Safeguarding patient wellbeing is a top priority for all healthcare professionals and dentistry has a whole range of procedures and protocols aimed at minimising cross infection. Decontamination and sterilisation equipment is at the forefront of the fight against the potential risk of prion transmission and ensuring that equipment is performing according to manufacturers’ parameters is an important first step in identifying possible shortfalls in performance. In order to validate the processes being performed, decontamination equipment must be operating effectively and being able to document and provide evidence of compliance is a vital aspect in adhering to infection control guidelines.
However, although there is a perceived logic of this approach, the detail can cause confusion. Firstly there are significant regional differences in regulations as well as anomalies in the type of cleaning processes that different authorities regard as suitable. Secondly there is a difference between ‘testing’ and ‘validation’, and thirdly there are a variety of guidelines as to the frequency with which different tests should be carried out.
HTM01-05 emphasises the need for testing and states in section 11.3 “Failure to perform these tasks or retain evidence of their performance may indicate non-compliance of the decontamination process.”
In Scotland, SHTM 2010 Sterilisation and SHTM 2030 Washer-Disinfectors provides guidance on validation, and the SDCEP documents Cleaning of Dental Instruments and Sterilising of Dental Instruments clarify which tests are required and how these should be carried out.
Failure to carry out routine periodic tests and maintenance tasks could compromise safety and have legal and insurance-related implications for the registered manager, therefore a testing schedule must be planned. The schedule should provide details of daily, weekly, quarterly and yearly testing (in accordance with manufacturers’ guidelines) and must be clearly laid down in the practice’s infection control policy.
Validation
Validation provides confirmation that equipment is operating in the way that the manufacturer intended, demonstrating that the equipment complies with the CE-marking process under the terms of the medical devices regulations and that all processes performed by the equipment are reliable and consistent.
Section 3.11 of HTM01-05 defines the need for validation; “Validation is the means by which an entire process is verified, tested and documented, with the ability to be consistently reproducible.”
In England the requirement is to have equipment validated and serviced annually by an accredited engineer and most service contracts will include an element of validation. In Scotland the CPI Checklist (published January 2013) forms the blueprint for practice inspections and states as ‘essential’ the need for evidence of validation and annual revalidation for washer disinfectors and autoclaves.
Testing
Testing on the other hand refers to the routine, regular tests that must be carried by the user to ensure the equipment meets specified parameters. There are a number of tests that should be carried out at specified intervals and the results must be recorded and form part of evidence of compliance required by the relevant regulatory bodies.
For ultrasonic baths and washer disinfectors there are two main testing areas which should be carried out weekly and quarterly. In addition, safety checks should be performed on a weekly basis to confirm that there is no visible damage to the equipment that could invalidate processes. Although there is no test as such for these visual checks, they should be recorded and filed as part of the practice’s decontamination processes.
Protein residue tests
A weekly protein residue test will determine if any residual protein remains on the dental instruments. This simple test should be carried out weekly on sample instruments that have been cleaned in either a washer disinfector or an ultrasonic bath.
At the end of the cleaning cycle, a random instrument is selected and its surfaced swabbed to determine if protein is present. The swab is placed in a colour changing solution and swirled for five seconds. This test should be able to detect protein levels as low as 1mg and if protein is present the reagent turns blue, providing an easy to read result; the higher the protein content the darker the colour. (Instruments cleaned in an ultrasonic bath must be rinsed with RO or distilled water before the protein residue test is carried out, but those from a washer disinfector don’t normally require this stage as the rinsing is carried out as part of the automatic process).
If the instrument passes this test, all instruments may be moved to the next stage of reprocessing. If an instrument fails the protein residue test, the equipment should be checked for visible signs of malfunction or in the case of washer disinfectors, error codes, and a second cycle should be run. If the test is failed again an engineer should be consulted.
Cleaning efficacy tests
Although normally carried out quarterly, the cleaning efficacy test or soil test is manufacturer-led, so the frequency with which this test should be performed may differ and should be checked first.
The cleaning efficacy test uses a chemical efficacy indicator which is normally painted red and contaminated with a quantitative measure of test soil. The indicator is placed inside a specifically designed holder, which in turn is placed in the bath or washer disinfector. After a predetermined time (manufacturer dictated), the indicator is removed and the absence of any visible colour indicates that the cleaning efficacy is satisfactory.
Manual cleaning
Although HTM01-05 covers the testing and validation for washer disinfectors and ultrasonic baths it does not lay out a specific timetable by which practices must achieve best practice and there are therefore a significant majority of dental practices in England that still carry out routine manual cleaning. Although this is still acceptable and sometimes necessary, manual cleaning is almost impossible to validate due to inconsistencies in the cleaning methods performed by different individuals. In Scotland and more recently in Northern Ireland manual cleaning is no longer considered accepted as a recognised cleaning method due to its inability to be accurately validated. For those practices in England and Wales still using manual methods it is vital to have specific protocols in place, such as set immersion times, which the team must follow and document.