JPH0727515U - Formwork for plaster - Google Patents

Abstract

(57) [Abstract] [Purpose] The jaw plaster model used for the preparation of wax crowns and the production of metal crowns in the field of dental fracturing is a jaw plaster model in which the tooth part has been restored by taking an oral impression. Form a plaster base. Dowel pins implanted in the lower part of the jaw plaster model penetrate the plaster base and the tip of the dowel pin reaches the back of the plaster base, but it is often hidden. To cut out the chisel, it is necessary to find the pin position and find the cue. An object of the present invention is to provide a gypsum mold that allows the dowel pins to be raised when forming a gypsum base. A gypsum mold is formed by attaching a plastic clay layer capable of receiving the tip of a dowel pin to a part of the inner bottom surface of a flexible and soft container-shaped mold.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a container-shaped mold for plaster gypsum molding, which is used to form a plaster base on a jaw plaster model in the field of dental filling.

[0002]

[Prior art]

 In the field of dental ridge filling treatment, a metal crown is applied to a missing tooth that has lost the apex of the tooth due to caries or the like, but in order to form a metal crown, first, the Take an impression of the upper and lower tooth rows around the target tooth with an impression material, restore the tooth row to the posterior upper and lower jaw plaster model, attach this plaster model to the articulator, and reproduce the occlusal state on the plaster model. Purpose A method of casting a metal crown made of a corrosion-resistant alloy by precision casting such as the lost wax method based on this wax crown is formed by shaping the shape of the wax that is to be applied to the tooth to form a crown. ing.

A plaster base is molded and attached to the upper and lower jaw plaster model, and this plaster base not only serves as a base for storage / placement, but its outer surface (back surface) is the above-mentioned occlusion. It is used for adhesive fixing to the model fixing plate provided on the upper and lower jaw arms of the vessel.

This gypsum base is usually formed by pouring gypsum slurry into a soft and flexible resin gypsum mold, and immersing the upper and lower jaw gypsum models on the upper surface to cure the gypsum.

To prepare a wax crown with an articulator and perform precision casting of a metal crown, as shown in FIG. 3, only the tooth 49 on which the wax crown (not shown) is to be formed is cut from the plaster model 4. It is necessary to separate them to form the abutment teeth 91 and finally form a casting mold from the wax crown. Therefore, when pouring the gypsum slurry inside the shape of the impression material taken in advance, the heads of several dowel pins 5 were buried along the tooth row including the target tooth, and the plaster model was prepared as described above. When making 4, 41 and forming the plaster base 42 on the plaster model, the tip of the tapered taper of the dowel pin 5 protruding from the plaster model is embedded at a position in contact with the bottom surface of the plaster model to cure the plaster. ing.

[0006]

[Problems to be solved by the device]

 To cut out the abutment tooth only for the target tooth on which the wax crown is formed from the plaster model, as shown in FIGS. 3B and 3C, the target tooth 49 among the teeth on the plaster model 4 is ground by the grinder. On both sides of the base, cuts (notches with narrow gaps) 6 and 6 reaching the plaster base 42 are made, and then a jig is pressed from the back surface 40 of the base 42 to the tip of the dowel pin 5 to obtain a wax crown. The target tooth portion 49 wearing a cap (not shown) can be separated from the plaster base 42, and this abutment tooth 91 is used for molding for precision casting.

However, in practice, the tip of the dowel pin 5 shown in FIG. 3A is often hidden behind the plaster surface of the back surface 40 of the base, and in this case, the plaster surface 40 on the back surface of the base is not visible. It was necessary to find the pin position by scraping off with a pointed instrument. Furthermore, the target tooth portion 49 divided by the notches 6 and 6 can be separated from the base by pressing the pin tip a short distance. For this purpose, the dowel buried in the outer surface is It was necessary to remove the plaster around the tip 5d of the pin with a special jig and to make a small hole 45d to poke the tip of the pin. The work of finding and pinching these pin positions was a cause of impairing workability.

In view of these problems, the present invention aims to provide a formwork for a plaster base that allows the dowel pin to be completed in the molding process of the gypsum base.

[0009]

[Means for Solving the Problems]

 The plaster formwork of the present invention is a container-like formwork for plastering a plaster mold for forming a plaster base on a jaw plaster model in which tooth rows are restored. It is characterized in that a plastic material layer for receiving the tip of the dowel pin is attached to the position corresponding to the row.

[0010]

[Function] When the plaster formwork is filled with gypsum sludge and the base side (jaw side) of the jaw plaster model (that is, the dentition model) is dipped in the sludge, the dowel previously embedded in the jaw plaster model The tip of the pin hits the plastic material layer on the inner bottom surface of the mold, and since this plastic material layer has plasticity, the tip of the pin is inserted inside the layer and comes close to the inner bottom surface. When the gypsum slurry hardens in this state, it becomes a gypsum base, but the outer surface (back surface) of the gypsum base after release is a recess corresponding to the plastic layer, and the tip of the dowel pin projects into the recess. Except for the concave portion, a flat surface corresponding to the flat portion of the inner bottom surface of the mold is obtained. The flat part on the outer surface of the plaster base is used as a fixed surface when mounting the articulator.

As the plastic material layer, a material obtained by thinly spreading mineral clay, plastic clay or putty, soft wax or the like, or a material obtained by casting and hardening a heated liquid material thereof is used. By adjusting the surface area to which this plastic material layer is attached and the layer thickness, the surface area of the recess (the area occupied by the dowel pin) and the recess depth (the protruding height of the dowel pin tip) on the outer surface of the gypsum base can be set arbitrarily. Can be adjusted.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a formwork of the present invention. FIG. 1A is a perspective view of a formwork 1 for constructing a plaster base on a jaw plaster model of a semi-arch row of tooth rows. The frame 1 is a flexible soft container such as silicon rubber, has a closed bottom surface 10 and a lid portion 13 having an opening 14 at the top, and has a generally oval outer shape in cross section.

FIG. 1 (B) is a view of the inner bottom surface 10 as seen on the cross section of the mold 1, and FIG. 1 (C) is a vertical cross sectional view of which the inner bottom surface 10 is divided by a series of ridges 11. A plastic material layer 2 made of thin plastic clay having a thickness of about 1 to 6 mm is adhered to the formed inner side surface region 10a. In the present example, the shape of the surface area 10a partitioned by the ridges 11 is a belt-like shape on the rear side of the form, and is widened in a substantially polygonal shape on the front side thereof, and is located at a position corresponding to the tooth row of the jaw plaster model 4. It is located. The shape of the plastic material layer 2 is for a half arch row of teeth and can be used for a jaw model of any of the left and right half arch rows. On the other hand, the outside of the area defined by the protrusion 11 is a bottom surface 10b that is as flat as possible. However, even if the ridges 11 are not formed, there is no problem. In short, the plastic material layer 2 should be arranged and fixed so as to be able to receive the tips of the dowel pins 5 at positions corresponding to the tooth rows of the jaw model. It's good.

The mode of use of the mold of the present invention is shown in FIG. 2 (A). The inner space of the mold 1 is filled with sludge 3 prepared by kneading hemihydrate gypsum powder with water. Next, the lower part of the main body of the jaw plaster model 4 in which the dowel pins 5a to 5f are planted is dipped into the sludge 3 from the inside of the opening 14, and the tips of the dowel pins 5a to 5f are the plastic material layer 2 on the inner bottom surface 10a. The gypsum slurry 3 is held until it hardens while being buried in and reaching the inner bottom surface 10a.

FIG. 1B shows the relative relationship between the arrangement of the tips of the dowel pins 5a to 5f and the shape of the plastic material layer 2 that receives them. In this example, the dowel pin 5a corresponds to the molar side and the dowel pin 5f corresponds to the anterior tooth side such as the central incisor of the jaw plaster model 4.

FIG. 2 (B) shows a partial cross-sectional view of the jaw plaster model 4 taken out from the mold 1 after the plaster slurry 3 is hardened. The hardened slurry 3 is the plaster integrated with the jaw plaster model 4. As shown in FIG. 2 (C), the back surface 40 of the plaster base 42 serves as the base 42, and the surface area corresponding to the plastic material layer 2 becomes the recess 21, and the recess 21 has the dowel pins 5a to 5f. Is protruding.

Therefore, since the back surface 40 of the plaster base 42 other than the recess 21 is a flat surface, it can be attached to the plaster model fixing plate of the articulator, and after preparation of the wax crown, as in the conventional case, By cutting the notches 6 and 6 on both sides of the tooth row of the target tooth 49 and pushing the projecting tip of the corresponding dowel pin 5d with a jig, the target tooth 49 can be easily separated and the dowel pin 5d is fixedly protruding. It becomes the abutment tooth 91.

The shape of the plastic material layer 2 is not limited to the shape shown in FIG. 1B as long as it can receive the arrangement of the tips of the dowel pins 5a to 5b determined by the jaw plaster model 4. In addition, when the jaw plaster model of the whole dentition is used for adjusting the denture of the edentulous person, the shape of the formwork 1 shall correspond to the plaster base for the whole dentition. The shape of the plastic material layer 12 attached or attached to the inner bottom surface of the mold 1 may be a U-shape or a horseshoe shape having an appropriate width corresponding to the shape of the dental arch or the alveolar crest of the jaw plaster model 4. .

[0019]

[Effect of device]

 The plaster formwork for plastering a plaster for forming a plaster base on the jaw plaster model of the present invention comprises a plastic material layer for receiving the tip of the dowel pin at the position corresponding to the tooth row on the inner bottom surface of the formwork. Therefore, the dowel pin tip is already protruding on the back surface of the formed gypsum base.Therefore, in cutting off the target tooth, it is necessary to find the pin position and to make a hole around the pin. Without doing so, the pin tip can be pressed immediately to facilitate easy separation, and the work efficiency of the crown production process can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view (A), a horizontal sectional view (B) and a vertical sectional view (C) of a plaster formwork for a base according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the form (A) in a state where the lower part of the jaw plaster model is immersed in the plaster form after injecting the plaster slurry (A), and a cross-sectional view of the jaw plaster model with the plaster base after release (B). ) And a perspective view of the back side of the formed gypsum base (C).

FIG. 3 is a perspective view (A) of the back side of a plaster base formed of a conventional plaster mold, and side views (B, C) of the jaw plaster model showing a process of separating the target tooth part from the jaw plaster model. ).

[Explanation of Codes] 1 Formwork for gypsum 10 Inner bottom surface 11 Projection 14 Upper opening 2 Plastic material layer 21 Recess on backside of base 3 Gypsum slurry 4 Jaw plaster model 40 Backside of gypsum base 42 Gypsum base 49 49 Target tooth Part 5 Dowel pin 6 Narrow gap notch 9 Tooth row 91 Abutment tooth

Claims (1)

[Scope of utility model registration request] 1. A container-shaped mold for plastering a plaster base for forming a plaster base on a jaw plaster model in which a dentition is restored, and a dowel pin tip is received at a position corresponding to the dentition on the bottom surface of the mold. A formwork for gypsum formed by attaching a plastic material layer.