Stress Analysis Of Zirconia Endocrowns For Mandibular Second Molars

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-channel 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-channel depth and diameter led to higher stress concentration at the post apex and lower stress at the mesial-buccal bonding interface. For ferrule-around designs, increasing ferrule height reduced stress at both the post apex and bonding interface. Stress in dentin increased with post-channel depth and diameter in butt-joint designs but decreased with increased ferrule height in ferrule-around designs. The study concluded that smaller post channel dimensions (diameter and depth) reduce dentin stress in both butt-joint and ferrule-around endocrown designs, thereby indicating better protection of the remaining tooth structure. Ferrule-around designs exhibited 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.