An in vitro study was designed to monitor the t–m transformation of biomedical grade 3Y-TZP ceramics produced from two ready-to-press granulated powders of the same nominal chemical composition, but differing in their specific surface area. The sintering-temperature-dependent transformability during ageing was confirmed, whereby the role of the starting-powder characteristics was more pronounced at lower sintering temperatures and was almost negligible at higher sintering temperatures.
COBISS.SI-ID: 25760807
The purpose of this study was to evaluate the effect of Y-TZP ceramic surface functionalization with a nano-structured alumina coating on bond strength of the resin modified glass ionomer dental cement.The shear bond strengths of the resin-modified glass ionomer cement FUJI+ (GC Japan) and the composite resin luting agent RelyX Unicem (3M ESPE, USA) were then studied for the coated and uncoated surfaces The SEM analyses revealed that the application of an alumina coating to the Y-TZP ceramics created a highly retentive surface for bonding. The bond strengths for the coated groups in both cements were significantly higher than the uncoated groups.
COBISS.SI-ID: 29929945
In this study the densification behavior of bimodal Y-TZP powder compacts consisting of nano/sub-micron-sized particles was studied and an explanation for their improved flexural strength while biscuit-sintered is provided. An in situ-heating TEM analysis revealed that up to 800 degrees C only the nanoparticles sinter in a bimodal mixture without any densification. By increasing the temperature to 900 degrees C the densification of the nanoparticles begins and partially densified nanoparticle clusters migrate into the contact area between the core particles. Consequently, the driving force for the sintering of the powder-blend compacts is reduced and this is reflected in a slower densification compared to that of the core material. At 1000 degrees C the sintered nanoparticle clusters begin to incorporate into the core material, resulting in a sharp increase in the strength due to the increased neck area. Biscuit-sintered powder-blend compacts reached a plateau of strength at 670 MPa, which was reached at a relative density of 70%.
COBISS.SI-ID: 26453031