Investigations into the interface failure of yttria partially stabilised zirconia - porcelain dental prostheses through microscale residual stress and phase quantification

Abstract

Highlights  Residual stress and phase analysis at the microscale at interface and coping edge  X-ray diffraction and Raman spectroscopy show comparable results  Cross validation using ring-core focused ion beam and digital image correlation  Monoclinic and highly stressed regions identified close to interface  Phase transformation volumetric expansion is the origin of porcelain failure

Eigenstrain boundary layer modelling of the yttria-partially stabilised zirconia–porcelain interface in dental prostheses

“…This validation has recently been provided in the literature, which shows nominally identical stress profiles in the two orientations being considered in this study (A. Lunt et al, 2019). Within an equibiaxial system, Mohr's circle for stress collapses to a single point, such that there are no shear stresses within this plane (Timoshenko, 1925).…”

“…In order to assess the validity of the proposed model, the residual stress and YPSZ phase distribution obtained in this study will be compared on those previously determined experimentally (A. Lunt et al, 2019). This analysis was performed on a representative incisal prosthesis which was produced from Wieland Dental Zenotec Zr bridge.…”

“…In order to characterise the phase variation as a function of distance from the interface, Raman spectroscopy of the sample was also performed on the coping with a measurement point every 1 μm (A. Lunt et al, 2019). This approach is based on the relative intensity of the monoclinic and tetragonal peaks which are observed in this spectrum (Clarke & Adar, 1982).…”

“…However, recent developments in experimental methods have begun to shed light on the near-interface characteristics. This has included the use of synchrotron methods to characterise the residual stress and phase variation in both the YPSZ and porcelain at microscale resolution, as well as Raman spectroscopy for quantification of the YPSZ phase variation at the interface (Lunt et al, 2019). The sequential and parallel ring-core Focused Ion Beam (FIB) and Digital Image Correlation (DIC) approaches have also been used to validate these experimental results at the microscale .…”

Fracture Load of Metal, Zirconia and Polyetheretherketone Posterior CAD-CAM Milled Fixed Partial Denture Frameworks

“…However, the interface between the two ceramics is one of the weakest aspects, and delamination and chipping of the veneering ceramic is the main failure mode of bilayer zirconia restorations [11][12][13][14]. A recent study evaluated the zirconia-veneer interface and reported new insights that explain the high chipping rates observed [15]. Successive generations of zirconia have been developed to solve the chipping problem of the first-generation zirconia and to improve its translucency [11,14].…”