TY - JOUR A1 - Hornberger, Helga A1 - Marquis, Peter M. A1 - Franks, J. T1 - The impact of diamond-like coatings on the strength of dental ceramics JF - Journal of Dental Research Y1 - 1995 VL - 74 SP - 522 ER - TY - PAT A1 - Aechtner, Stefan A1 - Hornberger, Helga A1 - Nagel, Emil A1 - Thiel, Norbert T1 - Composite material and method for the preparation thereof N2 - A composite material with a porous inorganic-nonmetallic matrix and a second material, characterized in that said porous inorganic-nonmetallic matrix has a bending strength of >=40 MPa as measured according to ISO 6 872; said second material is an organic material which at least partly fills the pores of said porous matrix; and said composite material has a modulus of elasticity, E, of >=25 GPa as measured according to ISO 10 477. Y1 - 2001 UR - https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=US020090001623A1 ER - TY - PAT A1 - Muerrle, Ulrich A1 - Hornberger, Helga T1 - Method of making a ceramic restoration N2 - Production of a dental reconstruction comprises: (a) forming a mold (12) from a model (10); (b) using (12) to make an isotropically heat-expandable replica from a ceramic precursor (14); (c) oxidizing (14) to produce an enlarged ceramic replica; (d) forming a silicone mold from this replica; (e) using (d) to make a second ceramic replica; and (f) sintering the second replica with volume reduction to form a replica identical to (10). T2 - Verfahren zur Herstellung einer Zahnrestauration aus Keramik Y1 - 2003 UR - https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=EP000001346702A1 ER - TY - JOUR A1 - Hornberger, Helga A1 - Weissmann, R. A1 - Lutz, N. T1 - Machining of silica glasses using excimer laser radiation JF - Glastechnische Berichte - Glass Science and Technology Y1 - 1996 VL - 69 IS - 2 SP - 44 EP - 49 ER - TY - JOUR A1 - Hornberger, Helga A1 - Witte, Frank A1 - Hort, Norbert A1 - Müller, Wolf-Dieter T1 - Effect of fetal calf serum on the corrosion behaviour of magnesium alloys JF - Materials Science and Engineering B N2 - The corrosion behaviour of WE43 magnesium alloys using the mini cell system was studied. Voltammetry and impedance spectroscopy were applied to study on the one hand the effect of microstructure of the working electrode and on the other hand the effect of proteins in the electrolyte. Two types of alloy samples were produced (i) by permanent mould casting and (ii) by gas atomization followed by extrusion. The results showed that the microstructure was strongly influenced by the production process. The extruded samples showed an improved homogeneity of phase distribution compared with cast samples as it was aimed for. Due to increased homogeneity it was expected to find higher corrosion resistance. However, the electrochemical results are contradictory and suggest an additional phase in the extruded microstructure. Using energy dispersive X-ray spectroscopy (EDX) the secondary magnesium rare earths (RE) phase of extruded samples showed differing composition than of cast samples as well as additional oxide phases. After the samples were electrochemically investigated in cell medium with and without fetal calf serum (FCS), an impact of FCS was detected in voltammetry due to the length of the polarisation curve. As the tip of the mini cell in contact with the working electrode is small, developing gases tend to spread on the working electrode and break the contact of liquid to the counter electrode; which results in disrupting the current flow. This effect was more pronounced when rising the voltage and was found reduced when using electrolytes with FCS. Impedance spectra were slightly deformed by FCS, seen as a kinetic effect but not as a basic differing corrosion reaction. The insight into the effects of FCS was provided by the mini cell system as this system enables to collect entire series of measurements. In contrast of two single measurements, those series reflected the slight difference caused by FCS. The focus of the electrochemical corrosion study was set on the first half hour of immersion. KW - Magnesium KW - Corrosion KW - Proteins KW - Impedance KW - Reproducibility KW - Polarization Y1 - 2011 U6 - https://doi.org/10.1016/j.mseb.2011.07.018 VL - 176 IS - 29 SP - 1746 EP - 1755 ER - TY - PAT A1 - Hornberger, Helga A1 - Thiel, Norbert A1 - Vollmann, Markus T1 - Fully ceramic tooth replacement with a frame made of cer-stabilised zircon-oxide N2 - Vollkeramischer Zahnersatz mit einem Gerüst, das aus einem Gerüstmaterial aus einem Cer-stabilisierten Zirkonoxid (Ce-ZrO2) mit einem Anteil von bis zu 25 Gew% Aluminiumoxid (Al2O3) bezogen auf den Anteil an ZrO2 aufgebaut ist und einem Infiltrationsglasanteil im Gerüst von 0-40 Vol% bezogen auf das Volumen des Gerüsts sowie einer auf das Gerüstmaterial abgestimmten Verblendkeramik.Die Erfindung betrifft die Verwendung von cer-stabilisiertem ZrO2 zur Herstellung von Gerüstmaterialien, die als Restauration im Dentalbereich einsetzbar sind. T2 - Vollkeramischer Zahnersatz mit einem Gerüst aus einem cer-stabilisierten Zirkonoxid Y1 - 2002 UR - https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=WO002002047616A3 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