A statement from the Belfast Trust said that a small number of instruments used in dental procedures had been decontaminated, but not sterilised.The incident at the centre, which is located at the Royal Hospitals complex on the Falls Road, is being treated as a single serious adverse incident, with the Trust saying the risk of cross infection is low.In this statement, the Trust said: "A small number of instruments have been decontaminated but not sterilised. They were all used in minor School of Dentistry procedures."The expert advice we have received is that any risk of cross-infection is extremely low. We are carrying out a full investigation and we will contact any patient who should be informed."Patients and the public should not be concerned as this was a single incident in our central decontamination unit," the statement concluded.