| Popis: |
Publisher Summary There is a continuous demand for dental and maxillofacial prostheses resulting from both disease and trauma. Specifically, the main causes of skull defects requiring implants are reported to be severe intracranial traumata, tumours, cerebral infarcts and osteomyelitis. Cancerous tumours often account for the necessary removal of significant amounts of hard and soft tissues in order to prevent the disease from spreading and surgery is a major treatment option. In such cases, significant reconstruction may be required to allow the person to return to as near normal living conditions as possible. The biomaterials that have been used for such reconstructions are many and include materials from the major classes – namely– metals, polymers and ceramics, and various composites of these. The properties of such materials vary considerably and some are more ideal than others for specific implant types. Superplasticity is the mechanism of deformation and it is one of grain rotation coupled with grain boundary sliding, with an inherent resistance to necking and thus to fracture, resulting in extremely high ductilities of the order of several thousand per cent in some materials, including titanium alloy. This chapter explores the use of Superplastic Forming (SPF) for medical and dental prostheses. SPF could become a niche manufacturing tool for certain types of customised prostheses especially since the combined advantages of low forming pressures, low-cost tooling, high dimensional accuracy and appropriate surface modification could make the process comparatively cost effective. An important aspect of the application of SPF to the medical and dental sectors is the development of sophisticated modelling tools based on finite element and geometrical simulation. |
