Abstract
The rapid growth of light-cured materials has been resulted in a general need and more frequent use of curing units. Several types of curing units offer to optimize polymerization of resin composites in a given situation. A curing unit which utilize a solid state light emitting diode (LED) as a light source has been developed. Though spectral distributions of LED curing units are thought to be suitable for polymerization of visible light-cured resins, little is known about the curing characteristics of the LED curing units. The purpose of this study was to evaluate the effect of LED curing units on mechanical properties of light-cured resins.
LED curing units Aqua Blue (Toesco) and Lux O Max (Akeda Dental), and a halogen lump curing unit Optilux 400 (Demetron) as a control, were used. Depth of cure and Knoop hardness number on longitudinally sectioned surface of Clearfil AP-X (Kuraray Medical), Lite-Fil II A (Shofu) and Filtek Z250 (3M ESPE) were measured. From the results of this study, depth of cure and Knoop hardness number of the light-cured resins polymerized with the LED curing unit, whose light intensity was lower than those of the halogen lump curing unit, were lower and the need of prolonged irradiation time was indicated.
