If a man with hepatitis B has oral sex with a woman (giving or receiving), can the woman get infected?
The hepatitis B virus has been found in semen, salivia, and vaginal secretions (as well as in blood, of course). The risk of transmission is lower for oral sex than it is for vaginal or anal sex, but it is not zero.
For oral sex with an infected man on the receiving end, a condom is recommended. As for giving oral sex, a dental dam can be used. To reduce the risk even more, a vaccine for hepatitis B is available.