Abstract: For use in making dental restorations, a model is prepared by taking an intra-oral impression and molding in the impression a replica model made from thermoplastic resin and an optional thermoset resin. The model includes a flexible support adhered to the underside of the model. When the model is flexed or cut, cracks will form through the replica gingival tissue between adjacent replica teeth. The flexible support acts as a hinge to provide access to interproximal spaces between replica teeth. A preferred flexible support is a layer of a tough and flexible second thermoplastic resin.

Abstract: An elongate piece of solid thermoplastic material having coaxial generally cylindrical portions with uniform predetermined axial and diametrical dimensions uniformly axially spaced along the piece by generally rectangular portions having diagonal dimensions about equal to the diametrical dimension of the cylindrical portions, and a device for continuously molding a continuous length of solid thermoplastic material between molds moved face to face along a linear path from which such elongate pieces can be cut.

Abstract: A device for dispensing molten thermoplastic material which an operator grips while using his thumb to press a solid block of the thermoplastic material through a sleeve and into a heated melting chamber from which the molten thermoplastic material is discharged through a nozzle. The device includes a magazine assembly adapted to hold a stack of thermoplastic material blocks which can be moved seriatim into the sleeve by reciprocation of the slide.

Abstract: An attachment adapted for use on a device for melting and dispensing thermoplastic material having a thumb operated drive assembly for driving a block of thermoplastic material into the device. The attachment comprises a lever having an upper end adapted for engagement with the drive assembly and a lower end pivotably attached to a collar adapted to be releasably attached to a handgrip of the device. With the attachment in place, a user can squeeze the lever toward the handle with his hand to dispense the thermoplastic material.

Abstract: A block of solid thermoplastic material comprising alternating sections of circular and rectangular cross section, a device for melting and dispensing thermoplastic material having a thumb operated drive assembly for driving the block into the device, and a molding mechanism including two chain like structures that move along linear path portions with molds included in the structures in face to face relationship while molten thermoplastic is injected in an inlet end of the linear path portion to continuously mold the block.

Abstract: A device for dispensing molten thermoplastic material in which a solid block of thermoplastic material is pressed through a sleeve and into a heated melting chamber from which the molten thermoplastic material is discharged through a nozzle. A cooling assembly can be disposed between the melting chamber and the nozzle to provide means for substantially cooling the molten thermoplastic material (e.g., by 30.degree. F.) which can be advantageous where the temperature of molten thermoplastic material in the melting chamber can become so high that it will damage certain substrates on which the molten material will be dispensed.

Abstract: A device for dispensing molten thermoplastic material which an operator grips while using his thumb to press a solid block of the thermoplastic material through a sleeve and into a heated melting chamber from which the molten thermoplastic material is discharged through a nozzle. The device includes a bracket adapted to hold a second block of thermoplastic material in end-to-end relationship with a first block in the sleeve, and a heated barrier ring at the inlet to the melting chamber that restricts escape of the molten thermoplastic material through the sleeve; and may also include a slidable pressure plate between the block and an operator's thumb and/or a trigger-operated outlet valve between the melting chamber and nozzle.

Abstract: A thermoplastic material-dispensing apparatus of the type wherein solid thermoplastic adhesive material is melted in a heated well and is dispensed from the apparatus due to force exerted on the molten material by means of a piston. The apparatus comprises a loading chamber which comprises an intermediate barrel section and a magazine. The intermediate barrel section is situated between the heated well and a piston chamber which houses the piston. The magazine is adapted to contain a plurality of thermoplastic adhesive slugs and to deliver the thermoplastic adhesive slugs to the intermediate barrel section when the intermediate barrel section is empty.