Improvement of prothodontic resin composite containing nano-filler

1. 纳米复合树脂的制备纳米复合树脂的填料由Al_2O_3、TiO_2、CeO_2和SiO_2组成，平均粒径为30 nm。用硅烷偶联剂、4-META和/或有效偶联剂对乙醇溶液中的每种金属氧化物进行处理。研制了一种离心光固化装置，该装置配有4盏150w的卤素灯、玻璃管和旋转开关。将含纳米填料的复合浆料填充在30 mm高的玻璃管中，以1500 rpm离心90 min，连续旋转光固化30 min。2、采用管底块状rein复合材料作为CAD/CAM复合块。冠状复合材料的制备利用CAD/CAM机床将上述块状rein复合材料加工成齿形复合冠。采用复合修复材料作为对照。采用伺服疲劳试验机对前磨牙复合冠进行抗断裂性能评价采用树脂粘接水泥将复合冠固定在钢基台上，然后采用伺服疲劳试验机对不同复合冠的抗断裂性能进行评价。高度填充的纳米复合材料冠的断裂载荷最大。

1. Preparation of nano-composite resinThe filler of nano-composite resin is consisted of Al_2O_3, TiO_2, CeO_2, and SiO_2 which of mean particle size are 30 nm. This filler was treated with silane coupler, 4-META, and/or effective coupler for each metal oxide in ethanol solution.2. Development of centrifugal light-curing apparatus and preparation of specimensA centrifugal light-curing apparatus was developed and this unit is equipped with four halogen lamps of 150 W, glass tubes, and switches for rotation. The composite paste containing nano-filler was filled in the glass tube of height 30 mm, and then centrifuged by 1, 500 rpm for 90 min, followed by light-cured for 30 min with continuously rotation. The bulk rein composites at the bottom of the tubes were used for CAD/CAM composite block.3. Preparation of crown-shaped composite specimensPremolar composite crowns were manufactured from described-above bulk rein composites by CAD/CAM machine. A prosthodontic composite material was used as controls.4. Evaluation of fracture resistance using servo-controlled fatigue machineThe premolar composite crowns were luted on the master-abutment made of steel with resin luting cement, and followed by evaluated fracture resistance of the different composite crowns using servo-controlled fatigue machine. The fractured load of crowns made of highly filled nano-composite showed significantly highest values.