[Psychophysical scaling of translucent sensory measurement of tooth crowns]

The purpose of this study is to investigate the translucent sensory measurement as a basic study for developing the translucent sensory scale (Haze Guide) of tooth crowns. Seven subjects with normal visual sensation were examined to search for the translucent sensory interval of uncertainty using methods of limits, and 3 panels were selected from this result and prepared for further experiments. Fact-findings of the translucent senses were performed on these 3 panels using the magnitude estimation method and the absolute judgement method. With these methods we were able to construct the translucent sensory measurement and to establish the ranges of Haze scores and magnitude of each step and a permitted limit of each Haze tab, which should be possessed with the tooth crown translucent sensory scale. The results were as follows: 1. The translucent senses were well adapted to the Stevens power law of modality characteristic exponent. The exponent was 1.74. 2. Standard light translucent sensory guide for tooth crowns were in the range between 25. 2% and 91.9% at Haze values. Eighteen steps were arranged within this range, and when the Haze difference was taken larger at lower Haze values and the difference was taken smaller accordingly at higher values, the visual sensation came to achieve an equally appearing interval of translucency.