(CNN) -- Testing continues for patients who may have been exposed to HIV and hepatitis from their visit to Dr. W. Scott Harrington's suburban Tulsa, Oklahoma, dental office.
By Monday, nearly 1,000 patients had been screened at a special clinic in the city, and most will receive results in about two weeks, state health officials said.
The screenings began Saturday, and the free tests will continue weekdays.
Harrington, 64, surrendered his dental license on March 20 after health investigators found sterilization, staffing and other infractions.
The dentistry board launched its probe after one of Harrington's patients came down with hepatitis C. That patient originally tested positive for HIV, too, but a subsequent test came back negative, the Tulsa Health Department said.
Investigators raised a number of sterilization and "cross-contamination" alarms -- such as "unauthorized, unlicensed" employees using IVs to sedate patients and that needles weren't handled properly.
"I will tell you that when ... we left, we were just physically kind of sick," Susan Rogers, executive director of the Oklahoma Board of Dentistry, said last week. "That's how bad it was, and I've seen a lot of bad stuff over the years."
The outward cleanliness of the office belied the mess elsewhere, Rogers said said, noting that "just basic universal precautions for blood-borne pathogens" weren't followed.
Besides being "unlocked and unattended," the drug cabinet was rife with issues -- containing, for example, a drug that expired in 1993 -- according to the official complaint filed before the state dental board. Other records showed that morphine had been used in patients throughout 2012, even though the dentist had not received a morphine delivery since 2009.
Harrington and his attorney have not returned multiple calls from CNN. And the oral surgeon wasn't home when a CNN crew went there on Saturday.
"How do you say you're sorry to 7,000 people that you could possibly have infected?" said Melissa Wood, whose daughter -- a patient of Harrington's -- spent part of her 18th birthday getting tested.
CNN's Susan Candiotti contributed to this report.