Dr. Sawyer: Dental dams are rectangular sheets of latex pioneered in the late 80’s to assist dentists when drilling teeth. They were co-opted by the safer sex crowd to cover the opening to the vagina during bouts of cunnilingus (that’s oral sex on a female to the uninitiated). The idea was to prevent direct contact and thereby reduce transmission of infections…nice idea until the dental dam got wet and relocated to the nether regions of the vagina. Some folks liked using them, but they probably weren’t much better than Saran Wrap and their use today seems pretty limited.