TY - JOUR A1 - Tezel, Tugce A1 - Schultheiss, Ulrich A1 - Hornberger, Helga A1 - Kovan, Volkan T1 - Operational wear behaviour of 3D-printed lightweight metal gears: EDS and oil analysis comparison JF - Materials Testing N2 - Additive manufacturing (AM) has come to the fore in recent years among manufacturing techniques. This technique, which has different advantages than traditional ones such as casting, forging and machining, is expected to be widely used in producing machine parts like gears in the coming years. Therefore, experimental data on AM parameters for lightweight metal gears are important for industrial production. In this study, a wear test was applied to AlSi10Mg and Ti6Al4V gears under operational conditions, and the wear behaviour of conventionally and additively manufactured gears was compared. The amount of abrasion elements was determined by analysing the oil in the gearbox. In addition, gear surfaces were analysed using scanning electron microscopy and an energy-dispersive spectrometer before and after wear. Thus, the wear behaviour of gears produced by conventional and AM under service conditions was demonstrated comparatively. KW - additive manufacturing KW - titanium KW - aluminium KW - gear KW - wear Y1 - 2024 U6 - https://doi.org/10.1515/mt-2023-0222 SN - 0025-5300 VL - 66 IS - 6 SP - 830 EP - 834 PB - de Gruyter ER - TY - JOUR A1 - Reich, Sven A1 - Hornberger, Helga T1 - The effect of multicolored machinable ceramics on the esthetics of all-ceramic crowns JF - Journal of Prosthetic Dentistry N2 - Statement of problems: Computer-aided design/computer-assisted machining systems offer the possibility of fabricating restorations from one machinable ceramic block. Whether multishaded blocks improve esthetic results and are a viable alternative to individually stained ceramics has not been fully determined. Purpose: The aim of this investigation was to examine the effect of multishaded blocks on the esthetic appearance of all-ceramic CEREC crowns and compare these crowns with single-shade and stained restorations. Material and methods: Ten subjects were included in this study. For each subject, 6 different crowns were milled with the use of a CEREC machine. One crown was milled from each of the following machinable ceramic materials: CEREC Vitablocs Mark II in classic colors; Vitablocs Mark II in 3D-Master colors; Vitablocs Mark II in either classic or 3D-Master colors, with additional staining; Megadenta Bloxx multishaded; Mark II experimental multilayer; and an experimental multilayer leucite ceramic. Three independent examiners assessed the esthetic appearance of crowns fabricated to match each subject's anterior tooth shade. A scale of 1 to 6 was used to score the shade match and esthetic adaptation of each crown, with 1 representing excellent characteristics and 3.5 serving as the threshold for clinical acceptability. The examiners' scores were averaged, and the mean values were analyzed with the Wilcoxon signed rank test (P