Abstract: An orthodontic appliance includes a base with an outer surface, as well as at least one passageway extending through the base. An element is received in each passageway and is made of a material that transmits actinic radiation. The element serves as a window to facilitate the curing of light-curable orthodontic adhesive beneath the appliance base, while simultaneously preventing movement of the adhesive through the passageway. Optionally, one or more optical fibers are provided to facilitate curing of the adhesive.

Abstract: This invention is directed to lithium disilicate (Li2Si2O5) based glass-ceramics comprising silica, lithium oxide, alumina, potassium oxide and phosphorus pentoxide. The glass-ceramics are useful in the fabrication of single and multi-unit dental restorations (e.g. anterior bridges) made by heat pressing into refractory investment molds produced using lost wax techniques. The glass-ceramics have good pressability, i.e., the ability to be formed into dental articles by heat-pressing using commercially available equipment. In accordance with one embodiment directed to the process of making the glass-ceramics, the compositions herein are melted at about 1200° to about 1600° C., thereafter quenched (e.g., water quenched or roller quenched) or cast into steel molds, or alternately, cooled to the crystallization temperature. The resulting glass is heat-treated to form a glass-ceramic via a one or two step heat-treatment cycle preferably in the temperature range of about 400° to about 1100° C.

Abstract: Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a shell or die used in the manufacture of a dental restoration. Three-dimensional printing comprises ink-jet printing a binder into selected areas of sequentially deposited layers of powder. Each layer is created by spreading a thin layer of powder over the surface of a powder bed. Instructions for each layer may be derived directly from a CAD representation of the restoration. The area to be printed is obtained by computing the area of intersection between the desired plane and the CAD representation of the object. All the layers required for an aesthetically sound shell can be deposited concurrently slice after slice and sintered/cured simultaneously.

Abstract: The invention relates to a method for producing crowns etc. by producing a frame, for example, made of alumina, whereby a film (6) is shrink-fitted on the die (3) of a working model. The film (6) is provided with a slip and the slip is baked on a frame after the film is removed. In order to accelerate the method and to avoid the loss of materials, the die (3) is placed on a rotatable shaft (2). The slip is deposited with a tool (5). A drying process using a hot air dryer (7) is carried out during and/or after depositing the slip. This method can also be carried out in a CNC machine with which the veneer ceramic is successively deposited. A separating agent similar to lipstick can be deposited in place of the film (6). Said separating agent melts at temperatures greater than 45 DEG C. when the spacer function is not used. The invention also relates to a crease-free shrink-fitting of the film (6).

Abstract: The invention provides a method for the manufacture of a dental restoration including the steps of forming a model of refractory material of a tooth, and forming, by flame spraying directly on to said refractory model, a base layer of predetermined thickness of said restoration, said refractory model being cooled during the formation of said base layer. The refractory model is subjected to burn out, and optionally hardening heat treatment, and one or more layers of dental porcelain are applied to the base layer following sintering of said base layer.

Abstract: A mill blank assembly for a dental prosthesis includes a milling section and a support section for supporting the assembly in a milling machine. In certain embodiments, the milling section is adhesively bonded to the support section by a direct chemical bond that provides enhanced resistance to unintentional detachment of the milling section from the support section during a subsequent machining operation. Optionally, the support section includes a passageway that receives a quantity of flowable dental restorative material used to make the milling section, such that the restorative material that is located in the passageway provides additional resistance when hardened to unintentional detachment of the milling section from the support section.

Abstract: The invention provides a method for the manufacture of a dental restoration including the steps of forming a model of refractory material of a tooth, and forming, by flame spraying directly on to said refractory model, a base layer of predetermined thickness of said restoration, said refractory model being cooled during the formation of said base layer. The refractory model is subjected to burn out, and optionally hardening heat treatment, and one or more layers of dental porcelain are applied to the base layer following sintering of said base layer.

Abstract: Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a shell used in the manufacture of a dental restoration. Three-dimensional printing comprises ink-jet printing a binder into selected areas of sequentially deposited layers of powder. Each layer is created by spreading a thin layer of powder over the surface of a powder bed. Instructions for each layer may be derived directly from a CAD representation of the restoration. The area to be printed is obtained by computing the area of intersection between the desired plane and the CAD representation of the object. All the layers required for an aesthetically sound shell can be deposited concurrently slice after slice and sintered/cured simultaneously.

Abstract: The invention provides high strength dental polymeric dental products made from wax-like polymerizable dental material. These dental products have superior strength compared to products formed from prior wax-like polymerizable materials. Prior wax-like polymerizable materials do not form strong enough polymeric material for making dentures. High strength dentures are made by positioning artificial teeth in wax-like polymerizable dental material of the invention. This material is then shaped and polymerized to the form a denture base of high strength dental polymeric material. These dentures are completed without forming wax and without applying inorganic plaster to the artificial teeth.

Abstract: A process for the fabrication of indirect dental restoratives includes the making of a first, pre-operative impression of a tooth to be restored using a first polyvinyl silicone (PVS) material disposed in a clear tray, followed by the preparation of the tooth. A second, final post-operative impression of the tooth is taken utilizing a second PVS material. A tooth model is then made by pouring a low viscosity and suitably rigid, third PVS material into the final impression. Prior to the complete setting of the low viscosity PVS material, a higher viscosity, fourth PVS material is applied onto the model PVS material to form a completed model with base. The model is then fitted into the pre-operative impression matrix made from the first PVS material. Layers of composite are packed onto the impression in the clear matrix.

Abstract: The present invention relates to a method for producing a multicolored shaped body for further processing to form a dental restoration, and to a device for carrying out the method.

Abstract: A method of making a new dental prosthetic from an existing dental prosthetic including the steps of providing an existing dental prosthetic; and providing a mold having a bottom half and a top half, the bottom half including a side wall, a closed bottom and an open top face for mating with the top half, the top half including a further side wall, an open bottom face for mating with the open top face of the bottom half, and a partially opened top. The bottom half is then partially filled with a first molding material, and a first portion of the existing denture of a first molded material. The top half of the mold is placed on the bottom half of the mold; and a portion of the first material and a further portion of the existing denture is covered with a second material. A mold for making a dental prosthetic includes a top half and a mating bottom half. The bottom half includes a side, an open top, and a substantially closed bottom.

Abstract: A metallic composite solid, containing alloys and/or intermetallics, is formed by compacting at moderate pressure a mixture of powder particles, foils or sheets at a temperature close to room temperature, well below the melting temperature of the constituent components and without the addition of low melting metals such as mercury, indium or gallium acting as a sintering agent. This low temperature consolidation of the powder mixture is enhanced by having the surface oxide of the powder particles removed, prior to consolidation, and/or by coating the particles with an oxide-replacing metal such as silver or gold. The coating process may be replacement reactions, autocatalytic reduction or electrolytic reduction. The composite formation is assisted by the addition of a liquid acid such as fluoroboric acid, sulfuric acid, fluoric acid, adipic acid, ascorbic acid, or nitric acid.

Abstract: Micaceous glass-ceramics are useful in the fabrication of single and multi-unit dental restorations including but not limited to orthodontic appliances, bridges, space maintainers, tooth replacement appliances, splints, crowns, partial crowns, dentures, posts, teeth, jackets, inlays, onlays, facing, veneers, facets, implants, abutments, cylinders, and connectors by machining the glass-ceramic using CAM/CAM devices. The micaceous glass-ceramics are provided in a plurality of shades and colors to adequately match the colors and shades of teeth found in 95% or more of the human population.

Abstract: A thermoformed plastic dental retainer and method of construction including rapid cooling of the retainer, typically using a refrigerant coolant, as the retainer sets on a dental impression cast. The dental retainer is constructed by first forming an impression of a patient's upper or lower dentition and constructing the cast from the impression The retainer is vacuum-thermoformed over the cast using a sheet, plate or disc of thermoformable plastic and a vacuum or pressure thermoforming machine. As the thermoformed plastic retainer sets on the cast, the retainer is rapidly cooled typically by spraying a refrigerant coolant on the retainer.

Abstract: Refractory investment material and method for forming a positive replication of a tooth structure on which a high-alumina based porcelain tooth restoration is to be formed, the material being formed from a refractory powder which includes calcined alumina mixed with a liquid carrier comprising an aqueous colloidal dispersion of silicon dioxide. The method comprises the steps of: preparing a negative impression of the tooth structure on which a tooth restoration is to be placed; forming a positive replication of the tooth structure by pouring the mixture of refractory powder and aqueous dispersion into the negative impression; allowing the positive replication to harden; removing the positive replication from the negative impression for degassing and cooling; and coating the positive replication with a mixture of high-alumina porcelain in an aqueous carrier to form a core layer of porcelain on which subsequent layers of high-alumina porcelain may be applied.

Abstract: A process for manufacturing an apatite ceramic, especially for biological use involves the preparation of a homogeneous mixture of powders to form a hydroxyapatite of formula Ca10(PO4)6(OH)2, stoichiometric or non-stoichiometric, possibly containing other additives or flaws, compacting the mixture under a pressure of 100 to 500 Mpa at room temperature, and subjecting it to hydrothermal treatment at low temperature (100 to 500° C.) in the presence of water and in a sealed chamber.

Abstract: The invention provides a curable system and method of making a dental prosthesis. The method of making a dental prosthesis includes providing a one component denture base resin composition which is polymerizable by microwave energy. The one component denture base resin composition is injected into a mold enclosed by a flask having a body wall which is substantially transparent to the microwave energy. The curable system includes microwave energy sensitive initiators and polymerizables (meth)acrylate Monomers having molecular weights preferably between 400 and 20,000. The initiators are adapted to initiate polymerization of the polymerizable Monomers by application of microwave energy to the flask. The initiators are adapted to remain stable and not initiate polymerization of the Monomers for at least one year at 23° C. in the absence of microwave energy.

Abstract: A container for cross-linking composite materials on dental bridges and arches and on individual teeth, comprising: a plurality of plate-like elements which can be stacked and clamped together, at least one of the plate-like elements, which is internal to the plurality of plate-like elements, being constituted by a plurality of blocks which can be removed independently of each other to form an area which is suitable to constitute a mold into which it is possible to place a metallic structure on which the elements of a dental prosthesis are to be formed, the at least one of the plate-like elements and a plate-like element that is adjacent thereto in an upward region and constitutes the top plate-like element of the container being both made of a material which is transparent to light.

Abstract: A block member is selectively positioned on a dental impression tray with an outer engagement surface of the block member in engagement with the tray portion defining a lingual recess to block entry of plaster or other casting material into the lingual recess.

Abstract: A disposable plunger for use in a pressing furnace for the fabrication of dental restorations. The plunger is fabricated of a refractory investment material such as gypsum-bonded, phosphate-bonded or ethyl silicate-bonded investment materials. The plunger is fabricated by known casting methods. The mold used for making the plunger can be supplied by a manufacturer of molds or can be easily made by using an alumina or similar plunger as a model. Laborious cleaning and grinding are not required with plungers herein described. Cracking problems that occur with prior art plungers are decreased, if not completely eliminated.

Abstract: A method of controlling an oven for producing tooth replacement components. An electric motor moves a piston that acts upon a moldable restoration material. The restoration material is introduced into a muffle oven having an oven hood that can be removed from the muffle. The compactibility curve is established as a function of the type of dental material utilized. Immediately after conclusion of the mold time, the motor is turned off and the oven hood is removed.

Abstract: A method for manufacturing a fiber rein-forced composite dental restoration comprising the steps of (i) preparing a mould; (ii) filling the cavity of the mould with a fiber-reinforced polymerizable material comprising an organic matrix and a fiber component embedded within the matrix; (iii) applying pressure to the fiber-reinforced polymerizable material; and (iv) curing the fiber-reinforced polymerizable material. The method is characterized in that the mould is designed in a way which allows excess organic matrix material to escape form the cavity during pressing.

Abstract: An apparatus and process for continuously producing composite structural beams is disclosed. The process includes a first step of forming a tubular element from fibers of composite material, a second step of separating the tubular element into longitudinally extensive, circumferentially separated, corner caps, a third step of securing sandwich panels between adjacent corner caps to form a tubular beam, a fourth step of shaping the tubular beam, and a fifth step of curing the shaped tubular beam. Also disclosed is an exemplary beam constructed in accordance with the process of the present invention.

Abstract: A method for making artificial tooth bridges having a ceramic densely sintered high strength individual core veneered with porcelain using powder metallurgical methods, wherein the individual bridge parts are joined together as a bridge core with glass, which in molten condition wets the ceramic core material. The glass therefore finds its way into the gap between the bridge parts and reacts with the ceramics so that during cooling it forms a strong joint between the individual densely sintered ceramic bridge parts.

Abstract: The invention relates to a method for manufacturing a fiber reinforced composite comprising the steps of (i) preparing a mould; (ii) filling the cavity of the mould with a fiber-reinforced polymerizable material comprising an organic matrix and a fiber component embedded within the matrix; (iii) applying pressure to the fiber-reinforced polymerizable material; and (iv) curing the fiber-reinforced polymerizable material. The method is characterized in that the mould is designed in a way which allows excess organic matrix material to escape form the cavity during pressing.

Abstract: A process for producing a ceramic network material including the steps of: introducing a ceramic powder into a mold to form a molded material; firing the molded material to form a ceramic, open pore network; infusing the ceramic network with a silane solution; infusing a monomer to at least a portion of the ceramic network; and forming an interpenetrating network. The ceramic network materials may be used as restorative materials and in various devices such as posts, implant abutments, orthodontic brackets and blocks.

Abstract: A shaped, high-strength dental ceramic prothesis is made by pressing a molding composition comprising about 1-50 wt % glass particles and about 50-99 wt % ceramic particles to form a ceramic frame, veneering the frame and firing the coated frame.

Abstract: A dental porcelain composition, comprising a glassy matrix and leucite crystallites embedded therein, and having maturing temperatures in the range from about 600.degree. C. to about 885.degree. C. and CTEs in the range from about 11 to about 19, more preferably in the range from about 11.5 to about 18, and most preferably in the range from about 12 to about 17.5.times.10.sup.-6 /.degree.C. (measured from 25.degree. C. to 500.degree. C.). The tetragonal leucite is preferably both fine-grained (i.e, having average diameters of less than about 7 microns) and uniformly-sized. Preferably, the average diameters are less than about 1 to about 3 microns.

Abstract: A method of taking dental impressions for various types of dental work which is a two step process with only one tray insertion. The impression materials are selected and have durometer measurements which permit a technique without the use of a retraction cord, and the materials are highly thixotropic providing accurate results with a minimum of patient discomfort.

Abstract: A simple, fast, and reliable method and apparatus are provided for replicating a light shaping surface structure on a laminated surface of a relatively rigid substrate. More specifically, after the substrate is mounted on a table and a layer of epoxy is deposited between the substrate and a submaster to produce a layered structure, the layered structure is automatically compressed in a nip formed between the table and an outer surface of a rotating impression roller, thereby replicating the surface structure in the epoxy layer. The epoxy is then cured, and the submaster is separated from the substrate to leave a laminated structure having the light shaping surface structure on a surface thereof. Preferably, the submaster is wrapped around the impression roller, and the impression roller is rotated while the table is reciprocated linearly to compress the layered structure in the nip.

Abstract: A method for producing a dental prosthesis to be fitted to a fitting member including the steps of: determining the three-dimensional contours of the fitting member; producing a three-dimensional form of the dental prosthesis; producing a working stump and/or a working pack; placing the working stump in the form and/or packing the working pack around the outside of the form to completely cover the form; sintering the form with the working stump and/or the working pack; and separating the working stump and/or the working pack from the dental prosthesis after sintering. The working stump and working pack are produced such that they are enlarged by a predetermined enlargement factor.

Abstract: A method of making embossed optical polymer films and embossed optical polymer films made are described. The embossed optical polymer films have substantially the same optical properties as unembossed optical polymer films. The method includes providing an optical polymer film having first and second major surfaces, softening at least one of the first and second major surfaces to produce a softened surface, embossing the softened surface to produce an embossed optical polymer film, and cooling the embossed optical polymer film.

Abstract: A dental porcelain composition, comprising a glassy matrix and rubidium leucite crystallites embedded therein, and having maturing temperatures in the range from about 650.degree. C. to about 800.degree. C. and CTEs in the range from about 13 to about 17, more preferably in the range from about 13.5 to about 16, and most preferably in the range from about 14 to about 16.times.10.sup.-6 /.degree. C. (measured from 25.degree. C. to 400.degree. C.). The tetragonal rubidium leucite is preferably both fine-grained (i.e., having average diameters of less than about 5 microns) and uniformly sized. Preferably, the average diameters are less than about 1 to about 2 microns.

Abstract: A method of using latex as a protective separator and release agent between a resin on-lay, in-lay, laminate, or other restorations, and a dental model or tooth to be restored includes the steps of applying the latex to a surface of the dental model preparation by substantially covering the surface area that is to contact and form the restoration, to prevent direct contact of thereto and with the dental model or tooth, while facilitating a mutual release of the elements after curing has occurred. The latex is in the form of an emulsion of about forty to about seventy percent of solids, the solids including a protein material within a water base in which such latex is primarily isoprene butyryl and about 0.04% to about 0.5% percent ammonium hydroxide, to a restoration-forming surface of a dental model of tooth preparation covering that area which is in contact with the resin or other material on-lay or in-lay designed for such fabrication.

Abstract: A lenticular pattern forming roll, used for forming a lenticular screen, includes a chill roll and a lenticular sleeve positioned on the chill roll. The lenticular sleeve has a lenticular pattern formed on an outer surface for forming a corresponding lenticular pattern in a plastic sheet. The sleeve may be readily manufactured and transported to a desired location to be installed on the chill roll. The lenticular pattern forming roll may be readily used in combination with an extruder for extruding a hot plastic sheet to form the lenticular screen. The sleeve may also be removed from the chill roll and transported for resurfacing and without requiring transporting of the chill roll. The lenticular sleeve may preferably comprise a nickel-phosphorous composition defining at least a radially outermost portion of the sleeve in which the lenticular pattern is formed.

Abstract: The invention concerns a process for the production of a frame for inlays, crowns and bridges in dental techniques. By means of the process, a considerable reduction in work and time expenditure is achieved in comparison with known processes. In the case of this process, frames of spinel, alumina, zirconia, metal powder or similar materials are produced in that a) a shrink foil is drawn on the stump or the stumps of a working model; b) the draw-non shrink foil is provided with a slip; and c) the shrink foil and the slip present on the shrink foil are removed from the working model and calcined to burn off the shrink foil.

Abstract: An object of the present invention is to provide a process for producing a lens sheet, which is safe, which can cut the material cost and the facility cost, which can continuously produce, by the use of a forming die, a formed lens sheet that contains no air bubbles in the lens area thereof and which can attain higher productivity, and reduction of costs by using a decreased number of forming dies or the like; and a projection screen. The process for producing a lens sheet according to the present invention includes the steps of coating a resin composition for a lens sheet onto a forming die by the use of a multiple nozzle in which a plurality of nozzles are arranged at intervals along the forming die for a lens sheet in a direction substantially rectangular to a direction in which the resin composition for a lens sheet will be coated, and superposing a base material on the resin composition for a lens sheet which has been coated onto the forming die.

Abstract: A polishing roll, used for forming a smooth plastic sheet, includes a chill roll and a polishing sleeve positioned on the chill roll. The polishing sleeve has a polished outer surface for forming a corresponding smooth surface in a plastic sheet. The sleeve may be readily manufactured and transported to a desired location to be installed on the chill roll. The polishing roll may be readily used in combination with an extruder for extruding a hot plastic sheet to form the smooth plastic sheet. The sleeve may also be removed from the chill roll and transported for resurfacing and without requiring transporting of the chill roll. The sleeve may preferably comprise a nickel-phosphorous composition defining at least a radially outermost portion of the sleeve in which the polished surface is formed.

Abstract: A device including an injection molding tool for use once or a few times for producing a sinterable ceramic and/or metallic product. The device includes at least one first tool part. At least one second tool part is combinable with the at least one first tool part to form a molding space for the product. The second tool part is produced using a wet composition and is made of a readily worked and form-stable material containing pores and admixed heat-conducting particles. A wet composition-enclosing member can engage the first tool part during the production of the second tool part. A unit can be connected to the at least one second tool part and can be arranged with the at least one first tool part for absorbing internal lateral displacement forces arising during squeezing or injection of an injection molding composition.

Abstract: Shaped article replicas which are proportionately accurate replicas of a shaped article and which are equal, greater or smaller in size than said shaped article are made by preparing a swellable polymer replica of said shaped article; immersing said swellable polymer replica in a swelling agent system under conditions which will enlarge said polymer replica to a predetermined extent; forming a casting mold of such enlarged polymer replica; making a powder compact in said casting mold and heating said powder compact to produced a proportionately accurate solid replica of a predetermined size.

Abstract: A method and apparatus for producing a lenticular plastic sheet from a plastic sheet having a first surface and an opposite second surface employs a first chill roller having an outer surface, a patterned chill roller having an outer surface defining a first lenticular pattern thereon, disposed adjacent and parallel to the first chill roller so as to define a first nip therebetween and a second chill roller, having an outer surface and being spaced apart from the first chill roller and disposed adjacent and parallel to the patterned chill roller so as to form a second nip therebetween. A plastic sheet is extruded into the first nip so that the plastic sheet is molten as it passes into the first nip and so that the first surface of the plastic sheet is in contact with the first lenticular pattern, thereby facilitating the formation of a second lenticular pattern on the first surface. The second lenticular pattern is complimentary in shape to the first lenticular pattern.

Abstract: A method and apparatus for molding an illumination device using an open mold are provided which allow for the addition of light extraction structures to a prefabricated light guide using a curable material. A mold containing the extraction structures is first provided. Curable molding material and the prefabricated light guide are placed into the mold, and an overlay comprising light extraction structures is cured onto the light guide, providing a functional illumination device.

Abstract: An impression composition which is based on an aziridine-free composition which can be vulcanized at room temperature, and which comprises wax is provided according to the invention. The wax increases the dimensional stability of the composition during mixing and curing. The invention furthermore provides a kit for the preparation of such compositions and a process for the preparation of the wax-containing components of these kits. The wax is dispersed throughout the composition and is prepared by shock-cooling. The wax forms a crystalline network.

Abstract: An embossed substrate comprising a substrate of a plastic material and having a surface and an embossed surface carried by the surface of the substrate. The embossed surface is characterized by having a pattern with an average roughness of between 100 nanometers and 300 nanometers with the roughness being distributed substantially uniformly over the surface, the pattern has ridges and valleys with the horizontal distance between adjacent ridges and/or valleys being greater than the depth between the ridges and the valleys. The peaks and the valleys are randomly disposed without periodicity to cause diffusion of light impinging thereon to minimize or eliminate interference effects when the embossed surface overcoated with thin planar organic layers is exposed to light.

Abstract: A method for making multilayer optical films is provided in which the degradation of the optical extinction of the thinnest optical layers is avoided by casting these layers close to the casting wheel.

Abstract: Provided is a method for manufacturing a thermoplastic resin sheet bearing an embossed pattern, which employs a manufacturing apparatus having a first roll having an elastic material coated surface, a mirror-faced metal, endless belt, which is wound around the first roll and a second roll, and a third roll so provided that the metal, endless belt is wrapped partially around the third roll, which contacts the first roll via the metal, endless belt and which has an embossed pattern formed on one surface. According to this method, the thermoplastic resin sheet, partially melted, is fed between the metal, endless belt, which contacts the first roll, and the third roll. The elastic member is elastically deformed by application of a pressing force between the first and the third roll, while face pressure welding the thermoplastic sheet by using the first and the third rolls to transfer the embossed pattern and to cool the thermoplastic resin sheet. A surface temperature for the third roll of from 0.degree. C.

Abstract: Improved very high viscosity (putty) two component polymerizable polyorganosiloxane composition for use in making dental impressions, having improved tear strength, handling and wettability. Improved tear strength results from inclusion of a quadri-functional polysiloxane having a vinyl content of 0.16 to 0.24 m-mole/g. Working time is maintained by including sufficient amounts of a retarder composition that delays onset of the vinyl polymerization. Handling is improved by the addition of a very high viscosity linear vinyl terminated polydimethylsiloxane which reduces tackiness and improves the shelf stability. Wettability is improved by including a surfactant resulting in a surface contact angle with water at three minutes of less than 50.degree.. The surfactant chosen has an HLB of 8-11, such that the wetting contact angle is achieved within less than two minutes and remains wetting throughout the working time of the impression taking, substantially improving the impression making process.

Abstract: A living tissue replacement of crystallized glass having bioaffinity and mechanical strength is briefly obtained simply by pressure molding or machining without using a special equipment. A glass material having a softening point below its crystallization temperature and exhibiting viscous flow at temperatures below its melting point is heated at a temperature above its Tg and pressed at the temperature to mold to a desired shape, thereby manufacturing a living tissue replacement such as a dental crown. Molding can be done under a pressure of up to 20 MPa.

Abstract: This invention provides a method for continuously forming an array of optical elements which includes feeding synthetic resin sheeting having a temperature in the flow temperature region of the synthetic resin directly to a thermoforming zone of embossing means; continuously pressing the sheeting against a mold provided on the embossing means and having a pattern for defining an array of optical elements while maintaining the sheeting at that flow temperature, to bring the sheeting into intimate contact with the mold and thereby form an array of optical elements on one surface of the sheeting; laminating a surfacing film to the side of the sheeting opposite to the mold as required; feeding a carrier film to the side of the resulting laminate opposite to the mold and bringing the carrier film into close contact therewith; and cooling the sheeting to a temperature lower than the glass transition temperature of the synthetic resin, as well as apparatus therefor.