Abstract: Objective:?The three-dimensional finite element models with different shapes of the split post were established, and the von Mises stress distributions were analyzed. Methods:?According to the slope angle (90°, 120°, 135° and 160°) formed between the root post (the split post in root canal) and the root canal orifice and the diameter difference between the crown post (the part above the root canal) and the root post (0.5 mm, 1 mm, 1.5 mm and 2 mm), the three-dimensional finite element models of 16 different forms of split posts were established by SolidWorks 2016 and ANSYS software. The Von Mises stress distributions of different forms of split posts were analyzed under the conditions of 600 N vertical loading and 225 N horizontal loading, respectively. Results:?The stress distribution of 16 groups of split post models was basically similar under different directions of loading, and the maximum stress was mainly distributed at the junction of crown post and root post; when the root canal orifice was not prepared for slope, the maximum von Mises stress at any diameter difference was significantly higher than that of obtuse angle group with slope (120°, 135° and 160°) under horizontal and vertical loading; When the slope was 120°, the von Mises stress under any diameter difference was lower than that at 135°and 160°angles; When the angle of slope was greater than 90°, the stress at the joint of crown post and root post decreased with the increase of diameter difference, and when the diameter difference between crown post and root post was 2 mm, the von Mises stress value under horizontal and vertical loads was the minimum, regardless of the angle at the joint of crown post and root post. Conclusions:?The slope angle of the split post is recommended to be 90° to 120° in the split zirconia post-crown, and the larger the diameter difference between the crown post and the root post, the better the stress distribution at the joint between the crown post and the root post.

Key words: split post-crown, zirconia ceramic, angle, diameter difference, finite element analysis