Personnel in the VA dental facilities were screened for the detection of viral hepatitis and identification of factors implicating infectivity. A total of 963 personnel from 126 dental facilities throughout the United States voluntarily participated in the study. The rate of seroconversion for any hepatitis B markers was approximately 1% per year. Serial positive tests for antibody to hepatitis B core antigen or antibody to hepatitis B surface antigen (or both) were present in 16.2% of dentists and 13.0% of dental auxiliary personnel. Oral and maxillofacial surgeons composed the highest prevalence occupation (24.0%), and clinical personnel composed the lowest prevalence occupation (8.9%). There was a significant association between years in dental environment and serological positivity for viral B infection. The dentists and dental auxiliary personnel had significant linear trends of increasing serological positivity with years in the dental environment. Although a majority of personnel reported wearing gloves while treating high-risk patients or performing invasive procedures, inadequate prophylactic measures were exercised for most patients undergoing a variety of less invasive procedures. The results of the study show the need for an active immunization program against type B viral infection for dental and dental auxiliary personnel, preferably before the initial exposure to the professional environment.