Bottom‐Up Assembling Hierarchical Enamel‐Like Bulk Materials with Excellent Optical and Mechanical Properties for Tooth Restoration

• Published in: Advanced healthcare materials 2024-10, Vol.13 (26), p.e2401095-n/a
• Main Authors: Zhang, Shan, Xu, Wu, Wu, Leping, Li, Xiaxin, Liu, Xingzi, Wu, Xiaoting, Wu, Guomin, Zheng, Shunli, Cao, Chris Ying, Zhou, Zheng, Wong, Hai Ming, Zhang, Xu, Li, Quan‐Li
• Format: Article
• Language: English
• Subjects: Aspect ratio; Assembling; Assembly; Biomimetic materials; Biomimetic Materials - chemistry; bionic; Bisphenol A; Bulk density; Bulk polymerization; Centrifugation; Dental enamel; Dental Enamel - chemistry; Durapatite - chemistry; Enamel; enamel‐like materials; Ethanol; Hot pressing; Humans; Hydroxyapatite; hydroxyapatite nanowire; Materials Testing; MDP; Mechanical properties; Nanomaterials; Nanotechnology; Nanowires; Nanowires - chemistry; Optical properties; self‐assembly; Shear forces
• ISSN: 2192-2640; 2192-2659; 2192-2659
• DOI: 10.1002/adhm.202401095

Enamel has good optical and mechanical properties because of its multiscale hierarchical structure. Biomimetic construction of enamel‐like 3D bulk materials at nano‐, micro‐, mesh‐ and macro‐levels is a challenge. A novel facile, cost‐effective, and easy large‐scale bottom‐up assembly strategy to align 1D hydroxyapatite (HA) nanowires bundles to 3D hierarchical enamel structure with the nanowires bundles layer‐by‐layer interweaving orientation, is reported. In the strategy, the surface of oleate templated ultralong HA nanowires with a large aspect ratio is functionalized with amphiphilic 10‐methacryloyloxydecyl dihydrogen phosphate (MDP). Furtherly, the MDP functionalized HA nanowire bundles are assembled layer‐by‐layer with oriented fibers in a single layer and cross‐locked between layers at a certain angle at mesoscale and macroscale in the viscous bisphenol A‐glycidyl methacrylate (Bis‐GMA) ethanol solution by shear force induced by simple agitation and high‐speed centrifugation. Finally, the excessive Bis‐GMA and ethanol are removed, and (Bis‐GMA)‐(MDP‐HA nanowire bundle) matrix is densely packed under hot pressing and polymerized to form bulk enamel‐like materials. The composite has superior optical properties and comparable comprehensive mechanic performances through a combination of strength, hardness, toughness, and friction. This method may open new avenues for controlling the nanowires assembly to develop hierarchical nanomaterials with superior properties for many different applications. 1D hydroxyapatite (HA) nanowires are aligned and assembled into 3D hierarchical enamel‐like block material through a bottom‐up strategy. The enamel‐like material mimics for the first time the cross‐arrangement structure of natural enamel crystals. This material combines optical and mechanical properties to meet the needs of restoring dental defects and has unique advantages.