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Updated: Aug 21, 2026
Multi-Scale Modification of Metallic Implants With Pore Gradients, Polyelectrolytes and Their Indirect Monitoring In vivo
Published on: July 1, 2013
Mechanical properties and bioactivity of customized titanium alloy implants based on TPMS gradient technology: An in
Huilin Hu1, Haichuan Sun1, Ziming Ma1
1School of Preclinical Medicine and School of Nursing, Clinical Medical College & Affiliated Hospital of Chengdu University, Chengdu, China.
Objective:
The porous structure and gradient design of customized dental implants are crucial for the success of bone defect repair. This study aimed to optimize the design of titanium alloy (Ti-6Al-4V) dental implants using a three-period minimal surface (TPMS) structure, and to investigate the effects of its gradient structure on mechanical properties and biocompatibility.
Methods:
Finite element analysis was employed to compare the mechanical properties of four typical TPMS structures (Schwarz, Diamond, SplitP, Gyroid), resulting in the selection of the Gyroid structure as having the best overall performance. Based on this structure, three Ti-6Al-4V implants were fabricated using 3D printing technology: G40 (gradient TPMS structure with 40% porosity), G50 (gradient TPMS structure with 50% porosity), and NG50 (TPMS structure with 50% porosity). The physicochemical properties of the materials were evaluated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), compression testing, and water contact angle measurements. Antibacterial experiments were conducted to investigate the antibacterial capabilities of the different groups. A mouse femoral defect model was established, and osseointegration was dynamically assessed at 4, 8 and 12 weeks post-surgery using micro-CT and histological staining.
Results:
Finite element analysis showed that the Gyroid structure performed best in terms of stress distribution and displacement transfer. Experimental results indicated that the gradient structure G50 possessed the best mechanical compatibility, with its yield strength and compressive modulus most closely resembling those of natural bone, whilst effectively preventing brittle fracture. In terms of bioactivity, the G40 and G50 groups exhibited good hydrophilicity (contact angle < 90°) and excellent antibacterial rates (>94%). Experiments showed that, as the implantation period increased, the bone volume fraction (BV/TV) and bone mineral density (BMD) in the G50 group were significantly higher than those in the G40 and NG50 groups in vivo (P < 0.05). Histological staining and histomorphometric analysis showed significantly greater new bone and collagen area fractions in the G50 group than that in the G40 group at 8 weeks.
Conclusion:
Within the conditions of this study, the G50 gradient Gyroid implant showed favorable mechanical behavior and greater peri-implant bone formation than the comparison groups. These findings support further investigation of gradient TPMS designs for customized bone implants.
