The Centers for Disease Control and Prevention (CDC) is the lead federal agency for protecting the health and safety of people in the United States and internationally. The CDC provides credible information to enhance health decisions and promote health through strong partnerships. It serves as the national focus for developing and applying disease prevention and control, environmental health, and health promotion and educational activities designed to improve the well being of all people.
The CDC recently issued a set of new infection control recommendations (Guidelines for Infection Control in Dental Health-Care Settings, 2003).1 These recommendations update those made in 1986 and 1993.2,3 They are available in print (Morbidity and Mortality Weekly Report, 2003;52 [RR-17]:1-68) or online at cdc.gov/mmwr/preview/mmwrhtml/rr5217a1.htm.
CDC Guidelines consolidate recommendations for preventing and controlling infectious diseases and managing personnel health and safety concerns related to infection control within dental settings. The Guidelines update several previous CDC recommendations, incorporate relevant infection control measures from other CDC guidelines, and discuss concerns not previously addressed in dentistry.
Many of the topics presented in the Guidelines are well known within the dental community. Because dental practices have long been involved with issues such as instrument sterilization, personal protective equipment, and environmental surface disinfection, compliance in these areas has generally been acceptable. However, the Guidelines introduce a number of new or significantly revised infection control and prevention issues. Two of the updated topics—standard vs. universal precautions, and dental water quality issues, will be discussed briefly.
STANDARD REPLACES UNIVERSAL PRECAUTIONS
Throughout history, persons with infectious diseases have been in some manner shunned from society. “Quarantine” was an isolation precaution that began soon after the Civil War. The concept was that the infected were sent to isolated facilities for treatment. At first, infected patients were grouped and simply kept away from persons who were not ill. Few special infection control procedures were employed for the sick. Persons were not isolated by disease, so the ill infected each other with new diseases. Use of isolation (infectious disease hospitals) continued to some degree in the United States until 1970. Very few facilities of this type remain. Classic examples would be tuberculosis sanitariums and Father Damien’s leper colony on Molokai. A modified form of the process was revived with the installation of “AIDS wards” in hospitals during the 1980s. This procedure, however, was short-lived.4,5
In 1970, the CDC released guidelines designed to isolate specific patients in given areas within a hospital.4-6 Seven categories of isolation were described. The effectiveness and efficiency of such practices were never fully studied. Isolation of a person with symptoms does not necessarily result in reductions in disease transmission. This is because an infected person is often most infectious shortly before overt symptoms develop.
The announcement of HIV/AIDS in the summer of 1981 pushed infection control and the treatment of infected and infectious patients forward with a jolt. Reluctance to treat HIV-positive patients became widespread. Isolation was not the concern; healthcare workers from all areas refused to become involved.
In 1985, the CDC changed its emphases from isolation to universal precautions. Most people with HIV disease do not have overt symptoms, thus medical histories and clinical examinations are not always reliable identifiers.4,5,7,8 The CDC chose precautions against blood and body fluids of all patients, independent of known or suspected infection status. Modes of occupational acquisition, such as needlesticks and mucous membranes exposure, became well described. Soon, the hepatitis B virus (HBV) became part of universal precautions. Preventive methods including personal protective equipment (eg, gloves, masks, gowns, and protective eyewear), handwashing, prevention of injuries, proper handling of patient care items, and HBV immunization, became widely applied. In time the hepatitis C virus also was added, and blood became the prime source of disease spread.4,5 These precautions were central elements of concern in the 1986 and 1993 CDC infection control recommendations for dentistry. Universal precautions are concerned with all patient blood and some other body fluids.2,3
Concern for other body fluids was not abandoned; new recommendations called Body Substance Isolation appeared in 1989.4,5 Attention was directed to all moist body fluids, which were to be considered as potentially infectious. Again, it did not matter if a patient was known to be infectious or not; body fluids were to be avoided. Gloves were the major preventive measure offered.
In 1996, the CDC combined the concepts of universal precautions and body substance isolation into one set of precautions called “standard precautions.” Standard precautions represent a system of barrier precautions to be used by all personnel for contact with blood, all body fluids, secretions, excretions, nonintact skin, and mucous membranes of all patients, regardless of diagnosis. Other potentially infectious materials (eg, semen, vaginal secretions, cerebrospinal fluid, synovial fluid, pleural fluid, pericardial fluid, peritoneal fluid, amniotic fluid, saliva in dental procedures, any body fluid that is visibly contaminated with blood, and all body fluids in situations where it is difficult or impossible to differentiate between body fluids) are also considered as problematic. These precautions are now considered as the “standard of care.”1,4,5
Standard precautions are designed to reduce disease transmission from both recognized and unrecognized sources of infection. Standard precautions are more procedure-directed rather than precautions against a specific patient. A dental health care practitioner (DHCP) may choose to double glove, not because of the status of a patient, but rather because of the length or type of procedure to be performed.1,4,5,9
Standard precautions should provide protection in most situations. However, there are some cases in which additional processes commonly called “transmission-base precautions” are required. Examples include additional ventilation requirements, special respiratory protection for DHCP, or postponement of nonemergency procedures.1,4,5,9
DENTAL UNIT WATER
For routine (nonsurgical) dental procedures, the CDC indicates that the water used should meet US Environmental Protection Agency regulatory standards for drinking water (<500 CFU/mL of heterotrophic water bacteria). Dental practices should consult with their dental unit manufacturer for appropriate methods and equipment to achieve and maintain the recommended quality of dental water.1
Periodic monitoring of dental unit water quality is recommended. Again, practices are asked to follow the recommendations provided by the manufacturer of their units or waterline treatment product.
Purging has benefits. Water and air should be discharged for a minimum of 20 to 30 seconds after each patient from any device connected to the dental water system that enters the patient’s mouth. This includes handpieces, ultrasonic scalers, and air/water syringes.
Dental handpieces and other devices attached to air and waterlines are to be removed, cleaned, and heat sterilized between patients. Manufacturer’s instructions for cleaning, lubrication, and sterilization of such items must be followed. Periodic testing and maintenance of unit antiretraction mechanisms are also necessary.
A variety of products and technology currently exist that will allow dental practices to meet the CDC recommendations. Dental offices must establish practices and install equipment that assure the routine release of potable water from dental units.
The new Guidelines prepared by the CDC should be considered as the standard of care for the practice of dentistry in outpatient as well as hospital healthcare settings. The first step is for each practice to obtain and carefully review the Guidelines.
The dental community is likely familiar with many of the topics presented in the Guidelines. For a long time, dental practices have been involved with issues such as instrument sterilization, personal protective equipment, and environmental surface disinfection; generally, compliance in these areas has been acceptable. However, many of the more familiar areas have been significantly updated. Also, there are a number of new recommendations to be considered.
The new Guidelines outline well what dental practices are expected to do. But, they do not often go into detail as to how specifically to meet the expectations. This allows practices to use professional judgment as how best to comply. Practices must become and stay aware of new techniques, materials, and equipment.
The Organization for Safety and Asepsis Procedures (OSAP) is dentistry’s resource for infection control and safety. OSAP has recently published a book on the CDC guidelines, From Policy to Practice: OSAP’s Guide to the Guidelines. The book is designed to support the efforts of dental practices to understand better the recommendations and to identify effective and efficient methods for compliance. Order information is available either at osap.org or by calling (800) 298-6727.
1. Centers for Disease Control and Prevention. Guidelines for Infection Control in Dental Health-Care Settings – 2003. MMWR 2003;
2. Centers for Disease Control and Prevention. Recommended infection control practices for dentistry MMWR 1986;35:237-242.
3. Centers for Disease Control and Prevention. Recommended infection control practices for dentistry MMWR 1993;42(RR-08):1-16.
4. Behnarsh H. Infection control guidelines, the new generation. Cont Edu Dent. 2004;25(Supplement 1):6-9.
5. Molinari JA. Infection control: its evolution to the current standard precautions. J Am Dent Assoc 2003;134:569-574.
6. National Communicable Disease Center. Isolation Techniques for Use in Hospitals. 1st ed. Washington, DC: US Government Printing Office; 1970: PHS publication No. 2054, 1-87.
7. Centers for Disease Control and Prevention. Recommendations for preventing transmission of infection with human T-lymphotropic virus type III/lymphapenapathy-associated virus in the workplace. MMWR. 1985;34:681-695.
8. Centers for Disease Control and Prevention. Perspectives in Disease Prevention and Health Promotion Update: Universal Precautions for Prevention of Transmission of Human Immunodeficiency Virus, Hepatitis B Virus, and Other Bloodborne Pathogens in Health-Care Settings. MMWR. 1988;37(24):377-388.
9. Centers for Disease Control and Prevention. Hospital Infection Control Practice Advisory Committee. Part I. Evolution of Isolation Practices. Atlanta, Ga, Centers for Disease Control and Prevention, 1997, pages 1-44.