Basic studies and clinical evaluation on calcium phosphate crystalline ceramic crown

1、全冠的尺寸精度和适合性：（1）无论是铸造玻璃还是微晶玻璃，其尺寸变化均随边缘宽度的增加而增加。（2）结晶过程导致0.9%-1.0%的边缘收缩。在肩部类型的情况下，外径为1.00%，内径为1.43%-1.62%。（3）临床冠的咬合面内适合度为160 μ m。（2）临床冠的断裂强度：玻璃陶瓷冠用临时粘固剂粘接树脂粘固剂粘接后，其断裂强度随肩宽的增加而增加。3、全冠的力学性能：采用有限元法对下颌第二前磨牙全冠的应力和变形进行分析。垂直载荷作用下的牙冠和牙体结构的变形和应力均小于水平载荷作用下的颊侧牙尖。4、磷酸钙晶体陶瓷的粘接强度：粘接表面处理的影响（硅烷偶联剂和底漆）通过拉伸和剪切试验倾向于增加粘结强度。5、磷酸钙结晶陶瓷上的食物纹理：6、全冠的临床应用：自1984年10月至1990年3月，为90例患者制作了150多个全冠。无冠折裂、变色、磨损等问题。

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.