Porous Bioceramics Produced by Impregnation of 3D‐Printed Wax Mold: Ceramic Architectural Control and Process Limitations

Abstract

Current architectural and production limitations prevent the manufacturing standardization and design of bioceramics. Such limitations have hindered advances in bone tissue engineering and regeneration. In this context, we propose a bioceramic manufacturing process based on the impregnation of wax molds produced by additive manufacturing. Hydroxyapatite bioceramics with custom architectures were fabricated to evaluate the reliability, robustness, and limitations of this process. Results indicate that this process preserves phase biocompatibility, permits homogeneous shrinkage of the biomaterial during heat treatment, and allows reproducible and precise manufacturing of custom architectures.

Custom-made macroporous bioceramic implants based on triply-periodic minimal surfaces for bone defects in load-bearing sites

“…After a maturation time of 20 ± 2 h, the resulting HA suspension was filtered and the precipitate was heat-treated at 400°C under air for 2 h and crushed to reach particle sizes in the 1 to 10 µm range (AFG100; Hosokawa Alpine, Germany). Finally, the synthetized HA powder was heat-treated at 1020°C for 2 h (LH40/13; Nabertherm, Germany) to obtain a specific surface area of 4.0 ± 0.1 m²/g [25], which was determined on the outgassed powder (200°C for 8 h) using N2 adsorption isotherms (Brunauer-Emmett-Teller 5 points method, ASAP 2010; Micromeritics, Germany).…”

“…HA implants were produced according to the AM-based process detailed and optimized by Charbonnier et al [25,28]. Briefly, wax molds, negative of the intended implant structure, were build layer-by-layer with each layer thickness of 25 µm ( Fig.…”

“…In vitro studies using non-ceramic materials have confirmed higher permeability of 3D implants and a better mesenchymal stromal cell infiltration in a gyroid network compared to a structure with a random-pore architecture of similar porosity and pore size [8]. Easily 3D-printed with either polymeric [7,8,16], metallic [17], [18], [19], [20], or composite [21], [22], [23] materials, TPMS structures are difficult to produce with CaP [24,25], due to the inability of most present-day AM to process bioceramics.…”

“…Using a precise approach based on the impregnation of wax molds, the authors were able to produce for the first time such TPMS structures in sintered HA [25]. Using these open, interconnected structures, the objective of the present study was to investigate the osteoconductive potential of TPMS-based HA implants (implants with gyroid porosity; GP) in large bone defects in a load-bearing, femoral site in rats.…”

Digitization and 3D printing for the reconstruction of volumetric losses in an anatomical wax model of the 18th century

“…Otro paso que puede ser ejecutado mediante dispositivos digitales -en lugar de medios tradicionales y que resultaría totalmente novedoso en este tipo de intervenciones -es la creación de moldes para la reproducción de la zona reconstruida en cera, toda vez que se pueden crear en programas de modelado 3D haciendo un negativo digital de la figura previamente modelada para después obtener una copia física de dichos moldes mediante impresoras 3D, algo que ya se ha ensayado en otros campos de conocimiento [9][10].…”