BS EN ISO 16954:2015 pdf download – Dentistry — Test methods for dental unit waterline biofilm treatment.
7.2.2 Pretreatment of the test apparatuses All test apparatuses shall be pretreated according to the instructions of the manufacturer of the dental unit prior to testing if specified. EXAMPLE If the instructions of the manufacturer indicate that a specified disinfection procedure is to be performed after the dental unit is installed and prior to use, the specified disinfection procedure shall be performed prior to performing this test method. 7.2.3 Concurrent exposure to inoculated test water and the treatment method for biofilm prevention or inhibition For the test group, inoculated test water as specified in 5.3 shall be supplied to the dental units or surrogate dental unit water systems in conjunction with the treatment method per the manufacturer’s instructions. For the control group, inoculated test water shall be supplied to the dental units or surrogate dental unit water systems without the treatment method. All dental units or surrogate dental unit water systems are to be operated according to 6.2. Inoculated test water shall be prepared daily within two hours of initiating the automated daily flow program. Microbiological sampling and testing of the inoculated test water supplied to the test apparatuses shall be performed in accordance with 8.1 before supplying to the test apparatuses at least once per week. 7.2.4 Microbiological sampling and testing To determine the effectiveness of the treatment method, microbiological sampling and testing of all dental units or surrogate dental unit water systems in both the test group and the control group shall be performed in accordance with 8.1 and 8.2. Sampling and testing for total viable counts according to 8.1 shall be conducted on all dental units or surrogate dental unit water systems at least once per week throughout the duration of the test. Sterilized test water (without inoculum) shall be supplied to the test apparatuses when samples for microbiological testing are collected.
7.2.5 Test duration Testing according to 7.2.3 and 7.2.4 shall continue until all of the following criteria have been met: — at least four weeks of testing have occurred; — a total viable count of at least 10 4 CFU/ml is measured in the effluent procedural water of all test apparatuses for the control group when sterilized test water is temporarily supplied to the test apparatuses instead of inoculated test water, flushing sterilized test water through the waterlines and waiting 5 mins before collecting the sample and then resuming normal operation with inoculated test water; — the presence of biofilm is confirmed in all dental units or surrogate dental unit water systems in the control group according to 8.2 with all of the tubing samples in the control group classified as exhibiting either semiconfluent coverage or substantial, confluent coverage by microorganisms and/or biofilm.