Abstract: Method for measuring the shape of a section of a semi-transparent object such as one section of a tooth, using a light source for generating light with a broadband spectrum in a device for generating a multifocal illumination pattern, a lens with a large chromatic aberration for imaging foci of the illumination pattern onto the object, and a detection device for determining the wavelength spectra of the foci confocally imaged onto the object via the lens, wherein a spectral peak position of each focus is determined from the respective wavelength spectrum, from which position the extent of the object in the direction of the imaging beam (Z coordinate) is calculated.

Abstract: A method for detecting contour data of a three-dimensional object, where a grid of illumination points of a multi-point illumination is projected onto the object using an optical device and the illumination points are then projected back onto a sensor containing pixels. In order to improve signal-noise ratio and reduce background signal, it is proposed that a grid of illumination points of at least two multi-point illuminations are projected onto the object, that the beams of the illuminating points of are modulated in intensity and that a frequency-selective and/or phase-selective detection is performed of mutually associated first and second illumination points back-projected onto the sensor. The first illumination points derive from a first of the multipoint illuminations and the second illumination points derive from a second of the multipoint illuminations.

Abstract: The invention concerns a process for the polishing of metallic dental prostheses, such as frames. In order to reproducibly obtain a defined surface roughness with no need for additional finishing, it is proposed for the dental prosthesis to be polished by means of plasma polishing.

Abstract: A method and arrangement for transmitting radiation emitted by LEDs operated in pulsed operation via at least one optical waveguide, wherein a first optical waveguide having first and second coupling surfaces is assigned to each LED, the first optical waveguides are in each case aligned, by their first coupling surfaces, with an assigned stationary LED, the second coupling surfaces are arranged on a closed path and a coupling surface of a second optical waveguide is assigned to the second coupling surfaces. In order that a high light power can be coupled into the second optical waveguide by means of the LEDs, it is provided that the second optical waveguide, in accordance with the clocking of the switched-on LEDs, can be aligned with the second coupling surface of a first optical waveguide from at least one switched-on LED.

Abstract: The invention relates to a method for detecting properties or alterations in at least one semitransparent layer of a body of a tooth by applying light escaping from at least one light guide via the front thereof to the body, as well as for recording at least one area of the body by means of a camera and subsequently assessing the image determined by the sensor. In order to be able to detect alterations or properties with high accuracy and a high image quality, it is proposed to place the front of the light guide on the body in order to subject the body to the light of the light guide.

Abstract: A method for determining the color perception of multi-layer dispersive materials or biological materials for layer thicknesses that are respectively selective, by the determination of the diffuse reflectance based on the respective intrinsic optical parameter using Monte Carlo simulations and taking into consideration the measurement geometries, anisotropy and the dispersion phase function in order to correctly take into account the multiple internal dispersion of the material. The color effect is calculated from the diffuse reflectance based on the various color systems in accordance with different algorithms.

Abstract: Method for measuring the shape of a section of a semi-transparent object such as one section of a tooth, using a light source for generating light with a broadband spectrum in a device for generating a multifocal illumination pattern, a lens with a large chromatic aberration for imaging foci of the illumination pattern onto the object, and a detection device for determining the wavelength spectra of the foci confocally imaged onto the object via the lens, wherein a spectral peak position of each focus is determined from the respective wavelength spectrum, from which position the extent of the object in the direction of the imaging beam (Z coordinate) is calculated.

Abstract: A device (10) for the dosed discharge of a powder-form medium, in particular ceramic powder for dental purposes, including a storage container (12) with a first outlet (40), as well as a slider (20) with a receptacle (18) for a quantity of medium to be dosed, which can be selectively aligned with a first outlet or a second outlet (50), through which the medium can be discharged. In order to achieve reproducible discharge of a defined quantity of free-flowing medium in an uncomplicated design, and since there is no requirement for re-usability after emptying the storage container, the invention proposes that the slider (20) be connected to at least one spring element (26, 28), which admits a force upon the slider to align the receptacle (80) with the first receptacle (40), and that the receptacle can be secured by a lock element (34) in a position aligned with the second outlet (50).

Abstract: The invention relates to a process for determining the form a duplicate of a residual tooth area, which is to be fitted with a dental restoration whereby the duplicate sections to be fitted with the restoration are removed from the duplicate and the form data to be allocated to their forms has to be determined and stored in a computer, by means of which the form of the restoration is calculated taking into consideration the spatial allocation of the duplicate sections. In order to be able to determine the shape of the residual tooth area to be fitted with the restoration, and thereby determine the shape of the restoration itself with high precision, it is proposed that the duplicate sections are or are being individually referenced to each other in their spatial allocation to each other according to a referencing stored in the computer.

Abstract: A method and device for detecting the contour data and/or optical characteristics of an object, such as a tooth or a tooth restoration, based on an interference and/or autocorrelation measurement using an image sensor. To permit an exact surface detection in addition to a determination of the optical characteristics of the object, individual light beams strike the object, which are located at a distance from one another in such a way that no impact of reflected individual light beams takes place on immediately adjacent pixels of the image sensor.

Abstract: A dental color system having primary and mixed colors with assigned coordinates in the CIElab color space, in which the colors of natural teeth are essentially located on coordinates within an ellipsoid-shaped space, which is assigned a longitudinal axis.

Abstract: A method for designing a connector between a first and a second element of a dental restoration, such as a connector between coping and coping, or coping and pontic, or pontic and pontic of a bridge, which is characterized by the steps of computing a (first) model of the first element and a (second) model of the second element, defining a connecting straight line between the first model and the second model, computing edge curves (?0, ?4) on the first model and the second model, whereby the edge curves are defined by origins of surface normal vectors of the models, which satisfy boundary conditions relative to the connecting line, computing offset curves (?1, ?3) on the first model and the second model from the first edge curves, and connecting the first edge curves and the offset curves of the first model and of the second model and computing the connector on the basis of the course of the connection between the curves.

Abstract: A method for manufacturing a dental restoration, including: determining an external form and dimensions available for a completed restoration; obtaining an image of a natural tooth to be replaced with the restoration or a tooth corresponding therewith, wherein the image comprises at least the external surface visible in use of the to be replaced or corresponding tooth, with variations in the appearance therein; defining locally on and at least to visible depth below the surface of appearance-determining properties of at least one material to be applied for the restoration in accordance with the obtained image and the variations in the appearance therein; constructing the restoration, including the steps of: providing at least one material to be applied in non-cohesive form; and providing cohesion to the material in accordance with the available form and dimensions.

Abstract: A method for the three-dimensional determination and digitization of a plaster- or positive-model, in particular for the production of replacement teeth, with improved handling and costs. According to the method, a plaster- or positive-model is clamped in a mounting with a defined orientation and irradiated by means of a radiation source; the radiation reflected by the plaster- or positive-model is recorded and evaluated by a scanning unit. Separation information is generated, and defined movement of the plaster- or positive-model relative to the radiation source takes place along an axis (y), approximately perpendicular to the direction of radiation and linking the displacement with the separation information. The invention also relates to a device for carrying out the method.

Abstract: The invention relates to a method for detecting properties or alterations in at least one semitransparent layer of a body of a tooth by applying light escaping from at least one light guide via the front thereof to the body, as well as for recording at least one area of the body by means of a camera and subsequently assessing the image determined by the sensor. In order to be able to detect alterations or properties with high accuracy and a high image quality, it is proposed to place the front of the light guide on the body in order to subject the body to the light of the light guide.

Abstract: The invention relates to a method for three-dimensional shape measurement of a body or of a part thereof, in particular of a dental object such as a model, by scanning non-contact distance measurement using an optical sensor device comprising a beam source, where the shape of the body subjects reproducing areas to a beam at various incidence angles (impinging beam), and the reflected beam (measuring beam) is measured, with the body being adjusted relative to the optical sensor device. To permit measurement with high precision of the body and undercuts thereof, without tilting being necessary, it is proposed that for shape measurement of the respectively measured area the beam (measuring beam) reflected therefrom, which describes an angle ? to a surface normal corresponding to the respective area, is taken into account, said angle being equal to or smaller than a predefined critical angle ?GR relative to the surface normal.

Abstract: The invention relates to the use of a cobalt-chromium alloy in the manufacture of a dental prosthesis. The alloy contains: 43-68% by weight cobalt, 12-30% by weight chromium, 8-25% by weight tungsten, 0-13% by weight iron, 0-30% by weight manganese, 0-10% by weight molybdenum, 0-5% by weight of at least one of the elements aluminum, tantalum, rhenium, titanium and less than 0.1% by weight carbon. A dental prosthesis with favorable workability and a low corrosion rate is obtained by manufacturing the dental prosthesis by means of a laser melting and/or sintering process.

Abstract: The invention concerns a process for the polishing of metallic dental prostheses, such as frames. In order to reproducibly obtain a defined surface roughness with no need for additional finishing, it is proposed for the dental prosthesis to be polished by means of plasma polishing.

Abstract: A dental alloy with a high gold content that is devoid of palladium and copper. To achieve high mechanical stability, the dental alloy contains between 75 and 95 wt. % Au, between 5 and 20 wt. % Pt, between 0.5 and 3.5 wt. % Zn and/or Sn and/or In, between 0.1 and 0.8 wt. % of an element of a group I, in addition to a single particle refiner of a group II. The weight fraction of the element of group I is between 2 and 6 times that of the single particle refiner of group II, and one element of group I is represented by Nb or Ta or Ti or V and the particle refiner of group II is represented by Ir or Rh.

Abstract: The invention relates to an opaque dental ceramic for burning on a rack or implant of dental restoration at least comprising SiO2, Al2O3, B2O3, Na2O, K2O as well as TiO2. To cover the non-dental-coloured implant material sufficiently the invention provides that the opaque dental ceramic is clouded by precipitation of one or more crystalline TiO2 phases.