Infection Control: Sterilization Techniques (BchD1 2020)

Infection Control Part III Instrument preparation and Sterilization.  Work flow pattern Receiving Sorting Dispose Holding solution (not always) Cleaning Packaging Sterilize Storage Sorting of contaminated instruments Note the thick non- puncture gloves...

Infection Control Part III Instrument preparation and Sterilization.  Work flow pattern Receiving Sorting Dispose Holding solution (not always) Cleaning Packaging Sterilize Storage Sorting of contaminated instruments Note the thick non- puncture gloves Full PPE’s worn during instrument processing  Holding solution ONLY IF Instruments are not cleaned immediately place in holding solution Prevent drying of blood and debris Enzymatic solution to dissolve organic debris SPAULDING’S CLASSIFICATION Critical instruments: Instruments that penetrate soft tissue or bone. E.g. forceps, scalpels, scalers, burs Semi-critical: touch mucous membranes or non intact skin. Mouth mirror, High Volume Suction, amalgam condensers Non-critical: Intact skin contact: X-ray tubes, lead apron,  Methods of cleaning of instruments Before sterilization clean all instruments 1 )Hand scrubbing 2) Ultrasonic cleaning/ 3)Instrument washing machines/ Thermal washers Hand scrubbing of instruments Not approved by CDC However if no other option follow the following guidelines (CDC) – Wear full PPE – Do not clean more than 1 or 2 instruments at a time – Use a long handled brushes to clean instruments – Allow to air dry (never rub or roll in a towel) risk of injuries Ultrasonic bath cleaning  Ultrasonic cleaning of instruments Action is to loosen and remove debris on instruments Advantage – Reduce risk of injuries while cleaning – No aerosol production Always wear PPE when working with the ultrasonic cleaner Forceps to place and remove instruments into liquid  Ultrasonic solutions The liquid itself has an Enzymatic activity – Prevents amount of MO increasing Never use disinfectants in ultrasonic cleaner (fixate blood, saliva and debris) Solutions and basis of Ultrasonic cleaner is highly contaminated- clean and replace liquid daily  Ultrasonic cleaning (cont.) Ultrasonic cleaner produces sound waves Sound waves travel from base plate to liquid Bubbles (cavitations) form in disinfectant liquid Bubbles burst by implosion (burst inward) Mechanical action of implosion remove and chemical action reduce debris 5-15 minutes (depend on how much debris) Automated washers to clean instruments Automated washer + disinfectant + HOT water = THERMAL DISINFECTING Instruments NOT STERILE at end of cycle Automated washer Preparation and packaging of instruments after cleaning Inspect instruments for any debri or blood If visible debri, start process again and clean Inspect all hinged instruments such as scissors and forceps Assemble trays or instrument holders Wrap & seal CLEANED INSTRUMENTS ARE NOT STERILE  Why Instrument Packaging? Prevent contamination after sterilization: 1)via aerosols and dust in the atmosphere 2)Handling and contact with non-sterile surfaces  Sterilization Methods – Steam autoclave – Dry heat – Chemical vapor – Ethylene Oxide sterilization  Autoclaving (cont.) Advantages: Short cycle 15-20 minutes Steam penetration through packaging to instruments are good with approved material Disadvantages: Damage some plastic and rubber items Requires use of distilled water May rust metal instruments and burs Cannot use closed containers Autoclave Statim Autoclave  Dry heat oven Heated air Heat transferred to instruments & equipment 160-190 degrees Celsius for 1- 2 hours  Chemical vapour Very similar to autoclaving Chemicals instead of water Alcohol, formaldehyde, ketone ,acetone and water –heated Safety sheet data- chemicals toxic Advantages: Do not rust or dull instruments Short cycle Instruments dry after cycle Disadvantages: Adequate ventilation due to toxic fumes Odour  Ethylene Oxide sterilization Function at low temperature Plastics, rubber, linen 4-12 hour cycle 16 hours post-sterilization aeration Used at larger institutions /hospitals Ethylene oxide cartridges Ethylene Oxide sterilization equipment Packaging materials for sterilization  Mistakes made during sterilization Using tap water in autoclave Not cleaning the sterilizer Interrupting the cycle- Not monitoring the process  Chemical liquid sterilization Less than 10 hours immersion will not be accepted as sterilization but only as disinfection Why? Cannot monitor the efficacy of the sterilization process Specific procedures should be followed-  Cold sterilization Water should be distilled water to mix solution Instruments should be washed and dried before placing into the solution. Why- water on instruments may dilute the solution Instruments should be placed with a forceps into the chemical Should remain in chemical for 10-12 hours Instruments once completely submerge should only be removed after 10-12 hours with a forceps and Rinsed with distilled water  Sterilizing monitoring Quality assurance..are the instruments sterile after the sterilization process – Physical monitoring – Chemical monitoring – Biological monitoring  Physical monitoring Monitoring the gauges and readings on the equipment – Temperature – Pressure – Exposure time This does NOT guarantee sterilization Usually first indication of incomplete sterilization Chemical monitoring Chemical monitoring  Chemical monitoring External and internal Use of heat sensitive chemicals that changes color exposed to certain conditions e.g. temperature Purpose to indicate that instruments have been exposed for a specific time to peak temperature (does not guarantee sterility of instruments)  Biological indicators Spore testing Only way to determine if instruments are sterile. Vials that contain harmless bacterial spores Highly heat resistant 3 BI per cycle (2 inside , 1 outside) All BI cultured post exposure to sterilization Positive reading (failed sterilization cycle) – review sterilization process and or check equipment Negative reading (successful cycle) BIOLOGICAL SPORE TEST  Dental Laboratory Dental prostheses, appliances, and items used in their fabrication (e.g., impressions,) are a potential source for cross-contamination and should be handled in a manner that prevents exposure of OHCW patients, or the office environment to infectious agents.  Dental laboratory asepsis Ensure that impressions are disinfected prior sending to dental lab Provide a written note informing lab staff of method of disinfection Trimming of models- use PPE such as eyewear and masks Appliances and prostheses delivered to the patient should be free of contamination and therefore disinfected  The end Questions? Email: [email protected]