TULSA, Oklahoma (CNN) — TULSA, Oklahoma (CNN) -- They'd gone to W. Scott Harrington's dentist office in suburban Tulsa, Oklahoma, for a cleaning, maybe a root canal.
On Saturday, scores of his patients were waiting to be checked once again -- this time not to fill a cavity, but to find out whether they'd been exposed to hepatitis or HIV.
Three hours after its doors opened, a line of Harrington's patients extended outside Tulsa's health department building early Saturday afternoon. More people were waiting inside, all because of an investigation that found unsanitary conditions at his office.
The building was slated to be open four hours Saturday -- the first day of testing, with 10 full hours of testing starting Monday -- but health department spokeswoman Kaitlin Snider said it wouldn't close until everyone was taken care of. Some 180 people were processed in the first three hours, she said.
They were among 7,000 of Harrington's patients from the past six years who health authorities urged to get checked.
Harrington surrendered his dental license on March 20 after health investigators found sterilization and staffing infractions.
Investigators initially alerted the dentistry board to a potential hepatitis C infection from Harrington's office. That patient originally tested positive for HIV, too, but a subsequent test came back negative, the health department said.
A complaint filed before the state dental board described violations, including "multiple sterilization issues, multiple cross-contamination issues, (and) the drug cabinet was unlocked and unattended."
There were no logs of inventory for the drug cabinet, the complaint states. One drug found in the cabinet had expired in 1993. Other records showed that morphine had been used in patients throughout 2012, even though the dentist had not received a morphine delivery since 2009. The complaint also says that Harrington's dental assistants did not have permits.
Harrington and his attorney have not returned multiple calls from CNN.
A teenage patient, who asked not to be named, told CNN he had a bad experience at Harrington's office a year ago.
During a surgery to remove three molars, he awoke momentarily to see profuse bleeding. He said he became alarmed but was told to "shut up" and hold gauze in place. When he awoke a second time, he was tied up on the floor. Harrington's staff explained that he had been "combative" during the operation, he said.
"I felt when I got out of there and went through all I went through, I felt they didn't know much of what they were doing at all," he said.
The patient's mother has had trouble sleeping since learning about the investigation.
"How do I tell him I have to take him to get tested because you may have caught this from a dentist? I'm scared," she said.
The U.S. Centers for Disease Control and Prevention provides national guidelines for dental offices to help prevent the spread of infections. They include cleaning and sterilizing all non-disposable items such as dental tools between patients, disinfecting surfaces and requiring staff members to wear protective masks, gloves and eye wear.
Since 1991, only three cases of dental infection in patients have been documented -- two with hepatitis B and one with HIV, according to the CDC. No cases of hepatitis C have been reported.
Harrington, 64, is a veteran oral surgeon who started practicing more than 35 years ago. He worked in the Tulsa suburb of Owasso.
-- CNN's Greg Botelho and Mariano Castillo contributed to this report.
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