TULSA, Okla. — About 150 to 200 patients of a Tulsa oral surgeon accused of unsanitary practices lined up outside a health clinic yesterday, hoping to discover whether they had been exposed to hepatitis or the virus that causes AIDS.

Letters began going out in stages 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.