Abstract: Molds for fabrication of custom and potentially modifiable abutments and impression posts for dental implants with various degrees of angulations (including zero degrees) and various dimensions are provided, with a generally oval shape that expands laterally upwards, a symmetrical or asymmetrical cross-section, and regular surfaces, that are fabricated as one piece, or as two coupling pieces snapping onto each other. Custom abutments achieve the development of a custom gingival emergence profile, three dimensionally, which is potentially modifiable according to the needs of each particular clinical case. Custom impression posts that correspond in dimensions and angulations to the abutments allow the accurate recording and transfer of the developed gingival emergence profile from the mouth onto the working cast, where the final implant prosthesis is fabricated.

Abstract: A separable ring apparatus for producing an investment mold is formed of a pair of semi-cylindrical half segments of flexible resilient high temperature resistant material; each having laterally opposed longitudinal sides, an interior with a longitudinal concave semicircular surface of a first smaller radius at opposed ends, and a longitudinal concave semicircular recess of a second larger radius intermediate the opposed ends. Each of the segments has a respective mating joint element extending longitudinally along the opposed longitudinal sides, respectively, for releasably joining the segments together in opposed facing relation to form an elongated generally cylindrical ring having opposed top and bottom ends defining a central circular bore of a smaller diameter at upper and lower ends, and a larger diameter recessed cavity intermediate the upper and lower ends.

Abstract: An aluminium-copper alloy comprising substantially insoluble particles which occupy the interdendritic regions of the alloy, provided with free titanium in quantity sufficient to result in a refinement of the grain structure in the cast alloy.

Abstract: A method for producing dental restoration components includes filling a retort cylinder of a retort system with a forming mass, the retort cylinder being at least partially encircled by a charging body, and hardening the forming mass. After the hardening of the forming mass, the retort cylinder and the charging body are removed from the forming mass, thereby leaving behind a retort. Thereafter, with the assistance of a press blank apparatus, a press blank having an outer contour substantially corresponding to the outer contour of the charging body is pressed into the retort.

Abstract: An apparatus comprising a casting ring and base sized and dimensioned to be coupled together to form a cavity having one or more walls comprising an inner surface of the casting ring, having a bottom comprising an upper surface of the base, and having a form receiving member portion of the base extending into the cavity. This embodiment includes an indicator forming portion sized and positioned to form an indicator on a mold produced by at least partially filling the cavity with investment and allowing the investment to harden. In some instances the casting ring may have a lower segment sized and dimensioned to surround and receive an upper segment of the base to couple the ring and base together, wherein, the casting ring latches onto an outwardly protruding shoulder of the base when the base and casting ring are coupled together.

Abstract: An investment molding flask assembly having a base with a central positioning boss protruded from a center thereof and at least one positioning annular groove defined therein around the central positioning boss, and a conical sleeve formed with a small opening end to be securely positioned on the base without any displacement in horizontal directions by means of the central positioning boss or the positioning annular groove. Whereby, the conical sleeve can be readily removable from a solidified semi-finished investment mold, and then the solidified semi-finished investment mold is sent into an oven independently for heating. Therefore the sleeve can be used repeatedly, and the investment mold can be manufactured rapidly and readily.

Abstract: Apparatus for forming a pour hole and main sprue in an investment mold for lost wax casting. A sprue having a flared base, a base member adapted to receive the flared base of the sprue for vertically supporting the sprue, and a flask for containing investment material immersing the sprue, define the casting apparatus of the present invention. The present investment casting sprue apparatus forms a pour hole in the hardened investment material suitable for smoothly introducing liquid metals into the cavity formed by the sprue, thereby reducing the number of casting defects related to turbulent filling. This is accomplished as a result of the flared base of the sprue, which forms a gentle transition into the sprue. The current practice, by contrast, uses a sprue having a cylindrical base which is simply inserted into a hole in a finger or button formed in the supporting base member for the sprue without regard to this smooth transition.

Abstract: The casting assembly includes a horseshoe shaped casting ring having a plurality of handling posts; a horseshoe shaped crucible former having a flange for retaining the casting ring and a top surface for supporting the casting ring; and a pair of tongs having a plurality of openings, each of the openings adapted to receive one of the handling posts.

Abstract: A paper receptacle is disclosed designed to improve the investment casting process in vacuum machines. The paper acts as both a vacuum liner and splash guard. It is fabricated as a perforated paper sheet having hooks, which is inserted in a cylindrical manner into casting flasks in order to provide a liner for congealing islands of solid investment plaster onto the surface of the casting flask resulting from the plaster slurry entering the holes; and a splash guard for investment slurry. After burnout, the liner facilitates the production of high-density metal porosity free castings at lower temperatures and in less time and with easy break away of investment plaster from the flask. The splash guard feature eliminates congealed slurry cleanup and prevents vacuum slurry boilover. The space saving resulting from this prevention enables more wax modules to be inserted into flasks increasing production.

Abstract: The apparatus includes a rubber base with two inlets, a two-chamber ceramic crucible with two identical outlets, and a model of the jewelry item with two sprues connected to two separate tree stems, with each sprue connected to a separate stem thus ensuring flow of different colors or different metals. Simultaneous casting of two different metal alloys of different colors in two separate chambers of the crucible is achieved by using a specially constructed two-head torch.

Abstract: Method of multi-color jewelry items production is based on a simultaneous casting of two metal alloys of different colors (yellow-red, white-yellow, etc.), as well as two different metals, with a purpose of obtaining jewelry art-works of high-quality and unique artistic impression. To serve that purpose, the following apparatus has been constructed: rubber base with two inlets, two-chamber ceramic crucible with two identical outlets, and a model of the jewelry item with two sprues connected to two separate tree stems, with each sprue connected to a separate stem thus ensuring flow of different colors or different metals. Simultaneous casting of two different metal alloys of different colors in two separate chambers of crucible is achieved by using a specially constructed two-head torch. Usage of this invention in the process of jewelry work casting ensures a unique natural effect of smooth transition from one color to another in a jewelry piece (ring, brooch, pendant, charm, etc.

Abstract: Compression and distortion on a wax pattern during curing are eliminated by employing a thermochromatic dye which changes color when investment material sets. By monitoring the dye, the set investment material can be removed from the assembly before curing, eliminating compression forces on the wax pattern from the exothermic curing process expanding the investment material against the constraints of the assembly.

Abstract: A cap for an investment vessel for receiving investment material comprises a platform having a contoured edge and an underside. A wedge is located on the underside of the platform and is frictionally engageable with at least a portion of an inner edge of the top of the vessel. When the cap is placed in frictional engagement with the vessel, the contoured edge provides a restricted opening to the vessel for controlling the flow of the investment material. A lip is provided on the platform at the contoured edge for channeling investment material to the opening.

Abstract: A device for receiving dental investment solution to create an investment mold, has an oval casing which fictionally engages an oval base. Anti-rotation tabs of the base extend into anti-rotation slots in the casing, with both casing and base made of flexible plastic material.

Abstract: In an improved method and apparatus for investment casting, a pattern (31) is mounted on a sprue base (19) of an spider gasket (12) that is secured to one end of a standard investment flask (11). A solid end cap (13) is secured to the other end of the flask. The end cap is provided with a matrix of holes (15) extending therethrough parallel to the axis of the flask, and a plurality of small diameter rods (16) are slidable secured in the holes in the end cap. The rods are extended into the interior of the flask about the pattern without contacting the pattern. Investment plaster (10) is poured into the flask through the spider assembly to immerse the pattern and rods, and the plaster is allowed to set. The rods are then withdrawn, forming a large plurality of channels (32) extending into or through the investment plaster, reducing the amount of investment plaster required in the flask. The channels greatly accelerate the drying time of the investment, and hasten the subsequent burnout process in a kiln.

Abstract: An inexpensive vacuum casting chamber is provided to considerable increase casting production in vacuum assist casting machines. This vacuum casting chamber will increase casting production in vacuum assist casting machines by allowing perforated flask to be casted in said machines.

Abstract: An apparatus comprising a batch hopper including a bottom wall having therein a plurality of openings, a plurality of walls dividing the batch hopper into a plurality of compartments each communicating with a respective one of the openings and each adapted to receive sand from a main hopper, and a sliding gate for simultaneously opening and closing the openings in the bottom wall of the batch hopper.

Abstract: An integral casting flask/vacuum chamber combination is disclosed in which an inner tube forming the casting flask is disposed coaxially inside of an outer tube thus forming a vacuum chamber between the two tubes. The inner tube has holes formed in its circumference to provide for uniform evacuation of air from the investment for pulling the casting material into the mold. A shoulder portion integrally connects the inner tube with the outer tube in such a way that the bottom edge of the inner tube is suspended above the bottom edge of the outer tube and the top edge of the inner tube is suspended above the top edge of the outer tube. This device is used in combination with a vacuum table and does not require the complex and expensive conventional vacuum chamber.

Abstract: A plastic base for use with a cylindrical flask for the elimination of wax patterns prepared for making metal castings by the lost wax process is identified. The base is made of a plastic material which is used in place of conventionally found rubber bases. The base is constructed of a thin-walled resilient plastic material and allows for direct set up of the wax patterns, as well as increased speed in the preparation of the plaster mold in the cylinder for making metal castings. The plastic base comprises an inner annular raised platform comprising a shoulder and the cylindrical flask is pressed on the shoulder deforming the plastic about the bottom edge of the flask to form a seal between the base and flask.

Abstract: An apparatus for the preparation of a dental casting from a dental pattern utilizing an exothermic investment material which expands upon curing which comprises a base having a top surface for supporting the dental pattern and a container having a first and a second open end. The container and the base partially enclose the dental pattern when the first open end of the container is disposed upon the top surface of the base. The second end of the container enables the introduction of the exothermic investment material to compeletly encompass the dental pattern. The container comprises a first and a second container portion with each of the first and second container portions having a first and a seond terminating edge. The first and second terminating edges of the first container portion respectively cooperate with the second and first terminating edges of the seocnd container portion for retaining the uncured exothermic investment material within the container.

Abstract: In casting metals for dental prosthetic use, superior dental castings free from shrinkage cavities can be obtained by delaying the cooling and solidification of molten metal in mold members such as a sprue, runner and gate and, if necessary, a molten metal reservoir into which the molten metal is poured. Such delay in cooling and solidification can be achieved either by forming the sprue and the like from a heat resisting ceramic tubular body or by further forming a heat insulating layer on the outer periphery of the tubular body.

Abstract: The apparatus comprises an expandable investment ring having a removable base. Formed on the top surface of the base, and within the void defined by the ring, is an indexed sprue former. A curved runner bar having an indexed coping is formed at one end thereof in mating relation to the sprue former. The curved full arch runner bar comprises a proximal end portion and distal end portion with the distal end forming a first and second curved configuration portion which together approximates the curved configuration of the jawbone of a patient. The first and second curved configuration portions are interconnected thereby resulting in extremely accurate full arch base metal castings. The apparatus is also useful for preparing precious metal castings.

Abstract: A process for making an investment mold wherein a paste composition is used as the separating layer between the investment mould of refractory material and the surface of the metal container in which the investment mould itself is located. The composition is constituted by an organic component which can be eliminated by thermal degradation at temperatures above 200.degree. C. and a refractory mineral component which is stable at the casting temperature of the alloy used in the casting process. In a preferred embodiment, the composition comprises vaseline, talc and kaolin.

Abstract: A spruing assembly for receiving investment material in the production of an investment mold for castings by the "lost wax" process which includes a hollow chamber to receive the investment material formed by a base member and an engaging tapered ring. A horizontal feeder bar is contained within the chamber and is supported by hollow sprue means. The feeder bar is open at its top and has a narrow channel for conducting molten wax into the hollow sprue support. The base member includes a centralized sprue base former and support means associated with the former to provide support for the hollow sprue means supporting the feeder bar.

Abstract: The apparatus comprises an expandable investment ring having a removable base. Formed on the top surface of the base, and within the void defined by the ring, is an indexed sprue former. A curved runner bar having an indexed coping is formed at one end thereof in mating relation to the sprue former. By virtue of this apparatus extremely accurate base metal castings may be obtained. The apparatus is also useful for preparing precious metal castings.