STUDY OF DENTAL GYPSUM USING FIBRE SENSORS - Analysis of Different Water/Powder Ratios of High Strength Dental Stone

Abstract

In this work, we present a device to measure strain and temperature, based on fibre Bragg grating (FBG) sensors. The performance of these sensors was assessed in the study of a type of dental gypsum, namely high strength dental stone. It was intended to know the influence of the water/powder (W/P) ratios in the setting time and expansion. The results show that, a change in the W/P ratio influences the setting time as well as maximum strain values. The data was compared with the values foreseen in ANSI/ADA specification nº 25. The information that can be obtained with these sensors is quite important to dental prosthesis technicians, in order to achieve more accurate dental prosthesis and these sensors can be a good substitute to the actually device that is used to evaluate the setting expansion: extensometer.