Thermal Behavior of Hybrid Composite, Giomer, Ormocer and Silorane: A Comparative Study Using Two Light Curing Intensities

Abstract

Purpose of the study was to evaluate the effect of type of composite resin (CR) and the intensity of curing device on thermal behavior. A microhybrid composite (C), a giomer (G), an ormocer (O) and silorane (S) were chosen. Specimens were polymerized with a higher (H) and a lower (L) energy LED curing device. Coefficient of thermal expansion (CTE) measurements were performed with a dilatometer at temperature range 20-60oC with temperature raise 2oC/min. CTE values in lower temperatures (21oC-37oC) (CTEa) were compared to CTE values in higher temperatures (37oC-55oC) (CTEb). CTEa for all resin composites ranged from 5.43 – 38.67 (x 10-6/oC) and CTEb from 22.20 – 48.87 (x 10-6/oC), thus depending on CR type, curing intensity and temperature range. Type of CR and light intensity of curing device have an effect on thermal behavior. The higher the temperature, the higher the CTE for all materials. It is advisable to polymerize C with lower intensity curing unit and S and O with higher intensity. G exhibits the highest CTE values with both curing devices, while O exhibits intermediate results with both light intensities in all temperatures.  Higher intensity LED resulted in inhomogenous thermal behavior of the tested materials, especially of S.