Examination of the particle’s shape, size and distribution of the commercial dental gypsum products
Abstract
Gypsum products used in dentistry are in the form of and calcium sulfate hemihydrate as dental stone and plaster.The aim of the study is examination of the particles shape, size and distrib-ution of the different commercial dental gypsum products. The particles shape was examined microscopically with trans-mitted light microscope instead of ref-lected light microscope or electron micro-scope. Analysis of the particles size distribution and the measurement of the powder particles fineness was performed by sieving procedure using sieving machine. The data was collected and calculated and then compared with the ADA Specification No. 25 for gypsum products.The results showed that the micro-scopical examination with transmitted light microscope give clear accurate and precise image about the different shapes of the stone and plaster. The results of the analysis for particles size distribution showed that there is a difference in the distribution between the different tested commercial dental gypsum products and also showed that all products have par-ticles size larger than the ADA Speci-fication No. 25.
