"Don't forget to floss" may soon be followed by "and don't forget to wear a condom," as dentists and clinics have started to administer state-of-the-art saliva tests that can detect HIV in minutes.

"The surprise factor is you are offering this," said Dr. Catrise Austin, who has tested some 100 patients for HIV at VIP Smiles, her New York City clinic, since July.

"The topic of HIV can be uncomfortable for some, so we decided we would talk about it with patients in a matter-of-fact way, the way we talk about cavities and gum disease."

To test for the AIDS-causing virus, all Austin needs to do is swipe a patient's upper and lower gums with a $15 OraQuick Advance kit.

Within 20 minutes, the swab will change colors to indicate a positive or negative result — just like a home pregnancy test.

Nationwide, a handful of public health agencies, including in New York City, are trying to bring HIV testing to the dental chair.

Approximately one in 10 Americans visit a dentist but not a physician each year, and about a quarter of HIV-infected people don't even know their status, according to the Centers for Disease Control.

The city is funding dental HIV testing programs at Metropolitan Hospital, Harlem Hospital and Jacobi Medical Center, as well as small community dental clinics.