Abstract: Composite dental prosthesis elements formed of filled acrylate- and/or methacrylate-based polymers and comprising a core having high flexural strength and a high bending modulus and an abrasion-resistant jacket with a highly lustrous surface are suitable for temporary and semipermanent as well as permanent installation with crowns and bridges, for inlays and the like.

Abstract: The irradiation apparatus for the photopolymerization of plastic embedding masses for histological preparations has a preparation support located in a housing and a plurality of irradiation lamps, with one lamp above and one lamp below the preparation support forming one lamp pair. In order to cure photopolymerizable embedding masses in a manner that does not harm the embedded preparations or specimens, and in particular to avoid an abrupt rise in the reaction heat, and so that a small number of irradiation lamps is sufficient, the preparation support is a rotary support plate having a plurality of light pervious preparation holding means located about its outer circumference, and the lamps are positioned such that in operation, the holding means sequentially pass in between the lamps of each lamp pair, and the centers of the holding means are located on a circle that is concentric with the axis of rotation of the support plate.

Abstract: A mold for embedding histological specimens made of transparent plastic of the kind that is hardenable by irradiation, usually with light, consists of at least one flat-bottomed oval basin depressed with respect to a surrounding surface which, in turn, is externally bounded by a peripheral channel. The containing walls of the basin are outwardly inclined from the vertical. A separating layer covers the entire upper surfaces of the mold, including those of the peripheral channel, and consists of a synthetic resin, such as polyethylene, which does not bond with the resin of the embedding material and can be applied to the sheet of acrylic resin or polyvinyl chloride before the latter is pressed into the shape of the mold. The specimen embedded in the hardened embedding resin can be easily expelled from the mold even if the mold is made from another resin to which the separation layer might bond.

Abstract: A treatment chamber as an accessory device for an illuminator for the photopolymerization of dental plastics. The chamber is both light-tight and has at least one movable chamber wall. A light conductor is provided for the light input.

Abstract: A terminal for a light conductor for uniform illumination of a rectangular field in medical and, especially, dental applications has a transparent, cylindrical lens body in a mount with its axis perpendicular to the axis of a socket for receiving the light exit end of the light conductor. The side of the cylindrical lens body facing the socket has a trough-shaped recess of symmetric cross section. The width of the trough-shaped recess continuously expands from the bottom to the margin of the trough-shaped recess, the bottom being perpendicular to the axis of the socket and perpendicular to the axis of the cylindrical lens body.

Abstract: A method for producing orthodontic devices and appliances having a highly accurate fit by building up a plurality of resin layers on a plaster cast comprising applying a first thin layer of a composition comprising a diurethanedimethacrylate prepared from 2,2,4-trimethylhexamethylenediisocyanate and 2-hydroxyethylmethacrylate, and a photopolymerization catalyst to the plaster cast and briefly exposing said thin layer to light whereby said thin layer is partially polymerized, successively applying at least one additional thin layer on said first thin layer and partially polymerizing each successive thin layer by brief exposure until the layer thickness and shape desired for the device or appliance are attained, and the shaped partially polymerized material is subsequently polymerized completely by exposure to light.

Abstract: A dental composition which when used together with a photopolymerizable dental sealing composition promotes adhesion of resin-based dental restorative materials to the tooth consisting ofa solution of (i) at least one phosphate selected from the group consisting of methacryloyloxyethyl dihydrogen phosphate and bis-(methacryloyloxyethyl) hydrogen phosphate and (ii) a photopolymerization catalyst comprising camphor quinone and an amine, in acetone.

Abstract: A dental composition which when used together with a photopolymerizable dental sealing composition promotes adhesion of resin-based dental restorative materials to the tooth consisting of a solution of tetramethacryloyloxyethyl pyrophosphate and a photopolymerization catalyst comprising camphor quinone and an amine in acetone.

Abstract: To improve coating of articles such as dental prostheses by flame hydrolysis, a zone of turbulence is generated at the tip portion of an elongated flame cone by a deflection surface (5, 5') located--with respect to flame projection--beyond holders for the articles and positioned to be impinged by the tip of the flame to be deflected and reflected thereby from the conical form, to cause the flame to swirl about the articles.

Abstract: Isolating agents consisting of aqueous alginate solutions which contain preservatives and have a pH between 5.5 and 8.5 are stable in storage and have uniformly good working properties even after a long period of storage. They are suitable for isolating the surface of plaster molds against plastic.

Abstract: To apply a silicon oxide adhesion-promoting layer to a metal prosthesis part or frame, for subsequent application of a dental plastic thereon, the prosthesis is subjected to flame hydrolysis derived from a flame hydrolysis burner (11) which has a silicon compound in vapor or gas form applied thereto in addition to a carbon-containing combustion gas, such as propane and air, the prosthesis part or frame being passed through the flame from the burner in the forward third thereof, the burner flame cone having, in operation, a length (L) of between 15 to 20 cm, a gas stream speed of about 1 m/sec., and wherein the length (L) of the cone exceeds the spacing distance (D) of the farthest part of the prosthesis from the mouth of the burner by only up to about 25%. For fine adjustment of the cone, a tinting substance can be added to the flame.

Abstract: A method for the production of a polymer composition comprising photopolymerizing at least one vinyl compound in the presence of at least one photoinitiator, said photoinitiator comprising at least one photosensitizer and at least one reducing agent selected from compounds of formula I and II. Polymerizable materials containing said photoinitiators and said at least one vinyl compound are also disclosed. The polymerizable materials are particularly suited for use as dental materials.

Abstract: Disclosed is a process for the photopolymerization of vinyl compounds and of photopolymerizable materials containing vinyl compounds and products produced thereby which are especially useful for dental materials. The process utilizes at least one photosensitizer of the formula ##STR1## wherein X is selected from the group consisting of CO, C(R.sup.1)(R.sup.2) and C(R.sup.3)(OR.sup.4); wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are each selected from the group consisting of hydrogen and a hydrocarbon radical;n is 0 or 1; andA is selected from hydrocarbon radicals which may be substituted and which may be bonded together with the proviso that when n is 1 and X is C(R.sup.1)(R.sup.2), and when n is 0, A is an aromatic radical; andat least one reducing agent of formula (I) or (II) ##STR2## wherein Y is selected from oxygen, sulfur or the group NR.sup.1 where R.sup.

Abstract: A method for producing orthodontic devices and appliances by building up a plurality of resin layers on a plaster cast comprising applying a first thin layer of a composition comprising a diurethanedimethacrylate prepared from 2,2,4-trimethylhexamethylenediisocyanate and 2-hydroxyethylmethacrylate, and a photopolymerization catalyst to the plaster cast and briefly exposing said thin layer to light having a wavelength of 400-450 nm whereby said thin layer is partially polymerized, successively applying at least one additional thin layer on said first thin layer and partially polymerizing each successive thin layer by brief exposure to light having a wavelength of 400-450 nm until the layer thickness and shape desired for the device or appliance are attained, and the partially polymerized material is subsequently polymerized completely by exposure to light having a wavelength of 350 nm.

Abstract: A dental opaquing composition comprising (a) at least one polymerizable ester selected from esters of acrylic acid and methacrylic acid; (b) a photopolymerization catalyst; and (c) 30 to 90 percent by weight, based on the weight of said composition, of a pigment mixture consisting essentially of 50 to 66.6% by weight zirconium dioxide and 33.33 to 50% by weight of titanium dioxide. The present composition is useful in the making of metal-based crowns and bridges and to coat natural and false teeth.

Abstract: A color scale palette has color sample rods tinted all along their lengths from a stem in a frame to the other end projecting from the frame. The frame has a window for exposing a portion of the color sample rods and, for example, a color key, and studs cooperative with a bore through the stem end of each color sample rod for snapping it into the frame. The bore is preferably a funnel-shaped for shadow-free as well as juxtaposed color comparisons.

Abstract: A process for photopolymerization of vinyl compounds and of photopolymerizable materials containing vinyl compounds which is especially useful for dental materials, and compositions useful in said process and the product of said process. The process utilizes a photosensitizer of the formula ##STR1## wherein X is selected from CO, C(R.sup.1)(R.sup.2) or C(R.sup.3)(OR.sup.4), R.sup.1,R.sup.2,R.sup.3,R.sup.4 is selected from hydrogen or a hydrocarbon radical;n is 0 or 1; andA are hydrocarbon radicals which may be substituted and which may be bonded together with a proviso that (1) when n is 1 and X is C(R.sup.1)(R.sup.2), and (2) when n is 0, then A is an aromatic radical; and at least one reducing agent of the formula ##STR2## wherein Y is selected from O,S or NR.sup.1, where R.sup.

Abstract: A process for the production of a polymer composition comprising photopolymerizing at least one vinyl compound in the presence of a photoinitiator comprising at least one photosensitizer and at least one reducing agent selected from N-alkyl-pyrazole, N-alkyl-triazole, N-alkyl-tetrazole, N-aryl-benzotriazole, N-aryl-pyrazole, N-aryl-triazole, and N-aryl-tetrazole. Polymerizable materials and products produced by the process are also disclosed which are particularly suited as dental materials.

Abstract: An improved dental composition which is opaque to X-rays comprising a polymerizable matrix and inorganic filler. The inorganic filler are formed of particles of zeolitic alumino-silicate of at least one metal selected from the group consisting of calcium, strontium, barium, lanthanum, rare earth metal having an atomic number of 58-71, tantalum and hafnium. The invention also provides dental prosthetic appliances found from said dental compositions.

Abstract: A bone cement in pliable and moldable form which when applied to bone and cured has superior characteristics containing an admixture of methylmethacrylate copolymers, methylmethacrylate, and between 15 and 75% by weight of an inorganic composition of between about 90 and 99% of a bio-active glass ceramic powder having a particle size of 10-200 micrometer and between 1 and 10% of vitreous mineral fibers having a length of less than 20 mm. The composition also contains a curing catalyst and, preferably, an accelerator.