#Multi-sensory Feedback.
Multi-sensory feedback when preparing a cavity
One of the most complex modelling requirements is the perception of different sensations when preparing a cavity. The clinicians gave a thorough account of the kinds of multi-sensory feedback below. However, their opinions about the importance of sound feedback are mixed.
Tactile feedback
First of all, the clinicians explained that there is a difference in the kind of perception of tactile feedback between novices and experts. They said that as novices become more and more experienced cutting different parts, they become more and more trained in sensing e.g. the difference sensation when cutting different tooth parts. It is important to exactly model the different hardness of enamel, dentine and pulp. The clinicians described how they can sense cutting through the different layers and the kinds of amount of pressure they exert in drilling through each part and the corresponding resistance from each part. According to one of the clinicians, the kind of tactile feedback in using different handpieces/burs/tools is important to be modelled because operators exert different pressures in using them.
Sound feedback The clinicians expressed mixed opinions about sound modelling. Some of them explained that in some ways, they base the pressure they need to exert on sound while others said that they want to be able to mute the sound as they base their judgement particularly on tactile sensation. They explained that there are attempts now-a-days to reduce the noise of physical handpieces, for example. Those who perceived the importance of sound said that they based the speed of the bur’s rotation on sound while others said that they based the speed on tactile feeling depending on the pressure they exert on a foot pedal (the device present in a dental station that controls the speed of bur rotation). The suggestion is therefore to have an option to mute the sound and also to have a graphic representation of controlling the speed of the bur.
Visual feedback Colour changes are important. Operators, according to the clinicians, need to check what they are cutting visually. They can tell the difference between tooth parts based on colour alone.
Drilling sound library based on different:
Affective feedback This is a particular requirement that can go under visual feedback. Aspects to consider include patient falling asleep due to prolonged treatment/operation, indications of pain through facial expression without making a sound.