Enhanced manufacturing of titanium prosthetics
Medical prostheses include not only prosthetic limbs but also miniature artificial devices such as dental implants that restore or replace living tissues and their functions. In fact, the use of titanium implants in dental, maxillofacial and cranial reconstruction applications has increased considerably in recent years. Titanium and some of its alloys (when titanium is combined with other metals) are biocompatible (non-toxic and not rejected by the body), strong and lightweight, corrosion resistant and cost efficient. However, many of the conventional casting processes are time consuming and expensive due to the numerous steps involved. In the case of emergency surgery, time is of the essence and a turnaround time of weeks is quite prohibitive. In addition, machining introduces contaminants from lubricants and cleaning agents. European researchers initiated the ‘Rapid manufacturing of titanium implants’ (Ramati) project to develop the technological foundations to quickly produce small (on the scale of 0.100 millimetres), tailor-made prostheses. The technology was based on scaling down the laser freeform manufacturing (LFFM) process. LFFM is used to produce ‘freeform’ metal components directly from computer-aided design (CAD) files without part-specific tooling or knowledge. Metal powder is injected into the focused beam of a laser creating a pool of metal on which subsequent layers are ‘built’. The process eliminates all of the pitfalls of traditional casting methods while enabling the use of superior titanium. Ramati researchers developed special equipment for scaling down the LFFM process including a novel microdeposition nozzle and a new powder feeder design. Furthermore, they improved materials processing by developing new methods for design and synthesis of titanium alloys. The scientists also developed software enabling design of prostheses from computed axial tomography (CAT) scans. Taken together, the Ramati team delivered a novel integrated LFFM system for rapid and cost-effective production of high quality customised dental prostheses and implants that should benefit manufacturers and consumers alike.
