目的:对不同局部托盘及处理方式制取印模后的石膏模型尺寸精确性作一研究。方法:使用局部托盘制取一上颌标准模型的藻酸盐印模,灌注硬石膏模型。分别测量龈缘24近中边缘至27远中边缘(4个牙位),24远中边缘至27近中边缘(2个牙位)的长度,再与标准模型相应位置的长度进行对比分析。实验根据选用局部托盘的材料不同,分为铝制局部托盘组和钢制局部托盘组;根据托盘边缘是否粘结医用胶布,分为铝制局部托盘胶布粘边组和钢制局部托盘胶布粘边组;根据模型硬固后的测量时间不同,分为1h组和12h组。每组重复6次,数据记录为均数±标准差,采用SPSS 17.0统计分析软件行t检验(α=0.05)。结果:当测量位置为24远中边缘-27近中边缘(2个牙位长度)时,标准模型-钢制托盘胶布粘边取灌模型间未见显著性差异(P=0.149),其余取灌模型组与标准模型组间均可见显著性差异;当测量位置为24近中边缘-27远中边缘(4个牙位长度)时,所有的取灌模型组与标准模型组间可见显著性差异。此外,不同长度的印模制取,任一铝制托盘(胶布粘边)取灌模型组和任一钢制托盘(胶布粘边)取灌模型组之间未见显著性差异。分别测量硬固1h和12h的石膏模型并进行对比,未见显著性差异。结论:2牙位长度的藻酸盐印模制取,钢制托盘胶布粘边制取印模后灌注的硬石膏模型与实物的尺寸更相符;4牙位长度的藻酸盐印模制取,钢制托盘制取的印模和铝制托盘印模在精确性方面没有区别;无论制取2个或4个牙位长度的藻酸盐印模,托盘材料和是否粘边取灌注的硬石膏模型尺寸比较没有显著性差异。 OBJECTIVE: To study the dimensional accuracy of gypsum models after different parts of pallets and processing methods are made. Methods: The local tray was used to prepare an alginate impression of the maxillary maxillary model and perfusion an anhydrite model. The lengths of the gingival margins 24 near the mid margin to the 27 distal margin (4 teeth), the 24 mid-margin to the 27 proximal and middle margin (2 teeth) were measured and compared with the length of the corresponding position of the standard model. According to the experiment, the experiment is divided into the aluminum partial tray group and the steel partial tray group according to the material of the selected local tray. According to whether the edge of the tray binds the medical adhesive tape, it is divided into the aluminum partial tray adhesive cloth sticking group and the steel partial tray adhesive cloth sticking edge Group; According to the different measurement time after the model was hardened, it was divided into 1h group and 12h group. Each group was repeated 6 times, the data were recorded as mean ± standard deviation, using SPSS 17.0 statistical analysis software t test (α = 0.05). Results: There was no significant difference (P = 0.149) between the standard model and the plastic model of the steel pallet adhesive tape when the measurement position was 24 near the mid-edge-27 near the middle edge (2 teeth length) There was a significant difference between the model group and the standard model group; when the measurement position was 24 near the mid-edge -27 distal edge (4 tooth-length), all the model groups were significantly different difference. In addition, there was no significant difference between the impression models of different lengths and the filling model of any aluminum tray (adhesive side) and the filling of any steel tray (adhesive side). The gypsum models which were hardened for 1 hour and 12 hours respectively were measured and compared, and no significant difference was observed. CONCLUSION: Alginate impression system with 2-tooth length and plaster model with perforated edge of steel pallet tape are more consistent with the physical size of the plaster model. 4 Alginate impression system with 4-tooth length , The impression made by the steel tray and the aluminum tray impression are indistinguishable in terms of accuracy; whether making alginate impressions of 2 or 4 tooth positions, the material of the tray, Gypsum model size comparison no significant difference.