What is a dental dam—and why would you need one?

I dont have to tell you how important it is to use protection during sex-but you know whats also important? Using protection during

Enter, the dental dam-an unfortunately-named device. While you can just use a condom if you're performing oral sex on a man, the dental dam comes into play if you're performing oral sex on a woman, or during a backdoor oral situation.

A dental dam is a contraceptive made of latex or nitrile (a latex-like material that's more resistant to punctures), says Lisa M. Valle, D.O., FACOG, an ob-gyn and CEO at Oasis Women’s Sexual Function Center. It’s a six-inch sheet held in front of the vagina or the anus during oral sex to reduce the chance of an STI spreading through fluids or possibly even skin-to-skin contact.

Also important to note: Dental dams have no business being on a penis (again, they're mainly used for cunnilingus or anilingus).

As for the strange name, dental dams “were originally created for use during dental procedures to isolate a tooth,” says Valle, explaining that they were meant to block the flow of saliva during procedures.

In fact, they weren't even considered a sexual device until the 1980s, when they were marketed toward queer women to protect from STIs-though dental dams never really took off in the queer community or any other, which would explain why you’ve likely never (or only rarely) seen them in at the store.

Again, because they're not terribly popular, dental dams can be super-hard to find-you can buy them online or at specialty sex stores.

According to the Centers for Disease Control and Prevention (CDC), you can also DIY it (yes, really). Make your own dental dam by cutting open a male condom and flattening it out into a sheet.

Just like condom use, there are a few rules to keep in mind when using a dental dam: “Every time you have oral sex, you want to use a new [dental dam]," says Valle. "You want to make sure there’s no tears or defects, you don’t want to reuse them, you don’t want to stretch them out,” she adds.

To keep them intact, she says not to use oil-based lubricants because they can weaken the material and lead to breakage-instead, use water or silicon-based ones, just like you would with a condom.

And make sure to keep a good grip on them-dental dams are small and the genitals are a pretty wide area, so make sure you keep your focus (as much as possible, at least) while performing any kind of oral sex to maintain the best protection, since dental dams don't grip onto anything like condoms do.

Honestly, dental dams (or makeshift dental dams made from condoms) are a source of sexual protection you might really benefit from, so it's not a bad idea to add them to your shopping list. They are, after all, not just the best protection option to use while performing vaginal or anal oral sex-they're the only one.