Development of Reinforced Glass Polyalkenoate Cement

由于对牙髓的刺激性较低，对牙釉质和牙本质的化学粘附性较好，氟化物释放少，而且具有美观的特点，牙科玻璃聚烯酸盐胶合剂被广泛用作修复剂、填充材料和修复体的衬里或基础。然而，这些材料也有一些缺点；脆性、溶解性和较低的耐磨性。因此，目前的应用范围是有限的。本研究的目的是改善牙科玻璃聚烯酸盐水泥的理化性能。在牙科玻璃聚烯酸水泥中加入了8种Aerosil、过滤器，它们分别包含在一种复合树脂和一种圆形高分子聚乙烯中。制备试样，改变粉末中添加剂的体积，测试粉末的抗压强度、直径抗拉强度、抗折强度、表面硬度、牙刷耐磨性、溶解度和透光度。结果表明，粒径为30 μ m的疏水性微颗粒降低了水泥的抗压强度。而粒径小于1 μ m的微颗粒则增加了材料的直径抗拉强度，从而控制了材料的体积。具有多面体形状和锋利边缘的填料增加了抗弯强度。7种粒径较小的气溶胶使表面硬度降低。在牙刷磨损和溶解度测试中，并不是每一个微粒都降低了性能。特别是一种Aerosil，它含有钛作为成分，增加了放射性。

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.