Dental Asia July/August 2021

User Report
Although mechanical and chemical
indicators do not prove sterilisation has
been achieved, they allow the detection
of certain equipment malfunctions and
identify procedural errors.
Thus, it is recommended that sterilisers are
monitored with spore tests at least weekly,
and any load with an implantable device.
She placed the spore test in the
centre of an empty chamber per the
manufacturer’s instructions and mailed
it for processing.
On Thursday, she received “immediate
notification” from the sterilisation
monitoring service that her spore test
failed.
Unfortunately, incidents such as this still
exist but some measures can be taken to
prevent such situations.
This article will address quality assurance
measures to ensure instrument sterility
and instil a sense of calm and confidence
as well as a culture of safety to dental
personnel who reprocess instruments.
While the combination of monitoring
methods is intended to provide
safeguards and ultimately ensure
sterility, gaps in quality assurance do
exist as demonstrated in the following
case scenario.
CASE SCENARIO
Kim, an experienced dental assistant
was a relatively new employee at a
dental facility. She performed a spore
test early Monday morning on an
autoclave – a different brand from which
she was trained.
Recognising the implications, slight
panic and a series of questions raced
through her mind: “Why did it fail? What
happened to the instruments that have
been processed since the test, and have
they been used for patient care? Could
I identify unused packages, retrieve and
reprocess them? Should the patients
who may be impacted be notified? And,
what should I do next?”
Kim immediately reported this situation
to her infection control coordinator and
the owner/dentist.
“IMMEDIATE NOTIFICATION” MAY
NOT BE SOON ENOUGH
In the scenario above, over three days
of patient care had been performed
utilising numerous instrument packages.
There is a possibility that the autoclave
had been malfunctioning for the entire
three days (or more), or that this was an
isolated cycle-failure incident.
Potentially, one or more patients over the
course of the three days, may have been
treated with instrumentation that failed
a spore test.
Chemical Indicator Types
Type 1
Process indicator
(Both Internal and
External)
Demonstrates that an item has been exposed to a sterilisation process and
distinguishes between processed and non-processed items.
Type 2
Indicators for use in
specific tests
Used in specific test procedures in certain sterilisers (pre-vacuum sterilisers).
The most common example is the Bowie-Dick test.
Type 3
Type 4
Type 5
Single critical process
variable indicators
(Internal)
Multicritical process
variable indicators
(Internal)
Integrating indicator
(Internal)
Responds to only one critical parameter of the sterilisation process (usually
time or temperature). Note: The sterilisation process has more than one critical
parameter, and all must be reached for sterilisation to occur.
Responds to two or more critical parameters of the sterilisation process.
Responds to all critical parameters of the sterilisation process (time,
temperature, and pressure.) The stated values are generated to be equivalent to,
or exceed, the performance requirements for biological indicators.
Type 6
Emulating indicator
(Internal)
Responds to all critical parameters of the sterilisation process for a specified
sterilisation cycle.
Reference: ANSI/AAMI/ISO 11140-1:2014
Table 1
DENTAL ASIA JULY / AUGUST 2021 45