Project Title: Additive manufacturing of ceramic/polymer composites with bioinspired microestructures for dental applications 

Acronym: ENAMEL (PID2021-123218OB-I00)

Funding Entity: Ministerio de Ciencia e Innovación  (MCIN) – Agencia Estatal de Investigación (AEI)

Participating Entities:  University of Extremadura

Duration: 01/09/2022 – 31/08/2025

Budget: 217.800,00  €

Principal Investigator (PI): Pedro Miranda

Number of researchers: 3

Abstract:

ENAMEL project will develop innovative manufacturing technologies that would enable the production of bioinspired ceramic-polymer hybrid materials with enhanced toughness and wear resistance. These high performance composites will find application, among other fields, as dental prosthesis and in other biomedical implants. Novel ceramic/polymer composites with a microstructure mimicking that of the enamel in our teeth will be produced with the aid of additive manufacturing (3D printing) techniques. Two high-resolution and versatile AM technologies, namely Digital Light Processing (DLP) and Two-Photon Polymerization (TPP), will be used in the fabrication of intricate columnar ceramic preforms with intercolumn gaps resembling the convoluted hydroxyapatite-rich rods found in natural enamel. A delicate and challenging multi-step fabrication process will be optimized in order to realize these preforms with feature dimensions approaching those of the natural tissue, while avoiding introducing any defects during fabrication in order to maximize mechanical performance. Two
AM strategies will be explored for this purpose: (i) direct printing using photo-curable ceramic slurries developed to be used as feedstock for DLP; and (ii) indirect printing strategies were a sacrificial negative mould will be fabricated by DLP or TPP using appropriate photocurable resins as feedstock. In the latter case, the ceramic preform will be produced by casting a suitable highly concentrated ceramic slurry into the mould and subsequently eliminating the latter through a suitable heat treatment before sintering the ceramic particles for consolidating the preform. In either case, the ceramic preform will be subsequently infiltrated by a ductile polymer to mimick
the inter-rod sheath in natural enamel. In this way, highly damage-tolerant and wear resistant hybrid biomaterials will be formed. Moreover, the actual design, material selection and the ceramic/polymer interfacial strengths of these innovative composite biomaterials will be optimized within the framework of the project. The developed materials will significantly improve the effectiveness and durability of dental restorations over existing commercial alternatives, thus helping to reduce the need for replacement interventions with their associated cost and risk for the patient. The new bioinspired composites and the novel manufacturing processes that will be developed and optimized for their production will become essential enabling technologies for the realization of bioinspired high-performance composites, that could not only revolutionize the dental prosthetic industry, but have a dramatic impact in mutiple other industrial (e.g., aerospace, automotive) applications.