Dental surgeons and dental assistants are exposed to risks of any kind, chemical, infectious, physical, radiological related to the dental care they provide to their patients: they handle irritating and allergenic products for patients. dental care or for the disinfection of instruments, they often have arduous postures during the care or the preparation of the products or the cleaning of the work plans, they undergo accidents with exposure to the blood or to the liquids and biological particles due to injuries with the instruments or by ocular projections or by inhalation, they can be exposed to the ionizing radiations of the radiology apparatus or to the ultrasounds of the cleaning tanks …
Collective and individual prevention measures can significantly reduce all these risks.
The main risks of dental care
- Biological risk
Biological risk is present in all the many invasive dental procedures performed by the dental surgeon or in the vicinity of his assistant. There is also in all cleaning and disinfection of medical equipment and instruments.
Infections can spread, for example, through syringe needles or hand wounds caused by sharp or rotating medical tools or eye splashes.
The risk of transmitting infectious agents concerns all the germs conveyed by the patient’s blood or body fluids.
Any contact with blood or a biological fluid on skin damaged by a break-in (sting or cut) or a projection on a mucous membrane (eye, mouth) is potentially contaminating.
These frequent accidents particularly affect the dental care staff when performing more or less invasive care involving different biological fluids (blood during extractions or scaling, more abscesses, but also saliva, nasal secretions, sputum due to the cough of the patient …).
Any pathogens (bacteria, viruses, …) are likely to be transmitted in this way to the caregiver and should be absolutely vigilant in all cases, because a positive serology may be unknown to patients themselves (viral hepatitis B, C or AIDS, ORL infection or pulmonary viral or bacterial infection transmitted by the patient …). Ocular contamination can cause viral keratoconjunctivitis.
Operations related to needles (anesthesia, …) or rotary and blunt instruments (strawberries, blades, …) used in the chair are the most likely biological risk, but we cannot exclude that of contact with surfaces inert and accessory materials contaminated by blood-borne viruses in particular.
- Chemical and allergic risk
Multiple toxic chemicals, susceptible to skin and lung irritation reactions or hypersensitization, are used in dental care.
Allergic occupational diseases caused by latex proteins are encountered when using medical equipment made of natural rubber (for example: surgical gloves), as well as eczematous lesions (or irritative dermatoses) in the hands for example, due to the repeated use of disinfectants and detergents, especially containing cationic surfactants (quaternary ammoniums), or due to contact with anesthetic products.
Detergents are chemical cleaning agents: soaps, detergents, cleaners for floors, surfaces or medical devices. The surfactants they contain, destroy the lipid protective film cutaneous and are therefore all irritants for the skin with a harmful power variable according to the chemical compositions.
Skin effects, irritation and sensitization, as well as respiratory and sensory irritant effects are produced by glutaraldehyde, used for cold sterilization of surfaces and medical equipment.
The dentist ( dentiste de garde ) also uses for the care or preparation of impressions or amalgam, glues, cements and resins responsible for dermatitis (skin irritations), allergic-type reactions, skin contact (eczema, urticaria), or inhalation of dust (rhinitis, asthma) related to the use of methacrylate resins (methyl methacrylate).
Dental professionals may also be allergic to nickel from certain medical instruments such as scissors or forceps, but also to certain antiseptics (quaternary ammoniums), and other heavy metals (chromium, cobalt).
Sodium hypochlorite, handled during the administration of treatments or cleaning, is caustic for the skin and mucous membranes and causes irritative dermatitis, the projection in the eyes is very corrosive and di-chlorine gas can be inhaled and therefore be toxic to the pulmonary alveoli.
During repeated hygienic hand rubs with hydro-alcoholic gels, the only risk of the skin comes from the alteration of the hydrolipidic film of the skin, which leads to dryness and irritation of the hands, with the possibility of slight erythema especially with isopropanol which is more irritating than ethanol.
- Physical risk
All surgical instruments of the dentist, high-speed rotary, sharp and sharp for working hard tissue, quills for anesthesia or exploratory sounding, … are the cause of injuries resulting from the mechanical action of these tools. Ocular projections of high-speed particles can be a source of corneal trauma.
The use of ultrasonic baths for instrument cleaning, causes harmful effects if these ultrasounds, inaudible or quasi-inaudible, are transmitted to sufficiently high and prolonged levels. Migraines, nausea, dizziness can occur especially for people with very fine hearing, especially among young people. The hand can be subjected to a strong vibration when in contact with the source of ultrasound (sonotrode or penetration of the hand in the bath), with skin irritations and vascular disorders.
Careful work with restrictive postures, repetitive gestures, visual constraints, expose dentists and their assistants to musculoskeletal and angioneurotic disorders: precise work standing up with an asymmetrical posture, during work or work. help at the wheelchair, can generate musculoskeletal disorders due to repetitive gestures associated with a leaning position to ensure close vision with outstretched arms. It follows the frequent occurrence of dorso-lumbalgia and cervicalgia, tendinopathies of the upper limbs (shoulders, elbows), carpal tunnel syndromes, and venous insufficiency associated with standing and trampling.
Work in permanent and intense artificial light is another physical constraint: it is a source of dazzling and eye fatigue Visual fatigue by dazzling, by working in near vision, is common among dentists. The eye is not adapted for this permanent accommodation and the eye muscles get tired after prolonged efforts. This tiredness of the ocular muscles results in an increasingly cloudy view as the effort, tingling and redness of the eyes, tearing, blinking of the eyelids, headaches …
Single story falls on uneven or congested ground, in a small room with traffic difficulties.
Burns with sterilization equipment.
Electrification / electrocution by contact with a live conductor (extension cord …) or by the use of poorly maintained tools or defective plugs.
- Radiological risk
X-rays, ultraviolet rays and lasers are used in dental practices.
The use of ionizing X-rays in diagnostic X-rays exposes to accidental irradiation: radio diagnosis exposes itself to repeated doses, stronger when the dental surgeon is close to the patient and all the radiations undergone are added and accumulate throughout life. The effects of “in utero” irradiation are particularly deleterious (teratogenic effects). The other effects, which do not always appear, that appear in a delayed way, without obvious threshold (radiation-induced cancers including those of the thyroid, bone sarcomas, leukemias, … and possibly malformations in the offspring) are related to the accumulation of doses on several successive irradiations.
The ultraviolet emitted by some generators for the polymerization of composites can create skin reactions with photosensitization, and eye disorders. The laser technique with exposure of the eyes to laser beams generates risks of eye damage.
Measures to prevent the risks of dental care
The means of
prevention to be implemented in order to mitigate the occupational risks of the
dental surgeons and their assistants (infectious, chemical, radiological,
physical, …) must be the object of a thorough analysis to allow the drafting
the Single Safety Document by appreciating both the material and technical
environment (tools, machines, products used) and the effectiveness of the
existing means of protection and their use according to the workstations and to
describe preventive actions complementary measures to be implemented. All
activities are to be taken into account, including those concerning the
cleaning of surfaces, worktops and instruments and medical equipment, waste
Also so that employees can be informed about the dangerous products used, the Safety Data Sheets (F.D.S.) must be made available and the knowledge of their risks explained through the understanding of their labeling.
Primary and collective prevention measures, which prevent the accident from occurring and which concern all dental personnel, including strict compliance with hygiene rules, should be implemented as a priority, but if they reduce the frequency of accidents, they are insufficient to eliminate all, and we must also use individual prevention measures to mitigate the severity of the consequences of an accident that would occur nevertheless, with specific protective equipment adapted to each risk as well as vaccination and staff training.
- Layout of dental office premises
Prevention requires optimized premises design in terms of safety and hygiene facilities. The dental office premises must meet standards, especially for the storage of pharmaceutical substances, the design of the operating room, or the standards of radiology equipment.
Ventilation, ventilation and aspiration adapted in the premises. This is to reduce the concentration of dust and gases, responsible for lung risks. Ventilation and extraction systems must be dimensioned with sufficient flow rates capable of ensuring minimum ventilation at all times in order to prevent the accumulation of gases or harmful substances, and to remove unpleasant odors and condensations, and the building should never be caulked. The dynamics of the renewal of the air is ensured by extractors regulated by a regulation box equipped with a temperature probe. Maintenance of the ventilation system according to the rules of the art is essential, because the networks clog up quickly with out-of-use filters, grids partly obstructed … Fans, ventilation channels, valves and other elements ventilation systems must be designed so that they can be inspected and, if necessary, cleaned.
Premises and equipment and equipment well designed and maintained. A good dental office design requires well-separated areas between the treatment room and instrument disinfection rooms, product storage areas and waste storage areas. Working conditions in dental practices, with multiple sources of biological staining, are conducive to contamination: floor coverings and their cleaning are basic hygiene elements with greater ease if the furniture and equipment are equipped with casters for moving.
Adapted storage. The storage of pharmaceutical and chemical products presents risks such as the risk of falling or overturning of packaging … All these characteristics make it necessary, in addition to the precautions during their use, transport and transfer, the arrangement of storage rooms with metal shelving, security cabinets for small quantities for the storage of flammable products, cabinets with retention shelves, storage equipment with retention tanks to prevent and control accidental leakage of liquid pollutants.
The reduction of existing risks requires a reflection on the structure of the room, the storage methods and the incompatibilities between the products that may correspond to hazardous storage situations. The smoking ban in the premises must be absolutely respected and prominently marked, as well as all other safety instructions.
The storage area must be locked and access restricted to authorized personnel. It is necessary to store the smallest possible quantities of products because the risk of incident or accident increases with the duration and the volume of storage.
The storage areas of pharmaceutical and chemical products should be regularly checked for leaks.
risk waste management of dental activities, anatomical waste, medical devices,
or toxic risks (expired medicines, etc.) must be carried out in specialized
containers and disposed of by authorized companies.
The presence of suitable and signaled fire extinguishers, emergency lighting, electrical installation in compliance with standards, is essential. Equipotentiality and proper grounding of all metal installations must be controlled, defective plugs replaced.
- Respect for hygiene rules and regulations on health prevention
The control of the infectious risk passes by the strict application of the principles of hygiene:
There should be a schedule of frequency and alternation cleaning-disinfection adapted to the occupation of dental premises. Single-use instruments must be used.
Appropriate changing rooms must be made available to the staff: the storage of city clothes and work clothes must be separated. Have a hand basin (non-manual, with hot water, equipped with liquid soap dispensers, disposable hand towels, disinfectant hydro-alcoholic solution, and a trash can).
Handwashing, cleaning and disinfecting soiled surfaces, transporting soiled materials in tight sealed packaging, must be subject to rigorous procedures.
Portable eye washers designed to immediately provide flushing liquid and fixed eye / face wash fountains must be available. Disinfection of surfaces and materials with adequate disinfectants and appropriate times and procedures.
The dress code of the dental staff corresponds to a high level of biological risk: short sleeves, tunic pants, hair up, short nails without varnish, hands and forearms without
jewelry. Do not eat or drink at the workstation.
Use appropriate collection containers for the disposal of care materials that have been in contact with the patient (cotton, compresses, probes, syringes, etc.), with separation at source of hazardous waste: collection containers adapted to products contaminated or at risk of infection, sharps collectors.
- Equipment and installations in compliance with standards
of the source reduces the X-ray exposure which can become very low.
X-ray equipment must be checked regularly (during periodic regulatory inspections by an approved body, the quality control of installations, etc.), in particular to check that the devices are correctly adjusted.
The reduction of the ultrasonic emission of the ultrasonic baths at the source is the priority preventive measure: it consists of choosing the least emitting equipment possible and having integrated protection means: for example, the ultrasonic tank frame independent of the tank itself, lid with perfectly adhered joints and electric locking device to prevent the operation of the bath with the lid open, absorbent internal acoustic coating …
Assistants should never touch the sonotrodes when the machine is turned on, nor park too close to the ultrasound generators, or unnecessarily in the room where they are located. Do not have direct contact with cleaning baths or parts immersed during ultrasonic treatment, or waterproof impregnated gloves with nets.
- The provision of ergonomic equipment
This is to avoid repeated physical efforts and to have ergonomic equipment and if possible mechanized. Various tools can reduce the hardness of work, such as carts, tables and chairs adjustable in height and inclination for care, etc.
- Wearing adequate personal protective equipment
protective equipment is necessary to reduce the risk of exposure not completely
eliminated by the previous collective protective measures: gloves, protective
clothing, safety glasses, masks, adapted to the task performed.
Wearing gloves. The type of disposable gloves is to be adapted to the type of activity: care or cleaning-disinfection.
The purpose of wearing surgical gloves is to protect the patient during aseptic care, and to protect the dentist and his assistant from infectious risks through contact with body fluids and / or the risk of injury. The gloves must be changed between two patients, during care at risk of punctures or cuts, when handling biological samples, cloth and soiled equipment, systematically during care when the hands of the carer involve lesions. Medical gloves for latex care should be replaced by neoprene gloves in case of allergy.
Preventive measures are essential for the handling of disinfectants, especially when diluting concentrated products: there are many possibilities of contact with the hand when transferring or dilution or application, and it is essential Wear protective gloves that are appropriate for the task performed and the product handled. Suitable gloves with long sleeves, to prevent penetration of products inside, vinyl, nitrile, butyl or polyethylene, are preferable to latex, responsible for allergies and too thin. Gloves must be worn when the labeling of the product to be handled contains the risk phrases R27 (very toxic in contact with the skin), R24 (toxic in contact with the skin), R21 (harmful in contact with the skin), R34 (causes burns) and R35 (causes severe burns).
Wearing gowns, glasses, masks, boots. The clean civil dress with short sleeves is protected for care by aprons or gowns. The wearing of surgical type mask, glasses and mask is indicated if care or handling expose to a risk of splashing blood, or any other biological product, during the operating procedures, the descaling …
Radiological monitoring. The monitoring is carried out by means of a dosimetric follow-up provided by individual measures of passive nominative reading dosimetry (dosimetric badge worn in the chest, …). These dosimeters provide the opportunity to take appropriate precautions to limit future exposure opportunities so that the maximum allowable dose accumulation is not exceeded.
- Medical supervision
How to deal with injuries. First aid kits should disinfect and dress a superficial wound after rinsing it thoroughly and immediately after it has occurred. A deeper injury absolutely requires urgent medical and surgical care, as part of the blood exposure accident procedure (AES) and must be declared and registered by the occupational health service.
Eviction of pregnant women from certain posts. If there is no requirement for systematic removal of the radiological post, exposure to ionizing radiation of pregnant (or lactating) women should be avoided and in any case limited to doses below 1 mSv throughout duration of pregnancy.
The vaccination. Compulsory vaccination allows for the control and tetanus (DT polio: diphtheria tetanus poliomyelitis) and hepatitis B with regular booster, and against tuberculosis (BCG and regular cuti reaction) in high risk institutions. Given the significant risks of respiratory contamination, vaccinations against mumps, measles, pertussis, influenza are recommended.
The medical examination. The medical prophylaxis of the dental staff is carried out during the annual visits or in the event of contamination identified with an employee.
In addition to conventional examinations, particular attention should be paid to skin and respiratory conditions, for possible allergies or other signs of pathogens (anti-HBs assay), blood count, and platelet count. .
- Information and training
Information and training for dental assistants are also necessary to make them aware of the dangers they face, to know how to identify them and to implement the means to prevent them.
art. 230-2 of the Labor Code “Every employer of manpower is obliged to
inform his employees about the occupational risks to which they are
exposed”. The employer must write a risk assessment document (Unique
Safety Document), share it and make it known and initiate action programs to
The most useful hygiene and safety training actions for dental assistants are as follows:
– Training PRAP (Prevention of Risks related to Physical Activities) to good gestures and postures that can fight against all musculoskeletal disorders (MSD).
– Training in the hygiene of workers, premises.
– First aid training.
– Training on the nature of the products handled (detergents, disinfectants, drugs), their potential adverse effects, and on the understanding of packaging labels and Safety Data Sheets.