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Micromechanics of roughened surfaces of zirconia-based materials: implications for long term mechanical reliability

Total activity: 1
Type of activity
Competitive project
Funding entity
MIN DE ECONOMIA Y COMPETITIVIDAD
Acronym
MICROZIR
Funding entity code
MAT2014-60720-R
Amount
121.000,00 €
Start date
2015-01-01
End date
2018-09-30
Abstract
Nowadays, the number of dental remplacements is growing, substituting natural teeth by artifical crows, bridges and implants. This is a
natural consequence of the agening of the population while mantaining masticatory functionality during their life span. Tetragonal Zirconia
doped with 3 mol% Yttria (3Y-TZP) is one of the relatively new and prefered material due to its aesthetic aparence, bioinertness and
mechanical properties for dental crowns and bridges (with a porcelain veneer). For its application in implants and abutments a certain
degree of roughening of the zirconia surface is desired, either to increase adhesion with other materials (as cements or veneers) or to
increase osseointegration. Today many research effords are being done to modify the surface by techniques such as laser patterning,
chemical attack, pore forming agents, etc.
However, all these surface modifications have the potential to compromise the structural integrity of the zirconia components, specially on
the long term. Although strength and fatigue tests are normally done after surface modification, these tests are usually performed by
bending under remote loads. The damage produced by surface treatments and in service by low temperature degradation (LTD) may be
not revealed under because of defect orientation, size and shape. However, they can be detrimental for the reliability of the component
under stresses generated perpendicular to the surface inducing chipping of local areas and resulting in a loss of adhesion of the material to
the body or other coatings. In addition, the microstructure of the surface may be altered either by the own surface treatment or, in the long
term, by LTD in the oral cavity environment.
The objective of this project is to study and design methods to avoid the failure of zirconia materials with roughened surfaces typical of
dental components. For that, we will (1) develop zirconia with higher fracture toughness and resistance to low thermal degradation by
finding mixtures of 3Y-TZP and 10Ce-TZP which give a correct distribution of grain size and composition of Y and Ce in order to increase
fracture toughness without impairing the strength. The surface of dental 3Y-TZP as well as the new developed material will be modified to
achieve optimal resistance to LTD. (2) To study the micromechanics of the roughened surfaces of these materials produced by laser
patterning and by acid etching and correlating the damage produced with the different parameteres used in the roughening techniques,
Because of the small scales involved, normally in the order of a few microns, advanced techniques as nanoindentation, focused ion beam
and tomography to reconstruct in 3D regions of interest. This last technique will allow not only to deepen the understanding of the damagemicrostructure
interactions, but also to provide real 3D meshes for finite element models, and help to close the gap beween experiments
and numercial simulations.
Scope
Adm. Estat
Plan
Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016
Call year
2015
Funcding program
Programa Estatal de I+D+i Orientada a los Retos de la Sociedad
Funding call
Retos de Investigación: Proyectos de I+D+i
Grant institution
Gobierno De España. Ministerio De Economía Y Competitividad, Mineco

Participants

Scientific and technological production

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