## 2 The Advent of 3D Printing in Medical Field  
Three-dimensional printing, also known as additive manufacturing, has emerged as a transformative technology in the last few decades [16]. The process involves creating three-dimensional objects from a digital file, typically by adding material layer by layer [17]. This contrasts with traditional subtractive manufacturing methods, which rely on cutting away material. Various types of 3D printing exist, including stereolithography (SLA) [18], fused deposition modeling (FDM) [19], and selective laser sintering (SLS) [20], each with its unique strengths and suitable applications (Figure 1). SLA stands out for its remarkable advantages, which include a high resolution and clean surface finishes [18]. The technique employs a liquid resin that is solidified layer  
Figure 1: There are several forms of 3D printing, such as (**a**) stereolithography, (**b**) fused deposition modeling (FDM), and (**c**) selective laser sintering (SLS), each possessing distinct advantages and appropriate areas of application. by layer using a laser or a UV light source (Figure 1a). This results in the production of intricate and detailed models. Furthermore, the SLA process enables the creation of smooth surfaces, enhancing the aesthetic appeal of the final product [21]. However, it is important to acknowledge the drawbacks associated with SLA. One significant limitation is the relatively long processing time required for the completion of the printing process [22]. Additionally, SLA is limited in terms of material choice, as it primarily relies on liquid resins [22]. Moreover, the post-production step of removing supporting structures can be time consuming and labor-intensive [22]. In the SLA classification of 3D printing, there is a 3D printing technology based on digital light processing (DLP) [23]. DLP stands out for several reasons. Its hallmark is its unparalleled accuracy, which is manifested in the creation of models that are not only precise but also have a smooth surface finish, thanks to the light-cured resin technique it employs [23]. The computer-generated surgical guide template, a product of this technology, emerged as a beacon of innovation, offering surgeons enhanced visualization, superior treatment planning, and outcomes that could be predicted with a higher degree of certainty [24]. Its versatility is evident in its wide range of applications, from crafting presurgical dental models to aiding intricate surgical procedures [24]. On the other hand, FDM offers distinct benefits that make it a popular choice in many applications [19]. Notably, FDM exhibits a high production speed, making it suitable for rapid prototyping and small-scale manufacturing (Figure 1b). Additionally, FDM is characterized by low startup and production costs, which makes it a cost-effective option for various industries [21]. However, FDM has certain limitations that should be considered. One significant drawback is the poor mechanical characteristics of the printed objects, which often exhibit reduced strength and durability [25]. Furthermore, FDM products may have a noticeable layered appearance, which can be visually unappealing. Additionally, the retained support structures in FDM prints require manual removal before the final product can be used [26]. SLS is another prominent 3D printing technique that utilizes a powder-based approach [27]. In SLS, a high-power laser selectively fuses powdered materials together, layer by layer, to create the desired object (Figure 1c). SLS offers several advantages, particularly in the production of patient-specific implants, such as titanium mesh or cranial plates. These implants require high biocompatibility and mechanical strength, both of which are achieved through the SLS process. The technique also allows for the use of a wide range of materials, offering flexibility in terms of material selection. However, it is worth noting that SLS has its limitations.