Optimization of endocrown design parameters for mandibular second molars: A 3D finite element analysis

This study aimed to investigate the optimal parameters for endocrown design in mandibular second molars using three-dimensional finite element analysis. Eighteen finite element models(n = 3)were created with varying ferrule heights (0, 1, 2 mm), post space depths (2, 3, 4 mm), and diameters (2, 3 mm). The models simulated zirconia endocrowns on root canal treated teeth. Von Mises stress distribution was analyzed under 200 N oblique loading. Results showed that in butt-joint designs, increasing post space depth and diameter led to higher stress concentration at the post apex and lower stress at the mesial-buccal bonding interface. For ferrule designs, increasing ferrule height reduced stress at both the post apex and bonding interface. Stress in dentin increased with post space depth and diameter in butt-joint designs but decreased with increased ferrule height in ferrule designs. The study concluded that smaller post space dimensions (diameter and depth) reduce dentin stress in both butt-joint and ferrule endocrown designs, thereby indicating better protection of the remaining tooth structure. Ferrule designs exhibited a more uniform stress distribution compared to butt-joint designs. These findings suggest that endocrown design can be optimized to enhance stress distribution and potentially improve clinical outcomes, though further long-term clinical studies are needed to validate these results.