What's a dental dam? – Maria* A dental dam is a square piece of stretchy latex or a similar material. It is placed over a woman's genitals when she receives oral sex. Oral sex is a sexual act where someone's mouth touches the other person's genitals. Genitals are the sexual or reproductive organs that are on the outside of the body (the testicles and penis of a guy, or the labia, clitoris, and vagina of a girl.) A dental dam helps prevent the spread of STDs (sexually transmitted diseases). If a guy is receiving oral sex, he should wear a condom to prevent the spread of STDs. You can buy dental dams online and at some drugstores. Some sexual health clinics have them available for free. *Names are changed to protect user privacy. Back to Articles Related Articles Condoms Condoms may be a good birth control option for couples who are responsible enough to use one each time and people who want protection against STDs. Read More Birth Control Methods: How Well Do They Work? Some birth control methods work better than others. This chart compares how well different birth control methods work. Read More STDs (Sexually Transmitted Diseases) You've probably heard lots of discouraging news about sexually transmitted diseases. The good news is that STDs can be prevented. Find out how to protect yourself. Read More Can You Get an Infection From Fingering or Oral Sex? Find out what the experts have to say. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.