# Fabrication and Analysis of a Ti6 Al4V Implant for Cranial Restoration
## 4 Conclusions  
The realization of cranial reconstruction significantly depends on the restoration of its appearance, aesthetics and mechanical properties. It has been a known fact that the traditional methods of cranial reconstruction are insufficient because they cannot successfully address customization. Therefore, an effective methodology has been developed in the pursuit of a customized, pleasing and reliable cranial implant. The EBM technology has been integrated with CT to accomplish the objective of a customized implant. Certainly, the remarkable features of this methodology were its four pillars, including image processing, modeling, fabrication, and testing. Generally, the difficult task in customized reconstruction, especially using AM is the specification of its approval tests. Therefore, in this work, several validation techniques have been utilized to ascertain the quality of the implant produced by the EBM. For instance, the 3D comparison analysis was utilized to determine the accuracy and fitting of the implant, the tensile test was employed to confirm the mechanical strength, FEA to verify its load resistance ability, etc. The implemented approach was unique and exhaustive as it intended to minimize uncertainty in each phase through techniques such as STL error correction, thickness reduction, etc. The segmentation approach was employed to slice the defective region, while the mirror reconstruction technique was applied to acquire the customized implant for the affected region. The results of the 3D comparison analysis established that the anatomy or the outer profile of the skull were dependable in terms of appearance, fitting and aesthetics. The average deviation lied within the range of \(-1.0587\) to \(0.9294\) mm, along with the RMS value of \(1.5347\) mm. These results also affirmed the mirror modeling technique as an ideal approach to reconstruct defects that exist on one side (left or right) of the head (imagine a plane \begin{table}
\begin{tabular}{c c c} \hline \hline
**Material** & **Volume (mm\({}^{3}\))** & **Weight (grams)** \\ \hline Replaced Cranial Bone & 84427 & 135 \\ \hline Titanium implant & 33277 & 128 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Weight details of the replaced cranial bone and EBM fabricated titanium implant. Figure 15: EDX Spectrum and SEM image of EBM produced Ti6 Al4V ELI part. running from head to tail leading to bilateral symmetry). Moreover, to minimize the shielding effect, the implant fabricated by the EBM was processed to achieve a thickness in the range of \(\simeq\)1.76-2 mm. The FEA analysis was imperative to ascertain the loading ability of the designed customized implant. This analysis based on maximum stress (2.5 MPa), strain value (\(1.49\times 10^{-4}\)) and maximum deformation (\(3.26\times 10^{-6}\) mm) deduced that the accomplished implant design can be employed convincingly in the restoration of the unhealthy skull region. The analysis results post-fabrication were also adequate as acknowledged by various mechanical test procedures. The average yield (825 MPa) and the tensile strength (880 MPa) of the EBM fabricated specimens were in agreement with the previous researches as well as the ASTM standards in the medical industry. Similarly, the surface hardness of these specimens was in the range of 30-35 HRC, which was consistent with the desired ARCAM and ASTM norms. The chemical composition of the manufactured specimen also did not alter appreciably in comparison to its raw state, thus validating its intactness. Besides, the weight of the EBM fabricated titanium cranial implant was in complete agreement with that of the substituted skull region. The employed approach is effective and useful because it can successfully minimize the revisions and errors, enhance fit and result in implant stability as well as reduce the treatment time and operative difficulties. The EBM produced cranial implant augments the aesthetic and functional recovery of cranium abnormalities to accomplish efficient and immediate reconstruction.