Dental Tribune United Kingdom Edition

temperature. The tempera- ture should then remain con- stant, within specified tem- perature band, throughout the whole sterilisation phase (plateau/holding time). In the post-treatment phase, either the steam or the re-vaporised condensed water are removed by vacuum to guarantee the goods to be dried rapidly. Virtually all air must be evacuated during pre-treat- ment (pre-vacuum phase) so that the saturated steam can affect the goods during the sterilising phase. If present, trapped air pockets in the goods prevent steam penetra- tion during sterilisation of po- rous material such as textiles and hollow items. Steam sterilisation of hol- low instruments (with long, narrow lumina) and porous objects always requires sev- eral (at least three (3)) pre- vacuum pulses to a defined, pre-set, vacuum level. Fewer instruments, better control The type of equipment and the type of procedures in use at the clinic will to a very high extent determine the safety margin of decontamination. A very important issue, that is often foreseen, is the logis- tics of instruments. A com- mon problem in many dental offices is an overload of in- struments, which will con- tribute to a more difficult and time demanding procedure to keep track of all instruments and to make sure that storage and sterile as well as packag- ing/wrapping conditions are maintained. An item heavily loaded with microbiological mate- rial will be more difficult to sterilise than one lightly con- taminated. The most effective stage of any decontamination procedure is thorough clean- ing and this should accom- pany or precede all disinfec- tion procedures. The effect of cleaning, disinfection and sterilisation is affected by the design of the cassettes/ trays being used. Shadow ef- fects may easily ensue from the use of solid cassettes so that instruments are not be- ing properly cleaned, neither in washer disinfectors nor in ultrasonic bath. Fastened but free Instruments should be free and fastened on trays so that ultrasonic waves, water jets and steam can reach every part to clean and inactivate efficiently during the whole procedure of disinfection and sterilisation. Even if fastened the instruments must be free and have no contact points/ areas with the locking device. An area of contact will not be properly cleaned and disin- fected. Two different metals will cause corrosion Corrosion is a common prob- lem. When in the same fluid, instruments and other articles made of different metals may corrode, and corrosion de- stroys sharp and delicate in- struments. Corrosion pits will also make the surface rough, which increases the possi- bilities of microorganisms to attach themselves to the in- struments. Mixing different types of metal in a liquid solu- tion will result in an electro- chemical cell and cause cor- rosion – this is often the case during cleaning, ultrasonic bath and washer disinfectors when using aluminium trays and instruments in stainless steel or when cleaning carbon burs and burs made of stain- less steel in the same liquid container. However, in daily dentistry we call this rust and blame the manufacturer for poor material – the actual problem is clinical routines! Don’t make it too heavy Metallic weight is another de- cisive in decontamination and sterilisation. The heat energy from the ultrasonic waves in the ultrasonic bath and/or the water in a dishwasher or washer disinfector as well as the saturated steam from the steriliser shall be concentrat- ed on the instruments that are to be processed. A load that is too heavy lessens the effect of disinfection and sterilisation. The steam sterilisers that are most frequently used in den- tal clinics are adapted to loads of 4.0–4.5 kilos. A stainless steel tray with instruments for endodontic procedures has a weight of approximately 1.5–1.7 kilos! This will be an important issue to consider when using trays made out Prices you can smile about Offers available from 1st May to 29th June 2012 Low Prices.. ..Every Day! FREEHD CAMCORDER ON ORDERS OVER £199* Phone for full offer sheet 5 Star Reviews! 720p HD Video Recording Mini HDMI Port Digital Zoom Rechargable www.topdental.org *Selected products from the current offer sheet. Full terms and conditions available on request. 0800 132 373 TGI INTRO KIT -refill packs also available ONLY £47.50 Handpiece Oil Admix Phase ll Alloy Capsules 50 1-SPILL ONLY £19.48 500ml FROM ONLY £5.99 Dentatemp Plus™ ONLY £32.50 Self-Seal Sterilisation Pouches BUY 2 GET 1 FREE! ON ALL SIZES FROM ONLY £3.27for 200 Aspirator cleaner & disinfectant i-Suc TM 2.5L BOTTLE, CONCENTRATE MAKES 125 LITRES ONLY £12.99 Disposable 3 in 1 Syringe Tips 250 TIPS SAVE 50% ONLY £19.45 ASK FOR A FREE SAMPLE PACK Spectrum Tips™ Dental tribune_May12_2.indd 1 17/05/2012 11:59 17Infection Control TribuneJune 4-10, 2012United Kingdom Edition 17 page 18DT ß