Asepsis-Sterilization-Disinfection
What is Asepsis?
Asepsis is described as the absence of microorganisms that can cause infections. In the dental environment, asepsis depends on a whole chain of actions that must be undertaken by dental personnel and each step must take place without introducing microorganisms.
Maintaining an aseptic environment involves the use of techniques such as handwashing, wearing protective gloves, masks and glasses, cleaning and disinfecting work areas and cleaning and sterilizing instruments that come into contact with the patient’s mouth.
Asepsis measurements
Here is an overview of the techniques used to prevent the spread of infections in dental offices.
Physical barriers
Staff wear equipment that allows them to protect themselves and patients:
- Sarrau or uniform: changed at least once a day;
- Mask;
- Protective lenses or visor: cleaned after each patient;
- Gloves: removed by turning them upside down and discarded after each patient.
Hand washing
Handwashing remains the most effective measure in preventing infections.
It is carried out:
- Before putting on and after removing gloves;
- After the mask is removed;
- Before and after meals;
- After contact outside the surgical field;
- After contact with blood or contaminated material;
- At the beginning and end of each day.
The washing lasts from 30 seconds.
Prevention with the patient
Some preventive measures can be prescribed to the patient. They protect the health of the patient, dental professionals and other patients in the clinic. Here are some examples:
- Premedication (e.g., an antibiotic) taken by the patient to prevent bacteremia (bacteria entering the bloodstream);
- A mouthwash containing chlorhexidine and used before the procedure (reduces the bacterial flora in the patient’s mouth by 90 to 98%);
- The patient can wear protective glasses to protect his eyes from aerosols and splashes;
- The medical questionnaire completed by the patient may reveal risk factors that warrant postponement of treatment or additional safety measures (e.g., tuberculosis, SARS, etc.).
Surface disinfection
Disinfection reduces the bacterial population by destroying some microorganisms but not bacterial spores. It is mainly used for work surfaces (counters, furniture, chairs, electronic equipment, garbage cans, floors, etc.).
The effectiveness of disinfection depends on the product used and the surface must have been cleaned beforehand for the disinfectant to be effective.
Sterilization of instruments
Sterilization eliminates all microorganisms, including viruses and bacterial spores. It always starts with a good cleaning of the instruments to remove all traces of blood, saliva and debris because they create a screen that limits the action of sterilization.
Sterilization is performed for all non-disposable instruments that come into contact with the mouth.
The sterilization methods used:
- Saturated water vapour (autoclave): water vapour under pressure;
- Unsaturated chemical steam (chemiclave): mixture of alcohol and formaldehyde heated under pressure;
- Dry heat: high temperature over a long period of time;
- Fast heat transfer: forced air convection;
- Cold sterilization: immersion in a chemical solution, when heat sterilization is not possible;
- Sterilizer type B: autoclave with vacuum pumping cycles before and after sterilization.
Sterilized instruments must be stored in a dark place. They are brought into the operating room in sealed packages to avoid contamination by microorganisms in the ambient air. The instrument packages are opened in front of the patient.
Important: Sterilization devices are checked regularly to ensure that they are working properly.
