数字化口腔修复（22）--牙体预备体轴壁倾斜度的数字化评价

目的：本研究旨在通过椅旁计算机辅助设计（ computer aided design，CAD）系统（ CEREC?）中的扫描设计软件（SW 4.4）获取预备体的光学模型数据，及利用牙体预备评估软件（PrepCheck 2.0）测量上颌前牙全瓷冠预备体的轴壁倾斜度（ axial inclination，AI）以评估学生临床前期牙体预备体位培训和CAD的系统性训练对于上颌前牙全瓷冠修复预备体AI的影响。方法：随机选择口腔医学专业40名大学三年级上学期学生，进行为期2周的临床前期牙体预备培训课程，主要内容包括牙体预备的体位培训和PrepCheck软件的运用。通过PrepCheck软件测量培训前后每位学生各预备的2颗预备体和标准预备体的唇侧、舌侧、近中向和远中向AI值。结果：培训前后预备体舌侧轴壁倾斜度及标准预备体舌侧AI值之间的差异均有统计学意义（ P＜0.05），培训后的舌侧AI值较培训前的小，但大于标准预备体的舌侧AI值。培训前唇侧、近中和远中AI值均大于培训后的AI值（ P＜0.05），但培训后的AI值与标准预备体之间的差异无统计学意义（P＞0.05）。结论：临床前期牙体预备体位培训和PrepCheck软件课程可有效提高牙体轴壁倾斜度预备的质量。

Digital restorative dentistry and prosthodontics(22)---Digital evaluation of the axial inclination in tooth prep-aration

Objective:To evaluate the effects of pre-clinical systematic training of the standard body posture for tooth preparation and CAD on the AI( axial inclination) of preparations for the all-ceramic crown restorations of maxillary anterior by using the scan and design software( SW 4.4) of CEREC?chair-side computer aided design( CAD) system to obtain the op-tical model,and the software(PrepCheck 2.0)to measure AI of maxillary anterior preparations.Methods:Forty junior dental students in college were randomly selected for participating in two-week preclinical training of the standard body posture for tooth preparation,and the application of PrepCheck software.Each student was required to prepare two teeth before and after training,respectively.AI of the preparations in groups of pre-and post-training and master were measured by the PrepCheck software.Results:It was shown that there was a significant difference in palatal AI of preparations among the pre-training group,the post-training group and the master( P<0.05).The average values of palatal AI in the post-training group were lower than that of the pre-training group,but it was still higher than that of the master preparation( P<0.05).AI values of la-bial,mesial,and distal in pre-training group were significantly higher than that of post-training(P<0.05),but no differences between the post-training group and the master group( P>0.05).Conclusion:The course of the standard body posture and PrepCheck software in pre-clinical tooth preparation training had improved the quality of AI of tooth preparation effectively.