Nearly 7,000 patients of an Oklahoma oral surgeon were urged to get themselves checked for HIV. The announcement came after the Oklahoma Board of Dentistry and other agencies began an investigation into the unsanitary conditions at the dental clinic.

The investigation of health practices of W. Scott Harrington, D.M.D. has so far shown that the dental office was in poor condition and that the oral surgeon violated many rules and increased the risk of diseases, including Hepatitis B, C and HIV. As people with these diseases don't show many symptoms for years, health officials have urged Harrington's patients to get themselves checked.

The dentist closed down his office since the investigation began and is now co-operating with the health agencies.

The Tulsa Health Department added that transmission of diseases from such occupational settings is rare.

"I want to stress that this is not an outbreak. The investigation is still very much in its early stages," Kristy Bailey, who is a state epidemiologist, told the Associated Press. The investigation of the dental clinic began after a patient who had no risk for hepatitis or HIV tested positive for both viruses. After that, investigators began looking for sources from where the patient might have got the virus. It turned out that the patient had a dental procedure done at about the same time as the exposure.

"All testing will be done free of charge at the Tulsa Health Department's North Regional Health and Wellness Center located at 5635 N. Martin Luther King Jr. Blvd. Services will be provided on a walk-in basis starting on Saturday, March 30 from 10:00 a.m. - 2:00 p.m. and will resume on weekdays beginning Monday, April 1 from 8:00 a.m. - 6:00 p.m," according to a statement from the Tulsa Health Department.