It's enough to give the tooth fairy a cavity. Dentists and PWAs share a history that's more complicated -- and painful -- than a self-administered root canal. Because oral lesions were often the first sign of undiagnosed AIDS, from the epidemic's first days dentists were at the heart of HIV hysteria. Here's a check-up:

1.84: The New York state health department releases guidelines to dentists treating HIVers: Wear protective gowns, masks, rubber gloves and eye goggles, and refrain from performing such elective dental treatment as bridges and caps.

12.87: Dentists' panic causes a shortage of disposable latex gloves; manufacturers scramble to fill the gap by importing gloves of questionable quality from Asia.

2.88: Despite the California Dental Association's published "Dental Patient Bill of Rights," 40 percent of AIDS Project Los Angeles' dental-clinic clients report that they have been turned away by private dentists.

12.88: A study finds that dentists who regularly wear gloves are more likely to be struck by lightning than infected by a patient.

9.89: A survey published in the Journal of the American Dental Association reports that fewer than a third of the nation's 140,000 dentists are willing to treat PWAs.

6.91: A San Francisco Chronicle ad reads: "Wouldn't it be reassuring to know that your dentist has tested negative?"

9.91: Kimberly Bergalis -- the twentysomething poster girl for "innocent victims" -- testifies before Congress that her dentist, David Acer, infected her with HIV. She urges mandatory testing of health care workers and maintains until her death three months later that she had never had sex or used IV drugs; posthumous evidence shows this to be unlikely.

10.91: Then-HHS Secretary Louis W. Sullivan argues against mandatory HIV testing for dentists and other health care workers.

12.94: The CDC announces: "Despite identifying numerous patients with HIV, we found no evidence of dentist-to-patient or patient-to-patient [via equipment] transmission of HIV during dental care."

6.95: New Orleans dentist Drew Morvant is ordered by the Justice Department to settle a lawsuit by paying $60,000 each to two HIVers he refused to treat.

8.95: A study in Nature Medicine reports that HIV can survive in mechanical dental instruments. "It's your right to say, 'Are you autoclaving?'" says one HIVer in response.

6.98: The Supreme Court's first decision regarding AIDS, Bragdon v. Abbott, applies the Americans With Disabilities Act (ADA) to HIVers. The landmark case stemmed from a complaint by a Maine woman, Sidney Abbott, whose dentist, Randon Bragdon, refused to fill her cavity because she was HIV positive.

4.99: The Los Angeles-based HIV/AIDS Legal Services Alliance reports still receiving more complaints of discrimination against HIVers by dentists than any other type of AIDS-related bias.

5.99: The ACLU files suit against dentists William E. Shelton and Julius McDaniels for refusing to treat an HIVer -- and disclosing her status. The ACLU argues that McDaniels' refusal to treat the woman after learning she was positive was a form of discrimination prohibited by the ADA.