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: A dental fastening device is disclosed for fastening a wax substructure of a subsequently fabricated dental bridge adjacent to a first and second dental die during the fabrication and shaping of the wax coping or substructure. The substructure includes a pontic portion disposed between a first and a second abutment portion. The fastening device inhibits relative movement between the pontic and abutment portions during solidification and shrinkage of the substructure. The fastening device comprises a first elongate tie down member having a first and a second end. The first end of the first tie down member is anchored to the lingual face of a cast adjacent to the first die and the second end of the first tie down member is anchored to the buccal face of the cast adjacent to the first die. The first tie down member extends from the lingual face of the cast over the occlusal surface of the first abutment portion and around the buccal face of the cast.

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: 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.