An Experimental Study on Particular Physical Properties of Several Interocclusal Recording Media. Part I: Consistency Prior to Setting

PURPOSE: To evaluate the consistency prior to the setting of 5 elastomeric interocclusal recording materials in comparison with a wax and a zinc oxide-eugenol paste. This property is related to the viscosity as well as to the working and setting times of these materials. MATERIALS AND METHODS: Testing of consistency was performed following a modification of the method described in ADA Specification No. 19, for elastomeric impression materials. Each one of the tested materials was mixed for 20 seconds and was then loaded into a 0.5 mL syringe. The material was syringed onto a 10 x 10 x 0.5 cm glass plate. A second 575 g glass plate was placed on top of the unset interocclusal registration material. A total of 10 samples were tested for each material. The surface area covered by the materials was measured with the help of a scanner and the use of appropriate computer software. RESULTS: One-way ANOVA revealed significant differences among the materials (F = 889.493, p < 0.0005). According to Tukey's honest significant difference test, all materials were significantly different (p < 0.05) from one another. All polyvinylsiloxanes occupied a smaller area than that of the polyether and of the zinc oxide-eugenol paste. CONCLUSIONS: Zinc oxide-eugenol paste was the most fluid of all materials tested. Polyvinylsiloxanes displayed less flow properties than polyether.