Evaluation of Stress Distribution in Tooth‐Supported Fixed Dental Prostheses Made of Translucent Zirconia with Variations in Framework Designs: A Three‐Dimensional Finite Element Analysis

Abstract

Purpose:To evaluate the influence of the framework designs on the stress distribution within tooth-supported partially veneered fixed dental prostheses (FDPs) made of translucent zirconia under simulated loads using a three-dimensional finite element analysis (3D-FEA). Material and Methods: For a linear 3D-FEA, simplified 3D solid models of prepared abutment teeth (first premolar and first molar) with different 3-unit FDPs were created. The models with different FDP designs-monolithic zirconia (control); semimonolithic zirconia with 0.3 mm veneer thickness (SM0.3); semi-monolithic zirconia with 0.5 mm veneer thickness (SM0.5); semi-monolithic zirconia with 0.5 mm veneer thickness supported with cap design (SMC), and semi-monolithic zirconia with 0.5 mm veneer thickness supported with wave design (SMW)-were analyzed using 3D-FEA. The elastic properties of the components (bone, dentine, cement, translucent zirconia, and veneering porcelain) were obtained from the published data for FEA. Simulated static loading forces (300 N) were applied at 10°oblique direction over six points in the occlusal surfaces of the FDPs. Maximum principal stress, shear stress, and safety factor were calculated and analyzed among the different models. Results: Semi-monolithic with cap design showed the smallest maximum principal stress levels in the veneering porcelain compared to all other models (SM0.3, SM0.5, SMW). The SM0.3 had lower maximum principal stress levels in the veneering porcelain compared to SM0.5. Regarding stresses in the zirconia framework, all models had comparable results in maximum principal tensile stresses, except SMW had a lower value. Maximum principal stress levels were located in the veneer component of SM0.3, SM0.5, and SMW, whereas, such levels were observed in the cervical areas of the zirconia frameworks of SMC and control. The SM0.3 had the highest maximum shear stress levels at the zirconia-veneer interface, while SMW had the lowest shear values. The 3D-FEA models with different FDP designs showed different minimum safety factor levels. Conclusions: Framework and veneer designs play a significant role in the stress distribution of the partially veneered zirconia FDPs under loading. The FDPs with zirconia frameworks with cap design minimize the maximum principal tensile stress in the veneering porcelain. The FDPs with 0.3-mm-veneering porcelain show low maximum principal tensile stress in the veneering porcelain, but highest maximum shear stress at the zirconia-veneer interface. The FDPs with wave design of zirconia frameworks minimize the maximum shear stress considerably.

Comparative Evaluation of Stress Acting on Abutment, Bone, and Connector of Different Designs of Acid-Etched Resin-Bonded Fixed Partial Dentures: Finite Element Analysis

“…A recent systematic review ( Reddy et al, 2019 ) suggested that FEA analysis enhances the validity of the models. A Swedish study ( Bakitian et al, 2020 ) recommended that the framework designs play a significant role in stress distribution. A Japanese study ( Tsouknidas et al, 2020 ) reported that ceramic veneers could restore the biomechanical behavior of prepared anterior teeth.…”

Inlay-Retained Dental Bridges—A Finite Element Analysis

“…Other factors that could further influence fracture resistance are the design of the preparation, framework design, and surface treatments of fixed dental prosthesis [24][25][26]. A study demonstrated that the highest fracture resistance values were observed in the case of the butterfly wings design followed by inlay and box designs [27].…”

Phase Transformations and Subsurface Changes in Three Dental Zirconia Grades after Sandblasting with Various Al2O3 Particle Sizes

“…Since ceramic materials could fail by brittle fracture, the maximum principal stress (MPS) was considered to evaluate the stress filed on loading below the impact zone. The analyses of tensile (positive) or compressive (negative) stresses at impact were conducted in the zirconia components of all models [ 23 ]. The contact between abrasive particle and the zirconia substrate was expressed by a simplified model of point-indentation microfracture patterns ( Figure 2 ) as a function of alumina particle size.…”

“…The contact between abrasive particle and the zirconia substrate was expressed by a simplified model of point-indentation microfracture patterns ( Figure 2 ) as a function of alumina particle size. The region of material erosion was calculated by adaptive mesh and element deletion [ 23 ]. The meshing process was performed on the models with 10-node quadratic tetrahedral elements and the mesh size was set to 0.001 mm.…”