[The resolution of a 2-dimensional ultrasonic velocity profile of human tooth sections]

In a previous study (Löst et al. 1992, Löst et al. 1994) two-dimensional ultrasound velocity profiles of human dentin were introduced, and their possible significance and the underlying measuring system were discussed. Profiles of ultrasound velocity enable us to differentiate the structure and the elasticity of dental hard tissues. The quality of these color-coded profiles enhances with improved lateral resolution of the used ultrasound measuring system. Establishing an optimal window for displaying longitudinal sound velocities increases topological statements. Under given conditions of the measuring system an optimal lateral distance between points of measurement could be found. The differentiation of values within the profiles of ultrasound velocity is most meaningful applying a standardized window within the range of ultrasound velocity. For the used 20 MHz-ultrasound transducer a 0.2 mm lateral distance of measuring points was found to be optimal and a chosen window of ultrasound velocity in dentin from at least 2800 to 4300 m/s, respectively.