On Dec. 19, 2003, the Centers for Disease Control and Prevention published updated infection control guidelines for dentistry. The guidelines provide comprehensive information on all aspects of dental infection control. The recommendations are designed to prevent or reduce the potential for disease transmission from patient to dental health care personnel, from dental health care personnel to patient, and from patient to patient. Most recommendations will be familiar and are already practiced routinely. This article highlights major updates and additions in the CDC guidelines and provides additional information to assist readers in applying the latest guidelines. Almost a year ago, the CDC and Prevention published updated dental infection control guidelines in a supplement to the Morbidity and Mortality Weekly Report. The Guidelines for Infection Control in Dental Health Care Settings--2003 represent a collaborative effort between leading experts in infection control from other federal agencies, public health, and hospital epidemiology and infection control. Unlike regulatory agencies such as the Occupational Safety and Health Administration, the U.S. Food and Drug Administration, or the U.S. Environmental Protection Agency, the CDC cannot mandate certain practices; it can only recommend. However, the CDC is recognized as the nation's disease prevention agency and develops a broad range of guidelines intended to improve health care and to inform clinicians and the public. As a result, many dental licensing boards adopt CDC's recommendations, or variations of them, as the infection control standard for dental practice in their states. In contrast to the 1986 and 1993 CDC dental infection control recommendations, the 2003 CDC publication includes more background information and the scientific rationale for the recommendations. Also, readers will notice that each recommendation has a rank assigned to it categorizing the recommendation on the basis of existing scientific data, theoretical rationale, and applicability (Table 1). Most recommendations will be familiar and already are practiced routinely. As with previous CDC recommendations, the guidelines are designed to prevent or reduce the potential for disease transmission from patient to dental health care personnel; from dental health care personnel to patient, and from patient to patient. The following is an overview highlighting major updates and additions in the 2003 CDC guidelines. It is not intended to be a comprehensive review. Readers can access the complete document (Figure 1) by visiting www.cdc.gov/oralhealth/ infectioncontrol.