Exploring the mechanical and biological properties of a resin-ceramic composite with biomimetic nacre structure containing zinc used for prosthodontics

Enhancement of the mechanical and biological properties of dental restoration materials is of significant importance. Drawing inspiration from the architecture and mechanical properties of natural nacre, we employed a low-cost accumulative rolling process to develop resin-ceramic composites with suitable hardness and high toughness. Plate-like aluminum oxide powder with diameters of 5–10 μm and nano-zinc oxide (ZnO) with antibacterial properties were mixed as the ceramic phase of the composite. Aluminum oxide ceramic plates were stacked using an accumulative rolling process to achieve a consistent orientation, followed by sintering to obtain porous ceramic scaffolds. The ceramic scaffolds were subsequently immersed in methyl methacrylate resin to complete the fabrication of the biomimetic composites. The mechanical and biological properties of the composites were comprehensively tested. The composites had a suitable hardness (1.09–1.63 GPa), excellent flexural strength (156.7–167.8 MPa), and fracture toughness (K_IC = 2.66–3.59 MPa m^1/2). Biomimetic composites are expected to mitigate the wear of natural teeth without developing fractures or deformations, while also exhibiting excellent cytocompatibility and antibacterial activity. This study investigated the factors influencing crack propagation in fracture tests and provided insights into enhancing the toughness of dental restorative materials. The biomimetic resin-ceramic composites containing Zn developed in this study have the potential to be used as functional dental restoration materials.