A clear understanding of viral hepatitis, especially that caused by hepatitis B virus, is essential for all dental practitioners, particularly in view of the serious sequelae of the disease and the potential risk of transmitting the infection to patients by the dentist and vice versa.

Viral hepatitis, in common with AIDS, is one of the few bloodborne viral hazards the dentist has to contend with in his practice. Although the AIDS epidemic has aroused the greatest concern regarding disease transmission, hepatitis B infection can be a much more real danger to both the patient and the dentist, due to the relatively high infectivity of hepatitis B virus compared with HIV. Furthermore, an unknown, but none the less significant number of dentists in the Western world have either contracted viral hepatitis from, or disseminated the infection to patients. In contrast, to date there is only a single documented instance where a dentist is believed to have become infected with HIV during dental treatment.

The term ’viral hepatitis’ is commonly used for several clinically similar diseases which cause inflammation of the liver but are epidemiologically and aetiologically distinct (Table 15.1). Two of these, hepatitis A (formerly called infectious hepatitis) and hepatitis B (formerly called serum hepatitis) are well characterized, while a third, non-A non-B hepatitis, is thought to be caused by at least three different agents. These viruses, together with the relatively recently discovered delta virus, are of concern in dentistry as they are responsible for the great majority of viral liver diseases. Table 15.2 shows the main differences between the hepatitis caused by hepatitis B, non-A non-B and delta viruses. It is worth remembering that hepatitis caused by the above agents are clinically indistinguishable, although they possess other differences.