Effect of span length and connector size on fracture resistance of monolithic zirconia FPDs: A finite element analysis

The effect of span length and connector size on the fracture resistance of monolithic zirconia fixed partial dentures (FPDs). Twelve mandibular FPD models with 3-, 4-, and 5-unit spans (9 mm, 16 mm, and 23 mm) were digitally created, each incorporating connector sizes of 12 mm², 15 mm², 18 mm² and 21 mm². Finite element analysis using ANSYS 2024 simulated physiological (324 N) and maximal (1270 N) occlusal forces. Longer spans with smaller connectors generated stresses exceeding zirconia's tensile strength, while larger connectors reduced stress values significantly. Data shows that optimizing connector size is essential to improve biomechanical performance and longevity of zirconia FPDs, especially in long-span restorations.