Abstract: The working model suited for extraoral fabrication has a dental cast connected via a dowel pin to a substrate in a predetermined position, the substrate including a gypsum forming frame and a gypsum portion. The frame has a peripheral wall being open in upper and lower faces, and is fabricated with plastics into a form of having a hollow space in the inner side of the peripheral wall. The gypsum portion has slurry of gypsum hardened which is filled in the hollow space of the frame. The working model is provided with a connection orifice for inserting the dowel pin into the gypsum portion which is filled and formed in the hollow space of the frame, so that the dowel pin is inserted into the connection orifice, thus connecting the dental cast to the substrate.

Abstract: A cover for a working cast makes it extremely easy to mount and dismount a working cast to and from an articulator, improves workability, and keeps the working cast as pollution-free as possible. An articulator is also proposed. The articulator has a base and a support member each carrying a rotatable and pivotable retainer plate. Each retainer plate can be fixed in position by turning a knob. Each retainer plate has a magnet plate on its outer surface. On the other hand, a base portion of a master model having a tooth portion is kept covered with the cover when molded. The cover has on its bottom surface a magnet plate. By magnetic attraction between the magnet plates of the cover and one of the retainer, the master model can be mounted on the articulator. On the other hand, a tooth portion of an antagonist model is fixed to a base member.

Abstract: Coupled artificial teeth which minimize the shaping work of gum when manufacturing a denture model and eliminates residues in the plaster mold are disclosed. A coupled artificial tooth assembly includes a plurality of teeth coupled together only by wax. On the front side of the gum, the wax covers a base portion of each of the artificial teeth and fills the interdental papillae, while exposing the tooth crowns. On the backside of the gum, the wax fills the space around the bottom portion of each of the artificial teeth so that the bottom portion is almost completely exposed. The backside of the gum is substantially flush with the bottom portions of the artificial teeth and forms a bow-shaped curved surface similar in shape to a real human gum.

Abstract: A sample of artificial teeth and gums of a display unit for dental surgeons arranges plural artificial tooth samples forming the anterior teeth along the natural arch of the teeth. The artificial tooth samples are fixed and arranged on an artificial gum sample tinted with a determined color. The artificial gum sample has an inner face designed with a contact face curved to a form allowing it to be aligned close to the gum of the anterior teeth of the patient. A handle allowing the artificial gum samples to be aligned with the gum of the patient is fixed to the artificial tooth samples or to the artificial gum sample. With samples of the artificial tooth and gum, the artificial tooth samples and artificial gum samples are both aligned along the anterior teeth of the patient by holding the handles, allowing the patient to decide the color, shape and teeth arrangement of the artificial teeth and the artificial gum.