Manufacturing Of Patient-specific Implants Research Articles

Reconstruction of the orbitozygomatic framework: State of the art and perspectives

The reconstruction of the whole orbitozygomatic framework (OZF) is complex and can be encountered in cases of congenital midface deformity, after tumor ablative surgery and in severe facial trauma. Nowadays, surgeon has a wide range of available techniques that have continually grown over the past years, optimizing the surgical management and the aesthetical outcomes. Among them, the autologous bone graft (ABG) remains one of the most suitable options : ABG is easy to harvest and has optimal biological properties for bone healing. It can be tailored to the patient anatomy thanks to the recent advances in computer-assisted surgery. However, substantial drawbacks remain such as the early resorption of the non-vascularized graft, the need of a donor site and its potential morbidity. Alloplastic reconstruction is another option that can resolve both the resorption issue and the donor site morbidity. Moreover, the 3D-printing technologies also allows the manufacturing of patient specific implants. However, alloplastic materials have a variable success, especially due to the high risk of infection or exposure. Consequently, regenerative medicine is a promising field that aims to find a procedure without the disadvantages of ABG or alloplastic based reconstructions, but displaying similar or even higher success rate. Indeed, recent tissue engineering strategies have demonstrated encouraging results for bone regeneration using natural or synthetic biomaterials, patient cells and synthetic bioactive substances. The objective of this review is to present the etiologies of OZF defect, the available reconstruction procedures as well as the current state of the research.

Composite grafts made of polycaprolactone fiber mats and oil-based calcium phosphate cement pastes for the reconstruction of cranial and maxillofacial defects

ObjectivesSynthetic bone substitutes which can be adapted preoperatively and patient specific may be helpful in various bony defects in the field of oral- and maxillofacial surgery. For this purpose, composite grafts made of self-setting and oil-based calcium phosphate cement (CPC) pastes, which were reinforced with 3D-printed polycaprolactone (PCL) fiber mats were manufactured.Materials and methodsBone defect models were acquired using patient data from real defect situations of patients from our clinic. Using a mirror imaging technique, templates of the defect situation were fabricated via a commercially available 3D-printing system. The composite grafts were assembled layer by layer, aligned on top of these templates and fitted into the defect situation. Besides, PCL-reinforced CPC samples were evaluated regarding their structural and mechanical properties via X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscopy (SEM), and 3-point-bending testing.ResultsThe process sequence including data acquisition, template fabrication, and manufacturing of patient specific implants proved to be accurate and uncomplicated. The individual implants consisting mainly of hydroxyapatite and tetracalcium phosphate displayed good processability and a high precision of fit. The mechanical properties of the CPC cements in terms of maximum force and stress load to material fatigue were not negatively affected by the PCL fiber reinforcement, whereas clinical handling properties increased remarkably.ConclusionPCL fiber reinforcement of CPC cements enables the production of very freely modelable three-dimensional implants with adequate chemical and mechanical properties for bone replacement applications.Clinical relevanceThe complex bone morphology in the region of the facial skull often poses a great challenge for a sufficient reconstruction of bony defects. A full-fledged bone replacement here often requires the replication of filigree three-dimensional structures partly without support from the surrounding tissue. With regard to this problem, the combination of smooth 3D-printed fiber mats and oil-based CPC pastes represents a promising method for fabricating patient specific degradable implants for the treatment of various craniofacial bone defects.

Fused filament printing of specialized biomedical devices: a state-of-the art review of technological feasibilities with PEEK

Purpose The potential implications of the three-dimensional printing (3DP) technology are growing enormously in the various health-care sectors, including surgical planning, manufacturing of patient-specific implants and developing anatomical models. Although a wide range of thermoplastic polymers are available as 3DP feedstock, yet obtaining biocompatible and structurally integrated biomedical devices is still challenging owing to various technical issues. Design/methodology/approach Polyether ether ketone (PEEK) is an organic and biocompatible compound material that is recently being used to fabricate complex design geometries and patient-specific implants through 3DP. However, the thermal and rheological features of PEEK make it difficult to process through the 3DP technologies, for instance, fused filament fabrication. The present review paper presents a state-of-the-art literature review of the 3DP of PEEK for potential biomedical applications. In particular, a special emphasis has been given on the existing technical hurdles and possible technological and processing solutions for improving the printability of PEEK. Findings The reviewed literature highlighted that there exist numerous scientific and technical means which can be adopted for improving the quality features of the 3D-printed PEEK-based biomedical structures. The discussed technological innovations will help the 3DP system to enhance the layer adhesion strength, structural stability, as well as enable the printing of high-performance thermoplastics. Originality/value The content of the present manuscript will motivate young scholars and senior scientists to work in exploring high-performance thermoplastics for 3DP applications.

Applications of three-dimensional printing in orbital diseases and disorders.

To comprehensively review the applications of advanced three-dimensional printing technology in the management of orbital abnormalities. Three-dimensional printing has added value in the preoperative planning and manufacturing of patient-specific implants and surgical guides in the reconstruction of orbital trauma, congenital defects and tumor resection. In view of the costs and time, it is reserved as strategy for large and complex craniofacial cases, in particular those including the bony contour. There is anecdotal evidence of a benefit of three-dimensional printing in the manufacturing of prostheses for the exenterated and anophthalmic socket, and in the fabrication of patient-specific boluses, applicators and shielding devices for orbital radiation therapy. In addition, three-dimensional printed healthy and diseased orbits as phantom tangible models may augment the teaching and learning process of orbital surgery. Three-dimensional printing allows precision treatment tailored to the unique orbital anatomy of the patient. Advancement in technology and further research are required to support its wider use in orbital clinical practice.

Low temperature fabrication of magnesium phosphate cement scaffolds by 3D powder printing

Synthetic bone replacement materials are of great interest because they offer certain advantages compared with organic bone grafts. Biodegradability and preoperative manufacturing of patient specific implants are further desirable features in various clinical situations. Both can be realised by 3D powder printing. In this study, we introduce powder-printed magnesium ammonium phosphate (struvite) structures, accompanied by a neutral setting reaction by printing farringtonite (Mg(3)(PO(4))(2)) powder with ammonium phosphate solution as binder. Suitable powders were obtained after sintering at 1100°C for 5 h following 20-40 min dry grinding in a ball mill. Depending on the post-treatment of the samples, compressive strengths were found to be in the range 2-7 MPa. Cytocompatibility was demonstrated in vitro using the human osteoblastic cell line MG63.