Occlusion trajectory and a concept of a device for testing operating life of dentures.

PURPOSE: This paper presents an original method for the assessment of occlusion trajectory. On this basis, a special device for the assessment of operating life of dentures was designed. MATERIAL/METHODS: For this purpose, the SMART system by BTS for a comprehensive movement analysis was used. In order to analyze occlusion trajectory, characteristic points on patients' heads were appointed in which markers were placed, in accordance with the rules of measurement in dentistry. Markers' movement was recorded by means of 6 cameras, and then composition of coordinates was performed in a 3D system. RESULTS: In this way, curves representing movements of the characteristic points were plotted which, after the composition, with a considerable approximation, can be regarded as occlusion trajectory. CONCLUSIONS: On the basis of the obtained results, a thesis was put forward to the effect that traditional tribological testing machines based on systems of the pin-on-disc, ball-on-disc, etc. types, due to the simplicity of their working movements, are not adequately precise for the purpose of operational assessment of elements of prosthodontics. On this basis, a tribological node for a specialist testing machine for the assessment of operating life of dentures was designed.