ST. LOUIS — The Veterans Administration said today the chief of dental services at a St. Louis VA Medical Center was placed on administrative after the hospital urged nearly 2,000 veterans to return for blood tests because inadequately sterilized equipment might have exposed them to viral infections during dental procedures.

An independent board will also investigate how employees failed to properly sterilize the dental equipment that potentially exposed veterans to infections including hepatitis and HIV, the administration said.

"The mistakes made at the St. Louis VA Medical Center are unacceptable, and steps have been and continue to be taken to correct this situation and assure the safety of our veterans," VA Secretary Eric Shinseki said.

The VA sent letters out Monday to 1,812 veterans who had dental procedures at the St. Louis center from Feb. 1, 2009, through March 11 of this year, saying reviews determined that some sterilization steps in preparing dental instruments were not in compliance with standards.

Officials say the infection risk is extremely low, and no illnesses have been uncovered so far out of some 100 veterans who have come in for blood work that will screen for hepatitis B, hepatitis C and HIV.

Rep. Russ Carnahan, D-Mo., said the House Veterans Affairs Committee also said they will investigate what happened at the center and planned to hold a hearing in St. Louis.