Ergonomics in dentistry 

Most dentists suffer from occupational strain

According to the “European Society of Dental Ergonomics”, about 65 % of all dentists have musculoskeletal complaints varying in severity but involving one or more of the following: discomfort, pain, limitation of functioning and loss of working time. The risk of disability is considerable. 

The reason is that dental practitioners often work in static unhealthy postures – and in some cases even with the units out of sight and reach. 


Traditionally the unit instruments have been placed “to the left” of the chair:

    • To reach a unit instrument the practitioner must look away from the area of treatment and turn the body

    • In doing so, the practitioner needs to move the hands from the primary area of work

    • As a result, the focus on the treatment is repeatedly disrupted

    • The eyes become tired from constant adaptation and accommodation (adjustment of the eyes to differences in light and changes in distance of objects)

    • The practitioner must carry the full weight of instrument and hose

    • The chairside assistant cannot help the dentist change contra-angles and burs and cannot transfer unit instruments to the dentist

    • The instrument holders are closed and difficult to clean and disinfect

Unit with instruments placed “to the left” of the chair 

XO ergonomics

Fourhanded operation 

With the XO solution the instruments are centrally placed over the chest of the patient:

        • The instruments are within easy reach of both operators without the operators looking away from the primary area of work

        • As a result, the operators’ eyes and hands are always free to focus on the task at hand

        • The chairside assistant can change contra-angles and burs on unit instruments – thereby saving time

        • The chairside assistant can transfer unit instruments to the practioner – thereby saving time

        • The instruments are almost weightless (in balance)

        • The unit instrument holders are open and easy to clean and disinfect

XO solution – four handed working technique 

Solo work 

When working solo, it is particularly important that all instruments are located within a short reaching distance. 

XO solution – two handed working technique


  • During endodontic treatment, it is useful to position a tray under the instrument bridge so that the endo files are within easy reach of the right hand.


XO solution – two handed working technique – endodontic treatment

Sit, see and work well

You sit, see and work well when you:

    • Sit in an upright balanced position

    • Place the patient in the supine position with horizontal backrest making it possible to to work in four working positions from 9 to 12 o’clock (right-handed operator)

    • Lift the chair so that the distance from your eyes to the oral cavity is about 30 cm

    • Place the patient’s head in six different positions

    • Combine the four working positions and the six patient head positions so that you see all surfaces of all teeth while sitting well

    • Position the instrument bridge close to the patient’s chest so that the distance from the instrument tips to the oral cavity is about 30 cm


XO ergonomics guide

In relation to the tooth and tooth surface to be treated, this interactive guide recommends healthy and optimal working positions and optimal patient positions.

Pretreatment checklist

This allows new users to get familiar with the XO solution in two minutes, The checklist is available as an app with XO FLOW and below:









What not to do

While the Pretreatment Checklist explains how to achieve maximum benefit from working with the unit, this film demonstrates what NOT to do when working with an over-the-patient delivery unit like XO: