abs plastic and is very light compared to metal if they use like resin as the material then it will be poisonous when breathed in so the most likely use abs. In dental the uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants. with human tissues their goal is to produce scaffolds to repair or replace damaged tissues and organs. Three-dimensional printing uses a bottom-up approach, and they use this as its strong and lightweight. the hearing aid is the same thing as the rest it’s because it strong which means that it won’t break when having it and also, they used fdm to make it out of plastic because if it was made out of metal then it might be too heavy by the ear. 3D printing made prosthetics cool and affordable. Almost as soon as affordable 3D printing technologies became available, literally dozens of projects have focused on using them to produce prosthetics at accessible costs to people in developing countries or to children.