In the initial phase, the development of dental ergonomics was mainly directed at the physical job component, the person behind it did not matter.

The real development started, when, in the early sixties, the slow drill was replaced by the water drill, the Borden air rotor, which worked far faster and was water-cooled. However, the water had to be drained away quite quickly and that posed a problem. Furthermore, the demand for dental care increased rapidly and various reports were published which drew attention to the serious problems caused by the dentists working posture.

The result was the development of modern treatment equipment, allowing the dentist to sit during the patient's treatment, which was not possible before. Here too it is true that the moment a classic working pattern does no longer function and the work gets more complicated, ergonomics was introduced. This development has exerted considerable influence on dental practices.

Working posture
It seems that two out of three dentists, about 65%, suffer from back, neck, shoulder, arm and hand complaints to some extent. In addition 40-50% run the risk of becoming disabled, where 1/3 have its origins in working posture. The 30% that leave the profession due to mental health problems often have posture-related problems.

The cause is a large number of dentists working in an unergonomic posture with few movements, so that functioning of the muscles, joints, spinal column etc. are affected. Ths results in pain often making it difficult or impossible to work. Usually the dentist has been insufficiently trained to adopt a correct working posture and also thinks that posture-related pain and discomfort are part of the job. Besides, much equipment does not allow adequately enough one to work in a healthy way. In the majority of cases, absence from work is not necessary, providing a good operating method is followed.

Healthy working posture
Ergonomics teaches us how to work with a healthy working posture. That is to sit upright with the head lightly bent and the arms loosely hanging down the body in a high seat so that the spinal column has the same forward curvature in the lumbar region as when standing. However, many dentists do not work in this way and do not use adequate equipment. The consequence is that the patient is not placed in a good position.

If you want to adopt a correct working posture, you have to place your operating field straight in front of you and position the patientís mouth towards you, enabling you to look properly into the mouth. You do that by positioning the patient more or less in the supine position and turn the head towards you. In reality, the working field in the mouth, causes an unhealthy posture.

The dentist often works with tiny details that are difficult to see, which require good illumination. Much light is needed to illuminate the operating field so a light beam running nearly parallel to the viewing direction is a must. In practice, illumination which is not very suitable is used resulting in very bright parts as well as many shadows in the mouth, which makes work rather tiring. Also the illumination in the direct operating area around the mouth must correspond, as must the illumination to the rest of the room. in order to prevent eye fatigue, light colours also must also be used. According to research this used to be done inadequately in 75% of dental practices.

Joseph Wouters, researcher and specialist within the field of dental ergonomics, and Oene Hokwerda, Professor and President of the European Society of Dental Ergonomics, performed a study into lighting conditions which enabled them to collect important information about how to use lighting and colours in the operating room, and additionally how to use spectacles, magnifying glasses and microscopes to see details more clearly. For various reasons the use of spectacles seems to be an important tool for a correct posture. Furthermore, the study showed that instruments should be matt and not reflective, as now often is the case, since this causes eye fatigue.

Sources of noise
Another physical source of strain is noise. There are many sources of noise present in the dental practice, such as the drill and the suction instrument. Often various sound sources are active simultaneously and although the sound level is not harmful it is often so high that a mental, as well as a physical, effect will arise, particularly in the form of hypertension and extra muscle strain, causing the work related strain to become even more noticeable. Solutions need to be found for using acoustic ceilings and walls and for minimising the pieces of equipment used in the operating room.

The dentist works with, what is called, a man-machine system since equipment is needed to carry out treatments. If this equipment has been designed well the instruments can be placed within reach and taken and returned in a natural way. However, this is often not the case and instruments have to be placed at distances that are to great either vertically or horizontally resulting in arm and shoulder complaints. Furthermore, much equipment is not fit for tall dentists. Variety of designis necessary for the use of equipment by both short and tall dentists.

Dentistís chair
The same problem applies to the dentistís chair. The dentist needs to adequately support the buttocks and the upper pelvis but most chairs are often not ergonomically designed and therefore cause an incorrect sitting position.
Handling instruments

Handling instruments is also an important part of ergonomics. Many dentists hold their instruments like an ordinary pen which is a tiring grasp requiring much strength. The instrument should be held with the tips of the first three fingers (modified pen grasp) allowing better manipulation and four times as much grip compared to an ordinary pen grasp. Intsruments must have a minimum shaft thickness of 7.5 mm in order to adequately hold them and so far, instruments that are too thin have often been used. On a variety of fronts, Joseph Wouters and Oene Hokwerda are still working on the problem of how instrument shafts should be designed ergonomically and further the use of thicker and matt-finished instruments.

Mental strain
Mental strain is a separate chapter within dental ergonomics. Nearly one in three cases where dentists are incapacitated for work purposes can be attributed to mental problems usually connected with posture-related problems. Stress is frequently caused by the lack of e.g. cooperation of several people in one practice, high demands of the patients, rapid job-related developments and the fact that both the dentist and his / her partner often have a job with their own social obligations. As with anybody, physical and mental powers diminish between the 40th and 50th year, but dentists have to work at high levels of strain. Many go beyond the boundaries and, quite frequently, develop burn-out.

In conclusion, a dentist works with an increasingly high number of strains, which are composed of a large number of high stress activities which have a cumulative, interactive effect. One has to look at many aspects of their work in order to get an ergonomic and therefore healthy working condition. A big problem is that there is very little equipment available to enable this. In the future, The Working Conditions Act and the appearance of personal injury lawyers urgently demand action.

Privacy Notice © 2007