Abstract: The present invention provides a manipulable or reconfigurable dental model system and methods for its use to model a series of tooth configurations corresponding to sequential tooth movements during an orthodontic treatment. When a patient undergoes orthodontic treatment, teeth and bite configurations are realigned in a series of stages. Each stage represents a new pattern or dental configuration that will eventually lead to a proper final positioning of the entire dentition. Progress from the initial configuration, through the intermediate stages and finally to the final configuration may be accomplished using any one or a combination of different dental appliances. Of particular interest to the present invention, many of these appliances may be made using a dental mold representing the patient's dental configuration. In particular, thermoformable plastic positioning appliances which fit over the patient's teeth may be formed over a three-dimensional mold of the patient's dentition.

Abstract: The invention relates to a mold for producing the model of a tooth from a dental impression (28), comprising a peripheral wall (12), a model plate (38) which is tightly arranged on the top thereof and an impression spoon (14) bearing the dental impression (28). Said spoon is tightly inserted into the lower end of the peripheral wall (12). The hollow cavity (42) thus obtained is filled with molding material to give a highly precise tooth model requiring no further mechanical processing.

Abstract: A mould for casting a base for a dental model when reconstructing teeth for dentures or parts thereof and including a base plate along the edge of which a mould cavity is placed, the mould cavity including a bottom with fixating structures for the dental model or parts thereof, and walls provided with ribs extending from the bottom, the mould cavity having the shape of at least a part of a jaw. With a view to creating a stable mould, in which the model cast on the base may be remounted and positioned without rocking, the mould is designed in such a way that the fixation structures are at least substantially cylindrical pins which can be inserted in corresponding holes in the bottom of the mould cavity and which each include a portion suited for being cast in the base of the dental model.

Abstract: A method and apparatus is provided for precisely positioning and bonding orthodontic appliances such as brackets and buccal tubes to a patient's teeth. The method and apparatus includes the use of a transfer tray and arms that are connected to the transfer tray. Orthodontic appliances are releasably connected to the arms and detached from the arms once the adhesive used for bonding the appliances to the tooth surfaces has sufficiently hardened. In certain embodiments, the transfer tray has a shape that helps hold the tray immobile relative to the patient's teeth also facilitates clean-up of any adhesive extruded from the base of the appliances during bonding. In other embodiments, fixture components are connected to the tray and include analogs for each orthodontic appliance. In certain embodiments, the tray is made by placing matrix material over arms for supporting orthodontic appliances or appliance analogs.

Abstract: A dental model die ejector tool is designed to loosen the individual model dies mounted on a model base with a tapered dowel pin extending through the base, but at the same time not to lift them for any substantial distance. In turn, that loosening step allows for further easy separation of all the model dies with a wax cast as a single unit from the model base for further individual removal of the model dies. At one end, the model die ejector contains a pushing rod equipped with an ejector shank having a length of less than 1 mm and preferably about 0.1 mm for pushing the dowel pin upwardly in the corresponding sleeve for a short distance equal to the length of the shank so that the wax cast is not disturbed but the dowel pin is loosened. On the other end, the die ejector contains another pushing rod with an ejector cavity for loosening another commonly used type of a dowel pin extending from its sleeve after the removal of a protective cap.

Abstract: A premanufactured dental model base, and method, for supporting a cast dental model where the dental model base has preformed apertures adaptable for securing the dental model to the dental model base and for disengagably retaining the dental model segment of a damaged tooth. The preformed apertures are adapted to form a stone dowel from the material used to cast the dental model.

Abstract: A premanufactured dental model base is disclosed for supporting a cast dental model. The dental model base has preformed integral pins adaptable for securing the dental model to the dental model base and for disengageably retaining a dental model segment representing a damaged tooth.

Abstract: A dental implant replica fixable to models made of scagliola has an element adapted to carry a wax prosthesis, a fixed part fixable in a scagliola model to remain an integral part of the scagliola model, and a removably mountable part which is removably mountable on the fixed part and carries the element.

Abstract: A model baseplate made of plastic for producing a dental working model has cutouts for receiving fastening elements, each having two recess-like bearing regions which are located opposite one another transversely to the direction of the maxillary arch, extend away from one another from the bottom towards the top, and are in each case bounded laterally by two bearing faces which extend away from one another towards the center of the cutout. The fastening elements, produced in one piece from stainless steel, each have two rigid limbs which are connected so as to be elastically pivotable by means of an intermediate piece, attached respectively at a distance from their ends, and have contact regions with contact faces on the outer sides for contact with the bearing regions. The limbs extend away from one another from the bottom towards the top corresponding to the bearing regions and enclose an angle of about 10.degree..

Abstract: A dental articulator (10) having a first arch (12) for receiving a dental cast of teeth having a first grid pattern (30) that includes a first plurality of dowel pin holes (60) that define multiple dowel pin locations for receiving a first plurality of dowel pins (34), and a first plurality of support pin holes (62) that define multiple support pin locations for receiving a first plurality of support pins (64) where in the dowel pin locations and the support pin locations are spaced apart such that a die may be held in place within the first arch by one or more of the first plurality of dowel pins and by one or more of the first plurality of support pins to prevent movement or rotation of the die.

Abstract: The invention concerns a set of casting elements for the realization of gypsum models for dental prothesis comprising a series of elements made up of rubber material opened above and at the bottom, and perimetrically closed, shaped in such a way to allow the inner coupling from the lower side to corresponding impression carrier. The invention also relate to a casting system employing the elements.

Abstract: A pin stabilizer fir dental models (14) has a plurality of positioning pins (1) extended from an articulator base plate (2) for insertion into positioning sleeves (3) that are cast in a dental model while the positioning pins are in the positioning sleeves. Quickly and easily then, the dental model can be attached repeatedly to and detached repeatedly from a dental articulator (15) to which the articulator base plate is affixed for work on a dental model. The positioning pins and the positioning sleeves can be made of materials which do not deform from repeated use. A plurality of dental models can be constructed to fit onto an articulator base plate that is attachable to a bottom and/or top articulator jaw (16) of known types and sizes of dental articulators.

Abstract: The invention relates to a device and method for confirming bite registration for dental implants. The device has an elongated plate having one or more openings formed at an angle to a longitudinal axis of the plate. A hollow post has an exterior wall corresponding in size and shape to the openings in the plate so as to fittingly slide through a selected plate opening. An inner aperture in the post is suitable for engaging with a portion of the dental implant that extends above the healed gumline of a patient. When the post is engaged with the implant, and the plate is placed over the post, an outer surface of the plate is oriented in a substantially parallel relationship to an occlusal plane. The post and the plate are secured together to register orientation of the dental implant in relation to the occlusal plane.

Abstract: A dental model for use with or without articulating devices, wherein the model has a front face and a rear face, at least one dowel pin affixed to the model and having a free end positioned outwardly from the rear face, a recess form nut having a bore which frictionally receives the free end, a support of rigid material having a proximal surface and a distal surface and positioned with the rear face of the model and the proximal surface of the support juxtaposed, the dowel pin with the form nut thereon removably extending through the support to position the free end adjacent the distal surface of the support, at least an outer portion of the form nut being exposed to view from the distal side of the support, and a shoulder on the outer portion of the form nut adapted for contact with a removal tool for removing the form nut from the dowel pin to leave the free end exposed through the distal side of the support whereby the free end becomes readily accessible for contact with an extraction tool for forcing the

Abstract: A dental articulation apparatus for creating a pinned model of a patient's mandibular and maxillary dental arches. The apparatus permits the simultaneous relation and construction of pinned, segmental models of the maxillary and mandibular dental arches and allows the model, die, and articulation to be accomplished in a single pouring. The articulator includes recessed maxillary and mandibular tray support members each containing a plurality of indexing holes into which indexing pins can be inserted. A negative dental impression is then filled with a casting material, or alternatively, the support members are filled with a casting material, and the support members and negative impression material are then joined together such that the indexing pins protrude through and into the casting material.

Abstract: An improved method and apparatus for producing a dental prosthetic with a minimum of time and labor. The preferred embodiment of the invention compresses first and second trays which are hingedly secured to allow articulating movement of the trays with respect to each other. At least one of the trays is provided with a grid having a plurality of holes in a spaced pattern to receive pins for supporting the model. In operation, one of the trays is filled with plaster and the negative impression of the teeth is placed therein. The operator then closes the articulator temporarily to determine the optimum location of the pins with respect to the various teeth marks in the impression. The pins are then inserted into the appropriate holes in the opposing tray, with the pins being parallel to each other. The impression is then filled with plaster and the tray containing the pins is then closed to cause the individual pins to be inserted into the plaster at the predetermined locations.

Abstract: A dental impression handling tool consists of two base structures shaped to approximate two opposite quadrants of a full dental arch, and two similarly-shaped inserts that snap fit into the base structures. Each base includes a wide, upward facing trough approximating the placement and curvature of teeth within a dental quadrant. The upper surface of each insert is attached to a positive dental mold by means of protrusions that extend from the top horizontal surface of the insert, the protrusions being encased within the mold material. Positive positional relationship is maintained between each base and its mating insert by the use of an interlocking and non-recurring geometric pattern that is carried by the internal vertical walls of the trough in the base, and by a matching geometric pattern that is carried by the outer vertical walls of two vertically downward extending ribs on the underside of the insert. A second deeper, narrower and centrally located trough is formed in each base.

Abstract: A one-piece molded dental dowel-pin adapted to be fixed to a tooth die and having an integral elongated locking-and-indexing arm which, after final trimming of a dental model, has an outer tip which is visible to a human observer when the tooth die is inserted in the trimmed, final dental model.

Abstract: A one-piece dental retention pin is symmetrical with respect to a central plane and has an upper end and a lower end and parallel first and second face surfaces. The pin has a top portion extending from the upper end toward the lower end and a bottom portion extending from the lower end to a location of juncture with the top portion and tapering from a location of minimum width at the lower end to a location of maximum width about halfway between the lower end and the juncture of the bottom portion and the top portion and then tapers to diminish in width to its location of juncture with the top portion. A central hole therethrough joins the face surfaces which have serrations in the bottom portion.

Abstract: The present invention relates to a process for producing dental working cast for use for preparing a crown or a denture of metal-bonded porcelein or of all ceramic in dental therapy, by preparing a removable positive model of tooth from impression, processing it into a model of the working cast and replicating the model using a suitable material chosen from resin, die material, refractory cast material and modified dental stone, to obtain the working cast.

Abstract: A one-piece molded dental dowel-pin adapted to be fixed to a tooth die and having an integral elongated locking-and-indexing arm which, after final trimming of a dental model, has an outer tip which is visible to a human observer when the tooth die is inserted in the trimmed, final dental model.

Abstract: A dental model and articulation system are disclosed. The dental model comprises cast mold material formed around an elongate pin or rod. A longitudinal, tapered pin or rod is embedded in the model during pouring of the casting material. The pin or rod extends longitudinally through the base of the model beneath the teeth impressions of the model. The longitudinal axis of the pin or rod lies in general parallel alignment with the line of teeth in the model. The pin or rod can be removed from the model, and the model can be cut into several sections or dies. These sections or dies can then be reassembled back on the pin or rod in the precise, true relationship that existed in the model prior to the model being cut into sections. The extending ends of the pins or rods can be removably attached to a flexible member such that models of the upper teeth and lower teeth of a person's jaws can be moved in lateral or protrusive movement and back to centric occlusion.

Abstract: Disclosed is a base plate assembly for use in mounting a die-stone dental replica, the assembly including a base plate that has a configuration commensurate with at least one dental quadrant, and having a planar upper surface characterized by an array of transverse elongate rectangular sockets. A plurality of mounting blocks are assembled in side-by-side relationship along the plate planar surface, each block having a downward projection adapted to frictionally and releasably hold the block on the base plate, and extending from the tops of the blocks are anchoring tabs designed to be embedded in the wet positive mold of a dental impression and affixed therein when the mold material cures. In a preferred embodiment, the base plate has a modular configuration and is interconnectable with an identical modular unit to form a combined base plate having a configuration commensurate with full bilateral upper or lower dental quadrants.

Abstract: A positioning stud for master models, formed by a cylindrical body, in which approximately one third of its length is threaded, this threaded area being separated from the rest which is smooth, by a circular boss, to limit the threaded area being inserted in the master model concerned. The free end of the stud is adequately shaped to fit the auxiliary tool used to place it in the model.

Abstract: The invention relates to a prosthetic positioning device for making removable portions of prosthetic prints and for producing them by single phase casting. The positioning device is comprised essentially of a positioning element (110) supporting the positive part of the print through a pivot with retaining throat (111) nested in a tapered element (20) integral with the positive print via two lugs (21) and two pins (3) used to immobilize the assembly with respect to the negative print via tongues (12) extending from the positioning element (10).

Abstract: A dental model of teeth mounted in a jaw comprises an artificial jaw member defining tooth-receiving sockets. The teeth have roots, the roots being removably seated in the sockets and bonded there by elastomeric adhesive, whereby the teeth exhibit a resiliently seated characteristic similar to that of the natural teeth in a human jaw. Also, a preformed, artificial gingiva may be applied which exhibits improved, lifelike characteristics for a practice experience that is closer to clinical reality.

Abstract: An improved method and apparatus for making cast dental models having integral dowel pins permitting segments or dies of a model to be attached and re-attached to a base plate in a precise location, by means of holes in the base plate adapted to insertably receive the dowel pins, is disclosed. The apparatus includes a base plate having a generally semi-circular shape, the arcuate outer wall surface of which is modified to have flat walls approximating the shape of a circumscribed polygon. A matrix positioning plate has a polygonal aperture through its thickness dimension adapted to insertably receive the base plate. A negative dental impression is attached to a first, lower surface of the matrix plate, and a transparent transfer plate of the same size and shape as the base plate inserted into the aperture of the matrix plate. Marks are placed at those locations of the transfer plate where dowel pins are desired to engage parts of the dental impression viewed through the transfer plate.

Abstract: A dental disc and sleeve assembly for removably coupling die portions of teeth from a dental model onto a cast base. The disc is inserted into a semi-circular cut formed in the underside of the die portions so that the disc is secured in the die and partially protrudes therefrom. A sleeve secured in the cast base has a head portion having a chamber matingly receiving the protruding portion of the disc and a tail portion. Two knobs provided on the opposite sides of the disc are snapped into two grooves formed at two opposite sides of the chamber. The grooves can release the knobs and the disc can be removed from the sleeve when slight pressure is applied to the tail portion of the sleeve to remove the die portion from the cast base.

Abstract: A dental articulator for use with a dental stone comprising; a lower jaw member and an upper jaw member mounted to the lower jaw member. One of said jaw members is provided with a pivot post and a key member and the other jaw member defines a apertre which fits around the pivot post and a key way which selectively receives the key member for positioning the jaw members in a selected fixed positional relationship. A plurality of slots are formed in each jaw member to give the jaw member flex in the vertical and lateral direction and serrations are formed in the end of each jaw member to prevent rotation out of the dental stone. A dowel holding rod with associated dowel pins mounted thereto is mounted to the ends of each jaw member for mounting in selective jaw casts in one embodiment of the invention.

Abstract: A prosthetic implant attachment system for mounting a dental prosthesis on a root implant including a base member having a lower end sized to seat on the upper end of an implant cylinder and an upper end of outer diameter substantially equal to the average outer diameters of various teeth, a securing device for securing the base member on the root implant, and various straight, angled or variable angled prosthetic heads for securing to the prosthesis. The upper end of the base member and the lower end of the prosthetic head have interengageable and indexable locking formations for preventing rotation between the parts which can be engaged in any of a number of possible relatively rotated fixed, indexed positions. A releasable securing device secures the prosthetic head to the base member. The prosthesis can be mounted on the prosthetic head by cementation, screw fixation, or other techniques.

Abstract: A mounting and alignment device for removably mounting a dental model or portion thereof to a base cast. The device comprises an alignment collar which is adapted to be fixedly secured to a dowel pin and a dental model, the combination being receivable in a complimentary depression in a base cast to align and retain the dental model, preventing it from rotating or moving transversely with respect to the base cast when the portions are cooperatively engaged. A gasket may be included in the base cast to further enhance the engagement between the dowel pin and the base cast.

Abstract: An apparatus for simultaneously separating segments of a dental cast from a plaster base wherein the segments are mounted to the base with pins positioned within holes that extend through the base with the apparatus comprising a platform and a clamp for positioning the base in a predetermined position spaced from the platform. A set of engaging pins are positionable upon the platform in alignment for insertion into the holes of the base. A threaded driver is provided for moving the platform and engaging pins thereon toward a base located at the predetermined position to engage the engaging pins with the dental cast pins thereby dislodging the pins and separating the segments from the base.

Abstract: An apparatus for use in preparing both metal and porcelain dental crowns. The apparatus has a plurality of upright supports and arms coupled therewith that are moved to contact with the tooth opposing the tooth to be crowned in the proper occlusal locations such that when the permanent crown is prepared it has all of the proper occlusal characteristics of the opposing dental structure. The apparatus is intended for use in and with a replica of the patient's dental structures. The apparatus has a plurality of pathways upon which the upright supports may be moved so as to position the supports in the proper contact points. Methods for utilizing the apparatus when preparing metal and porcelain crowns are also provided. A preformed, imitation dental crown having four layers for use in preparing porcelain crowns where each layer corresponds to one of the layers of porcelain or metal necessary to prepare the finished porcelain crown is also provided.

Abstract: A plug connection for fastening tooth or jaw segments to a pattern base is provided which consists of a pin and a matching sleeve which snugly receives the pin and from which the pin can be separated again by counter-pressure. The pin consists of a permanently lockable locking shank and of a detachable plug-in shank. The plug-in shank has two different coupling regions which, on the one hand, warrant precise fit of the plug-in shank in the matching sleeve and which, on the other hand, allow perfect uncoupling.

Abstract: Tooth and jaw models comprise a base and removable tooth sections which are fastened removably by pins put into suitable holes in the base. After the production of the jaw replica positive a hole is drilled in each section of the positive and the upper parts of the pins are cemented into the holes. The positive, including the pins, is then put into a casting mold having a height equal to the length of the insertion parts of the pins. The casting mold is then filled with gypsum, so that after cutting the positive into section, the sections are non-rotatably but removably fastened in the base and can be separated easily at the visible ends of said insertion parts of the pins.The pins have a cylindrical upper part and a profiled insertion part having a cross-shaped, star-shaped or triangular section. The prongs of the insertion parts have edges arranged parallel to one another.

Abstract: Phosphate bonded investments with solid high temperature dowels or pins for the preparation or making of all porcelain dental prosthetic restorations. More specifically, the solid, high temperature pin type dowels, when used in dies and models formed of phosphate bonded investment material for making porcelain restorations, when fired to a range between 1600.degree.-2200.degree. F. functions as a heat sink to effect a more uniform heating and cooling of refractory model and porcelain restoration thereon so that the form and shape of the vitrified porcelain restoration may be more accurately maintained.

Abstract: A base for holding a plaster of paris model for a set of teeth for the production of dentures, including a planar bottom to which is attached an upright circumferential exterior wall in the shape of a jaw. The base further includes perpendicularly projecting guide elements extending up from the bottom surface. The guide elements are tapered in the direction away from the bottom surface for example in the shape of a frustropyramid or frustocone and form at least one curved row which follows the curvature of the exterior wall in a U-shaped configuration. In preparing the plaster model within the base, the guide elements form corresponding holes in the plaster. The device may have a second U-shaped row of guide pins extending from the bottom surface to further guide and align the plaster mold when inserted into the base portion. This base then allows for the removal and reinsertion of a plaster of paris mold while maintaining the original and critical alignment of the model and or the individual pieces thereof.

Abstract: A supporting plate for a denture model includes a cheek-side portion and a tongue-side portion spaced from each other to define a groove therebetween and connected to each other by flexible pivotable webs so that the distance between those portions is changeable whereby an unavoidable expansion of a model material is compensated for by a change of the shape of the supporting plate.

Abstract: A dowel-pin for a tooth-die has two longitudinally spaced bore holes into which are inserted corresponding pins of a U-shaped locking device to form an assembly which is embedded in the base stone during the fabrication of a dental model. After trimming of the stone, the locking device is removed to permit a corresponding tooth die to be removed from the model. When the tooth die is returned to the model, the locking device is reinserted through the stone and into the bore holes of the dowel-pin, thereby locking the tooth die and dowel-pin against movement in all directions.

Abstract: This disclosure is directed to the use of phosphate bonded investment with solid high temperature dowels or pins for the preparation or making of all porcelain dental prosthetic restorations. More specifically, the solid, high temperature pin type dowels, when used in dies and models formed of phosphate bonded investment material for making porcelain restorations, when fired to a temperature range between 1600.degree.-2200.degree. F. functions as a heat sink to effect a more uniform heating and cooling of refractory model and porcelain restoration thereon so that the form and shape of the vitrified porcelain restoration may be more accurately maintained.

Abstract: A dental pin and bushing assembly for coupling of a removable die portion of a tooth from a working cast. The pin includes an axially extending head portion which can be secured within the die. The coaxial body portion depends from the die portion and includes an offset section for oriented insertion of the pin in the bushing. The bushing is secured in the working cast and includes an elongated sleeve with a mating chamber for receiving the pin. The bushing matingly receives the body portion of the pin so that the removable die can be inserted in only a single oriented direction into the bushing.

Abstract: A dental dowel pin includes an improved geometry for increasing the accuracy of placement of a tooth die in a base support in the dental laboratory, and for maintaining this accuracy despite dust or wear of the dowel or its retaining slot in said base support. The body is of generally oval cross section with side and end walls normally to a horizontal plane and a plurality of inverse angle indentations and fits accurately into a slot of negative impression in the base during utilization of the invention. The dental dowel pin of the invention has a knurled cylindrical head on an end that is insertable into a cast model die.

Abstract: An apparatus for the fabrication of models of teeth and their arrangement. The apparatus includes an approximately U-shaped tooth arrangement support, and a base plate to which the support is detachably connected. This connection between the tooth arrangement support and the base plate is ensured by magnetic forces.

Abstract: A tooth-block for fabrication of dentures, including a horizontally deformable bar of rectangular cross-section provided along its upper margin with outwardly projecting retentions, each retention having an individual artificial tooth securely mounted thereon in spaced separation from the bar, each retention and its respective tooth being selectively positional with respect to the bar and to each other tooth.

Abstract: This invention is directed to a means and a method for making a dental stone model. The NEGATIVE or impression of the teeth and gum of an individual is made as above described with respect to a yieldable material such as plastic, rubber and the like. After the NEGATIVE has been prepared the dowel and a parting guide are positioned in the NEGATIVE. The NEGATIVE is agitated and one pour of a pourable dental casting stone is made. The pourable dental casting stone surrounds the parting guide and almost all of the dowel pin. In time, the dental stone model or replica of the stub of the tooth is removed from the dental stone model by isolating the replica of the stub of the tooth. The parting guide allows the replica to be readily removed from the dental stone model. The dowel pin is an aligning means for the replica with respect to the dental stone model so that it is possible to position the replica of the stub of the tooth correctly in the dental stone model.

Abstract: A device and method for forming a removable die within a stone cast of a dental arch is presented. The die is attached to one end of a curved dowel pin which in turn slides into a curved channel in the base of the stone cast. The unique curved path of insertion and removal allow the die to be repositioned accurately and held securely with a single dowel.

Abstract: A method and apparatus for making a model of a set of teeth, in which each tooth is mounted on a holding pin (17) which is removably disposed in a base plate (15). For positioning of the holding pins, a datum plate (10) of transparent material is placed on the impression (5) of a jaw and the desired positions, of a respective holding pin for each tooth root, are marked. Then pins are inserted into a pre-perforated base plate (15) according to the markings, or a pre-perforated base plate of transparent material is used instead of the transparent datum plate (10), and is marked with desired pin positions on one side and provided with pins on its other side. The pins then penetrate molding material placed in the impression (5), and harden in place as the molding material hardens. The hardened molded material can then be sawed into separate parts.

Abstract: A protective carrier for a dental model including a tray portion hinged to a cover portion, a recessed cavity being provided in the tray portion to receive the pedestal part of the dental model. An arcuate rib member is removably coupled onto the tray portion and overhangs the cavity of the tray portion to thereby engage a ledge provided on the dental model to securely retain the dental model within the cavity. A recessed chamber is provided in the cover portion to mate with the cavity in the tray portion to define a closed compartment for the dental model.

Abstract: The present invention is provided to render quality orthodontic treatment, with proper dispersion of the patient's teeth roots in the supporting medium. The present system involves procedure which establishes and records the location of the patient's individual tooth roots to the visual crowns of the associated teeth. This is accomplished by use of simulated root structures that are attachable to individual crown models of the patient's teeth and oriented in relation to the models such that the axes of the associated roots are made accessible. The individual simulated root structures may be attached to crown models taken from a direct impression from the patient's mouth. The individual crown models are aligned in a surveyor mechanism and attached with their long axes in coaxial alignment with the central axes of dop rods. The dop rods are then held on a grinding rack and moved toward a flat grinding surface which produces a plane flat surface on each crown model.

Abstract: Disclosed is a base plate assembly for use in mounting a die-stone dental replica, the assembly including a base plate that has a configuration commensurate with at least one dental quadrant, and having a planar upper surface characterized by an array of transverse elongate rectangular sockets. A plurality of mounting blocks are assembled in side-by-side relationship along the plate planar surface, each block having a downward projection adapted to frictionally and releasably hold the block on the base plate, and extending from the tops of the blocks are anchoring tabs designed to be embedded in the wet positive mold of a dental impression and affixed therein when the mold material cures. In a preferred embodiment, the base plate has a modular configuration and is interconnectable with an identical modular unit to form a combined base plate having a configuration commensurate with full bilateral upper or lower dental quadrants.