Abstract: A method and article for fabricating gold crown tooth restorations by a novel modification of the lost wax process utilizes mold pattern pre-forms each having a generally cylindrically-shaped base made of material such as wax which is capable of having formed therein and retain an accurate impression of a tooth stump. The pre-form base is surmounted by a hollow cap made of a shape-retaining material such as tin, and a plurality of pre-forms are preferably provided, each having a different exterior shape and size which replicates a tooth of a particular type and size. A pre-form having a shape and size suitable for a particular restoration is selected from the plurality of pre-forms, and the base of the pre-form pressed against a tooth stump to form an impression of the stump in the base, thus converting the preform into a restoration casting pattern for casting a restoration. The pattern is then invested into a semi-liquid slurry of mold material, which is allowed to solidify into a mold.

Abstract: This invention relates to a child walker-trainer. The walker-trainer consists of a frame preferably in the form of a push toy. At least three wheels are mounted to the frame. At least one of the wheels is mounted axially to the frame to form a rear wheel axis rearward of the other wheels. The invention preferably includes two rear wheels and two forward wheels. A handle attached to the frame extends upwardly and rearwardly of the rear wheel axis such that a downward force applied to the handle causes the walker-trainer to pivot along the rear wheel axis. The invention includes means for immobilizing the walker-trainer when a downward force is applied to the handle which causes the walker-trainer to pivot along the rear wheel axis. The immobilizing means preferably includes a flat, "U" shaped skid attached either to the frame or to the handle, such that it extends rearwardly of the rear wheel axis and is substantially parallel to and positioned slightly above the walking surface.

Abstract: An improved telescoping retainer for dental prostheses includes a coping mounted to an abutment tooth and having an endless O-ring groove formed about the outer axial surface of the coping in a plane generally transverse to the coping axis. The coping mates closely with a retainer cavity in the dental prosthesis and has a complementary O-ring groove defined in the retainer surface. A resilient O-ring is fitted over the coping such that the ring cross section is partly received within the coping groove and partly within the retainer groove, thereby forming a resilient interference fit between the dental prosthesis and the coping. A method for making the grooved copings and retainers is disclosed.