|Budget Amount *help
¥4,800,000 (Direct Cost : ¥4,800,000)
Fiscal Year 1993 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1992 : ¥3,200,000 (Direct Cost : ¥3,200,000)
The dual-cured resin cements are polymerized with the chemical curing and the light activation. However, it is pointed out that the amount of light through an adherent material is important for its polymerization. The purpose of this study was to investigate the influence of irradiation conditions on the physical properties of dual-cured resin cements.
First of all, the marketed activator lights were evaluated. Their light intensity and distribution of wave length were many variances. The physical properties were influenced by trradiation conditions. The improvement of their physical properties was most likely due to increased light activating. The light energy (light intensity x irradiation time) was one of the most important factors for increasing physical properties. When the amount of light was the same. no differences were observed of these cements. The light activating intensity and sequence were very important factors influencing dentin bond strenghths.
And the pre-mix activation of the liquid as a new method. The setting time of the cement mix with pre-mix activation was shorter than with no activation. The compressive strength and flexural strength incresed with the pre-mix and post-mix activation.
As the conclusion, the performance of this product is highly dependent upon proper light curing tehnique. This demands the operator's close attention to the cure times, light access to the materials, distance of the light from the materials, and light intensity.