Asepsis, antisepsis, sterilization.

Asepsis, antisepsis, sterilization.

I – Introduction: 

• Tooth extraction is a surgical procedure in its own right and must be performed under the same conditions as those required for minor surgery procedures.
• The different links in the asepsis-antisepsis chain must be respected.

– Hand washing (before and after)

– Disinfection of the area where we work

– Use of sterile instruments. 

• Hygiene regulations are constantly evolving. In addition to well-established hygiene measures (hand washing, disinfection of the operating field, use of sterile and single-use equipment), more elaborate processes have been put in place to combat new forms of contamination that have become even stricter since the global Covid-19 pandemic.

2 – Definitions: 

• 1 – Sterilization: method for destroying various microorganisms (bacteria, viruses, fungi, parasites) present on the surface or in the thickness of any object.
• 2 – Disinfection: temporary destruction of pathogenic germs likely to cause infections and which are present on equipment or a surface. (Patient’s environment: linen, bedding, medical instruments, premises, furniture. Chemical means: bleach, formaldehyde or physical means: dry or humid heat, ionizing radiation. 
• 3 – Asepsis: absence of microbial germs likely to cause infection. This is the set of methods preserving from microbial contamination everything that is in contact with the surgical wound.
• Set of measures designed to prevent any exogenous contribution of micro-organisms or viruses to living tissues or inert environments. 
• Asepsis combines disinfection of the environment and air, rigorous technique, the use of sterile equipment and antiseptics. 
• 4 – Antisepsis: set of processes used to eliminate the risks of surface microbial infection (skin, mucous membrane). It is one of the foundations of medical hygiene. (chemical products in external applications: Dakin’s solution, iodine tincture, alcohol, etc.) 
• “Operation with a temporary result allowing, at the level of living tissues, within the limits of their tolerance, to eliminate or kill microorganisms and/or to inactivate viruses depending on the objectives set. The result of the operation is limited to the microorganisms present at the time of the operation.” 
• 5. Contagion: This is the act of transmitting a disease in a way that:
• direct (from individual to individual) or  
• indirect [through a contaminated animal or object] or, 
• most often, mixed. 

3 – The risks: 

• In the dental office, all bacterial, viral or mycotic diseases can be contracted or transmitted.
• The most feared are:

• Tuberculosis;
• Syphilis;
• Viral hepatitis (B and C);
• Herpes and 
• AIDS and
• Covid-19 since December 2019 
• 3.1. Microbial reservoirs
• Man:
• The contaminations involve patients, healthcare and service staff, and the prosthesis laboratory.
• Surfaces and materials:
• In the operating area and the pre-sterilization area, biological fluids and waste from healthcare activities can contaminate surfaces and equipment. Impressions, prostheses and various works intended for the laboratory also represent a potential contaminant.
• It should be added that ” the more an object is handled, the more it is contaminated and the more it becomes contaminating .”
• 3.2. Transmission routes 
• Microorganisms can be transmitted directly by contact or indirectly through materials or the environment (air, water, other surfaces);
•  Two modes of transmission are described:

– Airborne contamination: microorganisms are carried by dust, saliva droplets (coughing, sneezing, etc.), aerosol projections (instrumentation)

– Hand-borne contamination: transmission occurs through the hands.

• 3.3. The main sources of contamination: 

– Hands,

– The instruments,

– Clothes,

– The furniture,

– The spittoon,

– The aspiration,

– Ambient air.

• The danger comes from the asymptomatic patient who is unaware of it or who hides his illness.
• For the known patient, preventive measures must be taken. 

4 – Hygiene plan: 

– The hygiene plan must be practical, simple and effective.

– Epidemiological data clearly indicate that the notion of “population at risk” is largely outdated. 

– The rule of standard precautions is to consider every patient as potentially infectious.

• Among the factors of susceptibility to infectious risk we can cite:

• immune deficiencies;

• damage to the skin-mucous membrane barrier 

• the state of the commensal microbial flora 

• systemic conditions 

• subjects carrying implanted inert materials

• Through questioning, it is necessary to screen the high-risk patient:

• Patients on immunosuppressants,
• Heart surgery,
• Dialysis patients,
• Malignant blood diseases (leukemia, lymphoma, etc.),
• History of tuberculosis, 
• History of syphilis,
• History of hepatitis, 
• Drug addicts,
• Gay men,
• Tattooed patients,
• Patients under acupuncture,
• Polytransfused… 

• We must protect ourselves and protect staff and patients.
• It is recommended to use disposable paper pads on the worktop as they represent a physical barrier to contamination of fixed furniture surfaces. 
• 4.1. Hygiene measures 
• Standard precautions: 

– workplace hygiene: chair, premises, etc. 

– protective clothing: wearing gloves, mask, glasses, gown, overcoat, etc. 

– hand washing 

– prefer single-use equipment 

• 4.2. Risk areas in the dental office 

           5 – Instrument preparation cycle: 

• Instruments: cleaning, sterilization and storage.
• Using pre-packaged, sterile, single-use consumable materials is an excellent way to combat infection. 
• It is recommended to use disposable paper pads on the worktop as they represent a physical barrier to contamination of fixed furniture surfaces. 
• 5.1. Processing of reusable instrumentation
• 5.1.1. Pre-disinfection
• This operation is defined as “the first treatment to be carried out on soiled objects and materials, with the aim of reducing the population of micro-organisms and facilitating subsequent cleaning by avoiding the drying of organic materials”; it can be omitted if cleaning is carried out immediately after use.
• In fact, pre-disinfection is an operation which aims not only to reduce the initial contamination rate of soiled equipment but also to protect the personnel called upon to handle them and the environment in which they are located.
• To carry out pre-disinfection, the product used must have both detergent and disinfectant activity; it must be used at the correct dilution and constitute a solution in which the instruments will be soaked immediately after use, in a suitable tank, until they are cleaned. The minimum soaking time is generally 15 minutes, but it must be in line with the recommendations of the manufacturer of the detergent disinfectant product used. 
• 5.2. Cleaning
• The aim of cleaning is to remove dirt in order to obtain a clean medical device. This step is essential, it determines the effectiveness of the final treatment applied to the instruments.
• Cleaning is carried out either manually (brushing) or in a washing machine (ultrasonic tanks).
• The effectiveness of ultrasonic cleaning due to the phenomenon of cavitation is superior to manual cleaning using a brush. The risks of stinging or injury are eliminated.
• 5.3. Disinfection
• This step is performed on clean instruments.
• It is strictly reserved for heat-sensitive medical devices that cannot be sterilized. This operation is carried out by soaking in a suitable disinfectant solution. Drying is carried out in dry air and/or with a clean or sterile single-use cloth.
• 5.4. Sterilization 
• The sterilization operation is carried out on instruments packaged during the packaging stage; a product is only qualified as sterile to the extent that it is packaged before sterilization in packaging which maintains this state until its use.
• There are 04 sterilization modes:

– Dry heat oven (poupinel) abandoned since 2010

– Moist heat oven or saturated steam sterilizer also called autoclave

– Harvey’s Chemiclave

– Ethylene oxide

• The sterilization method currently recommended is saturated steam sterilization. Some processes long used in dental settings do not provide guarantees of results. Thus, the glass bead sterilizer was withdrawn from the market in 1998; Chemiclave® is now considered a disinfection process that cannot provide reliable sterilization.
•  Autoclave: moist heat 

– Mandatory in Algeria at the dental office since 2010.

• Device using the combined action of heat and pressurized water vapor. 
• Cycle 30 to 45 minutes with humid heat of 115 to 135° 
• The objects are placed in waterproof boxes.  
• Benefits : 
• Sterilization in closed boxes lasts for one week.
• Fast and efficient steam penetration. 
• Sterilization of textiles (fabrics); fragile materials and chemical solutions.
• Short sterilization time and therefore good rotation of equipment.
• Disadvantages: 
• Steam causes corrosion of steel and 
• Oxidation of metal instruments.
• High purchase price.
• Sometimes residual moisture persists on the surface of the instruments. 
• Then everything is wiped with a clean cloth or spread out on a paper sheet and left to air dry. Once dry, the instruments are placed in metal boxes or wrapped before being sterilized.
• In cases of contagious patients, the instruments go directly to the sterilizer and then they will be cleaned and sterilized a second time.
• Textiles and chemical solutions cannot be sterilized. 
• – Storage : 
• The equipment must be sterilized.
• Kept sterile and stored in tightly sealed boxes or bags.
• Sterile single-use consumable material is mandatory.
• Storage in clean boxes or drawers containing trioxymethylene tablets in a compress in one corner.
• The drawers are cleaned and disinfected every week.
• 6. Maintenance and monitoring of the environment
•    6.1. Water 🡨🡪: drinking water.

• The Pipes

• Run the water in the pipes for 5 minutes, every morning before the first patient and for 30 seconds between each patient,
•  The spittoon and its tap, possibly the cup
• The spittoon will be rinsed and disinfected between each patient using a cloth and detergent-disinfectant,
• The siphon will be disinfected at the end of the day with bleach.
• The hand washing point:
• The tap control will preferably be non-manual or even automatic/electronic.

– The liquid soap dispenser will have an elbow control,

– Hands will be dried with single-use paper, electric drying is prohibited

• 6.2. Air 
• Dusting will be exclusively wet

– It will be appropriate to limit the number of people in the room as well as the often excessive comings and goings.

• 6.3. Surfaces

– Cleaning soiled surfaces with a wipe impregnated with a bactericidal, fungicidal and virucidal product. 

• – Spraying an antimicrobial film on clean surfaces and drying without wiping.
• 6.4. Premises
• The architectural design of the premises must meet certain basic principles such as: 
• Separation of work and reception areas. 
• Communication between sterilization room and treatment room. 
• – Choice of easy-to-maintain coverings…
•  

 Conclusion : 

• It is necessary to systematically respect the general rules of hygiene with all patients and every day.
• The basic rules of hygiene are based on compliance with standard precautions, the basic principle of which is to “consider every patient as a potential carrier of a known or unknown infectious agent”
• Their aim is therefore to ensure dual protection for both the caregiver and the patient.
• The practitioner must avoid the risks of contamination of staff and patients . 

Asepsis, antisepsis, sterilization.

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Asepsis, antisepsis, sterilization.