The National Dental Centre Singapore (NDCS) has discovered that, on 5 and 6 June 2017, 72 packs of dental instruments which had undergone thermal washer disinfection, but had not completed the final step of steam sterilisation, had been used for patient treatment at its Specialist Outpatient Clinics on levels 2, 4 and 6 of the NDCS building.
NDCS is conducting a thorough review of the incident and the processes involved. In the meantime, we have also implemented additional controls to prevent any recurrence. All our dental instruments have since been verified to have undergone the complete sterilisation process.
Given the nature of treatment at the outpatient clinics and the completion of the earlier steps in the sterilisation process which would remove close to 100% of organisms of concern, the risk of infection to patients is assessed to be extremely low.
Nevertheless, NDCS is informing 714 patients who had visited the clinics during the period. Of these, up to 72 may have received treatment using the instruments as 72 packs of the affected instruments were already used for dental treatment before they could be retrieved2. We have been reaching out to reassure the patients on their low risk of infection, and are working with them to address any concerns.
Associate Professor Poon Choy Yoke, Director of the NDCS, said, “Patient safety and wellbeing are our first priority. We deeply regret this incident and sincerely apologise to our patients for the lapse and any anxiety caused. We have taken immediate steps to strengthen our processes and ensure the safety of all patients in our care.”
Sterilisation Process for Dental Instruments
At NDCS, the process for the sterilisation of dental instruments prior to usage comprises the following steps:
- Step 1: The instruments are thoroughly machine-washed to remove physical debris.
- Step 2: The instruments are then thermally disinfected.
These two steps remove and inactivate organisms, including viruses.
- Step 3: As a final step, the instruments are put through an additional steam sterilisation for destruction of bacterial spores.
On 5 June 2017, a NDCS staff found that a batch of dental instruments had not undergone Step 3 of the process. Efforts were made to recall the instruments from the affected outpatient clinics.
While all the affected instruments were retrieved by 6 June, 72 packs of instruments had already been used for dental treatment on patients. All dental instruments have since been thoroughly checked and confirmed to have undergone the complete sterilisation process before clinic operations commenced on 7 June.
Patients who have any queries can call hotline number: 6324 8005 or email: Ndcs_qsm@ndcs.com.sg.
Press release: National Dental Centre Singapore