The purpose of this study was to investigate the setting time, viscosity, surface detail re-production, working time, permanent deformation, strain in compression, compressive strength, temperature rise during gelation, differential thermal analysis, acidity and toxicological properties of representative fourteen commercially available dental alginate impression materials (AG, AP, AR, CC, ID-I, ID-II, JT, KG, PG, PC-I PC-II, SM-I, SM-II and ZG) and three experimental dental} alginate impression materials (Exp A, Exp B and Exp C).
These tests were performed by the methods of KDA specification No. Ei, ISO specification No. 1563 and ANSI/ADA specification No. 18.
From the experiments, the following results can be drawn:
1. The setting time of the fast setting types showed consideTable differences according to the products, but there was no significant difference in setting time of the normal setting types. The significantly difference of viscosity values for the normal setting types was observed with various commercial products, but there was no significant difference for the fast setting types.
2. The reproduction of surface detail of the normal setting types was higher than that of the fast setting types, and the working time of the alginate impression materials showed considerable difference according to the products.
3. The permanent deformation of the fast setting types was lower than that of the normal setting types, and the strain in compression, the compressive strength, and the temperaturerise during gelation of alginate impression materials showed considerable differences according i to the products.
4. The rapid endothermic temperature curves of the alginate impression materials proceed at 127.000 134.7`C, and the exothermic temperature curves showed at 327.7´C , 367.o´C.
5. The acidity of the alginate impression materials showed considerable differences `according to the products, and the fast setting types was lower than that of the normal setting types.
6. The results indicated that the dental alginate ingredients did not increased the frequencies of micronucleated-polychromatic erythrocytes when compared with negative controls.
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