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Zirconia restorations, which are fabricated by additive 3D gel deposition and do not require glazing like conventional restorations, were introduced as "self-glazed" zirconia restorations into dentistry. This in vitro investigation characterized the surface layer, microstructure and the fracture and aging behavior of "self-glazed" zirconia (Y-TZP SG ) three-unit fixed dental prostheses (FDP) and compared them to conventionally CAD/CAM milled and glazed controls (Y-TZP C -FDPs). For this purpose, the FDPs were analyzed by (focused ion beam) scanning electron microscopy, laserscanning microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and a dynamic and static loading test. For the latter, half of the samples of each material group (n = 16) was subjected to 5 million cycles of thermocyclic loading (98N) in an aqueous environment in a chewing simulator. Afterwards, all FDPs were loaded to fracture. Y-TZP SG -FDPs demonstrated a comparable elemental composition but higher surface microstructural homogeneity and fracture strength compared to Y-TZP C -FDPs. Microstructural flaws within the FDPs' surfaces were identified as fracture origins. The high fracture strength of the Y-TZP SG -FDPs was attributed to a finer-grained microstructure with fewer surface flaws compared to the Y-TZP C -FDPs which showed numerous flaws in the glaze overlayer. A decrease in fracture strength after dynamic loading from 5165N to 4507N was observed for the Y-TZP SG -FDPs, however, fracture strength remained statistically significantly above the one measured for Y-TZP C -FDPs (before chewing simulation: 1923N; after: 2041N). Within the limits of this investigation, it can therefore be concluded that Y-TZP SG appears to be stable for clinical application suggesting further investigations to prove clinical applicability., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: James Shen reports a relationship with ErranTech Co. Ltd., Hangzhou, China that includes: board membership., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The objective of this study was to investigate interactions of zein (Z) and zein/rosin (Z/R) nanoparticles with gum arabic (GA), at different pH. Nanoparticles were firstly prepared by antisolvent precipitation of biopolymers from aqueous ethanol solutions. Nanoparticles suspensions were then dialyzed against water in order to remove ethanol and other impurities, and water suspensions of zein and zein/rosin nanoparticles were obtained. It was shown that composition of nanoparticles affects their surface charge density. Zeta potential of nanoparticles was positive without GA and changed to negative after addition of GA, at all pH tested. SEM analysis proved both Z and Z/R nanoparticles to be spherical and in size around 200 nm. The effect of addition of GA on particle size was determined using dynamic light scattering method. It was found that addition of GA increases size of nanoparticles at pH = 4 and pH = 5.5, from 150 - 220 nm to 250 - 320 nm. However, at pH = 3 it causes aggregation process, and diameter of particles increases up to few micrometres. Isothermal titration calorimetry was used to measure enthalpy changes in reaction between Z or Z/R nanoparticles and GA. Results showed that reaction between GA and Z or Z/R NPs is exothermic at each pH tested, except for Z NPs at pH = 3, where it was endothermic. At presented pHs, Z/R NPs were less charged compared to Z NPs, and their surface get saturated with GA molecules more rapidly. Z NPs showed greater enthalpy change in reaction with GA, compared to Z/R NPs., (Copyright © 2020 Elsevier B.V. All rights reserved.)