Mechanical Properties of Visible Light Cured Composite Resins : (1) Effect of Exposure Time and Aging on the Compressive Properties

Abstract

Cylindrical specimens(4mm in diameter×4mm in height)of visible light cured composite resins were cured in white teflon mold by illuminating from the top for 10, 20, 40 and 60 sec and from the top and bottom for 60 sec each.Specimens were then stored in air at 23℃ for 30 minutes, in water at 37℃ for 24 hours, or in water at 37℃ for 7 days before testing.Compressive test was performed and compressive yield strength were calculated.Specimens stored for 30 minutes did not have sufficient strength, and the compressive yield strength could not be calculated for some specimens.Prolonged exposure times up to 40 sec increased the strength of the specimens but a 60 sec exposure had no clear effect.