The additive manufacturing of BaTiO₃ (BT) ceramics through stereolithography (SLA) 3D printing at 465 nm wavelength was demonstrated. After different milling times, different paste compositions with varied initial micron-sized powders were studied to find a composition suitable for 3D printing. The pastes were evaluated in terms of photopolymerization depth depending on the laser scanning speed. Furthermore, the microstructure and properties of the BT ceramic samples produced through SLA 3D printing were characterized and compared with those of ceramics fabricated through a conventional die semi-drying pressing method. Three-dimensional printed samples achieved relative densities over 0.95 and microhardness over 500 HV after sintering, nearly matching the relative density and microhardness attained by the pressed samples. Upon poling, the 3D-printed samples attained acceptable piezoelectric module d₃₃ = 148 pC/N and dielectric constants over 2000. At near full density, BT piezoceramics were successfully fabricated through SLA 3D printing at 465 nm wavelength, achieving photopolymerization depth of more than 100 microns. This work paves the relatively low-cost way for 3D printing of piezoelectric ceramics using conventional micron-sized powders and high printed layer thickness.

The immuno-compatibility of implant materials is a key issue for both initial and long-term implant integration. Ceramic implants have several advantages that make them highly promising for long-term medical solutions. These beneficial characteristics include such things as the material availability, possibility to manufacture various shapes and surface structures, osteo-inductivity and osteo-conductivity, low level of corrosion and general biocompatibility. The immuno-compatibility of an implant essentially depends on the interaction with local resident immune cells and, first of all, macrophages. However, in the case of ceramics, these interactions are insufficiently understood and require intensive experimental examinations. Our review summarizes the state of the art in variants of ceramic implants: mechanical properties, different chemical modifications of the basic material, surface structures and modifications, implant shapes and porosity. We collected the available information about the interaction of ceramics with the immune system and highlighted the studies that reported ceramic-specific local or systemic effects on the immune system. We disclosed the gaps in knowledge and outlined the perspectives for the identification to ceramic-specific interactions with the immune system using advanced quantitative technologies. We discussed the approaches for ceramic implant modification and pointed out the need for data integration using mathematic modelling of the multiple ceramic implant characteristics and their contribution for long-term implant bio- and immuno-compatibility.

3D printing allows the fabrication of ceramic implants, making a personalized approach to patients’ treatment a reality. In this work, we have tested the applicability of the Function Representation (FRep) method for geometric simulation of implants with complex cellular microstructure. For this study, we have built several parametric 3D models of 4 mm diameter cylindrical bone implant specimens of four different types of cellular structure. The 9.5 mm long implants are designed to fill hole defects in the trabecular bone. Specimens of designed ceramic implants were fabricated at a Ceramaker 900 stereolithographic 3D printer, using a commercial 3D Mix alumina (Al₂O₃) ceramic paste. Then, a single-axis compression test was performed on fabricated specimens. According to the test results, the maximum load for tested specimens constituted from 93.0 to 817.5 N, depending on the size of the unit cell and the thickness of the ribs. This demonstrates the possibility of fabricating implants for a wide range of loads, making the choice of the right structure for each patient much easier.