Basic studies and clinical evaluation on calcium phosphate crystalline ceramic crown

1、冠的尺寸精度和适合性：(1)无论是晶化前(铸造玻璃)还是晶化后(微晶玻璃)，随着边缘宽度的增加，冠的尺寸变化均增加。(2)结晶过程导致外径收缩0.9%-1.00%，肩型导致内径收缩1.43%-1.62%。(3)临床冠在咬合面上的内适合度为160微米。2、临床冠的抗折强度：临时粘接树脂粘固剂的玻璃陶瓷冠的抗折强度随肩宽的增加而增加。冠的力学行为：利用有限元方法，分析冠在下颌第二前磨牙上的变形和应力。牙冠和牙体结构在垂直载荷作用下产生的位移和应力均小于颊尖端的水平载荷。4、与磷酸钙晶体陶瓷的粘接强度：通过拉伸和剪切实验，粘附性表面处理(硅烷偶联剂和底漆)的效果趋于增加。5、食物质地对磷酸钙晶体陶瓷的粘附性和粘接性的影响：使用磷酸钙晶体陶瓷柱塞的粘附性和粘接性的下降幅度小于铝质柱塞(对照)。6、冠的临床应用：从1984年10月到1990年3月，为90名患者制作了150多个全冠。冠无折裂、变色、咬合磨损等不良反应。

1, Dimensional accuracy and adaptation of crowns : (1)There was an increase in dimensional changes as the width of the margin increased both before crystallization (cast glass) and after (glass-ceramic). (2)The crystallization procedure caused shrinkage of the margins of 0.9.%-1.00% for the external diameter and 1.43%-1.62% for the internal diameter in the case of the shoulder type. (3)Internal adaptation of clinical crowns was 160mum on the occlusal surfaces.2, Fracture strength of clinical crowns : The fracture strength of glass-ceramic crowns placed with temporary cement adhesive resin cement increased together with the width of the shoulder. The strength was significantly higher with the adhesive resin cement.3, Mechanical behavior of crown : With the use of the finite element method, deflections and stresses of crown on the mandibular second premolar were analysis. Deflections of the crowns and stresses induced in the crown and the tooth structure under the vertical load were less than the horizontal load on the buccal cusp.4, Adhesive strength to calcium phosphate crystalline ceramic : The effect of adherent surface treatment (silane coupling and primer)tend to increase the adhesive strength by tensile and shearing tests.5, Food texture on the calcium phosphate crystalline ceramic : Adhesiveness and stickiness by use of calcium phosphate crystalline ceramic plunger decreased less than aluminum plunger(control).6, Clinical application of crowns : More than 150 crowns were fabricated for 90 patients from October in 1984 through March in 1990. THere was no problem for fracture, discoloration and occlusal wear of crown.