Abstract: Objective To compare the stress distribution of endodontically treated premolar prepared with 3 different fiber post lengths and 2 different abutment heights, using finite element approaches. Methods A finite element model of the mandibular first premolar tooth defect was created, and 3 different fiber post lengths (11 mm, 14 mm and 17 mm) and 2 different abutment height (3 mm and 5 mm) were designed. A 100 N static load of 135° was applied on the buccal cusp of the mandibular first premolar to simulate occlusal force. The maximum compression and tension stress values were recorded respectively. Results The maximum tensile stress (16.47 MPa) and maximum compressive stress (-20.15 MPa) of the 11/5 combination were the highest; the maximum tensile stress (14.56 MPa) and the maximum compressive stress (-15.94 MPa) of the 17/3 combination were the lowest. The maximum tensile stresses of the 14 mm and 17 mm post length groups were lower than that in the 11 mm post length group. The maximum tensile stress and the maximum compressive stress concentration of the 3 mm abutment height groups were lower than those of the 5 mm abutment height group. Conclusion The finite element analysis results show that the fiber post length has a negative correlation, while the abutment height has a positive correlation with the maximum tensile stress and the maximum compressive stress in the cervical region.

Key words: Fiber post, Post length, Abutment height, Ferrule, Finite element analysis