Dental Instrument Sterilization PDF

Decontamination of Instruments and Equipments Decontamination process: - It is the physical or chemical process that makes an object that may be contaminated with harmful microbes safe for further handling Composed of the into the following A. Cleaning: Physical removal (including prion) but no...

Decontamination of Instruments and Equipments Decontamination process: - It is the physical or chemical process that makes an object that may be contaminated with harmful microbes safe for further handling Composed of the into the following A. Cleaning: Physical removal (including prion) but not necessary killing of microorganisms B. Disinfection: Reduction of the microbial load to a level that makes the disinfected object safe to handle - High level - Intermediate - Low level C. Sterilization: Killing and removal of all microorganisms including bacterial spores Levels of Disinfection 1. High Level: Kills all microorganisms (including TB) except bacterial spores. 2. Intermediate Level: Destroys vegetative bacteria, most viruses, inactivate mycobacterium tuberculosis, but doesn't kill bacterial spores 3. Low Level: Least e ective, destroys most vegetative bacteria, some viruses, and some fungi but not TB and bacterial spores Instruments categorization - According to the Centers for Disease Control, dental instruments are classi ed into three categories depending on the risk of transmitting infection: 1. Critical instruments 2. Semi-critical instruments 3. Non-critical instruments 1. Critical instruments: - Instruments used to penetrate soft tissue or bone, or enter into or contact the bloodstream or other normally sterile tissues. - Examples: forceps, scalpels, bone chisels, scalers and surgical burs. - They should be sterilized after each use. 2. Semi-critical instruments: - Instruments that do not penetrate soft tissues or bone but contact mucous membranes or non- intact skin - Examples: mirrors, reusable impression trays and amalgam condensers - These devices also should be sterilized after each use. - if some instruments or devices where heat sensitive high-level disinfection is appropriate 3. Non-critical instruments: - Instruments that come into contact only with intact skin. - Examples: External components of x-ray heads, blood pressure cu s and pulse oximeters - They may be reprocessed between patients by intermediate-level or low-level disinfection. 1 of 7 ff ff fi  Sterilization process - The workspace layout should facilitate a natural work ow that encompasses all of the important steps in the sterilization process. - Work ow direction is from dirty to clean - Oppositely the air ow direction should always be from clean to dirty - Ideally the Sterilization department or (CSSD) consists of a 3 rooms design, but depending on the work load and space it might be a two rooms or a single room design Central sterilization store department (CSSD) - The work environments for processing equipment should be separated into 3 key areas: - Decontamination/Dirty area. - Packaging/Clean area. - Sterile Store/sterile area. Decontamination cycle - Dirty – Red - Clean- Blue - Sterile- Green Decontamination room 1. Receiving transported soiled instruments from the clinics 2. Sorting 3. Cleaning: A. Manual B. Automated: (I. Ultrasonic machines or II. Washer- disinfector) Decontamination room ( more details) 1. Receiving transported soiled instruments from the clinics: - The contaminated items should be handled only while wearing the PPE - Rigid, durable, leak proof containers that have a tight tting lid which are easy to clean and disinfect is used to transport dirty instruments —> labeled - Trolleys or closed carts can be used 2. Sorting: Received instruments and handpieces are arranged to be cleaned either using the manual method or automated method. - Instruments with hinges are opened to facilitates cleaning - Instruments and equipment that consist of more than one component should be dismantled to allow each part to be adequately cleaned. 3. Cleaning: - Reduces the bacterial load —> reducing the risk of transmission of infectious agents. - Automated cleaning is preferred over manual cleaning —> decrease human error and risk 2 of 7 fl fl fl fi  A. MANUAL CLEANING - Procedure: - Full PPE using domestic household glove - Two sinks are required - Rinse the instruments in cold or lukewarm water then completely immersed in water and non- foaming detergent (sink 1). - Using the special long handled, nylon bristles brush, brushing in one direction, totally immersed in water to prevent splatter and splash. - Rinse the instruments in a separate sink under hot water (sink 2). - Clean instruments with lumens by water spray gun. - Dry the instrument using disposable lint free towels. Disadvantages: - Great risk of inoculation injury. - Di cult to validate as it is not possible to ensure that it is carried out e ectively each time. B. I. (ULTRASONIC CLEANER) - Procedure: - Rinse o blood or other debris on the instruments under running water, if necessary. - Fill the ultrasonic bath with water and enzymatic detergent. - Leave the machine to work for a little while for degassing, before placing instruments. - Place the instruments in suspended tray. Don‟t overlap them. - Use the beakers for placing burs and root canal instruments. - Only operate with the lid on to avoid aerosol contamination. - Remove the instruments only after the full clean cycle. - Rinse thoroughly by immersing in clean water. - Empty, clean and dry the bath at the end of the day. How does it clean the instruments? - It uses cavitation bubbles induced by high frequency pressure (sound) waves to agitate a liquid (enzymatic solution) - The agitation produces high forces on contaminants adhering to substrates causing their disintegration - 10 ml/L tap or distilled water Water temp not above 45°C Validation test: - Aluminum foil test should be carried out weekly. Procedure: - Turn the machine for 5 min. - Aluminum strips of 5 cm2 are suspended in the bath for 15 seconds. - Inspect the foil. The edges of the foil should be serrated with pitting and/or perforation of centre of the strip. Record the test results in the machine log book - Get the bath regularly serviced and tested. WASHER‐DISINFECTOR Two types are available: 1. Bench Top 2. Free stand (Single & double door) 3 of 7 ffi ff ff  B. II. (WASHER‐DISINFECTOR) Procedure: - Arrange instruments in the basket without overloading or overlapping. - Small and ne instruments like Burs and Root canal instruments should be placed only in the basket with small holes (meshed tray). - Opening instrument hinges and joints fully. - Attaching instruments requiring irrigation to the irrigation system correctly, ensuring lters are in place if required (hand pieces). - Heavy instruments should be placed in the lower shelf while the lighter instruments go into the top shelf Instructions for care - Clean the washer from outside with a clean damp cloth or wet wipes. - Always check spray nozzles for any block and the arms for free movement before operating - Don‟t overload the washer Validation test : - Done weekly test by using Load Check Procedure: - Place one Load Check indicator in the holder ensuring it is centrally placed and not protruding from either side. - Place a device (holder with indicator) into each tray or basket. - After running a complete cycle, inspect the indicator for evidence of soil by placing the plastic lm against a white background. - If evidence of soil remains on the indicator, cleaning of the load should be considered inadequate and the engineering department should be called for maintenance. 4 of 7 fi fi fi  Packing Room 1. Inspection 2. Packing 3. Place in the Sterilizer: 1. Bench top autoclave 2. Free standing (single or double doors) steriliser 1. Inspection : - Instrument received after the cleaning process through the dispatched window or through the double door of the washer- disinfector is inspected - A magnifying glass with task lighting is recommended. - If there is residual contamination , the instruments should be rejected and send back to the decontamination room for re‐cleaning. - Faulty instruments should be taken out of use. If it will be sent for repair, it should be decontaminated fully. 2. Packing: - Ensure dryness of the instruments before packing using lent free towel - Hinged instruments like hemostats, extraction forceps, scissors etc. should be packed with them open to permit the steam penetration. - Di erent pouches reel sizes are available - Choose a reel size suitable to the instrument getting packed - Cut with the cutter then place the instrument in the pouches then seal it using sealing machine Packing is done by: - Cassettes - paper wrapping - Laminated lm pouches—>Primary packaging for individual instruments or small instrument sets. - Paper bags BENCH TOP AUTOCLAVE A. Type N (non-vacuum): Passive displacement of air with steam. Designed for unwrapped, non‐ hollow and non‐air retentive instruments. B. Type B (vacuum):designed for hollow, air retentive and packaged loads. C. Type S: designed to reprocess speci c loads (determined by the manufacturer). Advantages of Type B Autoclaves Strict veri cation of sterility. Better penetration of steam through vacuum and therefore more e ective sterilization. Can sterilize instruments with a lumen. Can place instruments in poaches or bags before sterilization. Less corrosion of the instruments so they last longer. Instruments are dry at the end of the cycle. Conforms with the current “gold” standard for autoclaves. AUTOCLAVING - Saturated steam under pressure and heat based sterilization is preferable in dentistry, - With a temperature of 134‐137°C with a holding time of 3‐3.5 minutes and a pressure of 2‐3 Pascal. 5 of 7 ff fi fi fi ff  Arranging the sealed packages for sterilization: - Steam should contact all surfaces of the instrument for e ective sterilization. Therefore, avoid overloading of the autoclave chamber. - Sterilization pouches should be put upright in a grid basket or container and not too tight together, such that a hand can slide in between them. - Pouches should be positioned standing on edge, paper to paper and plastic to plastic, to facilitate circulation of the steam around items AUTOCLAVES Validation tests: - Chemical test: This test should be carried out daily using the available methods, such as the chemical strips, Bowie‐Dick type test, pack & Helix test. - Biological test: done at least once weekly or more often if the practice demands it, using the appropriate spore test. - Physical test: monitoring physical indicators like time, temperature and pressure. - Leak test: The Leak test is intended to check that air will not leak into the sterilizer during periods of vacuum, at a rate greater than speci ed by the manufacturer. Chemical tests: A. Bowie‐Dick type test: - Tests vacuum e ectiveness and air removal - Performed daily - Done in an empty sterilizer - Placed on the bottom near the drain B. Biological Indicators: - Proper functioning of sterilization cycles should be veri ed by periodic use of spore tests called biologic indicators. - Incubation periods can range from 24 hours, 3 hours and the new rapid readout biological indicator show result in 1 hour - It should be place with a load Sterile store - The storage area should be as far from the dental chair as reasonably practical - Air ow should be from clean to dirty areas. - The instruments stored should be away from direct sunlight, water and in a secure, dry and cool environment. - All sterile and clean instruments should be stored in closed cabinets preferably. - The principle of „ rst-in, rst-out‟ should be used for inventory management. - Each instrument pack should be labelled with the date (decontamination and expiry dates) and the name of the technician responsible for cleaning and packing the instrument. - Sterile goods are distributed back to the clinics by covered trays on trolleys 6 of 7 fl ff fi fi fi fi ff Sterilizing Dental Hand‐pieces A. Cleaning: - Either by washer‐ disinfector - Or manually using a soft nylon brush and use water gun for ushing and air gun for drying after cleaning. - It should never be soak in detergent or disinfectant solution - It should never be placed in ultrasonic cleaner B. Lubrication: - The manufacturer‟s instructions for lubrication should be followed. C. Packing - After drying with lent free towels and the removal of the excess oil pack them in pouches. D. Sterilization Recommendations - The sterilizer should be allowed to run through the FULL CYCLE. - Allow packages to dry in the sterilizer before they are handled to avoid contamination. - Do not disinfect when you can sterilize. - Heat sensitive instruments should be processed using a high level disinfection. - Single use disposable instruments are preferable. 7 of 7 fl  INFECTION CONTROL PROCEDURES IN THE DENTAL CLINIC Infectious diseases:Illnesses caused by microorganism (such as bacteria, viruses, and fungi) that enter the body, multiply, and can cause an infection. - For an infection to be transmitted, a number of elements must be present, referred to as the “chain of infection”. - Infection control polices involves breaking one or more links in the chain Modes of transition: - Direct contact - Blood borne: - Person to person - Infected blood directly enters the - Through body uids susceptible host blood - Through needlestick or other open wounds - Droplet - infected droplets from coughing, sneezing or talking is: - nhaled or entered the mucous membranes of the face - Settled on a surface that being touched by the host then touching their face (mouth, eyes, nose). - AIRBORNE - pathogens smaller than ve microns in size remain suspended in the air long after the infected person has left the area - Susceptible host enter the space and get infected - VECTOR - Through insects bites - eas, ticks, and mosquitos 1 of 9 fl fl fi  Standard Precautions ̈ De nition: They are the minimum infection prevention practices that apply to all patient care, regardless of suspected or con rmed infection status of the patient, in any setting where health care is delivered. STANDARD PRECAUTIONS 1. VACCINATIONS 2. HAND HYGIENE 3. USE OF PERSONAL PROTECTIVE EQUIPMENT (PPE) 4. RESPIRATORY HYGIENE/COUGH ETIQUETTE 5. ENVIRONMENTAL SURFACE CLEANING AND DISINFECTION 6. MANAGEMENT OF AEROSOLS AND SALIVA/BLOOD SPLATTER 7. PROPER HANDLING AND DISPOSAL OF SHARPS 8. PROPER WATER LINE DELIVERY 9. PROPER WASTE MANAGEMENT 10. USE STERILE INSTRUMENTS AND DEVICES. STANDARD PRECAUTIONS 1. Vaccinations: All those involved in clinical procedures must be vaccinated against the following diseases: - Hepatitis B - Tetanus / Diphtheria / Pertussis - Measles, Mumps, Rubella (MMR) - In uenza - Varicella - SARS-CoV-2 Disease (COVID-19) Hepatitis B Vaccination: - Primary course of vaccine includes 3 doses. - Antibody titers should be checked 1 to 4 months after completion of the primary course 2. Hand Hygiene - CDC supports that proper hand hygiene before and after contact with patients is the one most important measure for preventing the spread of infection. - Transient microorganisms on the hand are acquired by contact with patients, instruments and environment —> pose the greatest risk of cross infection. - DHCP should practice strict adherence to hand hygiene, including before and after all patient contact, contact with potentially infectious material, and before putting on and especially after removing personal protective equipment (PPE). The recognized types of hand hygiene in infection control practice are: 2 of 9 fl fi fi Hand hygiene: - Antiseptic hand wash: 4% Chlorohexidine gluconate & Detergent - Antiseptic hand rub: 0.5% Chlorohexidine gluconate & 70% ethanol - Fingernails should be kept clean, short and smooth. - False nails and nail polish should not be used. - Rings, bracelets and wrist watches should not be worn during clinical procedures. 3.Personal Protective Equipment (PPE) PPE include: - Gloves - Surgery clothing - Eye protection - Head cap - Face Mask - Shoe cover A. Gloves 1. Non-sterile gloves 3. Domestic household gloves 2. Sterile gloves Over gloves: - Worn over contaminated non-sterile gloves - to prevent contamination of clean objects handled during treatment. - Never be used alone. 1. Non-sterile gloves ¤ It protect against contact with blood, saliva and other body uids ¤ Should be worn for all clinical procedures and should be changed after every patient. ¤ Glove material – (vinyl, latex, nitrile) or (non-powdered) ¤ Single use 2. Sterile medical gloves: should be used for surgical procedures. 3. Domestic household gloves: ¤ Protection against burns or skin irritation ¤ Reusable ¤ Handling disinfecting agents while cleaning instruments in sterilization room , radiographic process 3 of 9 fl  B. Eye Protection - protection against foreign bodies, splatter and aerosols - Must be optically clear, anti-fog, distortion free, close tting, and shielded at the sides. - If reusable , decontaminate them according to the manufacturer’s instructions. - Patients should be provided with glasses to protect their eyes against possible injury and the operating light. C. Face Mask - They stop splatter from contaminating the face. - Single use and must be changed after every patient, not pulled down or re-used. - Should be handled by touching the periphery only - Should not contact the mouth while being worn as the moisture generated will decrease the mask ltration e ciency. - If your mask becomes damp during use, discard the mask as soon as possible, and put on a fresh mask. D. Surgery Clothing - Machine-washing with a suitable detergent at a minimum temperature of 60°C will reduce potential microbial contamination. E. Gown: 1. Disposable Gown: - Worn to protect skin and prevent soiling of clothing during procedures. - Should be changed between patients specially if visibly soiled. - Should be removed before leaving the work area. - It should be uid resistant 2. Sterile Gown: - Sterile gown that have a high neck & long sleeves made of material that can be sterilized - Should be used in theater, and during surgical procedures in the clinic. 4 of 9 fi fl ffi fi 4. Respiratory hygiene/Cough etiquette ̈ The following measures to contain respiratory secretions are recommended for all individuals with signs and symptoms of a respiratory infection. - Cover your mouth and nose with a tissue when coughing or sneezing; - Dispose of the tissue after use in the nearest waste receptacle ; - Perform hand hygiene (e.g., hand washing with antimicrobial soap and water or alcohol-based hand rub) after having contact with respiratory secretions and contaminated objects/materials. - Incase of no tissue available sneeze in your elbow 5. Environmental surface disinfection Dental Clinic Design ¤ Adequate ventilation. ¤ Impervious and non-slip ooring. ¤ Minimum Temperature of 16 °C. ¤ Minimum 11 cubic meters of space per worker. ¤ Minimum 9 square meters per surgery. Environmental Surfaces Decontamination ¤ Should be done at the beginning, in between patients and at the end of the clinical sessions ¤ All work surfaces, should be thoroughly cleaned. ¤ Surfaces can be cleaned using ready made disinfection wipes or a fresh prepared solution of disinfection tablets and gauze. ¤ Active agents may include: - Chlorine and chlorine compounds at a concentration of 100– 5000 ppm free chlorine - Quaternary ammonium compounds - Hydrogen Peroxide ¤ Alcohol, although e ective against viruses, binds to blood proteins and stainless steel; and should be avoided. 5 of 9 ff fl  6. Aerosols and Saliva/Blood Splatter is minimized by: ¤ Good surgery ventilation and e cient high-volume aspirators. ¤ High-volume aspirators turned on prior to the hand piece. ¤ Aspirators and tubing should be cleaned and disinfected regularly and ushed thoroughly at the end of each session with their recommended surfactant/detergent. ¤ Use of rubber dam 7. Handling and disposal of sharps - Inoculation Injuries is the most common route for transmission of blood borne viral infections in dentistry and must be dealt with promptly and correctly. - Sharps are discarded into an approved container —> sharp box - It should not be lled more than two-thirds. - All sta are immunized against Hepatitis B and their response to the vaccine checked In case of needle/sharp injury: First aid measures: Encourage wound to bleed Do not scrub the area Wash under running water Cover with water proof dressing Inform the in charge sister and ll the incident record form General notes: - According to the CDC, The estimated risks for infection after a needle stick or cut exposure to HCV infected blood is approximately 1.8% - In dentistry the risk of acquiring HIV infection following an inoculation injury is 0.3% - If the patient is infected by HIV, post exposure prophylaxis (PEP) should be commenced as soon as possible after the incident and ideally within an hour. - PEP used for (4 weeks) with anti-retroviral drugs to reduce the risk of infection even further 8. Water lines - Dental unit water delivery system: - The majority of dental unites will harbor bio lms that act as a potential source of infection - Main water supply should be protected from contaminated back ow by: - Using distilled water in bottled water system unites which should be emptied at the end of the shift and cleaned weekly using a chlorine solution. - Anti-retraction systems. - Regular monitoring by Culture test. - to ensure that bacterial counts are < 500 CFU/ml (CDC) *Note: Hand-piece, ultrasonic scalers, air/water syringes should be ushed for at least 20 seconds between patients. 6 of 9 ff fi fi ffi fi fl fl fl Dental unit water delivery system: - Heat sterilized or disposable air/water syringe tips and vacuum tips must be used. - Sterile irrigating solutions must be used as an irrigate during surgical procedures. - All vacuum lines must be ushed by appropriate antiseptic solution after every patient procedure to prevent drying of blood and debris in the lines: - Using chlorine solution (0.5 presept tablet to 5 litters of water) in units without amalgam separator - Or use other solutions as Orotol plus or Aspirmatic. Sterile Irrigation uids (Normal Saline) - Used as needed for up to 24 hours before discarding. - Discard any unused irrigation uid immediately after initial use. 9. Waste Management: Types of waste: A. Hazardous waste B. Non Hazardous waste A. Non-Hazardous waste (non-infectious): - General waste(paper, cardboard, packaging material) - Do not require special treatment for disposal. - Blue bag B. Hazardous waste: - Clinical waste (contaminated swabs, gloves, etc.): - Should collected in sacks, no more than three quarter full. - Be labelled. - Tied at neck (not knotted). - Sharps (needles, scalpel blades): - Must be discarded in puncture proof containers. - Must be located as close as possible to the point of use for immediate disposal. - Labelled. - No more than two-third full. - Blood spillages/ bodily uids: - The dental health care worker dealing with the spillage must wear PPE - Cover the spillage with freshly prepared sodium hypochlorite with 10,000 ppm chlorine - (7X(2.5g tablets of actichlor) in 1 liter of water) - Allow at least 5 min to elapse - Wipe with disinfectant saturated disposal cloth & disposing of the towels as clinical waste. - Good ventilation is essential. 10. Sterile instruments and devices: - Instruments used should be sterile and opened correctly - Instruments should not be used for more than one patient before sterilization 7 of 9 fl fl fl fl  Other important matters: 1. INSTRUMENTS MANAGEMENT - The instruments used for cementation or restoration placement should be wiped clean using a sterile, water moistened gauze BEFORE it dries o. - Blood or bone particles should be wiped from instrument before they dry as well 2. MINOR SURGERY SET UP - The environment should replicate that of an operating theatre. - The use of sterile aseptic technique. - The surgeon and assistant follow hand hygiene scrubbing-up procedure - They should don theatre gowns and sterile surgical gloves. - Direct air ow on to the sterile area should be avoided - A sterile eld is created with draping of the patient and surgical eld. - Cables and tubes that enter the sterile eld must be covered in sterile tubing covers 3. DENTAL RADIOGRAPHS - Gloves should be worn when taking radiographs - Radiography equipment (radiograph tube head and control panel) should be protected with surface barriers that are changed after each patient - Digital radiography sensors should be wiped with compatible disinfectant wipes then be barrier protected to reduce gross contamination during use. 4. DECONTAMINATION OF IMPRESSIONS, PROSTHESIS AND APPLIANCES - Make sure devices have been cleaned and disinfected prior to dispatch to the laboratory. - Devices/impressions should be labelled if disinfected. - Rinsed under running water to remove saliva, blood and debris; until it is visibly clean. - Decontamination by either dipping (alginate) or immersion ( PVS) in disinfectant. - If an appliance or prosthesis is grossly contaminated, it should be cleaned in an ultrasonic bath containing detergent and then rinsed. INFECTION CONTROL Options of materials include: - Cidex OPA - MD 520 - Descoprint 5. DECONTAMINATION OF DENTAL SHADE GUIDE - Since they are heat sensitive: - Wash with soap and water - Disinfect according to manufacturer’s instructions 6. DECONTAMINATION OF MIRRORS - The mirror surfaces can be cleaned with soap and water - Dry the mirrors with a soft cloth or micro ber towel - Be sure to completely dry the mirrors before placing them in an autoclave to prevent mineral spots on the mirror. - Autoclaving is the recommended method of sterilization - 121°C (249.8°F) for 20+ minutes - 134°C (273.2°F) for 10+ minutes - it is important to wrap the mirror in gauze or a paper towel to prevent the plastic from leaving an imprint on the mirror 8 of 9 fi fl fi fi ff fi 7. HANDLING OF BIOPSY - Each biopsy specimen should be put in a sturdy container with a secure lid to prevent leakage during transport. - If the outside of the container is visibly contaminated, it should be cleaned and disinfected or placed in an impervious bag 9. LAUNDRY - Contaminated towels and linen transported away from the clinic for laundering should be placed in appropriate plastic bags to prevent leakage, with appropriate color code (yellow bags or biohazard label). 9. GUTTA PERCHA POINTS DISINFECTION - Immediately prior to use, gutta percha points can be disinfected by a one-minute immersion in 5.25% sodium hypochlorite solution. 10. NO EATING, DRINKING, SMOKING 9 of 9