口腔修复学0303（Prosthodontics 0303）.docVIP

口腔修复学0303（Prosthodontics 0303） (six) impressions and models The impression and perfusion models of different restoration types for dental defects are basically the same, and the methods have the following aspects: 1. make impression according to the shape and size of the column, choose the suitable tray with holes, and ask that the tray can cover over two adjacent teeth of the teeth near and far. Strictly follow the instructions of the manufacturer of the impression material, take powder and liquid or powder and water, and mix it in the tray. Take a small amount of impression material with your fingers, press the hole in the nest, overflow the gas in the cavity, then send the tray to the population to keep the tray stable. After the impression material is solidified, gently remove it. The impression should be clear and complete. Determine the impression to meet the requirements, the excess impression material tray edge truncate, at the same time, take on the jaw impression and median wax. In addition, agar and rubber impression materials are available. The clarity, accuracy, volume stability and elasticity of the impression are better than those of alginate impression material. Rubber impression material is the best. 2. make model and making detachable detachable type generation type production generation there are two methods, namely irrigation model and irrigation model and nail after nail method. (1) irrigation model and nail method: the central impression preparation teeth, along the long axis of the insertion of a conical metal polyhedron pile or nail, pile head should be slightly higher than that in roots, the formation of undercut or toothed, to pile and artificial stone retention. The root of the pile is clamped with a small hairpin to determine the position of the pile head in the center of the impression for the preparation of the teeth, and is not in contact with the impression material, and the root is arranged in the direction of its long axis. The ends