Microstructure of veneered zirconia after surface treatments: A TEM study

ADM guidance-Ceramics: all-ceramic multilayer interfaces in dentistry

“…3 shows a cross-section of such an interface under TEM. The absence of any voids suggests that complete wetting and sealing has occurred, despite the rather rough, sandblasted zirconia surfaces [54,55]. However, some disintegrated zirconia particles became disd e n t a l m a t e r i a l s x x x ( 2 0 1 7 ) xxx-xxx solved in the glass matrix, most likely due to the sandblasting process.…”

Y-TZP zirconia regeneration firing: Microstructural and crystallographic changes after grinding

“…In general, studies showing 0% monoclinic content after sintering are usually associated with a post-sintering polishing, a procedure that was not performed in this study 20) . After grinding, both Lava TM and Ice Zirkon specimens presented crystallographic and microstructural changes.…”

“…When a new energy source, such as the regeneration firing is provided (annealing), the small amount of monoclinic phase reverses to tetragonal phase, generating a more stable material 15,20,[42][43][44] . The short duration and lower temperature (1,000°C for 30 min) of the regeneration firing in comparison with those of sintering does not induce the formation of cubic phase.…”

“…Once the adjustment procedures are finished, the regeneration firing might induce reverse transformation (m→t), returning the Y-TZP to a metastable tetragonal phase zirconia that, although less resistant, is more stable 15) . This heat treatment has already been studied, but still deserves attention because of the disagreement between protocols suggested by different authors and due to microstructural characterization after regeneration firing that has not been fully understood yet [18][19][20] . Thus, this study focused on analyzing Y-TZP microstructure after grinding and annealing (regeneration firing) in more detail in order to characterize the material's crystalline phases and draw initial conclusions regarding the interaction among its different phases.…”

Characterization of residual stresses in zirconia veneered bilayers assessed via sharp and blunt indentation

“…Although neither the analytical model, nor the Vickers indentation method applied here were able to address this issue (because of its limitation in measuring stress states at distances lower than 100 m from the interface), it has been shown that after a thermal treatment commonly used for veneering zirconia substrates, reverse m-t transformation takes place [47]. Further evaluation of the interface region using higher resolution methods (i.e.…”