数字化口腔修复(24)——牙体预备磨除量的数字化评价

Digital restorative dentistry and prosthodontics(24)——Digital evaluation of the reduction in tooth preparation

目的：本研究旨在利用椅旁计算机辅助设计（computer aided design，CAD）中的牙体预备评估软件SW4．4（CEREC@）测量上颌前牙全瓷冠预备体的磨除量，评估培训前后临床前期学生牙体预备质量的差异。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SW4．4软件学习。标准预备体和培训前后的预备体分别为对照组和实验组。通过测量软件比较唇侧、舌侧（各9点）及切端（3点）的磨除量与标准预备体之间的差异。结果：培训前的唇侧和切端磨除量与培训后和标准预备体的差异均有统计学意义（P〈0．05）。而培训后的唇侧和切端磨除量与标准预备体的差异均无统计学意义（P〉0．05），但培训前后及标准预备体三组之间的舌侧磨除量的差异有统计学意义（P〈0．05）。结论：SW4．4软件在临床前期学生的牙体预备训练中，能够有效提高学生在唇侧、切端的牙体预备质量。与标准预备体比较，培训前的牙体舌侧预备量不足，而培训后则预备过量。

Objective：To evaluate the differences of tooth preparation in pre-clinical dental students before and after the training SW 4.4 software（ CEREC ） by using of chair-side computer aided design （CAD）to measure the reductions of maxillary anterior teeth after preparations. Methods：The methods to use the software were trained in two-week preclinical curriculum for forty junior dental students in medical college who were randomly selected. The master and preparations of students before and after training were divided into control group and experimental group, respectively. To compare the differ- ences of labial, incisal （9 points, respectively）, and lingual（3 points）reductions in tooth preparation with those of the master by measuring software. Results ：There was significant difference in labial and incisal reduction of preparations between the pre-training group and the master（ P 〈 0. 05 ）, and that was none occurred between the post-training group and the master（ P 〉 0.05 ）. But there were significant differences in lingual reduction among the three groups （ P 〈 O. 05 ）. Conclusion： These results suggested that SW 4.4 software was to effectively improve the quality of labial and incisal tooth preparation after students finished their pre-clinical training course. But it also represented there were underreduced in pre-training and overre- duced in post-training in lingual part of preparation when compared with the master.