Development of Reinforced Glass Polyalkenoate Cement

牙科玻璃聚烯酸酯粘固剂因其对牙髓的刺激性低、对牙釉质和牙本质的化学粘附性、氟化物的释放和美观等特点而被广泛用作粘固剂、充填材料和修复体下的衬里或基材。然而，这些材料也有一些不利之处：脆性、溶解性和耐磨性较低。因此，目前的适用范围是有限的。本研究的目的是改善牙科玻璃聚烯酸酯粘固剂的物理化学性能。在牙科玻璃聚烯酸酯粘固剂中加入8种Aerosil、复合树脂中的填充剂和圆形高分子聚乙烯。通过改变粉料中添加剂的用量，测试了水泥的抗压强度、径向抗拉强度、抗折强度、表面硬度、牙刷磨损、溶解度和不透射线等性能，结果表明，直径为30微米的疏水微粒降低了水泥的抗压强度。然而，直径在1微米以下的微粒增加了径向拉伸强度，以控制体积。具有多面体形状和锋利边缘的填料提高了弯曲强度。七种直径较小的气溶胶降低了表面硬度。在牙刷磨损和溶解度测试中，并不是每一个微粒都会降低性能。特别是一种含有钛的Aerosil，增加了辐射不透明度。

Dental glass polyalkenoate cements have been widely used as a luting agent, a filling material and a liner or a base beneath restorations because of a lower irritation to dental pulp, a chemical adhesion to enamel and dentin, a fluoride release and an aesthetic characteristic. However, these materials also have some disadvantaged ; brittleness, solubility and lower wear resistance. Accordingly, the sphere of application is limited at present. The purpose of this study is to improve the physico-chemical properties of a dental glass polyalkenoate cement. Eight kinds of Aerosil, filers which were included in a composite resin and a round type of high molecular polyethylene were added to the dental glass polyalkenoate cement. Specimens were made to alter the volume of the additives in the powder and compressive strength, diametral tensile strength, flexural strength, surface hardness, toothbrush abrasion, solubility and radiopacity were tested.The results indicated that the micro particles which were 30 mum in diameter and were hydrophobic decreased the compressive strength of the cement. However, the micro particles which were under 1 mum in diameter increased the diametrical tensile strength to control the volume. The fillers which had a polyhedron shape and a sharp edge increased flexural strength. Seven kinds of Aerosol which had a small diameter decreased the surface hardness. Not every micro particle decreased the properties in the tests of toothbrush abrasion and solubility. One type of Aerosil, in particular, which included titanium as a component increased radiopacity.