A dental dam is a thin, flat sheet of latex or non-latex material that acts as a barrier during oral sex, reducing the risk of transmitting sexually transmitted infections. Using one is straightforward: you lay it flat over the vulva or anus, hold it in place, and keep it there for the duration of oral contact. The details below cover everything from setup to cleanup.
What a Dental Dam Looks Like
Most dental dams are thin, square sheets roughly 6 inches by 6 inches. They come in latex and non-latex (polyurethane or nitrile) versions for people with latex allergies. Some are flavored or lightly scented, while others are unflavored and powder-free. You can find them at pharmacies, sexual health clinics, and online retailers, though they’re less commonly stocked than condoms.
Step-by-Step Instructions
Check the expiration date on the package before you start. Carefully open the wrapper and remove the dam, avoiding scissors, teeth, or anything that could nick the material. Unfold it completely so it lies flat.
If you’d like, apply a small amount of water-based or silicone-based lubricant to the side of the dam that will touch skin (the body side). This serves two purposes: it increases sensation for the receiving partner, and it helps the dam stay put by creating a light seal against the skin.
Lay the dam flat over the vulva for oral-vaginal sex, or over the anus for oral-anal sex. It should cover the entire area of contact without being stretched or pulled tight. One partner holds it gently in place while the other performs oral sex through the barrier.
When you’re finished, carefully peel the dam away, fold it inward so the used surface stays contained, and throw it in the trash. Never flush it. Use a new dam if you switch between vaginal and anal contact, or if the dam tears or shifts significantly during use.
Who Holds It and How
Either partner can hold the dam, but having the receiving partner do it frees up the other person’s hands to stimulate other areas. The dam only needs to be held in place loosely, not stretched or gripped tightly against the skin. A light touch at two edges is usually enough.
One practical tip: keep the hands holding the dam free of lubricant. Lubricated fingers make the material slippery and harder to control. Apply lube to the body side of the dam before placing it, then wipe your hands dry before holding the edges.
Lubricant Compatibility
Use only water-based or silicone-based lubricant with latex dental dams. Oil-based products, including baby oil, lotion, petroleum jelly, and cooking oil, will degrade latex and cause the dam to tear. If you’re using a non-latex (nitrile or polyurethane) dam, oil-based lubricants won’t damage the material, but water-based and silicone-based options still work well and are the safer default choice if you’re unsure what your dam is made of.
What Infections Dental Dams Help Prevent
Oral sex can transmit herpes (HSV-1 and HSV-2), syphilis, gonorrhea, HPV, and, less commonly, chlamydia and hepatitis. A dental dam works by preventing direct skin-to-skin and fluid-to-mucous-membrane contact between the mouth and the genitals or anus. The CDC states that using a barrier method every time you have oral sex can reduce the risk of giving or getting an STI.
No large-scale randomized trial has measured exact percentage reductions for dental dams the way studies have for condoms during vaginal sex. The protective logic is the same, though: a physical barrier blocks the exchange of fluids and limits contact with sores or lesions that may not be visible.
Making a Dental Dam From a Condom
If you can’t find a dental dam, you can make one from an unlubricated external condom. Remove the condom from its wrapper. Snip off the tip (the closed end) with scissors. Then cut along one side from the open end to the tip, so the condom unrolls into a flat, rectangular sheet. Lay it over the vulva or anus the same way you would a store-bought dam. An internal (female) condom can also be cut open along one side and used the same way, and its larger size gives you a bit more coverage.
Common Mistakes to Avoid
- Flipping or reusing the dam. Once you place it, keep the same side facing the body throughout. Flipping it defeats the purpose of the barrier. A used dam goes in the trash.
- Using two barriers at once. Layering a dam over a condom, or doubling up dams, creates friction between the layers and increases the chance of tearing.
- Stretching it tight. A taut dam is more likely to tear and less comfortable. Let it rest naturally against the skin.
- Ignoring visible damage. If the dam has a hole, tear, or looks brittle before use, discard it and use a fresh one.
Making It Feel Better
The most common complaint about dental dams is reduced sensation, and lubricant is the simplest fix. A thin layer of water-based lube on the body side of the dam transmits warmth and movement more effectively than a dry barrier. Some people also prefer thinner dams or flavored varieties, which can make the experience more enjoyable for the partner performing oral sex. Experimenting with pressure, movement, and hand placement around the dam’s edges helps both partners find what works.