The attitude toward these mythical sheets of latex seems to be that no one actually uses them — if they even exist at all.
And a quick Google search always yields less-than-satisfactory results:
Let's get some real answers.
To find out everything one needs to know about the world's most misunderstood prophylactic, BuzzFeed reached out to sex therapist Dr. Madeleine M. Castellanos, author of Wanting to Want: What Kills Your Sex Life and How to Keep It, and the Mazzoni Center's HIV/STD Services Manager Rashita Hurst.
What is a dental dam, exactly?
"A dental dam is simply a rectangular piece of latex that is used to cover the genitals so there is no direct mouth-to-genital or mouth-to-anus contact," says Castellanos.
To put it bluntly: "With a dental dam you can pretty much lick anything," Hurst says.
But, did they really come from my dentist?
You're not falling for some universal practical joke, the name really does fit. "Originally, dental dams were created to protect the mouth when doing dental work on an isolated tooth. Those dams were flexible but quite thick, so thinner ones that would allow for greater sensation were created specifically for oral sex and oral-anal contact," explains Castellanos.
What do they protect against?
The consensus is that a dental dam, if used correctly, will protect you against the same viruses and bacteria that condoms protect you from. "It protects against STDs that can be transmitted orally. Infections like gonorrhea, chlamydia, herpes, HPV, hepatitis A and B, and syphilis," says Hurst. Plus, it can also protect against HIV transmitted via oral sex.
"Because it forms a complete barrier, it protects against all of these infections if used properly," Castellanos says. "Without barrier protection, any of the above viruses and bacteria could be spread through cunnilingus and/or oral–anal contact. Because of this, dams should be used carefully so they don't slip out of place and then allow for accidental skin-to-skin contact or contact with any bodily fluids from either partner."
What don't they protect against?
"Anything that's not skin-to-skin contact or having to do with the exchange of body fluids, such as body lice," says Hurst.
"They must be held in place on either side by your hands and you have to make sure to only use one side and not flip it over so that you don't contact any fluids from your partner," says Castellanos.
Do people actually use them? Should I be using them?
Castellanos keeps it real with this tidbit: "Despite offering great protection, less than 10% of women use them at all, with only a fraction of them using dams regularly."
"Maybe if people know what they were they'd be more likely to use them," says Hurst. "Anyone who uses their mouth for pleasure and/or are unsure of their partners status or looking to be more thorough in protecting themselves/their partner [should use them]."
Basically, if you don't know your partner's STI/STD status and you want to make sure you're both protected while going down on them, you should be using a dental dam. They should also be used if one of you knows you have an incurable STD like herpes and you want to stay safe!
So, how does one use a dental dam?
The dam is simply held in place, firmly, with both hands during oral sex or anus-to-mouth contact. Obviously, there should be no flipping of sides once you begin! A harness can also be purchased to hold the dam in place.
Castellanos suggests placing lube on the side of the receiver to enhance sensation: "Some women find that water-based lubes are too bulky, but a good-quality silicone lube like Wet Platinum works very well to create a slick, more realistic feel for them."
Remember: They are for single use only. After you use it — chuck it.
Can I just DIY myself a dam?
Yes, you can use plastic wrap — but it's not always your safest bet.
"Most microwave or plastic wraps have some level of porousness, which would allow viruses to pass through. Because of this, they wouldn't offer the same protection as would a dental dam or condom latex square," says Castellanos. "It's probably noisier too!"
All right, now where can I get some?
If you don't want to make your own, you can find dental dams at most sex stores along with lube and condoms. Unfortunately it's rare to find them in the condom aisle of your local pharmacy, but they can be easily purchased online.