Biomimetic bone-matching DLP-printed gradient TPMS ceramic implants.

Abstract

To overcome stress-shielding effects of homogeneous bone implants, this study fabricated triply periodic minimal surface (TPMS) scaffolds with 50-80% porosity gradients via digital light processing (DLP), mimicking the cortical-to-cancellous bone mechanical transition. Five TPMS topologies (Gyroid, Schwarz, Diamond, Lidinoid, Split-P) were designed with gradient/uniform porosity. Zirconia scaffolds were DLP-printed, sintered, and evaluated via compression tests, CFD simulations, and in vitro cytocompatibility assays (CCK-8/live-dead staining). Data were analyzed by one-way ANOVA (α = 0.05). The gradient Diamond scaffold achieved superior compressive strength (215.7 ± 8.3 MPa) and elastic modulus (4.2 ± 0.2 GPa), exceeding other groups (P=0.002). It showed 25% higher permeability than uniform designs, with optimal fluid shear stress (0.5-3 Pa). Cell proliferation reached 150 ± 8% of control at day 7, with>95% viability. This study fabricates biomimetic Diamond topology ceramic implants with gradient mechanical properties via digital light processing. With an elastic modulus of 4.2 GPa matching natural bone, it effectively mitigates stress-shielding. The optimized porous structure enhances nutrient transport and cell adhesion, demonstrating strong potential as a promising strategy for the development of next-generation implants aimed at improving the long-term stability of dental and craniomaxillofacial bone repairs. Further in-depth biological evaluation and mechanical fatigue testing are warranted to fully translate this potential into a clinical solution.