JPS6219860B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention is applied to general commercial dentistry, which is used for casting a golden core for supporting an artificial tooth crown to be implanted into a tooth root canal that has been arbitrarily drilled in advance. Concerning cores as therapeutic materials.

BACKGROUND OF THE INVENTION In dental treatment, golden cores have long been used as supports for dental crowns, which replace worn-out tooth material and cover tooth roots planted in the gums. Many attempts have been made to imitate living teeth with such golden cores within the limits of pulp expansion and dentin strength. Because the strength of gold is significantly greater than that of dentin, it is possible to make the gold core thinner without jeopardizing the strength of the core.

The possible thinness of the golden core is determined by (1) the strength of the gold, (2) the holding power of the artificial tooth crown, and (3) the shape of the root canal. That is, this core must not be made significantly smaller than the lumen of the root canal for reasons of retention and strength, and also from a practical manufacturing standpoint.

Although the longitudinal dimensions of the core and the number of roughly parallel surfaces on the core are very important when it comes to holding power,
The total surface area of the core is not very important.

Since the crown is inserted after the golden core has been fixed to the root of the tooth, the shape of the golden core does not matter at all as long as there is sufficient space for fitting the crown material. That is, regarding the raised part of the gingiva facing the implanted tooth crown, even if there are individual differences in the shape of the raised part and the root tubule, this golden core can be standardized into several shapes for convenience.

The production of golden cores, which are inserted into thin tubes drilled into the roots of teeth planted in the gums, is a task that requires a great deal of time for both dentists and dental technicians today. Obtaining a core that fits tightly into the root canal presents many difficulties.

The common method of making a gold core is to place a copper ring into the upper opening of a pre-drilled root canal. A pin or peg is inserted into this copper ring and inserted into the root canal. A molding material is then forced into the copper ring and root canal. After the molding material has hardened, the impression of the root canal is sent to a dental technician who makes a plaster cast or female mold of the root canal. From this plaster model he made a wax wick by injecting wax into the female mold of the root canal. The amount of wax to be injected is selected so that a mold of the upper core of the root canal can be taken. This wax mold is then placed in a casting, fired, and replaced by gold. This method requires a very long time and is therefore expensive. Because the mold is not made inside the patient's mouth, there is a risk that the resulting gold core will not fit correctly into the tooth.

Other methods may omit the production of plaster molds and wax cores. Instead, e.g.
RELIANCE DENTAL Product name made by MFG.Co.
DURALAY, a bulk polymerized plastic,
Alternatively, foundry wax may be used. Such plastic is delivered to the root canal through the copper ring in a manner similar to that described above. Extensive adjustment and shaping operations are then performed in the patient's mouth. The important thing is that the dentist himself shapes the upper part of the core mold. The plastic mold thus prepared is then sent to a dental technician, who will then cast it into a golden core. Although this method is certainly an improvement over the first method described above, the major drawback is that extensive adjustment must be performed in the patient's mouth.

OBJECT OF THE INVENTION An object of the present invention is to provide a generally commercially available core body for obtaining a core prototype for the above-mentioned golden core casting.

Structure of the Invention In the core body of the present invention, an upper core portion having a concave bottom surface and a lower mekugi portion integrally connected thereto are made of a bulk polymeric impression plastic material that can be vaporized by heating. The mekugi portion is substantially thinner than the optionally drilled root canal, and the root canal is filled with a bulk polymeric impression plastic material which, in use, can also be vaporized by heating. The upper part of the core body is made to have the same shape as the upper part of the finished golden core for supporting the tooth crown, and is inserted into the plastic material filled in the root canal and solidified together. A core prototype is extracted from the tooth root canal, and a golden core can be cast from this core prototype by a conventional method.

Function The above-mentioned core previously produced according to the present invention is used to facilitate the production of a prototype for producing a golden core. This core has a temperature of 600℃ to 800℃.
It is made of plastics such as polymethyl methacrylate, which is gasified without leaving any residue at °C. The core generally fits into the pre-prepared root canal, and by filling the gap between the root canal and the core with bulk polymerized plastic, a core prototype for the production of golden cores is obtained with an exact fit. be able to.

Effects of the Invention The core body according to the present invention is often manufactured in five different sizes, each suitable for most incisors, canines, and molars, and can be generally sold to dentists.

The advantages of the inventive core are that both dentists and dental technicians require less time and materials to produce the golden core, and that it provides the best fit to the teeth. It's about being able to do something. These advantages necessarily lead to a reduction in the cost of producing the golden core.

Embodiment One embodiment will be described below with reference to the drawings.

In FIG. 1, numeral 1 indicates a core body for making a golden core for incisors. The core 1 consists of an upper core part 2 with a concave bottom and a lower mekugi part 3, which are made in one piece from a vaporizable plastic such as polymethyl methacrylate. And the upper core part 2 is
This is a prototype having the same shape as the upper part of the finished golden core 8 (Figure 2D) on which a tooth crown (not shown) is to be inserted and fixed onto the tooth. The upper core portion 2 is then assembled to provide maximum retention for the crown and sufficient space for gold or other cosmetic materials. As a general rule, the core is manufactured and sold in a fixed, finished shape, but it may occasionally be adjusted and deformed vertically or horizontally during use. Mekugi part 3
serves for fixation to the block polymerizable impression plastic 6 filled in the root canal 5 (FIG. 2A) prepared in advance. The length of the mekugi portion 3 is adjusted during use depending on the depth of the root canal. The cores for canines and molars must have a corresponding shape, but it is necessary to consider the shape of the core so that crowns can be attached to these teeth without any problems.

From A to D in FIG. 2, the core 1 according to FIG.
Core prototype 7 for making golden core 8 with the help of
The order of manufacturing is illustrated. Figure 2A shows
The root canal 5 shows the root 4 of a tooth planted in the gums with a tapered hole bored to receive the golden core 8.
After preparing the tooth root 4 in this way, the root tubule 5 is prepared.
A core body 1 (FIG. 1) is selected that roughly matches the . If necessary, cut and adjust the length of the mekugi portion 3 of the core body appropriately. Apply sufficient Vaseline to the inner wall of the root canal 5 to prevent the impression plastic from sticking to this inner wall. Thereafter, a bulk polymeric impression plastic material 6, which can be vaporized by heating, is fed into the root canal 5 using a plastic tube 9. This bulk polymeric impression plastic material must fill up to the top of the tooth root 4. Next, as shown in FIG. 2B, the selected core 1 is inserted into the root canal 5 filled with impression plastic material so that the nail part 3 is inserted. Excess plastic overflows from the top of the tooth root. Leave this overflowing plastic 10 as it is for a while.

While the plastic is still soft, the formed core pattern 7 (FIG. 2C) is moved up and down in the canal several times to prevent the plastic from sticking to the canal. Remove the overflowing excess plastic 10 with a surgical scalpel. In addition, since the bottom surface of the core portion 2 is concave, when the core body 1 is pushed into the root canal 5, no gap is created between the core body and the impression plastic.

Once the impression plastic is completely set in the root canal 5, the height and width of the core body 1 are adjusted as necessary. The solidified core model 7 (Fig. 2C) is extracted from the tooth root 4, sent to a dental technician, and then the golden core 8 (second
Perform the casting shown in Figure D). Since plastics that can be vaporized by heating are used for both the core body 1 and the bulk polymerized impression material 6, the golden core 8 can be cast by heating the core pattern 7 embedded in the mold material. A mother mold (female mold) is obtained. A golden core 8 obtained by casting from this mold (not shown) is cemented into the root canal 5 (second
(Fig. D), and the overall finishing process is then performed.

As mentioned above, golden cores can be made for canines and molars by the same method as above. However, it is necessary to use a pre-made core whose upper part has been modified so that it fits well with the gold crown of a canine or molar tooth.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a core body consisting of an upper core portion and a lower mekugi portion according to the present invention. A to D in FIG. 2 are cross-sectional views for explaining each step of manufacturing the golden core inserted into the root canal. 1... core body, 2... upper core part, 3... lower mekugi part, 4... tooth root, 5... tooth root tubule, 6...
...Lumpy impression plastic, 7... Core prototype, 8...
Finished golden core, 9...tube for plastic injection, 10...plastic overflowing.

Claims (1)

[Scope of Claims] 1. An upper core portion 2 having a concave bottom surface and a lower mekugi portion 3 integrally connected thereto are formed of a bulk polymeric impression plastic material that can be vaporized by heating. The root canal 5 is made of a core body whose mekugi portion is substantially thinner than the optionally drilled root canal 5 and which is filled with a bulk polymeric impression plastic material 6 which can also be vaporized by heating in use. The upper core part 2 of the core body is made to have the same shape as the upper part of the finished gold core 8 for supporting the tooth crown, and is inserted into the plastic material 6 filled in the root canal. A core body used for casting a golden core for supporting a tooth crown, in which a core prototype 7 obtained by solidifying and solidifying the teeth is extracted from the root canal, and a golden core 8 can be cast from the core prototype 7. 2. A core according to claim 1, characterized in that both bulk polymeric impression plastic materials which can be vaporized by heating are polymethyl methacrylate.