Purpose – The aim of this study was to explore the application of rapid manufacturing (RM) to the production of patient specific, custom-fitting removable partial denture (RPD) alloy frameworks. RPDs are metal frameworks designed to retain artificial replacement teeth in the oral cavity. Design/methodology/approach – The study was undertaken by applied case study. An RPD was designed using computer-aided design software according to well-established dental technology design principles, based on a digitally scanned cast produced from an impression of the patient's mouth. The RPD design was then exported as an STL file in preparation for direct manufacture using selective laser melting. Dimensionally accurate frameworks were manufactured in 316L stainless steel and chromium-cobalt alloy. These were assessed for accuracy of fit and function on the patient cast and on the patient in clinic. Findings – This successful case study demonstrates that an RM approach can produce fully functional, precisely fitting RPD frameworks for specific individual patients. Research limitations/implications – The study was based on a single design produced using two materials. Further studies are in progress to show that the results can be achieved on a regular and predictable basis. Practical implications – This study provides some practical guidance for the application described and suggests that similar success may be achieved in related custom-fitting applications. Originality/value – The paper demonstrates the successful application of a novel approach to the design and manufacture of custom-fitting dental devices.

This study explores the application of computer-aided design and manufacture (CAD/CAM) to the process of electronically surveying a scanned dental cast as a prior stage to producing a sacrificial pattern for a removable partial denture (RPD) metal alloy framework. These are designed to retain artificial replacement teeth in the oral cavity. A cast produced from an impression of a patient's mouth was digitally scanned and the data converted to a three-dimensional computer file that could be read by the computer-aided design (CAD) software. Analysis and preparation were carried out in the digital environment according to established dental principles. The CAD software was then used to design the framework and generate a standard triangulation language (STL) file in preparation for its manufacture using rapid prototyping (RP) methods. Several RP methods were subsequently used to produce sacrificial patterns, which were then cast in a chromium-cobalt alloy using conventional methods and assessed for accuracy of fit. This work demonstrates that CAD/CAM techniques can be used for electronic dental cast analysis, preparation, and design of RPD frameworks. It also demonstrates that RP-produced patterns may be successfully cast using conventional methods and that the resulting frameworks can provide a satisfactory fit.

Purpose – The computer-aided design (CAD) and manufacture of custom-fitting surgical guides have been shown to provide an accurate means of transferring computer-aided planning to surgery. To date guides have been produced using fragile materials via rapid prototyping techniques such as stereolithography (SLA), which typically require metal reinforcement to prevent damage from drill bits. The purpose of this paper is to report case studies which explore the application of selective laser melting (SLM) to the direct manufacture of stainless steel surgical guides. The aim is to ascertain whether the potential benefits of enhanced rigidity, increased wear resistance (negating reinforcement) and easier sterilisation by autoclave can be realised in practice. Design/methodology/approach – A series of clinical case studies are undertaken utilising medical scan data, CAD and SLM. The material used is 316L stainless steel, an alloy typically used in medical and devices and surgical instruments. All treatments are planned in parallel with existing techniques and all guides are test fitted and assessed on SLA models of the patients' anatomy prior to surgery. Findings – This paper describes the successful application of SLM to the production of stainless steel surgical guides in four different maxillofacial surgery case studies. The cases reported address two types of procedure, the placement of osseointegrated implants for prosthetic retention and Le Fort 1 osteotomies using internal distraction osteogenesis. The cases reported here have demonstrated that SLM is a viable process for the manufacture of custom-fitting surgical guides. Practical implications – The cases have identified that the effective design of osteotomy guides requires further development and refinement. Originality/value – This paper represents the first reported applications of SLM technology to the direct manufacture of stainless steel custom-fitting surgical guides. Four successful exemplar cases are described including guides for osteotomy as well as drilling. Practical considerations are presented along with suggestions for further development.

Purpose – Maxillofacial prosthetics is faced with increasing patient numbers and cost constraints leading to the need to explore whether computer-aided techniques can increase efficiency. This need is addressed through a four-year research project that identified quality, economic, technological and clinical implications of the application of digital technologies in maxillofacial prosthetics. The purpose of this paper is to address the aspects of this research that related to the application of rapid prototyping (RP). Design/methodology/approach – An action research approach is taken, utilising multiple case studies to evaluate the current capabilities of digital technologies in the preparation, design and manufacture of maxillofacial prostheses. Findings – The research indicates where RP has demonstrated potential clinical application and where further technical developments are required. The paper provides a technical specification towards which RP manufacturers can direct developments that would meet the needs of maxillofacial prosthetists. Originality/value – Whilst research studies have explored digital technologies in maxillofacial prosthetics, they have relied on individual studies applying a single RP technology to one particular aspect of a prosthesis. Consequently, conclusions on the wider implications have not been possible. This research explored the application of digital technologies to every aspect of the design and manufacture of a series of maxillofacial prostheses. Unlike previous research, the cases described here addressed the application of RP to the direct manufacture of substructures, retention components and texture. This research analyses prosthetic requirements to ascertain target technical specifications towards which RP processes should be developed.