Title Participants Abstract "Influence of airborne particle abrasion on dentin bonding effectiveness of a 2-step universal adhesive." "Marleen Peumans, Bart Van Meerbeek" "OBJECTIVE: To determine the effect of airborne particle abrasion (APA) on micro-tensile bond strength (µTBS) to dentin using different air-abrasion/polishing powders. METHODS: The bonding effectiveness of G2 Bond Universal (G2B), used in etch-and-rinse (E&R) and self-etch mode (SE), was tested on bur-cut dentin and dentin air abraded/polished using six different powders (aluminum oxide 29 µm (AO29) and 53 µm (AO53), aluminum trihydroxide (AT), sodium bicarbonate (SB), sodium bicarbonate soft (SBsoft) and bioactive glass (BG); Velopex). Adhesive-composite resin specimens were immersed in distilled water at 37 °C for one week and cut into microspecimens. Half of the specimens were subjected to 50,000 thermocycles (aged). Immediate and aged μTBS to dentin were measured. Statistical analysis was performed using linear mixed-effects (LME) modeling (p < 0.05). RESULTS: Comparing the aged bond strengths to air-abraded/polished dentin with bur-cut dentin, pretreatment with SB and SBsoft in combination with G2B used in E&R mode, and BG air polishing in combination with both application modes (E&R, SE), resulted in a significantly higher bond strength. Dentin bond strength was only significantly lower when air abraded with AO29 and using G2B in SE mode. Aging did not significantly influence bond strength for both application modes (E&R, SE), except for AO29 and AT-treated dentin, where bond strengths decrea sed significantly using G2B in SE mode. In general, G2B reached significantly higher bond strengths on air-abraded/polished dentin in E&R mode than in SE mode. CONCLUSION: Air-abrasion/polishing did not impair dentin bond strength using G2B, except when dentin was air abraded with AO29 and using G2B in SE mode. Air polishing positively influenced the bond strength to dentin in specific groups. CLINICAL SIGNIFICANCE: APA is safe concerning bonding to dentin. The E&R application mode is preferred using G2B as adhesive on air-abraded/polished dentin. Air polishing with BG positively influenced dentin bond strength for both application methods." "Does the universal adhesive's film thickness affect dentin-bonding effectiveness?" "Marleen Peumans, Bart Van Meerbeek" "OBJECTIVES: To investigate the influence of adhesive resin application modalities on the film thickness of the adhesive resin and the effectiveness of a two-step universal adhesive (UA) bonded in self-etch (SE) bonding mode to high C-factor class-I cavity-bottom dentin. MATERIALS AND METHODS: After application of the primer of G2-Bond Universal (G2B, GC), the adhesive resin was applied into standard class-I cavities (human molars) following four application modalities: (1) one layer, strongly air-blown; (2) one layer, gently air-blown; (3) two layers, each gently air-blown; (4) one layer, not air-blown. After being restored with composite, each tooth was sectioned to obtain one micro-specimen (n = 10), of which the adhesive resin film thickness was measured using optical microscopy. The micro-tensile bond strength (μTBS) was tested immediately or upon 100,000 thermocycles. Statistical analyses involved Kruskal-Wallis and Mann-Whitney U testing (p " "UV-Curing Assisted Direct Ink Writing of Dense, Crack-Free, and High-Performance Zirconia-Based Composites With Aligned Alumina Platelets" "Shuigen Huang, Jeroen Soete, Bart Van Meerbeek, Jef Vleugels, Fei Zhang" "Additive manufacturing (AM) of high-performance structural ceramic components with comparative strength and toughness as conventionally manufactured ceramics remains challenging. Here, a UV-curing approach is integrated in direct ink writing (DIW), taking advantage from DIW to enable an easy use of high solid-loading pastes and multi-layered materials with compositional changes; while, avoiding drying problems. UV-curable opaque zirconia-based slurries with a solid loading of 51 vol% are developed to fabricate dense and crack-free alumina-toughened zirconia (ATZ) containing 3 wt% alumina platelets. Importantly, a non-reactive diluent is added to relieve polymerization-induced internal stresses, avoid subsequent warping and cracking, and facilitate the de-binding. For the first time, UV-curing assisted DIW-printed ceramic after sintering reveals even better mechanical properties than that processed by a conventional pressing. This is attributed to the aligned alumina platelets, enhancing crack deflection and improving the fracture toughness from 6.8 ± 0.3 MPa m0.5 (compacted) to 7.4 ± 0.3 MPa m0.5 (DIW). The four-point bending strength of the DIW ATZ (1009 ± 93 MPa) is also higher than that of the conventionally manufactured equivalent (861 ± 68 MPa). Besides homogeneous ceramic, laminate structures are demonstrated. This work provides a valuable hybrid approach to additively manufacture tough and strong ceramic components." "Production and characterisation of filament-based Material Extrusion (MEX) additively manufactured copper parts" "Fankai Meng, Jef Vleugels, Eleonora Ferraris" "Material Extrusion (MEX) Additive Manufacturing of metal components is increasingly applied in recent years due to its low cost and potential for multi-material printing, with filament-based MEX being widely developed among all subdivisions of MEX. This technology utilises a compounded filament of polymeric binders and metal powder. The printing process involves hot extrusion of the compounded filament, which acts as a carrier of the metal powder and is deposited along a programmed print path to construct a 3D part. The as-printed parts are debound in several steps to ensure complete binder removal and pressureless sintered, targeting high densification levels. In this work, a copper-based filament was utilised as feedstock material and a full factorial design of experiments was performed to study the effect of layer height, volumetric speed and flowrate multiplier on the density of the as-printed part. Selected specimens from the DoE were debound and sintered and characterised. Various tests including density measurements, SEM, optical microscopy, micro-CT, etc., were applied at different stages to evaluate the porosity in the filament and printed parts. As a result, a relative density of 94% and an electrical conductivity of 63 %IACS (international annealed copper standard) were achieved for the sintered copper, which could be directly linked to the purity of the feedstock material." "Effect of printing layer orientation and polishing on the fatigue strength of 3D-printed dental zirconia." "Stevan Čokić, Fei Zhang" "OBJECTIVE: The aim of the study was to evaluate the influence of surface polishing and printing layer orientation on the fatigue behaviour of 3 mol% yttria-stabilized zirconia (3Y-TZP) by stereolithography (SLA) in comparison with subtractive manufacturing. MATERIALS AND METHODS: 60 experimental zirconia bar-shaped specimens were 3D-printed (P) via SLA, and 30 specimens were milled (M) from commercial zirconia block (Lava™ Frame, 3 M ESPE AG). All specimens had the same dimensions (1 mm × 1 mm x 12 mm) after sintering. The 3D-printed specimens were randomly divided according to printing orientations: parallel or perpendicular to the tensile surface in the fatigue test. The specimens were subsequently submitted to two surface finishing protocols (n = 15/gr): unpolished or polished. Their phase compositions were analysed by X-ray diffraction. The fatigue behaviour was evaluated by a stepwise approach. RESULTS: The milled and both 3D-printed groups showed similar phase compositions for the as-sintered condition. Considerable amounts of rhombohedral phase were detected after polishing. Milled unpolished samples presented significantly higher fatigue strength than 3D-printed unpolished samples. Polishing did not improve the fatigue strength for milled zirconia but was advantageous for the 3D-printed specimens. 3D-printed specimens with parallel printing-layer orientation were significantly stronger than specimens with perpendicular layers regardless of surface finishing. CONCLUSION: The manufacturing techniques had a significant influence on the fatigue strength of 3Y-TZP, but not on the phase compositions of the surface. The polishing protocol showed different effects on 3Y-TZP fatigue strength and induced phase transition of the 3Y-TZP from Tetragonal to Rhombohedral. The best fatigue strength was achieved through milling using an unpolished surface and SLA-printed layers that were parallel to the tensile surface, followed by polishing." "Si-contamination driven phase evolution in Nd-doped UO₂ porous microspheres" "Gamze Colak, Jef Vleugels" "Influence of grit particles characteristics on the abrasive wear micro-mechanisms of NbC-Ni and WC-Co hard materials" "Shuigen Huang, Jef Vleugels" "Upscaled Synthesis Protocol for Phase-Pure, Colloidally Stable MXenes with Long Shelf Lives" "Nick Goossens, Steven De Feyter, Francisco Molina Lopez, Jef Vleugels" "MXenes are electrically conductive 2D transition metal carbides/nitrides obtained by the etching of nanolaminated MAX phase compounds, followed by exfoliation to single- or few-layered nanosheets. The mainstream chemical etching processes have evolved from pure hydrofluoric acid (HF) etching into the innovative ""minimally intensive layer delamination"" (MILD) route. Despite their current popularity and remarkable application potential, the scalability of MILD-produced MXenes remains unproven, excluding MXenes from industrial applications. This work proposes a ""next-generation MILD"" (NGMILD) synthesis protocol for phase-pure, colloidally stable MXenes that withstand long periods of dry storage. NGMILD incorporates the synergistic effects of a secondary salt, a richer lithium (Li) environment, and iterative alcohol-based washing to achieve high-purity MXenes, while improving etching efficiency, intercalation, and shelf life. Moreover, NGMILD comprises a sulfuric acid (H2 SO4 ) post-treatment for the selective removal of the Li3 AlF6 impurity that commonly persists in MILD-produced MXenes. This work demonstrates the upscaled NGMILD synthesis of (50 g) phase-pure Ti3 C2 Tz MXene clays with high extraction yields (>22%) of supernatant dispersions. Finally, NGMILD-produced MXene clays dry-stored for six months under ambient conditions experience minimal degradation, while retaining excellent redispersibility. Overall, the NGMILD protocol is a leap forward toward the industrial production of MXenes and their subsequent market deployment." "Cation-heterogeneity in internally gelated U1-zCezO2-x, 0.15 ≤ z ≤ 0.3 microspheres" "Jef Vleugels" "Review on high-pressure spark plasma sintering and simulation of the impact of die/punch material combinations on the sample temperature homogeneity" "Kim Vanmeensel, Jef Vleugels"