JPH04295351A - Crown - Google Patents

Abstract

PURPOSE:To provide a crown at low cost having a natural color and sufficient strength and capable of being repaired by laying over the surface of an inner crown made of a metal an outer crown via an adhesive layer, the outer crown being made of porcelain or resin. CONSTITUTION:A crown comprises a structure wherein an outer crown 3 made of porcelain or resin is laid via an adhesive layer 2 on the surface of an inner crown 1 made of a metal. A low-cost metallic material which cannot or is difficult to be baked, for example, a silver alloy is usable as the inner crown 1. Because the outer crown 3 is exposed to view, a material with a natural color is used for the crown 3: e.g. porcelain such as hydroxyapatite and alumina compound material, and resin are cited. As the adhesive, for example, feldspar to which sodium carbonate, potassium carbonate, calcium carbonate and the like are added as flux is suitable since it is not affected by high temperature at shading.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crown that is natural in color, has sufficient strength and excellent durability, and is repairable.

0002

[Prior Art] Conventionally, when tooth structure has been lost to the extent that it cannot be repaired using the filling method, the tooth above the neck is ground down and a so-called crown, such as a metal crown, porcelain crown, or resin crown, is placed over the tooth. A repair process is performed. 1 tooth lost again
If there are only two teeth and the adjacent teeth are strong,
A restoration method called a bridge is used.

[0003] In the case of metal crowns, noble metals are excellent, but they have the disadvantage of being expensive and furthermore, they have a problem that the color is far from natural. In the case of porcelain crowns and resin crowns, the color is closer to natural than that of metal crowns, but since the natural color differs slightly depending on each person, it is difficult to say that the condition is fully satisfactory, and the biggest drawback is that the strength of the material is Because it is weak, it is necessary to increase the thickness, which not only increases the amount of tooth removal and weakens the tooth, but also causes discomfort and pain to the patient.

[0004] A method of baking porcelain onto metal has also been used, but this method requires the use of expensive alloy materials such as nickel-chromium or platinum-gold in order to bond the porcelain and metal. This requires advanced technology and is extremely expensive. In addition, since metal is used, it is desirable to completely cover the metal with porcelain considering the natural color and the effect on living organisms, but it is impossible to completely cover the metal with porcelain using the conventional firing method. , it is inevitable that some metal will be exposed. In addition, when a bridge is made using the baking method, cracks are likely to occur at the joints between the teeth of the bridge due to stress concentration when it is attached to the teeth, and cracks may occur during use due to residual molding distortion from baking. Furthermore, if a crack occurs, it cannot be repaired and the whole thing must be replaced, which is extremely uneconomical, and the financial burden on the patient cannot be overlooked. There is.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a crown that is natural in color, has sufficient strength and excellent durability, and is repairable at a low cost.

[0006]

SUMMARY OF THE INVENTION The present invention provides a crown in which an outer crown made of porcelain or resin is laminated on the surface of an inner crown made of metal via an adhesive layer. The present invention will be described based on drawings showing embodiments. In FIG. 1, the crown of the present invention has an inner crown 1 made of metal and an outer crown 3 made of porcelain or resin with an adhesive layer 2 interposed on the surface of the inner crown 1 made of metal.
It consists of a laminated structure.

As the inner crown 1 made of metal used in the present invention, expensive alloy materials used in the baking method can of course be used, but inexpensive metals such as silver alloys that cannot or are difficult to bake can also be used. This is one of the features of the invention.

As the outer crown 3 made of porcelain or resin used in the present invention, a material with a natural color is used since it is a part that touches the exterior, and for example, porcelain or resin such as hydroxyapatite or alumina composite material is used. Among these, mica-based porcelain "Dicor (trade name, manufactured by Dow Corning)" is suitable.

The adhesive layer 2 used in the present invention is as follows:
Either organic or inorganic type may be used, but inorganic type such as feldspar (K2O ・ Al 2 O 3 ・ 6SiO 2 )
A mixture containing sodium carbonate, potassium carbonate, calcium carbonate, etc. as a flux is more suitable because it is not affected by high temperatures during shading. The melting point of the feldspar-based adhesive is adjusted by increasing or decreasing the amount of flux. It is also possible to mix a coloring agent made of oxides of iron, cobalt, nickel, etc. into the adhesive layer 2 to make the appearance seen from the outer crown more similar to the natural color unique to each person.

FIG. 2 shows an example of a bridge consisting of a crown according to the invention, in which the bridge 4 has solid teeth 5, 6 on both sides.
is crowned by 7 is the gums. The bridge 5 made of a crown of the present invention has an inner crown made of metal and an outer crown made of porcelain or resin laminated via an adhesive layer (not shown), so that the adhesive layer is used as a cushion. As a material, it absorbs stress concentration during bridge bonding and prevents cracking of the joint 8, and also absorbs molding distortion to prevent cracking during use. In addition, since the surface of the inner crown made of metal can be completely covered with the outer crown made of porcelain or resin, the appearance is extremely natural.Furthermore, if a part of the crown is damaged, the damaged part can be repaired. It is economical because it can be

[0011] The crown of the present invention is manufactured using the same method as conventional crowns, such as MMA (methyl methacrylate).
It is attached to the tooth using a resin adhesive and shaded.

0012

[Effects of the Invention] The crown of the present invention has a natural color appearance, and by mixing a coloring agent in the adhesive layer, it can be made as close to the natural color of each person's teeth as possible. Since the surface of the inner crown made of metal can be completely covered with the outer crown made of porcelain or resin, a more natural appearance can be achieved compared to conventional baking methods. It is inexpensive because it allows the use of inexpensive metal materials that previously could not be used. ■ Although the occurrence of molding distortion of the outer crown made of porcelain or resin is unavoidable, since it is laminated with the inner crown through an adhesive layer, The adhesive layer acts as a cushioning material that absorbs molding distortion, so it can be used without any problems even if there is slight distortion. ■ Because the adhesive layer acts as a cushioning material, it reduces stress when installed as a bridge. As mentioned above, the molding strain is also absorbed, so it is possible to prevent cracking during installation and use, and the impact on the teeth is alleviated, which is convenient. It has many advantages, such as being extremely economical because only the damaged part can be repaired, and its contribution to this field is enormous.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing another embodiment of the invention and showing a bridge consisting of a crown.

[Explanation of symbols]

1 Inner crown 2 Adhesive layer 3 Outer crown

Claims (1)

[Claims] 1. A crown comprising an inner crown made of metal and an outer crown made of porcelain or resin laminated on the surface of the inner crown made of metal with an adhesive layer interposed therebetween.