Fabrication and characterisation of a novel biomimetic anisotropic ceramic/polymer-infiltrated composite material

Objective. To fabricate and characterise a novel biomimetic composite material consisting of aligned porous ceramic preforms infiltrated with polymer. Method. Freeze-casting was used to fabricate and control the microstructure and porosity of ceramic preforms, which were subsequently infiltrated with 40-50% by volume UDMA-TEGDMA polymer. The composite materials were then subjected to characterisation, namely density, compression, three-point bend, hardness and fracture toughness testing. Samples were also subjected to scanning electron microscopy and computerised tomography (MicroCT). Results. Three-dimensional aligned honeycomb-like ceramic structures were produced and full interpenetration of the polymer phase was observed using micro-CT. Depending on the volume fraction of the ceramic preform, the density of the final composite ranged from 2.92 to 3.36 g/cm(3) , compressive strength ranged from 206.26 to 253.97 MPa, flexural strength from 97.73 to 145.65 MPa, hardness ranged from 1.46 to 1.62 GPa, and fracture toughness from 3.91 to 4.86 MPa m(1/2) . Significance. Freeze-casting provides a novel method to engineer composite materials with a unique aligned honeycomb-like interpenetrating structure, consisting of two continuous phases, inorganic and organic. There was a correlation between the ceramic fraction and the subsequent, density, strength, hardness and fracture toughness of the composite material. (C) 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.