Liciane Sabadin Bertol

Manufacture of Accurate Titanium Cranio-Facial Implants with High Forming Angle Using Single Point Incremental Forming

One of the key application areas of Single Point Incremental Forming is in the manufacture of parts for bio-medical applications. This paper discusses the challenges associated with the manufacture of cranio-facial implants with extreme forming angles using medical grade titanium sheets. While on one hand, the failure wall angle is an issue of concern, the parts also need to be manufactured with accuracy at the edges where the implants fit into the human body. Systematic steps taken to overcome these challenges, using intelligent intermediate part design, feature analysis and compensation, are discussed. A number of case studies illustrating the manufacture of accurate parts in aluminium, stainless steel and titanium grade-2 alloy are discussed.

Dimensional evaluation of patient-specific 3D printing using calcium phosphate cement for craniofacial bone reconstruction

The 3D printing process is highlighted nowadays as a possibility to generate individual parts with complex geometries. Moreover, the development of 3D printing hardware, software and parameters permits the manufacture of parts that can be not only used as prototypes, but are also made from materials that are suitable for implantation. In this way, this study investigates the process involved in the production of patient-specific craniofacial implants using calcium phosphate cement, and its dimensional accuracy. The implants were previously generated in a computer-aided design environment based on the patient’s tomographic data. The fabrication of the implants was carried out in a commercial 3D powder printing system using alfa-tricalcium phosphate powder and an aqueous solution of Na2HPO4 as a binder. The fit of the 3D printed implants was measured by three-dimensional laser scanning and by checking the right adjustment to the patient’s anatomical biomodel. The printed parts presented a good degree of fitting and accuracy.

Different post-processing conditions for 3D bioprinted α-tricalcium phosphate scaffolds

The development of 3D printing hardware, software and materials has enabled the production of bone substitute scaffolds for tissue engineering. Calcium phosphates cements, such as those based on α-tricalcium phosphate (α-TCP), have recognized properties of osteoinductivity, osteoconductivity and resorbability and can be used to 3D print scaffolds to support and induce tissue formation and be replaced by natural bone. At present, however, the mechanical properties found for 3D printed bone scaffolds are only satisfactory for non-load bearing applications. This study varied the post-processing conditions of the 3D powder printing process of α-TCP cement scaffolds by either immersing the parts into binder, Ringer’s solution or phosphoric acid, or by sintering in temperatures ranging from 800 to 1500 °C. The porosity, composition (phase changes), morphology, shrinkage and compressive strength were evaluated. The mechanical strength of the post-processed 3D printed scaffolds increased compared to the green parts and was in the range of the trabecular bone. Although the mechanical properties achieved are still low, the high porosity presented by the scaffolds can potentially result in greater bone ingrowth. The phases present in the scaffolds after the post-processing treatments were calcium-deficient hydroxyapatite, brushite, monetite, and unreacted α-TCP. Due to their chemical composition, the 3D printed scaffolds are expected to be resorbable, osteoinductive, and osteoconductive.Graphical abstract

Customized craniofacial implants: Design and manufacture

Abstract: This chapter provides an overview of the different methods currently available to design and manufacture customized craniofacial implants. Tools and techniques, such as computer tomography, CAD/CAM systems, 3D scanning, single point incremental forming, CNC milling and rapid prototyping are highlighted.

Designed in Brazil

Background Health design in Brazil has been characterized historically by replacing imported products with others that are locally manufactured on a small scale. In January 2007, the Health Design Group was created at the National Council for Scientific and Technological Development, a partnership between professors and scholars from the University of Sao Paulo. Aiming at documenting some important experiences on the Brazilian scene to provide historical and methodological subsidies for research, a survey was conducted to find the pioneer experiences that, using the technology available at the time they were developed, paved the way for the current research. Method Interviews and surveys in newspapers and journals were conducted with selection of some Brazilian experiences in design for health from the end of the 1950s till the early 2000s, along with its researchers.

Design and health care: a study of virtual design and direct metal laser sintering of titanium alloy for the production of customized facial implants

The increase in life expectancy and a great number of accidents lead to higher demand for medical products, including corrective implants. Patients with tumors or traumas need to replace injured areas in order to restore their aesthetic and structural function. Currently, the available craniofacial implants present a standard geometry and seldom generate satisfactory results. Customized implants, on the other hand, are designed to conform exactly to individual patient’s anatomy. This way, the use of customized implants can show beneficial effects to the patient and the surgical team. In this study, the design and manufacturing of customized implant prior to surgery were described. Implant shape and functional requirements were established by digital data based on CT-scans and mirroring operations. The design process of customized mandible prosthesis is illustrated as well as its manufacturing process (direct metal laser sintering) and quality control. Laser sintering process and its constraints for the production of customized implants in titanium alloy (Ti-6Al-4V) with complex geometry and internal structures are reported.