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.