A modified dilatometer for determining volumetric polymerization shrinkage of dental materials

Autor: Oberholzer, Theunis G, Grobler, Sias R, Pameijer, Cornelis H, Rossouw, Roelof J
Zdroj: Measurement Science and Technology; January 2002, Vol. 13 Issue: 1 p78-83, 6p
Abstrakt: A modified mercury dilatometer is described where any change in the volume of the sample is registered every 0.5 s as a change of the mercury height in the capillary, which is measured electronically instead of by the naked eye. The device is relatively low in cost and enables measurements to be made on samples regardless of their shape or size. Four different light-curing dental materials - Amelogen (Ultradent Dental Products, South Jordan, UT, USA), Z250 (3M/ESPE, Minneapolis, MN, USA), Permaflo (Ultradent) and Filtec flow (3M/ESPE) - were initially tested. From the results it was concluded that with this modified dilatometer reproducible measurements, with a measurement error (residual standard deviation) of less than 0.027% and an average coefficient of variation of less than 1.22%, could be obtained. Thus, the instrument is particularly suitable for the study of light-curing dental resins.
Databáze: Supplemental Index