Effect of photo-polymerization on flexural strength on hybrid composite resin for CAD/CAM milling / 대한치과재료학회지

ABSTRACT

The purpose of this study is to evaluate the effect of photo-polymerization on the mechanical strength of the hybrid resin block. Hybrid composite resin was fabricated by polymer matrix mixed with inorganic filler and various additive. Visible light (460 nm) LED curing device for photo-polymerization was designed and fabricated. Photo-polymerization of resin block was performed under 3 hrs at 1200 mW/cm2 , 2 hrs at 1600 mW/cm2 , 3 hrs at 1600 mW/cm2 , and 4 hrs at 1600 mW/cm2 of irradiation intensities and time. Mechanical strength was measured using flexural strength. In addition, the sample treated for 2 hrs at 1600 mW/cm2 was performed post-treatment under conditions of plasma surface treatment (100 W, 5 min) and light curing for 15 min in order to improve the degree of polymerization. And then specimen was measured for flexural strength again. After the photo-polymerization, surface morphology was analyzed by SEM. The flexural strength of the composite resin block was significantly increased as the irradiation time was increased. Especially, post-treated sample showed higher flexural strength than that of the other samples. In the SEM analysis, surface morphology was no significant difference regardless of the photo-polymerization conditions. Light irradiation and plasma treatment could be a powerful technique to improve the polymerization of hybrid composite resin block for CAD/CAM-processed prosthesis.