Photopolymerization of a dental nanocomposite as restorative material using the argon laser

The aim of this study was to investigate the effect of power density and irradiation time of an argon laser on the physico-mechanical properties of light-cured dental nanocomposites. The composites were cured with 260 mW/cm² and 340 mW/cm² power densities at different irradiation times. The degree of conversion (DC), flexural strength, flexural modulus, water sorption, solubility and reaction temperature were measured. The maximum DC (50%), which was achieved after approximately 20 s irradiation, and the reaction temperature rise (20°C) were demonstrated by composite containing 20% filler cured at 340 mW/cm². The composite with 25% filler cured at 340 mW/cm² showed the highest flexural strength and modulus, which were 32.2 MPa and 1.89 GPa, respectively. The minimum water sorption (3.8%) and solubility (1.2%) were achieved with the composite containing 25% filler cured at 340 mW/cm². Finally, the composite with 25% filler cured at 340 mW/cm² showed higher physico-mechanical properties.