Abstract: Dental materials based on polymerizable binders, which contain at least one chromophoric xerogel of the formula I: (SiO2)a(SiO1.5-Sp-X-CG)(MenOm)b  (I) in which Me represents a main-group metal of the 2nd to 3rd main groups or a transition metal of the 4th sub-group of the periodic table of elements; n being equal to 1 or 2, m being equal to 1 or 2 if n is equal to 1 and m being equal to 3 if n is equal to 2; Sp is a C1 to C10 alkylene radical or C2 to C10 oxyalkylene radical with 1 to 4 oxygen atoms or is absent; X is a compound group, such as CO—O, O—CO, CO—NH, NH—CO, O—CO—NH, NH—CO—O, NR, O or S or is absent, R being hydrogen or a C1 to C5 alkyl radical; CG is a chromophore; a is an integer from 0 to 20 and b is an integer from 0 to 5.

Abstract: A light hardening apparatus for effecting the photopolymerization of a light hardenable dental restoration material is provided and includes a plurality of light sources supported on semi-conductor bases, which are mounted on a substrate. The light sources are arranged in at least two light source groups such that one group of light sources is disposed for irradiating a region of the dental restoration material and another group of light sources is arranged for irradiating a different region of the dental restoration material. The two groups of light sources are controllable to irradiate their respective associated regions of the dental restoration material independently of one another.

Abstract: The invention relates to dental materials which contain a thermochromic dye and which display a reversible change of colour in the event of changes in temperature, so that they can be distinguished from the natural dentin.

Abstract: A light hardening device is provided for hardening a light hardenable mass applied for dental purposes that has a first light emitting diode for emitting light at a range of intensities corresponding to a set of wavelengths which at most only partially overlap a range of light sensitivities of a photo initiator comprised in the mass. The light hardening device also includes a second light emitting diode for emitting light at a range of intensities corresponding to a set of wavelengths which overlap the set of photo initiator light sensitivities to a relatively greater extent than the partial overlap of the range of first light emitting diode intensities with the range of photo initiator light sensitivities.

Abstract: Dental materials based on polymerizable binders, which contain at least one chromophoric xerogel of the formula I:

Abstract: A light hardening apparatus particularly suitable for effecting the hardening of dental restoration material is provided and includes two semiconductor light sources cooperable with a light-guiding element for guiding the light from the semiconductor light source to the dental restoration material to effect the hardening thereof. The two semiconductor light sources have an emission spectrum with at least two maximums of which one of the maximums lies at approximately 420 nm and the other maximum lies at approximately 470 nm.

Abstract: A light hardening apparatus for effecting the photopolymerization of a light hardenable dental restoration material is provided and includes a plurality of light sources supported on semi-conductor bases, which are mounted on a substrate. The light sources are arranged in at least two light source groups such that one group of light sources is disposed for irradiating a region of the dental restoration material and another group of light sources is arranged for irradiating a different region of the dental restoration material. The two groups of light sources are controllable to irradiate their respective associated regions of the dental restoration material independently of one another.

Abstract: A light curing device has a light source for curing light-polymerizable dental materials. A control circuit controls the light output of the light source according to a pre-determined output profile. The output profile has a starting time period with a decreased output relative to a maximum output, followed by a main curing time period. In the main curing time period, a pulsed output with alternating high output value and low output value is provided.

Abstract: The invention relates to dental materials which contain a thermochromic dye and which display a reversible change of colour in the event of changes in temperature, so that they can be distinguished from the natural dentin.

Abstract: A granular, polymerizable composition which contains at least one polymerizable monomer and/or oligomer and a polymerization initiator and optionally an accelerator and at least 70% by wt. filler and additionally 0.5 to 28% by wt. dendrimer and which becomes flowable under compressive or shear stress. The composition can be packed in similar manner to amalgam and is particularly suitable as dental material or for the production of a dental material.

Abstract: The invention relates to dental materials which contain a photochromic material such as for example a photochromic dye, a photochromic glass, a photochromic ceramic and/or a photochromic glass ceramic and which can be visually distinguished from natural tooth material after irradiating with light, but which assume their original colour again after a certain period has expired.

Abstract: A dental material which is curable in a first stage to an elastic phase in which the material can be worked mechanically or surpluses removed, and in a second stage to its final form, comprising:(a) at least one polyfunctional epimine (aziridine);(b) at least one ethylenically unsaturated monomer;(c) at least one catalyst for the hot, cold, or light polymerization of the ethylenically unsaturated monomer; and(d) at least one catalyst to accelerate the polymerization of epimine (a), but which does not however influence the polymerization of (b).

Abstract: A chlorhexidine adduct is described, which comprises one molecule of chlorhexidine with three molecules of hydrogen fluoride and one molecule of hydrogen tin trifluoride. The adduct displays a high antibacterial effectiveness against Streptococcus mutans even in very low concentrations.

Abstract: A chlorohexidine adduct comprising one molecule of chlorohexidine with six molecules of hydrogen fluoride and a process for its preparation are described, said adduct displaying a high anti-bacterial effectiveness vis-a-vis Streptococcus mutans even in very small concentrations and being valuable as anti-plaque agent and for caries prevention.

Abstract: A railroad track including rails and transversely extending ties. The end portions of the ties are placed on a rigid substructure. For reducing the sound emission, loading members are placed on the ties between the rails. These loading members have an essentially T-shaped cross-section, wherein the horizontally projecting portions are placed on adjacent ties. Sound-insulating elastic inserts may be provided between the ties and the loading members. Consequently, no fittings for fastening the loading members are required. In addition, the space existing between the ties is utilized in an optimum manner by filling it with sound-insulating material.