JPH10127662A - Denture attachment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain sufficient fixing strength even in a thin denture attachment by freely attachably and detachably mounting a magnet structure body attached to the base side of an artificial tooth by magnetic attraction force to a plate to be attracted which is implanted in the dental root part and constituting this structural body of an annular magnet body and the yoke part enclosing this magnet body. SOLUTION: The denture 11 comprises a dental plate 12, the artificial tooth 13 disposed in this dental plate 12 and the magnet structure body 14 attached by fixing means to the base side of the artificial tooth 13. The plate 15 to be attracted which consists of a soft magnetic alloy previously disposed in the dental root is attracted by the magnetic attraction force to the magnet structural body 14 and is thereby freely attachably and detachably fixed into the dental root. The magnet structural body 14 comprises the annular magnet body 16 intersecting with a tooth height direction A and the yoke part 17 enclosing the magnetic body 16 so as to embed its central hole. The yoke part 17 comprises a crowned yoke 18 having an annular housing groove corresponding to the magnet body 16 and an annular cap yoke 19 for sealing the magnet body 16 into this housing groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a denture attachment for detachably fixing a denture to a root portion by magnetic attraction.

[0002]

2. Description of the Related Art Conventionally, there has been provided a denture attachment in which an artificial tooth is removably fixed to a suction plate made of a soft magnetic material implanted in a root portion of a tooth extraction patient by a magnetic attraction force (Japanese Patent Laid-Open Publication No. Hei. 303145, U.S. Pat.
3,243). As shown in FIG. 7, the magnetic attraction type denture attachment includes a magnet structure 3 attached to a denture element in which an artificial tooth 2 is integrated with a denture base 1 conforming to the surface layer shape of a tooth root. The artificial tooth 2 and the denture base 1 are configured so that the lower surface of the magnet structure 3 facing the adherend plate 5 is exposed from the denture base 1 and is flush with the denture base 1 in FIG. It is provided between them. The magnet structure 3 is shown in FIG.
As shown in FIG. 5, a flat columnar permanent magnet 3a is surrounded by a corrosion-resistant yoke portion 3b. A soft magnetic alloy is used. The yoke 3b has a non-magnetic ring 7 as a magnetic resistance.
Is provided on the lower surface facing the adherend plate 5.

In a denture attachment using the magnet structure 3 shown in FIG. 8, as shown in FIG. 8, a magnetic circuit φ formed by the magnet structure 3 and the adherend plate 5 is formed in a donut shape. An attraction force is generated between the lower surface side of the yoke portion 3a and the adherend plate 5 to fix the denture to the root portion.

[0004]

By the way, the fixing strength of the denture is determined by the amount of the permanent magnet used for the magnet structure 3. Therefore, assuming that the area condition of the magnet structure 3 is constant, the larger the thickness of the magnet structure 3 (the dimension in the tooth height direction of the magnet structure 3), the greater the permanent magnet thickness and the higher the fixing strength. Can be.

However, in particular, a back tooth such as the artificial tooth 2 shown in FIG. 7 has a meshing groove portion 4 in which the center is fitted with the opposing tooth, and a tooth height for incorporating the magnet structure into the artificial tooth. Space in direction is limited. Therefore, in the case of the magnet structure 3 as shown in FIG. 8, a thin and sufficiently large fixing strength that can reduce the height H of the engagement groove portion 4 is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. In a magnet structure constituted by surrounding a magnet body with a yoke, the magnet structure is thinner and more sufficient than when a flat columnar permanent magnet is used. An object of the present invention is to provide a technical means for obtaining a high fixing strength.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the technical means adopted in claim 1 of the present invention is to provide a magnet structure of a magnet structure to be embedded in a denture, which has a substantially ring-like shape crossing the tooth length direction. It was formed in. According to the invention of claim 1 employing the above technical means, the magnet body surrounded by the yoke portion is ring-shaped, and the magnetic circuit formed by the yoke portion and the adherend plate by the magnet body includes: Donut-shaped magnetic circuits are formed doubly on the outside and inside. For this reason,
In comparison with a flat columnar magnet body which can be formed only one time, in the ring-shaped magnet body, the area which substantially contributes to the attraction between the yoke portion and the adherend plate increases. Thus, when the magnet structure is composed of the flat columnar magnet body and the ring-shaped magnet body having the same outer diameter, even if the magnet structure of the ring-shaped magnet body is thin, the fixing strength is strong, and it is like a back tooth. It can be easily embedded in a denture with a small space in the tooth height direction.

In addition, since the influence on the height of the artificial teeth is reduced, it is easy to adjust the meshing height, which varies greatly between individuals.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In a preferred embodiment of a denture attachment according to the present invention, a magnet structure attached to the bottom surface side of an artificial tooth includes a ring-shaped magnet body crossing the tooth length direction, and a magnet body. And a yoke made of a corrosion-resistant soft magnetic material for forming a magnetic circuit between the magnet body and the adherend plate.

The magnet body is made of Nd (neodymium) -Fe-B
A (boron) -based rare-earth magnet or an Sm-Co-based rare-earth magnet is used. In the case of Nd-Fe-B system, 40MGOe or more, Sm
In the case of -Co system, the energy product is 30 MGOe or more. The yoke portion includes a crown yoke and a lid yoke. The crowned yoke is formed in an M-shaped cross section having a ring-shaped receiving groove, and one of the magnetic pole surfaces (the surface facing the denture base side) of the magnet body is exposed so that the magnet body can be fitted into the receiving groove. . The cover yoke seals the magnetic pole surface to cover the magnet body. Although the crown yoke and the lid yoke may be made of Cr alone, it is preferable to use Cr-
A Mo-Ti alloy is used. A non-magnetic ring may be interposed between the outer and inner joints between the crowned yoke and the lid yoke, or the crowned yoke and the lid yoke may be formed by modifying one of the yoke materials with a laser or the like. Can be.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the drawings. Denture 1 using denture attachment according to the present invention
Basically, as shown in FIG. 1, a denture base 12 having a divergent shape, one or a plurality of artificial teeth 13 provided on the denture base 12, and positioning and fixing in an attachment mounting groove of the denture base 12. And a magnet structure 14 attached to the bottom surface side of the artificial tooth 13 by a fixing means such as adhesion or press-fitting. By being attracted to the structure 14 by magnetic attraction, it is detachably fixed to the root portion.

As shown in the enlarged view of FIG. 2, the magnet structure 14 of the first embodiment used for the denture 11 has a ring shape crossing the tooth height direction A and has a magnetization direction in the tooth height direction A. And a yoke 17 surrounding the magnet body 16 so as to fill the center hole of the magnet body 16. As shown in FIG. 3, the yoke portion 17 has a substantially M-shaped cross section having a ring-shaped accommodation groove 18 a corresponding to the magnet body 16.
It comprises a Y-shaped crowned yoke 18 and a ring-shaped lid yoke 19 which covers the opening side of the accommodation groove 18a and seals the magnet 16 in the accommodation groove 18a. Non-magnetic rings 20 and 21 serving as magnetic resistance are disposed in the outer and inner gaps between the crown yoke 18 and the cover yoke 19.

Here, as the permanent magnet of the magnet body 16,
Rare earth magnets having an energy product of 30 to 40 MGOe or more, for example, Sm-Co alloys and Nd-Fe-B alloys are practical. The soft magnetic material of the yoke 17 is preferably stainless steel having corrosion resistance. Thereby, corrosion of the magnet body 16 is prevented. In the denture attachment having such a configuration, the magnet structure 14 attached to the bottom surface side of the artificial tooth 13 is attracted to the attachment plate 15 to form a magnetic circuit between the yoke portion 17 and the attachment plate 15. I do. In this magnetic circuit, the magnet body 16 surrounded by the yoke portion 17 has a ring shape and is formed in a double donut shape as indicated by reference numerals 22 and 23. When the magnetic circuit is formed in this manner, the cross-sectional area of the magnetic flux flowing through the adherend plate 15 increases, and the area where the yoke portion 17 and the adherend plate 15 are substantially attracted is shown in FIG. It is wider than the suction surface between the yoke portion 3b and the adherend plate 5. Therefore, the yoke portion 17 surrounding the ring-shaped magnet body 16 is the yoke portion 3b surrounding the flat columnar magnet body 3a.
The fixing strength can be increased. According to this, the magnet body 16
A sufficient fixing strength can be ensured even if the thickness is smaller than that of a simple flat column that is not a ring. For this reason, the thickness (height) of the entire denture attachment 14 can be reduced, and it can be easily incorporated into an artificial tooth having a small space in the length direction such as a back tooth.

As a secondary effect, the magnet structure 14
The height of the denture can be kept low,
The range in which the height H of the engagement groove portion 13a is adjusted according to the individual difference is widened, and the adjustment of the engagement height can be performed more freely. Table 1 shows an example of the specifications of each component of a specific denture attachment configured based on the first embodiment.
Table 2 shows the specifications of a denture attachment manufactured using a flat columnar magnet as shown in FIG. 8 as a comparative example.

[0015] As can be seen by comparing Table 1 and Table 2, in order to obtain almost the same fixed strength of the energy product, the denture attachment of the present invention requires the height h1 of the magnet body 16 to be equal to the height h of the conventional magnet body 3a.
It was half of a.

When a magnet structure is actually manufactured using the magnet 16 having the above height, a magnet structure 14 having a size as shown in Table 3 is obtained.
Can be manufactured. As shown in Table 3, the height of the magnet structure 14 can be 1.0 mm, and the crowned yoke 3 when the flat columnar magnet body 3a is used.
Since the height of b is 1.5 mm, it becomes possible to manufacture a denture attachment having substantially the same fixed strength in two-thirds thinness.

The denture attachment 14 is provided with a crown yoke 18, a magnet body 16, a lid yoke 19, and non-magnetic rings 20 and 21. The recesses 18a are formed on the lower surface of the crown yoke 18. After the magnet body 16 is fitted to the cover, the cover yoke 19 and the non-magnetic rings 20, 21 are assembled in this order by fixing means such as adhesion as shown in FIG. As another method, since the non-magnetic rings 20 and 21 can modify the magnetic material by a modifying means using a laser or the like, after covering the magnet body 16 with the lid yoke 19, the outer and inner gap positions are irradiated with the laser or the like. May be formed.

Next, a second embodiment of the present invention will be described with reference to FIGS. Magnetic attachment 32 shown in FIG.
The (magnet structure) includes a ring-shaped magnet body 33 intersecting with the tooth height direction A, and a yoke portion 34 made of a corrosion-resistant soft magnetic material surrounding the magnet body 33 so as to fill a center hole of the magnet body 33. The yoke part 34 is a crowned yoke 35 covering the magnetic pole side of the magnet body 16 facing the bottom side of the artificial tooth 13.
And a cover yoke 36 for covering the magnetic pole surface side serving as a denture base surface, and the non-magnetic rings 38 and 37 are arranged in gaps between the crown yoke 35 and the cover yoke 36 on the outside and inside. This is the same as the first embodiment, but differs from the first embodiment in the configuration in which the concave portion 39 is formed in the crowned yoke 35 on the upper surface facing the bottom surface side of the artificial tooth.

The above-described denture attachment 32 can also be manufactured by the same assembling procedure as in the first embodiment, or by a modifying means using a laser beam. Even with the denture attachment 32 having the above-described configuration, the magnet body 33 has a ring shape, and the magnetic circuit formed by the magnet body 33 and the adherend plate 15 has a double donut shape as indicated by reference numerals 39 and 40. Thus, the area of the magnetic flux flowing through the adherend plate 15 can be increased, and the fixing strength can be increased.

By forming the concave portion 39 in the yoke portion 34 as compared with the first embodiment, the height H of the meshing concave portion 13a in FIG. 1 can be further reduced. This makes it possible to further increase the degree of freedom in adjusting the engagement height. The second
Table 4 shows an example of the specifications of each component of a specific denture attachment configured based on the embodiment.

[0021] In Table 4 above, the outer diameter of the crowned yoke refers to the outer diameter of the recess 39.

Such a denture attachment is shown in Table 5 below.
As shown in (1), the height H (minimum height) of the engagement concave portion 13a can be set to 0.5 m. In the conventional magnet structure, the maximum height and the minimum height are 1 mm, and since the magnet body 33 is ring-shaped, the concave portion 39 can be provided, and it can be seen how the minimum height can be reduced by this. As a modification of the second embodiment, as shown in FIG. 6, a through hole 41 penetrating through a central hole of the ring-shaped magnet 33 is provided.
Is provided, the double donut-shaped magnetic circuits 39 and 40 are formed, the fixing strength is almost the same as in each embodiment, and a denture attachment thinner than the conventional one can be manufactured. In this modified example, a second recess 139 is provided by the through hole 41.
The point is that the height of the engagement concave portion 13a can be further reduced as compared with the embodiment.

Table 6 shows a specific configuration example of this modified example.
In this specific example, since the Sm-Co alloy is used as the magnet 33, the fixing strength is slightly lower than that of NdFeB, but there is no practical problem.

[0024]

As described above, according to the present invention, by forming the magnet body into a ring shape, sufficient fixing strength can be obtained even if the magnet body is thinner than a flat columnar magnet body, The magnet structure can be easily incorporated into a denture having no space in the tooth height direction. In addition, since the magnet structure can be made thin, there is an advantage that the range of adjusting the mesh height at the artificial tooth can be widened.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a denture employing a denture attachment according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a denture attachment according to the first embodiment of the present invention.

FIG. 3 is an assembly configuration diagram showing components of the first embodiment in an exploded manner.

FIG. 4 is a sectional view showing a denture attachment according to a second embodiment of the present invention.

FIG. 5 is an assembly configuration diagram showing components of the second embodiment in an exploded manner.

FIG. 6 is a sectional view showing a modification of the second embodiment.

FIG. 7 is a cross-sectional view showing a denture using a conventional denture attachment.

FIG. 8 is a cross-sectional view showing a conventional denture attachment.

[Explanation of symbols]

11 is a denture, 12 is a denture base, 13 is an artificial tooth, 13a is a meshing groove, 14 is a magnet structure (denture attachment), 1
5 is an attaching plate, 21, 39, 41 are concave portions, 16 and 33 are magnet bodies, 17 and 34 are yoke portions, 19 is a cover yoke, 22, 3
9 and 40 are magnetic circuits, 20, 37 and 38 are non-magnetic rings, and the same reference numerals are given to common elements in FIGS.
Elements common to FIGS. 4 to 6 are denoted by the same reference numerals.

Continuing from the front page (72) Inventor Tadashi Wanowari, Aomachi, Tokai City, Aichi Prefecture Inside Aichi Steel Works Co., Ltd.

Claims (1)

[Claims] 1. An artificial tooth comprising a magnet structure attached to the bottom side of an artificial tooth. The magnet structure is attracted by a magnetically attractive force to an adhered plate made of a soft magnetic material implanted in a tooth root and treated. A denture attachment for removably fixing a denture having artificial teeth to the root portion, wherein the magnet structure has a substantially ring-shaped magnet body that intersects with the tooth length direction and a center hole of the magnet body. And a yoke portion surrounding and enclosing the magnet body and the adherend plate to form a magnetic circuit.