Light-curing units for composite resin polymerization

Abstract

Light-curing units for light polymerization of composite resins are important instruments of dental practice, and their proper use has a direct impact on the physical characteristics of the material being illuminated, its biocompatibility, as well as on the overall clinical success and durability of dental composites. Irradiance represents the power of radiation per unit of irradiated surface and should be distinguished from irradiance measured directly at the lamp head, which is called output irradiance or emittance. Also, different areas on the surface of the material can be exposed to different radiation powers, which sometimes significantly deviate from the given average value. The reason for this is the inhomogeneity of the radiation beam. The 3D profile of the light beam gives the most precise information about the quality of radiation to which the material will be exposed. Due to the existence of different photoinitiator systems, the use of devices with a wider emission spectrum that covers a larger range of light wavelengths is often recommended today. An important characteristic of the light-curing unit is its power, but the use of lamps of higher power does not mean a proportional reduction in polymerization time. The quality and maintenance of light sources are certainly one of the important factors that influence the success of restorations.