问题的提出 新旧石膏的结合,在口腔矫形工作中是经常遇到的问题,但由于不了解影响其结合的原因,使用的结果,常常是事与愿违。不需其结合得很牢的,如上(牙合)架时用新石膏固定上下颌旧石膏模型,有时却结合得很牢,装盒前要把模型从架环上取下来很困难。有的需要其结合得很牢的,如石膏填充倒凹、 The question put forward The combination of old and new plaster, Oral orthopedic work is often encountered problems, but because they do not understand the reasons for the combination, the results used are often counterproductive. It is not necessary to combine it firmly, as above (occlusal) frame with the new plaster cast on the mandibular old plaster model, sometimes combined with a very strong, it is difficult to remove the model from the frame ring before boxing. Some need to be very strong combination, such as gypsum fill concave,