A Colorado dentist and oral surgeon put his patients at risk for contracting HIV and hepatitis due to unsafe injection practices, and state officials are set to notify patients who saw Dr. Stephen Stein over a 12-year period to inform them of their risk.

The Colorado Department of Public Health and Environment stressed that there have been no infections linked to the offices of Dr. Stein, who practiced oral surgery in Highlands Ranch, Colo., and Denver.

The state said patients who received IV medications, including sedation, at Dr. Stein's offices may have been exposed to HIV, hepatitis B and/or hepatitits C.

State officials learned of the HIV risk the dentist may have exposed his patients to following a report of unsafe injection practices at his offices.

Upon investigation, it was determined syringes and needles used to inject medications through patients' IV lines were saved and used again to inject medications through other patients' IV lines, the agency said in a statement. This practice has been known to transmit infections.

The agency said the investigation into the HIV risk the dentist may have passed on to his patients is still continuing.

State health officials are working with health officials at Tri-County Health Department and Denver Public Health due to the locations of Stein's practices in those counties, the agency added.

The agency said patients may be at risk if they received those services under the dentist's care between September 1999 and June 2011 at the Highlands Ranch office and between August 2010 and 2011 at Stein's Denver office.

The health department said it was working to obtain Stein's records so his patients could be notified directly.

Notifications are being sent to patients for whom the department believes it has correct contact information, the agency said in a statement. Those patients should receive the letters within the next few days.

The department cautioned that records may be incomplete and urged patients who remember receiving IV medications at Stein's offices to get tested for HIV and hepatitis, as the dentist may have put them at risk for the diseases.

If you are unsure if you received IV medications at the dentist, the department is still advising to get tested. Patients who know they didn't receive such treatment do not have to be tested for HIV, the agency said.

If you're a patient of Dr. Stein's and need more information about your HIV risk, call CO-HELP at 1-877-462-2911 or visit http://www.cdphe.state.co.us/.

Symptoms of HIV and hepatitis might not show up for years, the department noted, meaning it's possible the dentist's patients might be infected and not know about it.

Although testing cannot determine where or how someone was infected (at Stein's offices or from another exposure), it is important to know so treatment can begin, the agency said.

Data from any positive HIV or hepatitis tests taken by Stein's patients will be reported to the state since they are reportable conditions in Colorado.