German study

March 20, 2012
German study indicates bacteria present on 70% of bib holders.

OXNARD, California--Researchers at the University of Witten/Herdecke in North Rhine-Westphalia, Germany, have released a clinical study that indicates the sterilization protocol for dental bib holders is inconsistent, and can result in the presence of germs, microorganisms, and pseudomonas on bib chains and holders.

The study examined a total of 30 metal and plastic bib holders and found bacteria present on more than half of them.

"The analyses of the bacterial load showed that 70% of all reusable bib holders were contaminated with germs," said professor Stefan Zimmer, MPHD, PhD, the lead investigator of the study and scientific director at the University of Witten/Herdecke.

"The predominant colony types identified were staphylococci and streptococci. But on several bib chains we also found various bacterial rods, pseudomonas, fungi and other types of cocci. Although the bacteria found in this study were all nonpathogenic bacteria, in principle reusable bib holders can cross contaminate dental patients."

The bacteria found on the bib holders in the University of Witten/Herdecke study do not usually cause disease in healthy people, but they can be a threat to immune-suppressed patients, and young children and the elderly who also often have compromised immune systems.

Bacteria from an unsterilized bib holder can enter the body when a patient touches the bib holder or their neck after a dental visit, and then rubs an eye or touches their mouth. Cross-contamination can also occur:

* when a bib chain is splattered with saliva, plaque, blood, and spray from the mouth
* when a bib chain catches onto hair and accumulate with the wearer’s sweat, make-up, and neck acne
* if the dental worker applies a dirty bib chain with their gloved hands before the examination or cleaning

“Four clinical studies have demonstrated that the dental bib holder is a risk point in dental office cross contamination,” said Michael Durda, vice president of clinical affairs at DUX Dental headquarters in Oxnard, Calif.

"Since dental teams are not adequately cleaning, disinfecting, or sterilizing the bib holders, the dental community must step forward and establish a method where an aseptic product is offered to every patient as a standard practice."

Multiple studies show infectious bacteria regularly present on bib holders
Three other U.S. studies have found unacceptable levels of microbial contamination on dental bib holders, including pseudomonas, E. coli and S. aureus (the most common cause of staph infection).

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In a supplement to the March 2011 issue of Dimensions of Dental Hygiene titled “Infection Control Update,” Dr. John Molinari, an expert in the areas of infection control and infectious disease in dentistry, referenced a study he conducted that looked at the presence and composition of bacterial contaminants on patient bib chains before and after patient care appointments.

His results showed that microbial contamination was present on metal and coiled plastic bib chains after use during patient care, with the highest bacteria levels found on bib chains that were not cleaned between patient uses.

Noel Kelsch, RDHAP, a registered dental hygienist and former president of the California Dental Hygienists’ Association, conducted a study on various types of dental chains and clips. Her findings, which were published in RDH magazine, showed that on average dental bib chains had five times the levels of viable bacteria and fungus than the limit established by the Environmental Protection Agency for safe drinking water (500 CFU/mL). Disposable clips and holders opened fresh for each patient were free from contaminants and posed no cross-contamination threats.

Kelsch’s findings echoed a study published by the University of North Carolina at Chapel Hill’s School of Dentistry oral microbiology lab that found bib chains and clips are potential sources of contamination. In sampling 50 bib clips from various hygiene and dental operations, researchers discovered one in five bib clips were contaminated with “significant microorganisms,” according to Dental Health magazine.

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