Study on 1. C-shaped root canal system: An improved Melton classification model was put forward, the X-ray classification standard of main root canal system of C-shaped root canal system was established, and the three-dimensional morphological classification of C-shaped root canal system was constructed. The International Journal of Dentistry (SCI) published two research papers.

2. Research on the apical locator: An in vitro experimental model was established to clarify the influence of apical pore diameter and electrolyte in root canal on the measurement accuracy of the third and fourth generation root canal length electrometers.

3. Study on root canal microleakage: The glucose measurement model of root canal microleakage was constructed for the first time, which revealed the relationship between root canal deviation and root canal microleakage, and related papers have been included in SCI.