## 8 Current Challenges in the Development of 3D-Printed Prostheses  
Despite the significant advances that 3D printing has brought to the field of prosthetics, there are still technical and economic challenges that limit its widespread adoption. The upfront costs of high-quality 3D printers and specialized materials remain major barriers, especially in developing countries. In addition, although technologies such as FDM and SLA allow for the rapid production of prosthetics, the time and post-processing costs to improve finishes and functionality still represent a challenge [11].  
The future of 3D printing in prosthetics looks promising, with advances in hybrid technologies that combine plastic and metal materials, as well as the use of bio-compatible materials that allow for a more natural integration with the human body. More advanced 3D printers that can print on multiple materials simultaneously are also being devel  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Technology** & **Materials Used** & **Precision and Detail** & **Print Speed** & **Production Cost** & **Applications in Prosthetics** \\ \hline \multirow{3}{*}{Fused Deposition Modeling (FDM) [4,5]} & \multirow{3}{*}{Plastics such as PLA, ABS, PETG} & Moderate accuracy, limited detail & \multirow{3}{*}{Medium to fast} & \multirow{3}{*}{Low} & Manufacture of functional and economical prostheses. Common use in low-cost prototypes. \\  & & & & & & \\ \hline \multirow{3}{*}{Stereo-lithography (SLA) [6,7]} & \multirow{3}{*}{Light-curable liquid resins} & High precision and surface quality & \multirow{3}{*}{Slow to medium surface quality} & \multirow{3}{*}{Moderate to high} & Highly detailed prostheses, especially small parts and aesthetic components. \\  & & & & & & \\ \hline \multirow{3}{*}{Selective Laser Sintering (SLS) [8,9]} & \multirow{3}{*}{Nylon powders, polymers} & High precision, complex details & \multirow{3}{*}{Medium to fast} & \multirow{3}{*}{High} & Creation of robust, resistant, and customized prostheses; ideal for functional applications. \\  & & & & & & \\ \hline \multirow{3}{*}{Metal Powders (Metal 3D Printing) [1,10]} & \multirow{3}{*}{Metal alloys such as titanium, steel, cobalt} & Very high precision, complex parts & \multirow{3}{*}{Slow} & \multirow{3}{*}{Very high} & \multirow{3}{*}{Bionic or mechanical prostheses, and strong and resistant structures, such as hip implants and joints.} \\  & & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 6: Comparison of 3D printing technologies for prosthetics.  
oped, which could further expand the design and functionality possibilities of robotic prosthetics [12].  
Despite significant advances in 3D printing and its application in the development of robotic prosthetics, several technical, economic, and integration challenges persist that limit its large-scale adoption. Key challenges include material optimization, prosthetic durability and functionality, advanced customization, integration with biological systems, and affordability. In addition, aspects such as regulation and standardization in the use of these technologies also play a key role in their expansion.