Impact of First Maxillary Molar Abutment Inclination on Stress Distribution in Two Types of Zirconia Crowns: A 3D Finite Element Analysis
Sara Jahaf, Abdulwahab Al-Kholani, Asma Al-Rumaimah, Ibrahim Al-Shami, Mahmoud Almustafa
Background: This study aimed to evaluate the impact of abutment inclination on stress distribution
in monolithic and bi-layered zirconia crowns for maxillary first molars, using three-dimensional finite
element analysis (FEA).
Methods: Three-dimensional models of maxillary and mandibular first molars were developed from
micro-computed tomography data, incorporating detailed anatomical and material properties. Six FEA
models were created to simulate three occlusal conditions: centric occlusion, palatal crossbite, and
buccal crossbite. A static load of 200 N was applied in vertical, oblique, and horizontal directions to
replicate physiological masticatory forces.
Results: The analysis revealed marked differences in von Mises stress distribution and magnitude across
crown types and abutment inclinations. Stress concentrations were notably higher under oblique and
horizontal loads, especially in crossbite conditions. Monolithic zirconia crowns exhibited more uniform
and favorable distribution than bi-layered crowns across all scenarios.
Conclusions: The findings suggest that abutment inclination and crown type significantly influence
stress behavior in zirconia restorations. Monolithic zirconia crowns are preferable for managing stress,
particularly in non-ideal occlusal situations, and may contribute to enhanced durability and clinical
performance.
