TULSA -- Health officials urged an Oklahoma oral surgeon's patients Thursday to undergo hepatitis and HIV testing, saying unsanitary conditions behind his office's spiffy facade posed a threat to his 7,000 clients and made him a "menace to the public health."State and county health inspectors went to Dr. W. Scott Harrington's practice after a patient with no known risk factors tested positive for hepatitis C and the virus that causes AIDS. They found employees using dirty equipment, reusing drug vials and administering drugs without a license.Harrington voluntarily gave up his license and closed his offices in Tulsa and suburban Owasso and is cooperating with investigators, said Kaitlin Snider, a spokeswoman for the Tulsa Health Department. He faces a hearing April 19, when his license could be permanently revoked."This is an unprecedented event," Susan Rogers, executive director of the state Board of Dentistry, said in an interview. "To my knowledge, this has never happened before as far as a public notification of a [hepatitis C] case involving a dental office."The Oklahoma Board of Dentistry said the inspectors discovered multiple sterilization issues at Harrington's offices, including the use of a separate, rusty set of instruments for patients known to have infectious diseases."The CDC [Centers for Disease Control and Prevention] has determined that rusted instruments are porous and cannot be properly sterilized," the board said in a 17-count complaint against the dentist.Officials are sending letters to 7,000 known patients of Harrington, but they said they do not have information for patients before 2007. The letters urge the patients to be tested for hepatitis B, hepatitis C and HIV -- viruses typically spread through intravenous drug use or unprotected sex, not occupational settings."It's uncertain how long those practices have been in place," Snider said.Harrington could not be reached for comment Thursday. A message at his Tulsa office said it was closed and the doctor's answering service referred callers to the Tulsa Health Department.