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Publications

by Keyword: Zirconia

Hodásová, Ľudmila, Morena, AGala, Tzanov, Tzanko, Fargas, Gemma, Llanes, Luis, Alemán, Carlos, Armelin, Elaine, (2022). 3D-Printed Polymer-Infiltrated Ceramic Network with Antibacterial Biobased Silver Nanoparticles Acs Applied Bio Materials 5, 4803-4813

Minguela J, Müller DW, Mücklich F, Llanes L, Ginebra MP, Roa JJ, Mas-Moruno C, (2021). Peptidic biofunctionalization of laser patterned dental zirconia: A biochemical-topographical approach Materials Science & Engineering C-Materials For Biological Applications 125,

A dual approach employing peptidic biofunctionalization and laser micro-patterns on dental zirconia was explored, with the aim of providing a flexible tool to improve tissue integration of restorations. Direct laser interference patterning with a femtosecond Ti:Sapphire laser was employed, and two periodic grooved patterns were produced with a periodicity of 3 and 10 μm. A platform containing the cell-adhesive RGD and the osteogenic DWIVA peptides was used to functionalize the grooved surfaces. Topography and surface damage were characterized by confocal laser scanning (CLSM), scanning electron and scanning transmission electron microscopy techniques. The surface patterns exhibited a high homogeneity and subsurface damage was found in the form of nano-cracks and nano-pores, at the bottom of the valleys. Accelerated tests in water steam were carried out to assess hydrothermal degradation resistance, which slightly decreased after the laser treatment. Interestingly, the detrimental effects of the laser modification were reverted by a post-laser thermal treatment. The attachment of the molecule was verified trough fluorescence CLSM and X-ray photoelectron spectroscopy. Finally, the biological properties of the surfaces were studied in human mesenchymal stem cells. Cell adhesion, morphology, migration and differentiation were investigated. Cells on grooved surfaces displayed an elongated morphology and aligned along the patterns. On these surfaces, migration was greatly enhanced along the grooves, but also highly restricted in the perpendicular direction as compared to flat specimens. After biofunctionalization, cell number and cell area increased and well-developed cell cytoskeletons were observed. However, no effects on cell migration were found for the peptidic platform. Although some osteogenic potential was found in specimens grooved with a periodicity of 10 μm, the largest effects were observed from the biomolecule, which favored upregulation of several genes related to osteoblastic differentiation in all the surfaces.

JTD Keywords: alumina toughened zirconia, cell alignment, grain-size, implants, interference, laser patterning, osteogenic differentiation, osteointegration, peptides, surface functionalization, surface-topography, tissue, titanium surface, Laser patterning, Low-temperature degradation, Osteointegration, Peptides, Surface functionalization, Zirconia


Hodásová L, Sans J, Molina BG, Alemán C, Llanes L, Fargas G, Armelin E, (2021). Polymer infiltrated ceramic networks with biocompatible adhesive and 3D-printed highly porous scaffolds Additive Manufacturing 39

© 2021 Elsevier B.V. Herein, for the first time is described the design of a novel porous zirconia scaffolds manufactured by using polymer-infiltrated ceramic network (PICN) and 3D-printing technologies. Cubic geometry of pieces was obtained by perpendicular layer-by-layer deposition of yttrium-stabilized tetragonal zirconia polycrystal (3Y-TZP) and Pluronic® hydrogel ceramic paste. The specimens were prepared by robocasting assembly with 50% infill and 50% of pores, as feed setup. Bisphenol A glycerolate dimethacrylate (Bis-GMA) and tri(ethylenglycol) dimethacrylate (TEGDMA) copolymer, a well-known biocompatible adhesive, which is widely used in dentistry field, was employed to reinforce the pores of the 3D-printed ceramic structure. The success of the acrylate polymer infiltration above the scaffold surface and among the 3Y-TZP filaments was achieved through previous ceramic functionalization with 3-(trimethoxysilyl)propyl methacrylate (γ-MPS). The well infiltration of the material on pores was evaluated by gravimetry, obtaining a value of 87.5 ± 6.6% of pores covered by the adhesive. Such successful infiltration of methacrylate copolymer had also a positive effect on the mechanical properties of the scaffold material, being the PICN sample that one with the highest elongation resistance. The new system showed reduced bacteria proliferation, over 24 h of incubation with Gram-negative Escherichia coli and Gram-positive Streptococcus salivarius bacteria lines, when compared to the control.

JTD Keywords: acrylate polymer, bacteria colonization, yttrium stabilized zirconia, Acrylate polymer, Bacteria colonization, Robocasting, Yttrium stabilized zirconia


Minguela, J., Slawik, S., Mücklich, F., Ginebra, M. P., Llanes, L., Mas-Moruno, C., Roa, J. J., (2020). Evolution of microstructure and residual stresses in gradually ground/polished 3Y-TZP Journal of the European Ceramic Society 40, (4), 1582-1591

A comprehensive study of progressively ground/polished 3Y-TZP was performed with the aim of better understanding the mechanisms driving the microstructural modifications observed after such procedures, and identifying the processing parameters leading to optimal microstructures (i.e. ageing-protective and damage-free). Gradually ground/polished surfaces were produced, yielding four different topographies of increasing roughness (grades 1–4) and two different textures (unidirectionally, U, and multidirectionally, M). Phase transformation, microstructure and residual stresses were investigated by means of advanced characterization techniques. It was found that low-roughness mildly ground/polished specimens (i.e. 2-M/U) presented a nanometric layer with the ageing-related protective features generally associated with coarsely ground specimens. A lower limit for grain refinement in terms of surface abrasion was also found, in which partial recrystallization took place (i.e. 1-M/U). A mathematical relation was established between average surface roughness (Sa), monoclinic volume fraction (Vm) and surface compressive residual stresses, demonstrating that if the processing parameters are controlled, both Vm and residual stresses can be predicted by the measurement of Sa.

JTD Keywords: Grinding, Microstructure, Phase transformation, Residual stresses, Zirconia


Minguela, J., Ginebra, M. P., Llanes, L., Mas-Moruno, C., Roa, J. J., (2020). Influence of grinding/polishing on the mechanical, phase stability and cell adhesion properties of yttria-stabilized zirconia Journal of the European Ceramic Society 40, (12), 4304-4314

The changes in mechanical properties, hydrothermal degradation and cell adhesion were studied in 3Y-TZP under two different superficial modification patterns (uni- and multidirectional) with a surface roughness ranging from 16 to 603 nm. In this sense, mechanical properties (i.e. hardness, indentation fracture toughness and scratch) and accelerated tests in water steam were measured to evaluate the influence of the surface treatments on the superficially modified layer. Moreover, a detailed characterization through micro-Raman spectroscopy and X-Ray diffraction was performed. Finally, SaOS-2 osteoblasts were used for the evaluation of the cell adhesion behaviour on the surfaces. Overall, ground/polished specimens increased the mechanical properties and ageing resistance of mirror-like polished specimens, although resistance to degradation was maximum at intermediate conditions (Sa ≈ 40−180 nm). The studied surfaces allowed cell attachment, but promoted contact guidance (i.e. cell alignment) only on unidirectionally ground surfaces above Sa = 150 nm.

JTD Keywords: Cell adhesion, Grinding, Hydrothermal degradation, Mechanical properties, Zirconia