Dental dams

While many people believe that sexually transmitted infections (STIs) can only be passed on via sexual intercourse, AKA penetrative/penis-in-vagina (PiV) sex, it is also possible for STIs and other infections to be contracted through oral sex. 

While safer sex precautions typically focus exclusively on penetrative sex—which explains why condoms are so readily available—this approach is limited. Although you can use a condom to perform oral sex on a partner with a penis, condoms don’t offer any protection during vaginal or anal-oral play, AKA rimming. 

Enter the dental dam. While dental dams are an effective form of protection for all types of oral sex, they’re not popular, and chances are you’ve never even heard of them.

What are dental dams?

A dental dam is a thin, 6-inch square sheet of latex or polyurethane you can use to reduce your risk of spreading bodily fluids which may carry STIs during oral sex. More specifically, it protects against direct mouth-to-genital or mouth-to-anus contact, thereby reducing your risk of getting an STI while still allowing for pleasurable clitoral, vulvar, or anal stimulation.

A little background for the curious at heart: rubber ‘dental dams’ were first used by dentists to separate sections of the mouth, hence their name. Dental dams were given FDA approval for use during oral sex in 1998.

Why use a dental dam?

Dental dams can provide protection against the following STIs: syphilis, gonorrhea, chlamydia, herpes, hepatitis, HIV, and genital warts, among others. Depending on the nature of contact, it is possible to get an STI infection in the throat, mouth, anus, rectum, genitals, or even the urinary tract. Many people with an STI in their throat or mouth only suffer from a sore throat, and some are completely asymptomatic—yet a lack of symptoms doesn't make an STI any less harmful to you, or contagious to another person.

Dental dams are a barrier method, and they can greatly reduce your risk of sharing the fluids that carry these STIs during oral sex.

Another reason to use a dental dam: if you’re curious about oral-anal play but are a tad squeamish, a dental dam can allay your concerns, at the same time helping you to avoid contact with fecal matter, which can carry harmful bacteria like E. coli and Shigella, or even intestinal parasites.

What dental dams don’t protect against

While a dental dam can stop fluid exchanges, it cannot prevent you from passing on an infection or condition in cases where exposure occurs due to skin-to-skin contact. A few such scenarios include the following:

- Human papillomavirus (HPV) can be shared via contact with skin (whether warts are present or not), and it's the most common STI there is, affecting 85% of women at some point in their lives. 

- If you come into contact with a herpes lesion that isn’t located in the area covered by the dam, transmission is a possibility. 

- Pubic lice too, is beyond the dental dam's purview, as these bugs can easily move from one partner’s body hair to another.

- It should go without saying, but a dental dam cannot be used as a contraceptive.

How to use dental dams

Dental dams are simple to use. Nonetheless, it’s important to apply the dam slowly and carefully to prevent any tears.

After gently opening the package and removing the dam, unfold it and lay it over your or your partner’s vagina or anus. The material should be large enough to cover the entire area. Avoid stretching the dam or pressing it down. Let it cling naturally to the body via moisture or static. Leave the dam in place until you’re finished performing oral sex, and then throw it away. Never reuse a dental dam.

If the dam gets jumbled or torn in the heat of the moment, throw it away and get another one. If it starts to slip around during the act, you or your partner can simply hold it in place with one or both hands. You can also stop the slippage by placing a little lube between the dam and the skin. This might make it more pleasurable too. Be sure to use a water- or silicone-based lube though, as oil-based ones can damage latex. And, as with condoms, always check expiration dates and store them in a cool, dry place.

Where to get dental dams

Unlike condoms, dental dams aren't always readily available in pharmacies. You might start by checking out a sex shop, or else look for them online where they're abundantly available. They come in a range of sizes, colors, and even flavors. If you or your partner has a latex allergy, look for dams made with polyurethane. 

Since dental dams typically cost $1 to $2 each, check family planning or sexual health clinics before you purchase any, as these places sometimes offer them for free.

How to make a dental dam from a condom

The CDC has simple instructions on how to take a condom and transform it into a dental dam. All you need is a pair of scissors. After removing it from it’s package, simply cut off both the tip and the rolled end of the condom. Then, cut straight down one side of the condom. Voila, a DIY dental dam.

Dental dams have a reputation for being cumbersome, unsexy, and uncool—all somewhat controversial ideas worth unpacking. Consequently, while you may or may not have seen them passed around in sex ed class, most people who know about them don’t go out of their way to use them. 

Bottom line: for those who prefer to always put safety first, dental dams provide an integral layer of protection during oral sex. This can be particularly useful among non-monogamous couples or those dealing with an active STI.