Dental dam
Dental dams are essentially square sheets of latex used in dentistry, specifically endodontic treatment (root canals). They are also used during sexual activities as a safer sex technique.
When held over the vagina or anus, they protect a person performing oral sex on those body parts from potential harm from sexually transmitted diseases. A make-shift dental dam can also be created by slicing open a condom horizontally and spreading open the latex. Also a piece of plastic food wrap can be used if nothing else is available.
