ABSTRACT
Background and aim: Zinc oxide eugenol [ZOE] impression material, due to its favorable characteristics, has numerous uses in removable denture impression making and jaw relation recording. In Iran, this material is commercially produced as Duralite. The purpose of this study was to investigate consistency and working time of Iranian ZOE [Duralite] and compare it with foreign ZOE ]Luralite] based on British standard 4284: 1981
Materials and Methods: in this invitro experimental study, forty samples were studied. An apparatus for the determination of material consistency and a penetrometer for working time measurement were used. For consistency measurement, 0.5cc of each impression paste was put between two glass plates and under one 1500gr. load. After 15 seconds, the diameter of resulting disk was measured with a digital caliper. For working time measurement, each paste was put in a metal ring [diameter: 30mm, height: 3mm] and then in 30-second intervals the penetration of penetrometer needle was measured. Data were analyzed by t-student test
Results: mean consistency of Duralite impression material was measured 43.42+/-2rnm and that of luralite was 45.22+/-lmm. Mean working time for Duralite impression material was measured 2':50"+/-01:19" and for Luralite was 81:30"+/-0:25". The results of this study revealed that the consistency and working time of Duralite and Luralite impression materials are within the range of British standard
Conclusion: no statistically significant difference was found in mean consistency of Duralite and Luralite impression materials [P=0.08], but there is a significant difference between their mean working times [P <0.001]