PREVENTION OF INFECTION IN THE DENTAL OFFICE
COURSE HANDOUT PREPARED AND PRESENTED BY
P r BOUDJELLEL
HYGIENE AND PREVENTION MODULE
2nd YEAR
2023/2024
INTRODUCTION
Like all surgical specialties, dentistry presents a high risk of occupational infections transmitted by blood.
It should also be noted that protection against infections in the dental office, including hepatitis and HIV infection , requires compliance with universal precautions, while remembering that these precautions apply to the dentist and his assistant.
These precautions appear in ministerial instruction no. 19 of November 19, 2002 relating to the prevention of viral hepatitis, HIV and blood exposure accidents in dental practice.
This instruction mainly targets the risk of transmission of certain infectious agents (hepatitis B and C, HIV) present in the blood and saliva during dental care.
This risk concerns staff and patients.
This strategy is based on:
- 1 – Vaccination of dentists and dental auxiliaries against hepatitis B
- 2 – The need to control the risk of transmission of all infectious agents by general hygiene precautions. These measures must be implemented for all patients and for all dental care.
- 3 – Rational use of suitable equipment
- 4 – The establishment of a system for managing blood exposure accidents (AES)
- 5 – Interpretation of AES monitoring data
- 6 – Information and training of staff.
- 7 – Evaluation of actions taken. The hygiene rules intended to protect staff and patients are based on concrete actions that must be implemented under the responsibility of the head of the establishment, in consultation with the committees for the fight against nosocomial infections and occupational physicians.
- Most feared infectious diseases
- Hepatitis B and C : the known risk of contamination for the hepatitis B and C virus (HBV and HCV), which can develop into acute fulminant hepatitis, cirrhosis or hepatocellular carcinoma, was highlighted in the 1980s with the human immunodeficiency virus (HIV) epidemic.
- HIV infection : The seriousness of this pathology requires us to classify it among the most serious infectious diseases.
II. Contamination, sources and transmission routes
- Accidental exposure to contaminated blood or saliva on the occasion
- From percutaneous break-in by contaminated material (needles, hand instruments, rotating instruments, etc.)
- From an injury related to the participation of others, particularly when passing equipment to the dental assistant.
- From skin-mucous membrane contact with contaminated blood or saliva by inserting the hand into the patient’s mouth while the dentist’s skin has a lesion, even a minor one (chapping, eczema, cut edge of the nail, etc.).
- From contact with a soiled surface (unit, surgical light, spittoon, chair, etc.) while the dentist’s skin has a lesion, even a minimal one.
- From transcutaneous inoculation with infected blood by needle stick
2. Airborne transmission
Saliva poses a major risk for this specialty when splashed onto the face, particularly the mouth, the ocular conjunctiva or other entry points because hepatitis B is transmitted through saliva, and small quantities of HIV viral particles can be found in the saliva of patients with AIDS.
3. Transmission routes
- From patient to caregiver : By direct contact of the hand in the patient’s mouth on injured or damaged skin or by accidental exposure to contaminated blood or saliva.
- From patient to patient : Through unwashed or poorly washed hands of caregivers or through contaminated instruments.
- From caregiver to patient : If the dental surgeon is contaminated (whether his serological status is known or not).
III – Prevention and risk management
- In addition to patients who declare their HIV status, it is necessary to consider that any patient is potentially contagious and to systematically take precautions to combat these diseases.
1 – Medical prevention
- Based on vaccination with the anti-HBV vaccine made compulsory by the decree of April 25, 2000.
2 – Technical prevention
- It is based on compliance with universal hygiene measures of disinfection and asepsis in order to interrupt the transmission routes of the infectious agent. To do this, the following points must be taken into account:
1. Instruments and materials to be used which will come into contact with the patient’s mucous membranes must undergo high-level disinfection or sterilization, always preceded by thorough cleaning.
2. The caregiver must protect his face by wearing a mask and protective glasses or screen.
Wearing a mask is also recommended to protect the patient if the practitioner has an infection transmitted through the respiratory tract (rhinitis, flu).
The practitioner wears glasses or visors that are wide enough to ensure that projections cannot reach the eye in risky situations (projection of particles with risk of injury or contamination, particularly of the conjunctiva).
3. The caregiver must wear latex or PVC gloves for any manipulation in the oral cavity.
A new pair of gloves will be used for each patient.
Gloves do not necessarily have to be sterile but must meet the following requirements: – Perfect fit to the hand – Maintenance of tactile sensitivity – Impermeability – Resistance to chemicals and compatibility with certain products
If the quality of the gloves is not certified, it is recommended to use two pairs of gloves for all surgical procedures or on a patient with positive serology; After removing the gloves, the caregiver must wash their hands.
4. Dental office staff must wear a gown or apron.
These must be changed regularly and whenever they are visibly soiled. They must replace or largely cover civilian clothing and have short or semi-long sleeves that facilitate hand washing. They will be made of materials that easily withstand washing at temperatures and times that guarantee disinfection.
5. Prohibit the recapping of needles and promptly dispose of them, along with any other sharp or cutting objects that are no longer in use, in a waterproof container specially designed for this purpose. This container may be a container containing 12% bleach.
6. Prohibit the passing of instruments from hand to hand between the dentist and assistant, but use a field or tray on which the objects are placed.
7. Mouth impressions, prostheses , etc. are cleaned and treated with a disinfectant before being sent to dental prosthesis laboratories.
3– Importance of anamnesis:
Taking a good history is an important element in protecting patients and those providing care because certain elements may justify other working methods:
- a severely immunocompromised patient may warrant the use of sterile water.
- It may also be useful to see this patient first thing in the day to reduce the risk of cross-infection.
- A patient carrying a virus (HBV, HCV or HIV) must be seen at the end of the consultation so that more care can be taken with cleaning and sterilization.
4 – Hand hygiene
In dentistry, hand hygiene is essential, both for the comfort and safety of the patient and for the safety of the practitioner.
Fingernails should be cut short.
Wearing jewelry on the hands and wrists can cause injuries, provide niches for microorganisms, and present an obstacle to hand washing.
Hand washing: This is done before and after each treatment and whenever the hands are soiled.
Washing and disinfecting hands is not a substitute for wearing gloves and vice versa; bars of soap should be avoided altogether.
Hand disinfection:
- aims to have a bactericidal action by chemical effect. It must be carried out as soon as contamination has occurred and can be carried out before each treatment. It must destroy the transient flora. It can be done: With 70° alcohol or an alcohol-based antiseptic solution and to avoid drying out the skin of the hands, a lubricant can be added to the alcohol, for example 1% glycerol or silicone oil (2 drops per liter).
- Surgical hand disinfection:
It is performed before any surgical procedure.
It should allow the elimination of transient flora, this hand disinfection simultaneously slows down the development of resident flora. In addition to the immediate bactericidal effect of this disinfection, a prolonged effect of two to six hours can be obtained.
- Drying:
After washing hands, the drying medium must be clean, individual, soft and presented in a dispenser.
Hand towels must be single-use: multiple-use towels, generally made of fabric, which are real breeding grounds, must be avoided.
IV- Equipment, Premises and Work Organization
1 – Cleaning the medical area:
After each patient, the workstation must be cleaned and disinfected: all surfaces that have been touched by the soiled hands of the practitioner or assistant or on which contaminated instruments have been placed must be washed and disinfected.
- The unit:
Instruments attached to the unit, such as multi-function syringes, motors, turbines, scalers, electric scalpels, etc. must be disconnected, their covers and tips disinfected (or even sterilized).
The surface of the unit will also be cleaned, the coating of which must be as smooth as possible and resistant to the products used for cleaning and disinfection.
– The spittoon: This part of the equipment is particularly contaminated, it must not be touched without protection and must be cleaned and disinfected after each patient.
- The tips:
- The tips of water, air or multi-function syringes and other devices that enter the mouth become contaminated with each use.
- It is therefore necessary to ensure that they are sterilized if they are not single-use.
- It is also necessary to clean and disinfect the handles of the shelves, drawers, seat, surgical light, RX device as well as all switches and control buttons that were touched during treatment.
To clean and disinfect all these elements, it is preferable to use single-use cloths or paper towels soaked in a detergent solution (and preferably disinfectant);
All surfaces are wiped thoroughly to ensure mechanical removal of all soiling; then an active disinfectant is applied.
It should also be noted that for the telephone, computer and other non-medical equipment, especially when they are in the medical area, in addition to the usual household detergents, the use of compatible disinfectants must be prescribed.
2 – Care premises, work organization:
The treatment room must be reserved exclusively for chairside work. It is therefore not recommended to install other workstations there, such as the practitioner’s desk. It must be able to be maintained and disinfected optimally.
Controls and handles:
Control buttons and handles are handled with dirty hands without us being aware of it and can therefore insidiously contribute to cross-contamination.
Contact with handles (scialytic light, tablets) will be limited to what is strictly necessary.
- Air and water supply :
- When the motor and cooling spray are turned off, breathing in germs from the patient’s mouth can contaminate not only the line into the instrument, but also beyond.
- At the start of the day and after each patient, you should remember to run the turbine motor(s) empty (outside the mouth) for a few seconds with the spray and the multi-function syringe.
- Furniture:
The arrangement of instruments in drawers near the workstation has two significant drawbacks: on the one hand, these instruments will quickly become contaminated by the ambient air, which is particularly contaminated in this area, and on the other hand, gripping them will frequently be a source of contamination.
It is better to use prepared tray systems as much as possible.
3 – Cleaning and disinfection of instruments
Blood residue or debris will reduce the effectiveness of disinfection and sterilization. This is why proper cleaning is important.
For manual cleaning, a brush is used.
For disinfection, there are different techniques:
- thermal disinfection (autoclave) and
- disinfection using chemicals.
4 – Sterilization of instruments
- The hot air sterilizer uses dry heat to destroy microorganisms. At a temperature of 160°C, the necessary contact time is 120 minutes. At 170°C, it is 60 minutes and at 180°C, 30 minutes.
- The autoclave sterilizes using saturated water vapor.
At a temperature of 134°C and an overpressure of 2 atmospheres (200 kPa), a contact time of 3 minutes is sufficient.
At 121°C (100 kPa) 15 minutes are necessary.
5 – Hygienic treatment of contra-angles, handpieces and turbines
These instruments are soiled with saliva, possibly blood, or even pus, certainly on the outside, often also on the inside of the instrument.
As with any sterilizable instrument, it is recommended to clean and sterilize rotating instruments after each use, following a specific procedure:
- Run the instrument empty with its spray for about ten seconds to rinse the fluid pipes.
- Wash the external face, either with a brush and detergent or in an autoclave.
- Inject the lubricant recommended by the manufacturer, following its instructions.
- Remove traces of oil and clean the optical fibers with alcohol.
- Pack.
- Sterilize. Both the classic autoclave and the chemiclave can be used.
- Before using the instrument again, operate it for a few seconds empty, with its spray.
- There are autoclaves designed specifically for rotating instruments. Their sterilization cycle is shortened, which saves time.
V – CONCLUSION
The extreme vigilance that must be exercised with regard to any act involving a risk of contamination by blood or saliva will allow the dental surgeon to concentrate entirely on the intraoral treatment , guaranteeing, in addition to the protection of the patient , meticulous and careful work.
PREVENTION OF INFECTION IN THE DENTAL OFFICE
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