Dyer R A, Howlett J A
Department of Prosthetic Dentistry, Institute of Dental Surgery, University of London, UK.
J Dent. 1994 Aug;22(4):236-41. doi: 10.1016/0300-5712(94)90120-1.
The dimensional stability of a commercially available acrylic resin, designed specifically for polymerization by microwave irradiation, was compared with that of a conventional water-bath-cured resin. Resin bases were processed on duplicate stone casts prepared from a cobalt chromium master die. Twenty bases were polymerized, using acrylic resin modified for rapid heat curing, in a water-bath at 100 degrees C for 22 min. A further 20 bases were polymerized using a microwave curing acrylic resin, in a conventional microwave oven at 500 W power output for 3 min. Ten bases from each group were sectioned in a parasagittal direction and repaired using the microwave curing resin. Following each curing cycle the fit of the posterior border of each base was evaluated via a silicone index formed between the base and the master die. The index was invested in stone and sectioned through the posterior palatal region to allow measurement of its thickness by means of an eyepiece micrometer. One-way analysis of variance and unpaired Student's t tests were employed to compare the differences in distortion at the initial cure and following repair. No significant differences were found in the distortion of the acrylic resin bases produced from the heat-cured or microwave-cured materials. All bases exhibited significant further distortion on repair with the microwave-cured acrylic resin.
将一种专门设计用于微波辐射聚合的市售丙烯酸树脂的尺寸稳定性与传统水浴固化树脂的尺寸稳定性进行了比较。树脂基托在由钴铬母模制备的复制石膏模型上加工。使用经快速热固化改性的丙烯酸树脂，在100℃水浴中固化22分钟，制备20个基托。另外20个基托使用微波固化丙烯酸树脂，在功率输出为500W的传统微波炉中固化3分钟。每组取10个基托沿矢状旁方向切片，并用微波固化树脂修复。在每个固化周期后，通过基托与母模之间形成的硅橡胶指数评估每个基托后缘的贴合度。将该指数嵌入石膏中，并通过后腭区域切片，以便用目镜测微计测量其厚度。采用单因素方差分析和非配对学生t检验比较初始固化和修复后变形的差异。热固化或微波固化材料制成的丙烯酸树脂基托的变形没有显著差异。用微波固化丙烯酸树脂修复时，所有基托都表现出明显的进一步变形。
