Thousands of Oklahoma Dental Patients Possibly Infected With HIV, Hepatitis medical headline, a trip to the dentist creating a fightening prospect for 7,000 people in tulsa, oklahoma. People urged to get tested for a host of serious diseases, including hiv, hepatitis. Health officials say they may have been exposed by their dentist, a trusted man in their ghunt. How could it happen? Abc's david wright has clean his instruments properly. Instead of using a state-of-the autoclave, he -- authorities say say he routine he reused needles and vials. And that some medications were 20 years past their expiry date. Finally, authorities say dental assistants without proper training were allowed to administer injections of anesthesia. State officials want to be sure. The federal seshts for disease are assisting in the investigation. And I want to bring in abc's chief medical editor, dr. Richard besser now because 7,000 people, what does this is a about scope, severity? This is absolutely unbelievable if these allegations are true. I talked to the cdc today, and with millions of people who see the dentist every year, there's only been a handful of infections transmitted over the past 20 years. A member of the team who went in, could not believe what she saw in this dentist office. So tell us the red flags for somebody going to the dentist tomorrow morning. Ask what they do to prevent infections. If you ever see old or rusty instruments, that's a warning sign. Because it's so hard to clean them. If your dentist isn't wearing gloves or changing gloves between patients, time to find another dentist. A developing story. We'll continue to follow it.