Dental instruments that were not fully sterilised may have been used on eight patients at Tan Tock Seng Hospital (TTSH).
In a news release yesterday, the Ministry of Health (MOH) said it was informed of the lapse by TTSH on Saturday.
Last Tuesday, a staff member at the clinic discovered that a dental instrument had not gone through the final step of sterilisation.
When TTSH checked all dental instruments at the clinic the next day, they realised that a total of eight packs that had been used for patient treatment had not been fully sterilised.
TTSH said the instruments may have been used on up to eight of the 575 patients who visited the clinic between Nov 28 and Dec 5.
The hospital is contacting all of those patients to provide support and address any concerns.
Elective procedures, which are non-emergency procedures, have also been suspended at the clinic since Saturday.
A spokesman said this precautionary measure will allow a "safety timeout".
Procedures will resume tomorrow.
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MOH said it is also rendering support to TTSH in the implementation of additional control measures and the reaching out to patients.
The process for sterilisation at TTSH comprises three steps.
Instruments are first manually washed and subjected to ultrasonics and an enzymatic solution.
They are then air dried before being packed, sealed and labelled.
The final step - which was where the lapse happened - required the sealed instruments to be put through steam sterilisation to remove any remaining bacterial spores.
According to TTSH, even before the instruments are subject to the final step, almost all "organisms of concern" would have been eradicated, making the risk of infection "extremely low".
Despite this, Minister for Health Gan Kim Yong said he was disappointed that the lapse occurred.
"We take a serious view of the incident... and I am disappointed it has happened despite our efforts," he said.
"MOH will study the incident closely, consult relevant technical experts, and consider further actions to be taken to reduce the risks of a re-occurrence across the healthcare sector."
MOH said it has also directed the National Healthcare Group and TTSH to conduct thorough reviews of the incident, and report their findings and follow-up actions to the ministry.
This article was first published in The New Paper. Permission required for reproduction.