Indicator pastes: their behavior and use.

Abstract

Indicator pastes were subjected to a laboratory investigation and a clinical trail. The tests showed: 1. An increase in temperature increased the rate of flow of the pastes. 2. An increase in applied pressure increased the rate of the flow of the pastes. 3. Pastes containing a small percentage of filler were compressed to a smaller thickness than those containing a greater percentage of filler. 4. The zinc oxide-hydrogenated oil mixture demonstrated a biphasic flow pattern. Pressure Indicator Paste demonstrated a simple flow pattern. 5. Similar tests did not give identical results. However, the characteristics of flow curves for similar tests were consistent. 6. A clinical trial using eight subjects showed no marked differences between three indicator pastes but did show significant differences between the interpretations of paste patterns by four dentists. This evidence suggests that the nature of the suspension medium affects both the type of flow and the rate of flow of an indicator paste. The percentage composition of filler affects both the final film thickness and the rate of flow. Improved criteria for the interpretation of paste patterns must be developed before clinical differences in paste behavior are noted.