The Significance of Computer Modeling and 3D Printing Technology for Facial Ectoprosthetics

The integration of information technologies in healthcare practice significantly changes the methods of diagnosis and treatment, the forms of interaction of doctors with patients and colleagues, the organization of treatment and recovery of health. The field of reconstruction of the auricle is still a huge challenge for facial plastic surgeons and requires at various techniques to find the best treatment for each patient. The paper describes the application of computer modeling and laser stereolithography technology in surgical practice for auricular surfaces ectoprosthetics. To improve the accuracy and quality of the surgical intervention the positioning of external prosthesis is applied with the aid of personal templates and computer navigation. The accuracy of ectoprosthesis positioning when using a plastic mask template was 0.3-0.4 mm, while computer navigation was 0.1 - 0.2 mm. Using personalized templates is a simpler and more intuitive way of positioning that does not require expensive computer navigation systems. This example of ectoprosthetics shows the possibilities of various reconstructions of facial organs, not only the ear, but also, for example, the nose, using computer modeling and 3d printing technologies

Physical and Chemical Properties Characterization of 3D-Printed Substrates Loaded with Copper-Nickel Nanowires

This study deals with the laser stereolithography manufacturing feasibility of copper-nickel nanowire-loaded photosensitive resins. The addition of nanowires resulted in a novel resin suitable for additive manufacturing technologies based on layer-by-layer photopolymerization. The pure and nanowire-loaded resin samples were 3D printed in a similar way. Their morphological, mechanical, thermal, and chemical properties were characterized. X-ray computed tomography revealed that 0.06 vol % of the composite resin was filled with nanowires forming randomly distributed aggregates. The increase of 57% in the storage modulus and 50% in the hardness when loading the resin with nanowire was attributed to the load transfer. Moreover, the decrease in the glass transition temperature from 57.9 °C to 52.8 °C in the polymeric matrix with nanowires evidenced a decrease in the cross-linking density, leading to a higher mobility of the polymer chains during glass transition. Consequently, this research demonstrates the successful dispersion and use of copper-nickel nanowires as a reinforcement material in a commercial resin for laser stereolithography.

Photocurable Methacrylate Derivatives of Polylactide: A Two-Stage Synthesis in Supercritical Carbon Dioxide and 3D Laser Structuring

A two-stage polylactide modification was performed in the supercritical carbon dioxide medium using the urethane formation reaction. The modification resulted in the synthesis of polymerizable methacrylate derivatives of polylactide for application in the spatial 3D structuring by laser stereolithography. The use of the supercritical carbon dioxide medium allowed us to obtain for the first time polymerizable oligomer-polymer systems in the form of dry powders convenient for further application in the preparation of polymer compositions for photocuring. The photocuring of the modified polymers was performed by laser stereolithography and two-photon crosslinking. Using nanoindentation, we found that Young’s modulus of the cured compositions corresponded to the standard characteristics of implants applied in regenerative medicine. As shown by thermogravimetric analysis, the degree of crosslinking and, hence, the local stiffness of scaffolds were determined by the amount of the crosslinking agent and the photocuring regime. No cytotoxicity was observed for the structures.

Use of powder silicon as a photocurable resin filler for laser stereolithography and prospects for transforming stereolithographic parts with silicon from polymeric to ceramic ones.

The article deals with the peculiarities of using silicon micropowder as a chemically inert filler when creating photocurable resins (PCR) for laser stereolithography. The authors provide the results of their experiments on making three-dimensional parts from such resins and discuss the feasibility of transforming the parts from polymeric, containing a filler, into ceramic ones through annealing. The use of silicon allows for a two-fold increase in the mass of the ceramic component due to the interaction of silicon with air oxygen and with products resulting from the thermal decomposition of the photopolymer's polymer base.