Chris Miller, PHD
Some dental team members forget that barriers help protect both themselves and patients. The purpose of OSHA`s Bloodborne Pathogens standard, of course, is to protect workers against exposure to human body fluids. Clearly, protection is provided to team members who wear such barrier equipment. However, barrier protection extends beyond the wearer to the patients involved or to others.
The common barriers are gloves, masks, protective eyeglasses, and protective clothing. They are commonly referred to as personal protective equipment. This article examines some benefits of personal protective equipment for the patient.
For example, the true infection control rationale for wearing gloves is twofold. One is to provide protection to dental team members, and the other is to provide protection to the patients. Gloves are worn by the dental team when there is a chance of touching surfaces, instruments, or equipment that may be contaminated with potentially pathogenic microorganisms. This certainly includes touching:
- Any surface in any patient`s mouth.
- Contaminated operatory surfaces.
- Instruments or equipment that were used in the mouth, touched with saliva-coated fingers, or spattered with oral fluids.
For the dental team, gloves prevent microbes from entering the body through breaks in the skin on the fingers and hands.
Another benefit is that it eliminates or reduces the amount of bioburden that can contaminate the skin and serve as a "nest" for subsequent transfer. Gloving restricts the numbers of microbes that can hide in the grooves of the skin and around the fingernails to be "spread" at another time. Obviously, patients are protected too when gloves can prevent this type of contamination.
Lingering presence of blood
Blood remains in some areas of dental workers` hands for at least five days - even with handwashing. A 1982 Journal of American Dental Association study described testing the hands of 29 periodontists for the presence of blood at an evening meeting of their local society. Blood was found on:
- 78 percent of those who "seldom" wore gloves for patient care.
- 67 percent of those who "sometimes" wore gloves.
- 13 percent of those who "routinely" wore gloves.
- 20 percent of control subjects who were not involved with patient care activities.
While confirming that patients` blood can contaminate ungloved hands, the numbers also suggest that perhaps our own blood may sometimes exist around our fingernails. Some of the control subjects, as well as some of the dentists who routinely wore gloves, also had blood present.
The mere presence of blood on the hands does not confirm that contact with such blood will definitely transmit a disease. Development of a disease would depend on the presence, numbers, and properties of microbes in the occult blood or saliva, the proper entrance into the new host`s tissues, survival and multiplication of the microbe in the new host, and resistance of the host. Nevertheless, the presence of occult blood or saliva on ungloved hands presents some potential for cross-contamination, whether involving a previous patient`s blood and saliva or the dental team member`s blood.
If this material around fingernails becomes wet while working in a subsequent patient`s mouth with ungloved hands, it could be transferred to that patient. A very small group choose not to wear gloves because they "know their patients," are "not afraid of catching anything," are "just going to treat a family member," or "can`t practice with gloves on." They will not only become exposed to their patients` blood and saliva but also will reduce protection of those patients from contact with blood and saliva from others.
The transfer of herpes disease from the mouth of one patient to the ungloved hands of a dental hygienist and then to the mouths of several other patients has been demonstrated. The real culprit in this case was the dermatitis on the hands of the hygienist. Handwashing was ineffective since it was painful and so microbes had even more places to hide. When the hands become contaminated and the microbes can`t be effectively washed off, the hands serve as a mode of transfer to other patients.
Wearing gloves and changing them between patients provides a solution to this problem.
A face mask serves as a barrier against contact of the mucous membranes of the nose and mouth of the wearer with spatter from the patient`s mouth. Secondarily, it reduces inhalation of aerosols of the patient`s oral fluids.
Masks protect patients by preventing respiratory droplets from the dental team member from entering the mouth of the patients. While this mode of cross-contamination is likely not terribly important in the office, preventing contamination of any open tissue in a patient`s mouth to any outside microbes is a goal worth pursuing, particularly during surgery.
Protective clothing worn by the dental team at chairside prevents contamination of underlying skin, work clothes, or street clothes with spatter of the patient`s oral fluids. From the patient`s perspective, protective clothing worn by the dental team reduces the chances for exposure of the patient to microbes that may be present on work clothes or street clothes.
While this may not be an important mode of cross-contamination during most dental procedures, it is important during surgery when open tissues need to be protected from outside microbes. A dental team`s clothing is not likely to be an important mode of disease transmission from patient-to-patient in the office. When protective clothing is changed, however, the potential for this transfer is eliminated. Not wearing contaminated protective clothing out of the office also protects others from potential exposure.
Chris Miller is director of Infection Control Research and Services and professor of oral biology at Indiana University.