Composite Restorative Resins

Part 1 Setting Characteristics of UV and Visible Light-activated Composite Resins

Abstract

The setting times of 18 commercial light-activated composite resins were measured using an oscillating rheometer, and the effects of specimen thickness, exposure time and distance from the fiber tip of light curing unit to the specimen on the setting time were examined. In addition, the curing shrinkage in the direction of tooth axis and the effect of inorganic filler content on the curing shrinkage were evaluated.
The setting times for specimens of maximum depths of cure recommended by the manufacturers were in the range 0.9-2.5min. These values varied with the thickness of the specimen, exposure time and distance from the fiber tip of light curing unit to the specimen. The curing shrinkage in the direction of tooth axis for a 2.5mm specimen was in the range 1.5-2.8%.