Are 3D printed parts sterile?
Due to the way in which they are manufactured, 3D printed materials are frequently more porous than typical medical device materials, allowing them to harbor microbes if they are not carefully sterilized. Medical sterilization techniques require heat, radiation, and chemical sterilization processes.
Any 3D printed device made for use with patients must be able to withstand repeated exposure to these processes. Most common 3D printing materials will warp, melt, or lose tensile strength when exposed to medical sterilization; see previous link for a list of materials that can be sterilized. There is some sterile 3D manufacturing but it is rare, mostly proprietary, and usually already located in a hospital or research lab. Not usually conducive to mass-scale production.