Guidelines for Infection Control in Dental Health Care Settings Updated

By Dr. William G. Glecos
The Centers for Disease Control and Prevention (CDC) distributed to dental health care personnel (DHCP) its new Guidelines for Infection Control in Dental Health Care Settings 2003 via the December issue of Morbidity and Mortality Weekly Report (MMWR). The new guidelines provide extensive background information and the scientific rationale behind the recommendations. The recommendations are categorized by the strength of the supporting scientific evidence.

Many of the topics covered will be familiar to you and may be routinely practiced already. New topics that may affect your current office procedures include the following:

Standard Precautions vs. Universal Precautions

Universal Precautions

Universal precautions assumed that all blood and body fluids that might be contaminated with blood should be treated as infectious. Patients with bloodborne infections can be asymptomatic or unaware they are infected. These practices emphasized prevention of blood exposures.

Standard Precautions

Standard precautions expand the universal precautions concept to protect against pathogens that can be spread by any body fluid, excretion or secretion (except sweat) regardless of the presence of blood.  These practices emphasize prevention of exposure to bloodborne diseases and diseases that are transmitted through airborne, droplet or contact transmission. Back to top

Hand Hygiene

CDC considers hand hygiene the single most critical measure for reducing the risk of transmitting organisms to patients and DHCP. Wearing gloves does not eliminate the need for hand washing. DHCP should wash their hands immediately prior to donning gloves and immediately after removing gloves. Back to top

Environmental Infection Control

Environmental surfaces in the dental operatory do not directly touch the patient but can become contaminated during patient care. These surfaces are split into housekeeping and clinical contact surfaces. 

Housekeeping surfaces

Housekeeping surfaces have a limited risk of disease transmission. Unless the surface is visibly soiled, these surfaces do not require rigorous decontamination. Types of housekeeping surfaces includes floors, walls and sinks.

Clinical contact surfaces

Clinical contact surfaces are commonly contaminated during dental procedures by patient spray or splatter and from contact with the DHCP’s gloved hand. These surfaces should be cleaned and disinfected at the end of each day.

For difficult to clean surfaces, barrier protection is an effective method to prevent clinical contact surface contamination. Impermeable disposable barriers, such as clear plastic wrap, bags and tubing, are ideal for protection.

Examples of common clinical contact surfaces include the following items:
  • Dental unit surfaces
  • Light handles
  • Switches
  • Pens
  • Countertops
  • Drawer handles
  • Dental radiograph equipment
  • Reusable dental materials’ containers
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Dental Unit Waterlines

Drinking Water Standards

The Environmental Protection Agency (EPA), the American Public Health Association and the American Water Works Association established drinking water standards based on the concentration of heterotrophic bacteria. Drinking water may not exceed 500 colony-forming units per milliliter (CFU/mL) of drinking water. CDC suggested the same level should be applied to dental unit water. 


Studies have demonstrated that dental unit waterlines can become colonized with bacteria, fungi and protozoa. These microorganisms colonize and replicate on the interior surface of waterline tubing to form biofilms. Biofilms can form in any type of waterline tubing, like grocery store misters, showerheads, faucets and dental handpieces. 

A measurable risk of adverse health effects from exposure to dental water has not been demonstrated. However, the presence of unknown levels of pathogens and the uncertainty of dental water quality are not consistent with accepted infection-control principles. 

CDC’s Recommendations

CDC recommends the following strategies to improve dental unit water quality:

  • Use chemical germicides to prevent, inactivate or destroy biofilms when using dental waterlines with a self-contained water system.
  • Install an in-line microfilter for units connected to the municipal water supply.
  • Discharge water and air for 30 seconds after each patient for devices connected to the dental water system that enters patients’ mouths.
  • Consult with the dental unit manufacturer to determine the best method for maintaining acceptable water quality.
  • Follow the dental unit manufacturer’s instructions on the frequency of monitoring the unit.
  • Do not deliver public water through dental waterlines during a boil-water advisory unless the dental water source is isolated from the municipal water system.
CDC also recommends that sterile solutions be used as the coolant or irrigation fluid during oral surgery procedures to minimize the potential for localized or systemic infections. Back to top

Handling Extracted Teeth

Occupational Safty and Health Administration (OSHA) considers extracted teeth to be potentially hazardous material that should be disposed of in medical waste containers. Extracted teeth are subject to the containerization and labeling provision of OSHA’s bloodborne pathogens standard.

Do not put an extracted tooth containing amalgam in medical waste containers if incineration is the final disposal method of medical waste. Amalgam should be recycled. Check with your vendor to see if the whole extracted tooth with amalgam will be accepted for recycling. Back to top

Postexposure Management and Prophylaxis

Because accidents happen, no infection control program would be complete without a written postexposure plan. CDC recommends the following elements be described in postexposure protocols:
  • Types of blood and other potentially infectious materials that can place DHCP at risk for infection.
  • Procedures for promptly reporting and evaluating the contact type.
  • Identification of a qualified health care professional to provide counseling and medical evaluation.
Refer to the CDC’s guidelines for a sample postexposure-report outline. Back to top

ADA Online Resources

ADA developed an online Roadmap to help member-dentists understand significant changes to the CDC’s Guidelines.

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