72 packs of dental instruments not sterilised completely used for patient care at National Dental Centre

The National Dental Centre's three-step process for sterilising its dental instruments. Steps 1 (top left) and 2 (bottom left) remove and inactivate organisms.
The National Dental Centre's three-step process for sterilising its dental instruments. Steps 1 (top left) and 2 (bottom left) remove and inactivate organisms. PHOTOS: NDCS

SINGAPORE - Dental instruments not completely sterilised were used in patient treatment last week at the National Dental Centre Singapore (NDCS), it said in a statement on Monday (June 12).

A total of 72 packs of instruments were compromised on June 5 and 6, NDCS added.

All the packs were used for dental treatment before they could be retrieved, although the risk of infection to patients has been assessed to be "extremely low".

This is because the earlier steps in the sterilisation process would have removed close to 100 per cent of organisms of concern, NDCS said.

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Explaining the lapse, NDCS said the instruments had undergone thermal washer disinfection but had not completed the final step of steam sterilisation before being used at its specialist outpatient clinics on levels 2, 4 and 6 of the NDCS building.

The Ministry of Health (MOH) was informed on June 9. A spokesman said: “MOH has directed SingHealth and NDCS to conduct a thorough review of the incident and the processes involved, and to report its findings and follow up actions to MOH. 

“MOH will review the report and determine if any regulatory actions are to be taken against NDCS.” She added: “Our priority is the safety and wellbeing of patients.”

NDCS has since conducted a thorough review of the incident and the processes involved, and has also implemented additional controls to prevent any recurrence.

It is also informing the 714 patients who visited its clinics over the two days, and has been reassuring them on their low risk of infection and address their concerns.

Of these, up to 72 could have received treatment using the instruments.

NDCS also shared its three-step sterilisation process of its dental instruments, of which the first two remove and inactivate organisms, including viruses.

- The instruments are thoroughly machine-washed to remove physical debris;

- The instruments are then thermally disinfected;

- As a final step, the instruments are put through an additional steam sterilisation for destruction of bacterial spores.

NDCS director Poon Choy Yoke said: "Patient safety and well-being 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."

Patients with queries can call NDCS's hotline on 6324 8005 or e-mail ndcs_qsm@ndcs.com.sg.

Such problems have occurred in other countries. Last year in the United States, a Veterans Affairs dentist did not sterilise his equipment properly. About 600 patients he treated were contacted, warned of possible infection and offered free screening for HIV and hepatitis, and free care should they have caught the diseases.

The NDCS said the final sterilisation would remove bacterial spores particularly clostridium perfringens which affects the gut with illness usually lasting a week, and clostridium tetani which causes tetanus, are very rare here.