# Fabrication and Analysis of a Ti6 Al4V Implant for Cranial Restoration
## 1 Introduction  
Cranial restoration or cranial defect replacement can be defined as a medical procedure to reinstate an unhealthy or damaged region on the skull [1]. The primary objective is the shielding of tissues and nerves within the skull, along with the realization of body shape and the achievement of mentalstability in the patient [2]. Cranial restoration is generally carried out on patients who suffer from head trauma as a result of any injury (accident), infection or congenital deformities [3]. The skull injuries or malformation are considered as one of the most critical and worrying health concerns, which affects a large population all over the world [4]. Moreover, the repairing of cranial abnormalities poses serious challenges, even to experienced surgeons, because the body part being operated on comprises of nerves, soft tissues, or other delicate organs, inside a confined zone [5]. A variety of different approaches, such as autologous bone grafting [6; 7], utilization of standard implants manufactured from traditional methods, like casting, forging, machining and powder metallurgy techniques [8; 9], etc., were the common techniques in cranial restoration. However, in recent times, the application of these approaches has been minimized owing to their compelling drawbacks. For example, the autologous bone grafting technique involves complicated operative methods, blood loss, and pain in the patient, etc., [10]. Similarly, the employment of regular implants, which necessitates physical bending or rearrangement using trial runs to custom fit the patient bone contour, is a time-consuming, inaccurate, and laborious approach [11]. Furthermore, any discrepancy would result in implant failure, a greater number of amendments and psychological stress on the patient's mind. Henceforth, to minimize disparities and conform bone contours as well as provide enhanced cosmetic output, it is imperative to make use of the concept of customized implant design [12; 13]. The customized design of an implant can improve fitting accuracy significantly and reduces the operation time in contrast to standard plates. The rapidly growing health care demands owing to aging, expanding the global population, etc., emphasize the importance of innovative technologies in the medical field. The unification of medical data imaging, image processing software and additive manufacturing (AM) has the potential to produce any complex structure (customized implant) with a perfect fit, which can match the bone contour and result in a trimmed appearance. The implementation of integrated techniques can save a huge cost for health systems in addition to improving the quality of life for a large population [14]. A favorable outcome in implant reconstruction depends on several factors such as the material characteristics, implant design, fabrication method and skills of the surgeon. Certainly, the design of customized implants must conform to the individual patient's needs, inclusive of the size, shape and mechanical properties of the implant. As a consequence of unique human anatomy, AM is very useful to accomplish patient-specific implants, matching the bone contours with a perfect fit. The AM has significantly upgraded the ability to manufacture intricate geometrical structures with precision in comparison to the conventional processing methods [15]. It can produce sufficiently packed and graded structures with appropriate accuracy and process adaptability. The applications of AM, especially in the medical sector, have been increasing very quickly and are expected to revolutionize the health care sector. It can successfully manage the requirements of medical devices, in terms of product customization, efficient and cost-effective production, short delivery time, etc. In addition to the appropriate fabrication approach, the precise and pertinent requirements of customized implants also necessitate the implementation of relevant bio-materials.