关键词: 箍结构, 抗力, 桩核, Ferrule, Fracture resistance, Post and core

Abstract: Objective To evaluate the effect of one-wall ferrule with different location and height. Methods 35 mandibular first premolars were divided into seven groups: Group 1 to Group 3: teeth with a 1 mm ferrule only in the buccal, lingual or proximal region; Group 4 to Group 6: teeth with a 2 mm ferrule only in the buccal, lingual or proximal region; and Group 7: teeth with no ferrule. All the teeth were restored with fiber posts, composite cores and full-metal crowns. Each specimen was subjected to an increasing compressive force at 135 degrees from the long axis in a universal testing machine with a crosshead speed of 1.0 mm/min until fracture. Data were recorded and analyzed using One-way and Two-way ANOVA tests. Results The fracture resistance of teeth was significantly affected by the location of ferrule（P＜0.025）, and the mean failure strength of the buccal group was significantly higher than the lingual group（P＜0.025）. Group 4 demonstrated the highest mean failure strength value in all groups, and the value was significantly higher than group 2, group 3, group 5, and group 7（P＜0.025）. The remaining groups showed no statistical significance. All the fracture mode of specimens were repairable. Conclusion The fracture strength was higher when the dentin wall of ferrule was closer to the loading force. Compared with the no ferrule group, to provide a one-wall ferrule with at least 2 mm high on the main loading force side could improve the fracture strength of teeth.