TULSA, Okla. (AP) — Health department officials say 420 patients were screened at a Tulsa clinic after the Oklahoma Board of Dentistry said an oral surgeon may have put clients at risk for exposure to hepatitis and HIV. Letters began going out Friday to 7,000 patients who had seen Dr. W. Scott Harrington during the past six years, warning them that poor hygiene at his clinics created a public health hazard. Officials say hundreds of patients were screened for hepatitis B, hepatitis C and the virus that causes AIDS on Saturday at a special testing clinic in Tulsa. Health department officials say most people will be notified of their test results in about two weeks. Testing will resume Monday from 8 a.m. to 6 p.m. at the North Regional Health and Wellness Center.