UPDATE: Patients react to news of possible dental infection

FAYETTEVILLE (KFSM) - Hundreds of dental patients in Arkansas may have been exposed to an infectious disease.

The dentist at the center of the possible contamination committed suicide last February. One of Dr. William Stewart's patients said she's stunned.

"I was like, wow, I may have these diseases that he may have given to me," said 18-year-old Tiana Newberry. "That's crazy."

Not all of Dr. Stewart's patients are at risk for infection, according to the Arkansas Department of Health (ADH). Officials there said the recommendation to get tested for HIV and Hepatitis B was only for patients between the ages of 14 and 22 who were treated between November 2011 and February 2012.

"My younger sister actually went and a few of my cousin's went previously and it's just scary," said Newberry. "My whole family may have it."

Dr. Stewart worked in Ocean Dental Clinics throughout the state and at Bevans Pediatric in Little Rock. Still, health officials cautioned against panic.

"The general public does not need to be overly concerned about this," said Dr. Dirk Haselow with ADH. "This is not an emergency....We just think the potential exists. However small, it's worth notifying patients."

Investigators believe some of Dr. Stewart's medicine vials may have been tampered with, which could damage the sterile nature of the medicine. They said, though, that there has been no evidence to this point that the vials he used for IV medication were infected or that anyone has gotten sick because of this case.

According to Dr. Haselow, "We don't know who, we don't know why, we don't know what. But we know that the lids basically had been removed and put back on."

Whenever a doctor with a controlled substance license dies, federal agents confiscate their medicines. Those vials are then taken to the state crime lab to be tested. Ocean Dental said they are cooperating with ADH.

While little information is known about how big this infection is - or if it has even affected patients at all - ABC News has confirmed Dr. Stewart committed suicide on February 29, 2012 after he lost his job with Ocean Dental when he refused to take a drug test. The coroner said he overdosed on drugs.

He was in rehab for a time and, in 2000, asked for a dentistry license in Arkansas. He was granted the license on the condition that he complete a five year program with daily drug testing. Stewart relapsed in 2005 and had to complete the program again.

He was under investigation at the time of his death because of a patient complaint.

Click here for more on this story from our CNN station in Fayetteville, KFSM.