JPH0454956A - Artificial tooth attachment - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of an attracting force between a root face plate and a magnetic body by varying a thickness of a holding plate to make adjustable the attracting force between the root face plate and the magnetic body. CONSTITUTION:A spacer 13 comprises an anti-corrosive non-mangetic alloy and is so arranged to traverse the center on the side of a root face plate of a magnetic body 10. A pair of yokes 11 comprising an anti-corrosive soft magnetic alloy is erected on both sides of the spacer 13 as opposed to the root face plate 93 so as to sandwich it 13. A magnet 12 is put between the pair of yokes 11 and disposed on the spacer 13 with an N pole on one yoke 11 and an S pole on the other yoke 13 contacting each other. A cap 14 is made of an anticorrosive non-magnetic alloy and an integral combination of the spacer 13, the yoke 11 and the magnet 12 covers the entire circumferential surface except for an undersurface facing the root face plate 93. A holding plate 96 is welded on the side of the magnetic body of the root face plate 93 by cast welding, and thus, an attracting force can be adjusted by varying a thickness of the holding plate 96.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a denture attachment that utilizes magnetic attraction, and more specifically, a retainer plate made of a soft magnetic alloy that is bonded to the upper surface of a root plate embedded in a tooth root. The present invention relates to a denture attachment which is composed of a magnetic material embedded in a denture base, has excellent adsorption force and corrosion resistance, and is capable of adjusting the adsorption force.

[Prior Art] Conventionally, as a denture using magnetic attraction force, for example, the 8th
The denture shown in FIG. 9 and FIG.
A denture part 95 is provided so as to face a root plate 93 made of a magnetic material and embedded in an inner root 92. Thus, the second denture part 95 has a denture base 94 made of plastic or the like below, and the root plate 93 is disposed within the denture base 94.
It has a magnetic body 8 at a position opposite to.

As shown in FIG. 9, the magnetic body 8 has a magnet 82 arranged inside a stainless steel case 81 having a projection 83 on the upper part. As the magnet 82, an SM (samarium)-Co (cobalt)-based rare earth magnet having a strong magnetic force is used.

[Problems to be Solved by the Invention] However, all conventional magnets have a low magnetic attraction force of about 200 g to 300 g. This suction force is lower than the force of 500 g or more when mechanically holding the tooth between natural teeth with a spring, which has traditionally been frequently used.

In addition, since magnets are easily corroded in the oral cavity, if the rare earth magnet is exposed in the oral cavity, the magnet will rust and the attraction force will rapidly decrease, which also poses a safety problem. In addition, when the entire magnet body is covered with a case made of a non-magnetic alloy such as stainless steel as in the above publication for rust prevention, the non-magnetic alloy is interposed between the magnet and the base plate, so the attraction force will decrease.

In view of this problem, the inventors first placed a rare earth magnet between a pair of yokes perpendicular to the root plate.
We also proposed a denture attachment consisting of a spacer made of a non-magnetic alloy placed on the lower surface of the magnet, and a magnetic material covered with a camp except for the yoke and the root plate side of the spacer.

Since the denture attachment according to the above proposal by the inventors uses a soft magnetic alloy for the pair of yokes, a magnetic circuit is formed between the two yokes and the root plate, and a large attractive force can be generated. . Further, since the spacer and the cap are not interposed between the yoke and the root plate and are made of a non-magnetic alloy, a strong attraction force can be ensured. Also,
13Cr-2Mo, 17Cr-2MO on the -F side of the root plate
By adhering a retaining plate made of a soft magnetic alloy such as, the suction force can be further improved.

By the way, when designing a denture, it is preferable that the suction force of the denture attachment can be adjusted based on the shape of the tooth root π and the shape of the denture. However, the denture attachment in the above proposal has an extremely excellent suction force.
There is a problem in that the suction power cannot be adjusted.

Conventionally, the interface between the cap and the yoke and the spacer and the interface between the caulk and the spacer on the root plate side were bonded by brazing, adhesive, or resin.

When the interface is bonded by brazing, the yoke may be corroded by electrolytic corrosion, and the adhesion with each member may be unstable and the brazing material may become Th1M. In addition, poor flow of the solder may leave gaps, resulting in incomplete sealing, which allows corrosion to progress through these gaps. moreover,
Since brazing filler metal has low strength, joints may peel off when strong external stress is applied.

When bonding interfaces using adhesives such as composite resin (commonly known as Panavia), Superbond, or resin, the bond itself has poor durability and cannot completely prevent saliva from entering over a long period of time. .

On the other hand, without the cap, the entire attachment is made of gold,
There is a method of plating with silver or nickel, but with this method, the plating tends to peel off and it is difficult to maintain the anticorrosion effect for a long period of time.

In the present invention, a magnet body made of a rare earth magnet is arranged between a root plate and a pair of yokes perpendicular to the root plate, and a spacer made of a non-magnetic alloy is arranged on the lower surface of the magnet body, and the roots of the yoke and the spacer are arranged. This was done in view of the above-mentioned problems in the adjustment of the suction force and the joints between the cap, yoke, and spacer, and the joints between the yoke and the spacer in a denture attachment consisting of a magnetic material covered with a cap except for the face plate side. To provide a denture attachment that is small, has high suction power, completely seals against saliva corrosion, has excellent strength and durability, and allows easy adjustment of the suction force between the root plate and the magnetic material. and three objectives. .

[Tr, Means for Solving the Problem] In order to solve the above-mentioned problem, the inventors have conducted extensive research on the relationship between changes in the attraction force of the magnetic material and the holding plate attached to the root plate, and each member. As a result, it was found that there is a proportional relationship between the suction force and the thickness of the holding plate as shown in FIG. Based on this, the present invention was completed based on the new finding that by adjusting the thickness of the retaining plate that is adhered to the root plate, the attraction force between the root plate and the magnetic material can be adjusted.

In addition, in order to ensure sufficient rust prevention at the joints between the cap, yoke, and spacer, and between the yoke and spacer, welding should be used instead of brazing. I came up with the idea that it was necessary to have a unique melting process.

The present invention was completed by applying welding to the joint based on this knowledge.

The denture attachment of the present invention has, as its first invention,
A denture attachment consisting of a retaining plate made of a soft magnetic alloy bonded to the magnetic side of a root plate embedded in a tooth root, and a magnetic body embedded in a denture base to face the root plate, the magnetic body is a spacer made of a corrosion-resistant valve 1ifi alloy provided on the root plate side, a pair of yokes made of a corrosion-resistant soft magnetic alloy that is erected toward the root plate side while sandwiching the spacer, and a reverse root of the spacer. A denture that is a magnetic material comprising a magnet having an S pole and an N pole facing the two yokes on the surface side, and a cap that covers the magnet, the pair of yokes, and the spacer except for the root plate side. In the attachment, the attraction force between the base plate and the magnetic body can be adjusted by changing the thickness of the holding plate.

Moreover, in order to improve the 111 eating property and durability of the first invention, the gist of the second invention is that the cap, the yoke, and the boundary surface of the spacer on the root plate side of the magnetic material are joined by welding.

As a magnet used for magnetic materials, the maximum energy product is 20
It is preferable to use rare earth magnets that are MGOe (Mega Gauss Erste 71 months or higher), which results in approximately 50
7 Such rare earth magnets that can be used as a denture attachment having an attraction force of 0 g or more include SmCo9,
Examples include SmCo-based alloys such as SmCot, Nb-Fe-B-based alloys, and the like.

Further, as the soft magnetic alloy for the yoke and the holding plate, it is preferable to use one having a saturation magnetic flux density of 13,000 G or more and a magnetic permeability of 3,000 or more. Soft magnetic alloys for the yoke and retainer plate having such characteristics include pure iron, 13Cr-2
Examples include Mo steel and 17Cr-2Mail. In addition, the saturation magnetic flux density of the soft magnetic alloy of the yoke and retaining plate is 2000
In the case of 0G or more, the suction force further increases. Pure iron is an example of a soft magnetic alloy that is susceptible to warping. In addition, Figures 4 and 5
The figure shows the relationship between saturation magnetic flux density, maximum energy product, and attractive force.

It is desirable to adjust the thickness of the holding plate within a range of 0.311 Im or more. This is because if it is less than 0.31, suction force that can maintain the denture cannot be obtained.

In addition, in the denture attachment of the present invention, laser welding or electron beam welding can be used for welding the joint, but the penetration depth by welding must be 0.02 mm or more and not more than the height of the spacer. It is preferable to do so. The penetration depth of welding of the joint is 0. This is because if it is less than 1 m, sufficient strength of the joint cannot be obtained and sealability against saliva cannot be ensured. Conversely, if the weld penetration depth of the joint exceeds the height of the spacer, the magnetic body will be affected by the heat of the welding and the magnetic properties of the magnetic body will deteriorate.

In addition, in the present invention, the spacer height is 005 to 1.
It is preferable to set it to 0-. Spacer height is 0.05+
If the spacer height is less than 1.0 mm, it will be difficult to ensure sufficient wear resistance, and therefore, sufficient sealing performance and strength of the joint will not be obtained. However, if the spacer height exceeds 1.0 mm, magnetic attraction will occur. The power will not be enough.

In addition, in order to improve the corrosion resistance of the joint, the yoke has a weight ratio of c, o, o3q, hereinafter Cr; 11 to 30%,
A corrosion-resistant soft magnetic alloy with Mo: 4% or less is used, and the spacer and cap are made of Ti, Ti alloy, or C.
It is preferable to use non-magnetic stainless steel with an O content of 3% or less. Note that it is also possible to add Nb or Ti to the corrosion-resistant soft magnetic alloy as necessary.

[Function] By adjusting the thickness of the retaining plate bonded to the root plate of the denture attachment of the present invention, the bow suction force can be easily adjusted, and the design and construction of the denture can be made very efficiently. .

The magnetic material of the denture attachment of the present invention is welded to the joints of the cap, yoke, and spacer, and the joints of the yoke and spacer by completely welding the two adjoining members, so the interface disappears. This completely prevents saliva from entering. This completely protects the magnetic material from corrosion due to the ingress of saliva. In addition, the corrosion resistance of the joints is
It is equivalent to or better than the base metal, and there is no risk of corrosion or electrolytic corrosion from the joints.

Furthermore, the strength of the joint is higher than that of brazing, there is no damage due to mechanical stress, and there is no risk of the joint being worn out. Therefore, the corrosion resistance is stable and there is no fear of peeling. [Examples] Examples of the present invention will be explained together with conventional examples to clarify the effects of the present invention.

First, the structure of a denture attachment to which the present invention is applied will be explained. FIG. 1 is a sectional view of a denture attachment to which the present invention is applied, and FIG. 2 is an exploded perspective view of a magnetic body. The spacer 13 is made of a corrosion-resistant nonmagnetic alloy, and the magnetic material 1
A pair of yokes 11 and 11 made of a corrosion-resistant soft magnetic alloy are arranged so as to cross the center of the root plate side of 0.
is erected toward the base plate 93, and is shaped to sandwich the spacer 13. The magnet 12 is a pair of corks 1], 11
The N pole is placed on one of the yokes 11 and 8% of the cork 11 on the other side is placed on the spacer 13. The can knob 14 is made of a corrosion-resistant non-magnetic alloy, and includes a spacer 13, a yoke 11.1] and a magnet 1.
2 are introduced to form a single body, and the entire circumferential surface is covered except for the lower surface facing the root plate. In addition, the book board 9
A retaining plate 96 is bonded to the magnetic material side of 3 by steel welding.

Regarding the denture attachment having the above configuration, three dimensions, magnetic properties, and materials of each part were selected as examples of the present invention as shown in Tables 1 to 3, and the parts were joined by laser welding.

Furthermore, as a conventional example, denture attachments (conventional examples and E) with different structures and materials were bonded with dental adhesive according to the dimensions, magnetic properties, and materials of each member shown in Tables 4 and 5. . The magnetic material of conventional denture attachments is as shown in Figure 6.
It consists of a yoke 71 with an inverted U-shaped cross section, and a magnet 72 in which an S pole and an N pole are arranged vertically. The magnet 72 is attached to the holding plate 9
6 is in direct contact with the root plate 93 to which is adhered.

Furthermore, as shown in FIG. 7, the denture attachment of Conventional Example E has a magnetic material having the same structure as the conventional example, with a non-magnetic foil 73 disposed on the entire surface of the portion facing the retaining plate 96.

The corrosion resistance, abrasion resistance, and suction force of the denture attachments of the present invention example and the conventional example prepared as described above were measured, and the measurement results are shown in Table 6.

Regarding corrosion resistance, magnetic material was added to artificial saliva at 37°C for 1
Evaluation was made based on the degree of discoloration after immersion for 000 hours, and those that did not change color were marked ○, and those that showed discoloration were marked x.

Wear resistance was evaluated based on the condition of the attachment side surface after rubbing the root plate and the magnetic material 1000 times under a load of 5°Og, and those with excellent abrasion resistance and no change were given a score of 0. For items with missing parts>
' was shown.

Regarding the attraction force, the magnetic attraction force (ε) between the magnetic body and the root plate was measured.

(Margin below) As shown in the measurement results in Table 6, the conventional example in Table 4 and the conventional example E in Table 5 have a low suction force of 2.0 to 300 g, and both joints are Since it is attached with adhesive, both corrosion resistance and abrasion resistance are poor.

In contrast, invention examples A in Tables 1 to 3, which are examples of the present invention,
~C has excellent corrosion resistance and abrasion resistance by welding the cap, yoke, and the interface on the root plate side of the spacer, and has an excellent suction force of 520 to 900 mm, and the thickness of the retaining plate can be It was found that the suction force could be adjusted by changing the amount, and the effect of the present invention was confirmed.

[Effects of the Invention] The present invention arranges a rare earth magnet between a holding plate adhered to the root plate and a pair of yokes perpendicular to the root plate,
and placing a non-magnetic alloy spacer on the lower surface of the magnet,
In a denture attachment consisting of a yoke and a magnetic material covered with a cap except for the root plate side of the spacer, the thickness of the retaining plate is adjusted, and the interface between the magnetic cap, yoke, and the root plate side of the spacer is adjusted. L:5, which is characterized by being joined by welding, can adjust the attraction force between the root plate and the magnetic material, and is joined so that the boundaries between each member of the magnetic material completely disappear. Since the parts are melted and penetrated, complete waterproofing is achieved and the magnet body is protected from corrosion. In addition, the joint has excellent corrosion resistance, sufficient strength, and excellent wear resistance.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a denture attachment to which the present invention is applied, Fig. 2 is an exploded perspective view of the magnetic material shown in Fig. 1, Fig. 3 is a diagram showing the relationship between the thickness of the retaining plate and the suction force, Figures 4 and 5 are diagrams showing the relationship between saturation magnetic flux density, maximum energy product, and suction force, Figures 6 and 7 are cross-sectional views explaining the basic structure of conventional denture attachments, and Figure 8. 9 is a sectional view of a conventional denture, and FIG. 9 is a sectional view of a magnetic body of a conventional denture attachment. 1. - Denture attachment, 10. Magnetic material, 1
DESCRIPTION OF SYMBOLS 1... Yoke, 12... Magnet, 13... Spacer, 14... Cap, 91... Alveolus, 93 Root plate, 94... Denture base, - Denture part, 96... Retaining plate, - Conventional Magnetic material patent applicant for denture attachment Aichi Steel Co., Ltd.'ip, Figure 1, Figure 2, Figure 8? Figure A3 Thickness of holding plate (mm) Figure 4 Saturation magnetic flux density (G) Maximum energy product (MGOe) Figure 6 Figure 7

Claims (2)

[Claims] (1) A denture attachment consisting of a retaining plate made of a soft magnetic alloy bonded to the magnetic side of a root plate embedded in the tooth root, and a magnetic body embedded in the denture base so as to face the root plate, The magnetic body includes a spacer made of a corrosion-resistant non-magnetic alloy provided on the root plate side, a pair of yokes made of a corrosion-resistant soft magnetic alloy that sandwich the spacer and stand upright toward the root plate side, and the spacer. A magnetic body comprising a magnet having an S pole and an N pole facing the two yokes on the opposite root side, and a cap that covers the magnet, the pair of yokes, and the spacer except for the root plate side. A certain denture attachment, wherein the attraction force between the root plate and the magnetic body can be adjusted by changing the thickness of the retaining plate. (2) The denture attachment according to claim 1, wherein the cap, the yoke, and the boundary surface of the spacer on the root plate side of the magnetic material are joined by welding.