A dental dam is a thin sheet of latex or polyurethane placed between the mouth and a partner's genitals or anus during oral sex, where it works as a physical barrier that helps reduce STI risk by limiting direct skin contact and the exchange of bodily fluids. Despite being one of the simplest safer sex tools available, most people have never used one.
If you’re sexually active and want safer oral sex during cunnilingus or anilingus—or you’re simply curious about barrier methods for oral sex—this guide explains what dental dams are, how they work, which materials and sizes exist, and how to use a dental dam properly for both protection and pleasure. It also covers storage and single-use rules, DIY alternatives, what infections dental dams can and cannot help protect against, and where to get them so you can make informed choices with less anxiety about oral STI exposure.
Key Takeaways
- A dental dam is a thin, flexible sheet (typically 15 cm square) that acts as a barrier during oralvaginal and oral anal sex, reducing the risk of STI transmission through fluids and mucous membranes.
- Place the dental dam flat over the vulva or anus, apply water based lubricant on the side facing the genitals, and never reuse or flip the dam during a session.
- Dental dams reduce the risk of STIs during oral sex, including chlamydia, gonorrhea, syphilis, and HIV, but do not fully protect against skin-to-skin infections like herpes or HPV located on uncovered areas.
- Dental dams are easy to use and carry for safer sex; they are single-use, discreet, portable, and available at pharmacies, online retailers, or sexual health clinics without a prescription.
- Check the expiration date before use, store dental dams in a cool, dry place away from heat and sunlight, and consult authoritative health resources (CDC, local clinics) for STI testing or symptom questions.
What Is a Dental Dam? (And What Are "Barriers" for Oral Sex?)
A dental dam is a thin, flexible sheet, usually about 15 cm square, made of latex or polyurethane. During oral sex, it sits flat between the mouth and the vulva or anus, acting as a barrier that stops direct mouthto-genital contact. Dental dams do not prevent pregnancy; their purpose is specifically to lower STI risk during cunnilingus and rimming.
"Barriers for oral sex" is a broader category. It includes commercial dental dams, cut-open condoms, a latex glove opened into a flat sheet, and in some cases food-grade plastic wrap. All serve the same basic function: separating the mouth from a partner's genitals or anus.
The device originated in dentistry. In 1864, New York dentist Sanford Christie Barnum invented the rubber dam to isolate teeth during dental procedures. Its adaptation for safer sex came during the 1980s HIV/AIDS crisis, when advocacy groups, particularly those serving lesbians and women in correctional settings, promoted it as a tool for disease control during oral contact. For oral-penile sex, condoms remain the standard barrier.
How Dental Dams Work During Oral Sex
Dental dams work like condoms: they create a physical barrier that blocks the exchange of bodily fluids between partners. The dam covers the vulva or anus so that saliva, vaginal fluids, blood, and fecal matter stay on their respective sides. They reduce the risk of sharing fluids during oral sex and prevent the spread of sexually transmitted infections transmitted through mucous membranes.
Activities where dental dam use is recommended:
- Cunnilingus (mouth on vulva)
- Anilingus/rimming (mouth on anus); dental dams prevent contact with fecal matter and bacteria like E. coli and Shigella during analingus
- Perineum stimulation near the vagina or anus, where secretions may be present
By blocking fluid exchange, dental dams lower the risk of infections including gonorrhea, chlamydia, syphilis, hepatitis B, and HIV. However, dental dams do not fully cover surrounding skin. Infections spread by skin-to-skin contact, such as herpes (HSV) and HPV, can still occur from areas the dam does not reach.
Common Materials, Sizes, and Features
Not all dental dams are identical. Material choice affects comfort, allergy safety, and lubricant compatibility.
Most dental dams are made of latex. Latex offers good stretch and tear resistance, with thicknesses ranging from about 0.14 mm (thin) to 0.22 mm (heavy) based on technical data from manufacturers like Medicom. Latex dams are not suitable for anyone with a latex allergy, and oil based lubricants degrade them.
Some dental dams are made of polyurethane or polyisoprene for people with latex sensitivities. These tend to be less stretchy but can feel thinner and transmit warmth more effectively. Dental dams are made of latex or polyurethane materials depending on brand and intended use.
Dental dams come in various sizes, colors, and flavors. Standard sizes include 5" x 5" (127 mm) and 6" x 6" (152 mm). They can be unflavored or flavored for enhanced pleasure, with options like mint, strawberry, and chocolate. Scented and unscented versions exist. Colored dams range from clear to black. Many arrive unlubricated; users add water based or silicone based lubricant themselves.
Step-by-Step: How to Use a Dental Dam
Correct usage of dental dams requires inspecting for damage and checking the expiration date before anything else. Open the packet along the indicated tear line. Stretch the dam gently and hold it up to light to check for holes or thin spots.
Decide which side will face your partner's genitals and which side will face your mouth. Once the dam touches skin, do not flip it; keeping one side toward the body prevents transferring fluids back to your tongue or lips.
Place the dental dam over the vulva or anus before starting any oral contact. The receiving partner should be in a comfortable position. Lay the sheet flat so it covers the vaginal opening or anal opening and as much surrounding skin as possible.
Apply a small amount of water based lubricant or silicone based lubricant on the side facing the genitals. This increases sensation and keeps the dam from dragging. Too much lube makes the dam slippery and harder to hold; a thin layer is enough. Dental dams should be used with water based lubricants to prevent breakage when using latex.
Hold the edges with your fingers. Avoid stretching the material too tightly, which raises the chance of a tear. If the dam slips, folds, or tears at any point, discard it and use a new dental dam before continuing.
After oral sex, carefully remove the dam by peeling it away from the body. Fold it inward so the used side faces itself. Dispose of it in the trash, not the toilet. Wash your hands.
Using a Dental Dam: Practical Tips for Pleasure and Comfort
Dental dams can enhance comfort and enjoyment during oral sex when you add the right lubricant and communicate with your partner. The feeling of a barrier does not have to be a distraction.
Using flavored dental dams can enhance the experience if taste is a concern. Check the ingredient list for glycerin or artificial sweeteners if you or your partner has sensitivities. A thin layer of lube between the dam and the vulva or anus transmits warmth and movement; lube on the mouth side is usually unnecessary and can feel distracting.
To keep the dam from bunching, hold the edges firmly with both hands or have the receiving partner help anchor it with their fingers or thighs. You can use your lips, tongue, and gentle suction through the barrier. Combining dental dam use with external clitoral or anal stimulation using clean, gloved fingers adds variety.
Using dental dams can improve sexual comfort and pleasure. Additionally, using a dental dam can decrease anxiety about STI transmission, and dental dams provide peace of mind against STIs during oral sex. Talk during sex about pressure, positioning, and what works. If a dam feels too thick, try a different brand or non-latex material.
Single-Use Guidance, Storage, and Shelf Life
Dental dams should only be used once before disposal. One dam, one body area, one partner, one session. Reusing a dam risks microscopic tears, stretched material, and contamination with bacteria that make the barrier ineffective.
Never flip or reverse a dam mid-session. Moving fluids from one side to the other defeats the purpose of the barrier. If you switch from anal stimulation to vaginal contact, use a new dental dam for each site to avoid spreading bacteria that can cause urinary tract infections or bacterial vaginosis.
Store dental dams in their original sealed packaging in a cool, dry place. Keep them away from direct sunlight, sharp objects, and heat sources like car glove compartments in summer. Most latex and polyurethane dams have an expiry date printed on the packaging; using a dam past that date increases the risk of breakage or degradation of the material. Oil based lubricants, petroleum jelly, and coconut oil weaken latex; avoid them with latex dams.
DIY Dental Dams and Other Barrier Options
Dental dams can be hard to find on some store shelves. When commercial options are unavailable, people sometimes improvise. Commercial dams remain the tested, preferred choice, but workable alternatives exist.
DIY barriers can be made from non-lubricated male condoms. Simply cut the tip off a new latex or polyurethane condom, then cut along one side lengthwise. Unfold it into a flat rectangle. Avoid condoms with spermicide. You can also make a dental dam from a condom or latex glove: cut the fingers off a new, intact glove and slit down one side to open it into a flat sheet, though the resulting barrier will be smaller.
An internal condom can be cut open similarly for a larger coverage area. Some people use saran wrap (food-grade plastic wrap) as a barrier, but only non-microwave, non-porous wrap offers any protection, and it is not medically approved like condoms or dental dams. Treat it as a last resort.
All DIY barriers are also single-use. Check for holes before contact and pair with water based or silicone based lubricant if using latex-based materials.
What Dental Dams Protect Against, Including Sexually Transmitted Infections (and Their Limits)
Dental dams reduce STI transmission during oral sex, but they do not eliminate all risk. They are one component of a broader safe sex strategy that includes testing, communication, and vaccines for HPV and hepatitis B.
Dental dams can protect against STIs like chlamydia and HPV, as well as gonorrhea, syphilis, hepatitis B, and HIV transmitted via oral contact. They also reduce exposure to fecal bacteria and other infections that can cause gastrointestinal illness during oral anal sex. Dental dams protect against infections like herpes, HPV, and HIV to the degree that the barrier covers the affected area.
Dental dams do not protect against skin-to-skin contact STIs when lesions, warts, or sores sit outside the covered area. They also do not protect against pubic lice, which spread through close body contact rather than fluid exchange. Visible sores, rashes, or cuts around the genitals or anus are signs to pause sex and seek treatment from a medical professional.
Combine barrier use with regular STI screening, vaccination where appropriate, and honest conversations with your partner about sexual health history. The FDA classifies oral sex barrier devices as medical devices requiring demonstrated barrier integrity, which underscores that these products go through real safety review.
Where to Get Dental Dams and When to Seek Expert Advice
Dental dams are easily accessible and do not require a prescription. They are available online and at some drugstores, typically in the condom or family-planning aisle. Sexual health clinics, campus health
centers, LGBTQ+ community centers, and some Department of Veterans Affairs facilities also distribute them, sometimes for free.
On packaging, look for products labeled as dental dams or oral barriers for safer sex. Check the material type (latex vs. non-latex), the expiration date, and whether the manufacturer lists certifications. Different sizes and flavors may be available depending on the brand.
For detailed guidance, consult authoritative resources: the U.S. Centers for Disease Control and Prevention, the World Health Organization, or your local sexual health clinic. Educational videos on YouTube from verified health organizations can also walk you through proper use. Seek professional medical advice if you suspect STI exposure, notice unusual discharge, sores, burning, or bleeding, or have questions about using barriers alongside specific medications or during pregnancy.
Frequently Asked Questions About Dental Dams
Can I use the same dental dam for both the vagina and anus during one session?
No. Moving a dam from the anus to the vulva (or the reverse) can transfer bacteria and raise the risk of urinary tract infections, bacterial vaginosis, and other infections. If you switch between oral anal sex and oral vaginal contact, use a new dental dam for each body area. This is not optional; it is a core part of prevention.
Do I still need STI testing if I always use a dental dam?
Yes. No barrier is 100% effective, and some infections can transmit from uncovered skin or through activities other than oral sex. Most sexually active people should test at least once a year, and more often with new or multiple partners. Your local clinic can recommend intervals based on your life and sexual activity.
Can I use a dental dam if I have braces, tongue piercings, or rough facial hair?
Braces and piercings increase the chance of tearing a dam. Remove oral piercings during sex if possible, and be mindful of sharp edges from teeth or orthodontic hardware. Rough facial hair creates friction that can damage thin latex. Apply extra lube on the genital side and check for tears periodically. Discomfort on either side is a signal to pause and inspect the barrier.
Are dental dams safe to use during menstruation?
Yes. Dental dams are suitable during menstruation and can be especially helpful for reducing contact with blood and potential bloodborne infections. Make sure the dam fully covers the vulva. The receiving partner can use a tampon, pad, or menstrual cup as desired. Dispose of the dam in the trash after use.
What if my partner doesn't want to use a dental dam?
Explain that dental dams protect both partners and can reduce anxiety, making oral sex more relaxed. If your partner resists, you can negotiate alternatives like STI testing together, vaccination, or choosing lower-risk activities. Everyone has the right to insist on barriers as a boundary for their own safety. No one should feel pressured into transmitting STIs or having unprotected contact. Open conversation is key; if a partner dismisses your sexual health concerns, that itself is information worth acting on.
Barriers for oral sex work best alongside the right lubricant and open communication. See our Condoms & Barriers guide for the wider context, and our condoms and lubricant compatibility article for how lube base affects barrier materials. If you use lube for oral, our flavored lubes guide covers ingredients and compatibility.