This document contains sexually graphic images and may not be suitable for some audiences. Dental dams are latex or polyurethane sheets used between the mouth and vagina or anus during oral sex. Ready-to-use dental dams can be purchased online. Condom Effectiveness.

If you buy something through a link on this page, we may earn a small commission. How this works. A dental dam is a thin, flexible piece of latex that protects against direct mouth-to-genital or mouth-to-anus contact during oral sex. This reduces your risk for sexually transmitted infections STIs while still allowing for clitoral or anal stimulation.

If you buy something through a link on this page, we may earn a small commission. How this works. It is possible to pass a sexually transmitted infection to a partner through oral-genital or oral-anal sex. A device known as a dental dam can be effective in reducing this risk.

Dental dams are thin, flexible pieces of latex or polyurethane used as a barrier between the mouth and the vagina or anus during oral sex. Like condoms, they're designed to protect against sexually transmitted diseases STDs and other infections and should be used only once. Ready-to-use dental dams can be purchased online or at some drug stores; you also can make a DIY dental dam out of a condom. A dental dam is similar to a condom, in that it is used to help protect sexual partners from sexually transmitted infections, but is designed to be used during oral sex. Dental dams originally were developed for use by dentists to isolate areas of the mouth being treated and to prevent bacterial contamination.