Functional Limit and its evaluation method in oral cavity of restorative composite resin.

本研究主要由以下四个部分组成：紫外光和可见光活化复合树脂的固化特性。制造商推荐的最大固化深度标本的设置时间在0,9 -2,5分钟范围内。这些数值随试样厚度、曝光时间和光固化装置光纤尖端到试样的距离而变化。2.5m试件沿牙轴方向的固化收缩率为1,5-2,8%。紫外光和可见光活化复合树脂的物理和机械性能。材料的硬度在光照后显著增加，并在24小时后达到大约恒定的值。硬度和弹性模量强烈依赖于填料含量。填料含量与抗压强度之间无显著关系。紫外光和可见光活化复合树脂对小鼠成纤维细胞的细胞毒性试验。以培养的L929小鼠成纤维细胞为材料，进行了光活化复合树脂琼脂覆盖层细胞毒性试验。随着固化材料中未反应物质的增加，l细胞的损伤面积增大。牙本质扭转的动态剪切模量。牙釉质的动剪切模量和损失切线明显稳定，且与温度无关。37℃时的剪切模量范围为2,35 x10 ^<11> ~ 4,48 x10 ^<11 >dyne /cm^2。当温度接近50 ~ 100ºC时，牙本质的剪切模量略有增加，这是由于水分的损失造成的。牙釉质的模数大约是它的三到五倍。剪切模量与性别、年龄、牙型无显著相关性。结果表明，尺寸稳定性试验是评价复合修复树脂口腔功能极限最有效的方法。

The present investigation is composed of the following four Parts.1. Setting characteristics of UV and visible light-activated composite resins.The setting times for specimens of maximum depths of cure recommend by the manufacturers were in the range 0, 9-2,5 min. These values varied with the thickness of the specimen, exposure time and distance from the fiber tip of light curing unit to the specimen.The curing shrinkage in the direction of tooth axis for a 2.5m specimen was in the 1,5-2,8%.2. Physical and mechanical properties of UV and visible light-activated composite resins.Hardness of the material increased considerably after exposure to light and reached approximately constant values after 24 hours. Hardness and elastic modulus were strongly dependent upon the filler fraction.There was no significant between filler fraction and compressive strength.3. Cytotoxicity test to Mouse Fibroblasts in culture of UV and visible light-activated composite resins.Agar overlay cytotoxicity tests of light activated composite resins were carried out, using L929 mouse fibroblasts in culture.The injured area of L-cell was enlarged as the unreacted substances in the cured material increased.4. Dynamic shear modulus in torsion of human dentin.For enamel, the dynamic shear modulus and the loss tangent were markedly stable and independent of the temperature. The shear moduli at 37ﾟC ranged from 2,35X10^<11> to 4,48X10^<11> dyne/cm^2. For dentin, the shear modulus slightly increased for temperatures near 50 to 1OOﾟC, which was caused by a loss of water.Enamel had a modulus which was approximately three to five times higher. There were no significant correlations between the values of the shear modulus and sex, age or tooth type.It was found that the dimensional stability test is the most effective in the estimation of the functional limit in oral cavity of the restorative composite resins.