Chris Miller, PHD
Misconceptions about infection control should be clarified. In this issue, we focus on the areas of barrier techniques and instrument processing.
Who is protected by the barrier?
Barrier techniques involve gloves, masks, eyeglasses, and protective clothing. They prevent contact with contaminated materials. One question is: Who does a barrier really protect?
Development of the 1991 OSHA bloodborne pathogens standard brought a new phrase, personal protective equipment (PPE), into the health-care community. OSHA defines PPE as "specialized clothing or equipment worn by an em-ployee for protection against hazards." PPE refers to gloves, masks, eyeglasses and protective clothing, some of which actually afford protection to both the "wearer" and the patient.
Gloves: When we hear the statement, "Oh, I don`t need to wear gloves for this patient, I know who she is," it`s obvious that no thought is being given to patient protection. Microbes on the hands of the dental professional (or any microbes that may exit the body through invisible breaks around the fingernails) can contaminate a patient if gloves are not worn.
Spread of human herpes virus type 1 (herpes simplex virus) from one patient to several other patients via the ungloved hands of a dental hygienist has been documented (Manzella et al: "An outbreak of herpes simplex virus type 1 gingivostomatitis in a dental hygiene practice." J Amer Dent Assoc 1984, 2522:2019-2222).
Masks: Masks protect the wearer by preventing contact of the mucous membrane of the nose and mouth area with patient spatter. They also reduce inhalation of contaminated respiratory droplets from the patient.
The original purpose for wearing a mask in surgery (which began decades ago, long before the bloodborne pathogens standard) was to reduce chances for post-surgical infections in the patients caused by respiratory microbes from the surgeons. In dentistry, masks provide some degree of protection to the patient (particularly during surgery) from open-tissue contact with microbes in respiratory droplets from the dental team.
Protective clothing: This clothing is worn to prevent contact of contaminants with work clothes, street clothes, undergarments, and skin.
Although disease spread in dentistry from clothing has not been documented, protective clothing worn by the dental worker gives a degree of protection to the patient because it is likely less contaminated than street clothes. This, of course, depends upon how recently the protective clothing was changed.
Eyeglasses: Protective eyeglasses or plastic shields certainly protect dental workers` eyes from contamination. But they give no protection to the patient. On the other hand, more offices are now providing eyeglasses for patients to use during dental care to prevent possible foreign-object and chemical injury.
Surface covers: This barrier technique protects an operatory surface from contamination during patient care. A surface cover impervious to moisture is used. Unfortunately, some offices have the misconception that a surface is to be cleaned and disinfected and then covered with a surface cover between each patient. Either:
- Clean and disinfect the surface between each patient.
Or,
- Clean and disinfect the surface at the beginning of the day, use a surface cover to prevent the surface from becoming contaminated during patient care and simply change the cover between patients.
When used properly, surface covers eliminate the need for cleaning and disinfection between each patient.
Confusion during sterilization monitoring?
Sterilization monitoring: Sterilization monitoring involves the routine use of chemical and biological indicators to monitor the sterilization process. The CDC and ADA recommend at least weekly spore-testing (use of biological indicators) of all dental office sterilizers. Several states have actually entered this as a requirement in their state laws or dental-practice acts.
Some offices have a misconception that sterilizers must be tested by an outside spore-testing service to be valid. While such a third-party verification of sterilization performance may have its advantages, it is not required. If desired, an office can purchase the proper spore tests and incubator, perform and analyze the tests and maintain records. Others prefer to have a sterilization-monitoring service that operates through the mail manage this for their office.
Chemical indicators are being used more and more in addition to spore tests during instrument sterilization. This is done to better document patient-protection procedures. Although chemical indicators do not provide as much information as a spore test, they do provide immediate results.
Some dental workers have a misconception about what information the chemical indicators provide. One popular type of indicator is in the form of a heat-sensitive ink present on sterilization pouches, paper wrap, autoclave tape, or on tabs or strips that turn dark after processing through the heat sterilizer. This ink changes color rather rapidly after the sterilizing temperature has been reached during the early part of the sterilizing cycle. However, the sterilizer could malfunction during the sterilization cycle after the indicators have already changed color. These indicators are commonly referred to as process indicators and show only if a package has been processed through the sterilizer (i.e., has been exposed to the sterilizing temperature).
Other types of chemical indicators called integrators change color more slowly and require a combination of the proper temperature and time. These provide more information than the rapid-change indicators - showing that the packages have been exposed to sterilizing temperatures for a period of time, indicating a higher probability for sterilization.
Understanding some of the misconceptions in infection control can facilitate greater efficiency in performing these important procedures for the protection of both patients and the dental team.
Chris Miller is director of Infection Control Research and Services and professor of oral biology at Indiana University.
