Confocal Raman microscopy and SEM/EDS investigations of the interface between the zirconia core and veneering ceramic: the influence of a liner and regeneration firing

Abstract

The aim of this study was to evaluate the changes in the transition layer at the interface between yttria partial stabilized tetragonal zirconia polycrystalline (Y-TZP) core and veneering feldspathic ceramic (VITA VM(®)9), under different manufacturing methods. Confocal Raman microscopy and energy dispersive X-ray spectroscopy (EDS) analyses were carried out on tapered veneered cross sections of the interface. For some samples, an additional firing of the core was used, as the application of an optional liner material between the core and veneer. Single Raman spectra were distinguishable between Y-TZP and the veneering materials. VM(®)9 and liner spectra were broadly superimposable. No substantial differences appeared in their chemical elemental composition. 2D Raman images and EDS analysis emphasized changes in the interdiffusion thickness; the additional firing of the core decreased the interdiffusion zone, and the highest firing temperature of the liner increased the interdiffusion zone. These results, which will help us understand the changes in this transition layer, are discussed.

Surface characteristics and optical properties of plasma deposited films on indirect aesthetic restorative dental materials

“…There are other studies that bring the chemical proportions of the porcelain with and without the presence of C, [62] as done in this study, or even report the obtained values and do not go in further details on the presence of this element [63]. Feldspathic VM9 porcelain, Enamic and Lava Ultimate chemical composition, obtained from XPS analyses, were consistent to previous studies [59,62,64,65] and showed agreement with the atomic proportions obtained in previous works [66][67][68][69].…”

Effect of various intermediate ceramic layers on the interfacial stability of zirconia core and veneering ceramics

“…Studies of microscopic analysis on the zirconia/feldspathic porcelain interface also revealed a mutual diffusion process, with an estimated elemental transition area having a maximum thickness of 2 mm [32]. It was also proposed that the mutual diffusion area tends to increase with the application of the liner [33]. In agreement with previous findings, the line profile analysis of EDS in the present study showed the transition of elements at the bonded interface.…”

Effect of differences in coefficient of thermal expansion of veneer and Y-TZP ceramics on interface phase transformation

“…The observation of this transformation for the nonfractured veneered copings can be explained by the diffusion of the veneer into the surface of zirconia during the firing processes, which results in a high stress concentration at the veneer-framework interface. Durand et al 39,40 confirms this suggestion. In the case of nonfractured veneered copings, the temperature gradient factor is excluded.…”