## 3 Results  
After the numerical calculation, von-Mises stress (MPa) and Equivalent Strain results were obtained for each simulated condition. The stress data were summarized using colorimetric maps (Figures 4-8). The stress peaks in each structure were reordered and summarized in Table 2. The Yield strength of crown materials is summarized in Table 3. The red color indicates the maximum value obtained by calculation as a standardized limit to show difference between the models. The strain is the elongation or deformation of the material that undergoes stresses. The required energy to store the total strain on the whole body is the strain energy, summarized in Table 2 according to the different materials combination. For the Von-Mises stress (Figure 4), a similar stress trend was calculated regardless of the PC material. However, the lower the rigidity of restorative material, the higher the stress concentration on the SC intaglio surface near the load application area. In addition, for the restoration margin, similar stress magnitudes were observed irrespective of the crown materials. The restoration failure risk consisted of the material highest peak divided per its strength [34] and is summarized in Table 4. It is possible to observe that regardless of the material combination, that SC presents superior failure risk in comparison with the PC. In addition, all PC showed reduced failure risk. With only a 0.05 difference between the calculated ratios for the SC, the clinical behavior and the use of fatigue methods were necessary to indicate a significant difference between the models. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Model (PC + SC)**} & \multicolumn{2}{c}{**Failure Risk**} \\ \cline{2-3}  & **SC** & **PC** \\ \hline PEKK + PEKK & 0.96 & 0.28 \\ Titanium + PEKK & 0.92 & 0.13 \\ Zirconia + PEKK & 0.92 & 0.06 \\ CoCr + PEKK & 0.91 & 0.13 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Failure risks for primary and secondary crown according to the different materials combination. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Model (PC + SC)**} & \multicolumn{4}{c}{**Stress (MPa)**} & \multicolumn{4}{c}{**Microstrain**} \\ \cline{2-7}  & **SC** & **PC** & **Cement Layer** & **PDL** & **Bone** & **Strain Energy (mJ)** \\ \hline PEKK + PEKK & 158.3 & 46.4 & 2.15 & 126 & 365 & 0.111 \\ Titanium + PEKK & 152.2 & 67.5 & 3.28 & 126 & 364 & 0.115 \\ Zirconia + PEKK & 151.1 & 68.8 & 3.29 & 125 & 365 & 0.115 \\ CoCr + PEKK & 150.9 & 68.9 & 3.29 & 125 & 366 & 0.115 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Outcomes based on stress peak values (MPa), micro-strain, and strain energy (mJ), according to the primary crown material. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Material**} & **Yield Strength** & **References** \\ \hline PEKK & 165 MPa & [30] \\ Titanium & 519 MPa & [31] \\ Zirconia & 1190 MPa & [32] \\ CoCr & 540 MPa & [33] \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Yield strength of crown materials. Primary crown (Figure 5) stress analysis showed a proportional pattern of distribution between the structures as the restorative material elastic modulus decreased. However, for this structure, the effect of restorative material was more evident, with lower stress concentration in the PEKK-PEKK combined model. The occlusal surface showed high stress magnitude; however, this was the case in all models regardless of the restorative material. For the PC, the stress peaks ranged from 46.4 to 68.9 MPa. These differences in stress values were proportional to the material stiffness. Therefore, the higher the elastic modulus of the primary crown, the higher the stress magnitude in its structure. A similar  
Figure 4: Stress distribution (MPa) in the secondary crown’s intaglio surface according to the PC restorative material: (**a**) PEKK; (**b**) Titanium; (**c**) CoC; and (**d**) Zirconia.