence based protocol for dentist to control the microbial quality of water from DUWLs (Liaqat & Sabri 2011;Schel et al 2006;Walker et al 2000). Distilled water does not prevent biofilm formation in DUWLs without proper and regular maintainence (Kettering et al 2002).…”

“…Researches that have been done in many countries showed that microorganism contamination of DUWLs is a problem (Al-Hiyasat 2007;Blake 1963;Ma et al 2012;Mavridou et al 2006;Schel et al 2006;Singh et al 2003). Various microorganisms have been isolated from DUWLs, including environmental bacteria and human pathogens such as Pseudomonas (Al-Hiyasat et al 2007;Ma et al 2012;Mavridou et al 2006), Legionella pneumophila Walker et al 2000), Mycobacterium spp.…”

The Rationale of Guidelines for Infection Control in Dentistry: Precautionary Principle or Acceptable Risk?

“…Before NHSN opened enrollment to all facilities, its forerunner (the National Nosocomial Infections Surveillance system) was known to overrepresent large academic centers, and few other study groups focused on smaller hospitals. 7,8 NHSN now serves as the major secure data network for statewide mandatory public reporting programs, so accurate classification of teaching status is important to ensure fair representation of all hospitals. Hospitals joining NHSN fill in a survey screen that asks them to indicate whether they are affiliated with a medical school (yes or no) and, if yes, to characterize their involvement as one of the following 3 types: (1) major (facility is an important part of the teaching program of the medical school, and the majority of medical students rotated through multiple clinical services), (2) graduate (facility is used by the medical school for graduate training programs only-that is, residency and/or fellowships), or (3) limited (facility is used in the medical school's teaching program to a limited extent only).…”

“…However, the risk of infection among dental patients and healthcare personnel exposed to water contaminated by these microorganisms is minimal, because the bacterial load produced during therapy and their spread in the environment is low. 6 Nevertheless, most guidelines recommend disinfection of dental unit waterlines, 7 thus posing a risk of toxic effects.…”