通过研究模拟口镜练习对口腔临床前期实践操作水平的影响，探索其在牙体牙髓实验教学中的应用前景。

将中山大学光华口腔医学院2012级口腔临床医学五年制本科60名学生使用随机数字表法随机分为实验组和对照组，每组30人。实验组学生课前进行模拟口镜练习，对照组不参加练习。在实验课上两组学生均在仿头模上完成窝洞预备，预备完成后教师对牙体预备情况（窝洞深度、鸠尾宽度）进行评分，学生通过自制口镜使用调查问卷进行自评，记录出现每个问题的人数并计算百分比。将数据录入SPSS 20.0统计软件，不同分组窝洞预备质量采用非参数秩和检验（Mann-Whitney U）进行分析，口镜使用调查问卷结果采用卡方检验进行分析。

教师对窝洞预备进行等级评分：实验组窝洞深度获优、良、差的人数分别为22、7、1人，对照组分别为15、10、5人，实验组成绩优于对照组成绩（Z = -2.308，P = 0.021）。实验组鸠尾宽度获优、良、差的人数分别为20、9、1人，对照组分别为12、14、4人，实验组成绩优于对照组成绩（Z = -2.177，P = 0.029）。口镜使用调查表发现，实验组学生出现问题"口镜中没有距离感，无法判断预备窝洞的深度"的学生百分比（6.67%），明显低于对照组（33.33%），差异具有统计学意义（χ² = 6.667，P = 0.01）；实验组学生出现问题"口镜视野不清晰，图像失真，有重影"的学生百分比（0%），明显低于对照组（23.33%），差异具有统计学意义（χ² = 7.925，P = 0.005）。

模拟口镜练习有助于判断窝洞预备的深度，提高术区视野清晰度，有利于提高口腔医学生临床前期的实践操作技能，提升牙体牙髓病学临床前期教学质量。

To explore the effects of odontoscope simulation practice before class on improving students′ clinical operational skill and its application in the experimental teaching of endodontic.

Using Random Number Tables, 60 students from grade 2012 Guangzhou School of Stomotology were randomly divided into two groups, odontoscope simulation practice in experimental group and non-practice in control group. During the experimental courses, the two groups of students completed teeth preparation on the head-simulators. The teacher scored the quality of teeth preparation (cavity depth, dovetail width) . The problems encountered during preparation of teeth before and after odontoscope simulation practice were recorded with self-made questionnaire and the percentage of each problem was calculated. The teaching quality of the practice was also evaluated. Using SPSS 20.0 statistical software, the preparation quality of cavity in different groups was analyzed by Non-parametric rank-sum test (Mann-Whitney U) , and the questionnaire data were recorded and analyzed by t-test.

The number of excellent, good and poor in cavity depth in the experimental group was 22, 7 and 1 respectively. The number of excellent, good and poor in cavity depth in the control group was 15, 10 and 5 respectively. The experimental group′s performance was better than that in the control group (Z = -2.308, P = 0.021) . The number of excellent, good and poor dovetail widths in the experimental group was 20, 9 and 1 respectively, while the number of excellent, good and poor dovetail widths in the control group was 12, 14 and 4 respectively. The experimental group′s performance was better than that in the control group (Z = 2.177, P = 0.029) . The questionnaire on the use of oral mirror found that the percentage of students in the experimental group (6.67%) who had problems "no sense of distance in the oral mirror and could not judge the depth of the prepared cave" was significantly lower than that in the control group (33.33%) with statistical significance (χ² = 6.667, P = 0.01) . The percentage of students in the experimental group (0%) who had problems "unclear visual field of the oral mirror, distortion of the image, and double shadow" was significantly lower than that in the control group (23.33%) . The difference was statistically significant (χ² = 7.925, P = 0.005) .

Odontoscope simulation practice contributed to the improvement of the students′ ability of clinical operational skill and the teaching quality of clinical training.