JPH0454958A - Artificial tooth attachment - Google Patents

Abstract

PURPOSE:To prevent slippage off artificial teeth with improvement in strength and durability by making a side of a cap of a magnetic body rugged to join border faces between the cap, a yoke and a spacer on the side of a root face plate. CONSTITUTION:An artificial tooth attachment 1 comprises a holding plate 96 bonded on a root face plate 93 and a magnetic body 10 in which a magnet body 12 made of rare earth magnet is arranged between a pair of yokes 11 vertical to the root face plate while a spacer 13 made of a non-magnetic alloy is arranged on the underside of the magnet body and covered with a cap 14 except for portions on the side of root face plate of the yoke and spacer. Then, a side of the cap of the magnetic body is made rugged to prevent the magnetic body from slipping off the artificial teeth while border faces between the cap, yoke and spacer on the side of the root face plate of the magnetic body are joined by welding. In this manner, the respective members of the magnetic body melts into one another at the joint thereof so as to eliminate border parts thereof, thereby protecting the magnet body from corrosion with a complete prevention thereof secured.

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 denture attachment consists of a magnetic material embedded in the denture base, and has excellent adhesion and corrosion resistance, and prevents the magnetic material from falling off the denture.

[Prior Art] Conventionally, as a denture using magnetic attraction force, for example, the 8th
What is shown in FIG. 9 and FIG. 9 has been proposed (Japanese Unexamined Patent Publication No. 62-231653). This denture has alveolar 91
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. This denture part 95 has a denture base 94 made of plastic or the like below, and inside the denture base 94 is the root plate 93.
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 gauge 81 having a protrusion 83 on the upper part. As the magnet 82, an Ss (samarium)-Co (cobalt) rare earth magnet having strong magnetic force is used.

[Problem to be solved by the invention] However, all conventional magnets have a low magnetic attraction force of about 200g to 300g. It is low compared to the force of 500g or more when holding.

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 coated with a non-magnetic alloy gauge such as stainless steel for rust prevention as in the above-mentioned publication, 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 cap 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,
If a holding plate made of a soft magnetic alloy such as 13Cr-2Mo or 17Cr-2Mo is adhered to the upper surface of the base plate, the suction force can be further improved.

However, since the magnetic material of the denture attachment is a small, almost cylindrical part with no protrusions on the sides, the magnetic material may fall out of the denture even if it is embedded in the denture and used for many years.

Furthermore, in the past, the interface between the cap, yoke, and spacer on the root plate side, and the interface between the yoke and spacer 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 peel off. In addition, poor flow of the solder may leave gaps, resulting in incomplete sealing, which allows corrosion to progress through these gaps. Furthermore, since the strength of the brazing filler metal is low, the bonded portion 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.

The present invention arranges a rare earth magnet between a holding plate attached to the root plate and a pair of yokes perpendicular to the root plate, and arranges 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 magnetic material may fall off from the denture, and the above-mentioned problems may occur at the joints between the cap, yoke, and spacer, and at the joints between the yoke and the spacer. This was done in view of the problems such as
The purpose of the present invention is to provide a denture attachment that is small in size, has high suction power, completely seals against corrosion caused by saliva, has excellent strength and durability, and prevents the denture from falling out.

[Means for solving the 8 problems] In order to solve the above-mentioned problems, the inventors conducted extensive studies on the resistance of the magnetic material to fall off from the denture, and created unevenness on the side surface of the magnetic material as a means to prevent the magnetic material from falling off. This idea led to the completion of this invention.

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 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;
The spacer includes a magnet having an S pole and an N pole facing the yokes on the side opposite to the root surface of the spacer, and a cap that covers the magnet, the pair of yokes, and the spacer except for the root surface plate side. In a denture attachment made of a magnetic material, the cap of the magnetic material is provided with unevenness on the side surface to prevent the magnetic material from falling off the denture.

Moreover, in order to improve the corrosion resistance and durability of the first invention, a second invention is characterized in that the cap, the yoke, and the boundary surface of the spacer on the root plate side of the magnetic body are joined by welding.

As a magnet used for magnetic materials, the maximum energy product is 20
It is preferable to use a rare earth magnet of MGOe (Mega Gauss Oersted) or higher.

Thereby, the denture attachment can have a suction force of about 500 g or more. Examples of rare earth magnets that can be used include S-Co alloys such as 3mCo5 and Sm2Co+t, and Nb-Fe-B alloys.

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
There are Mo steel, 17Cr-2Mo steel, etc. In addition, the saturation magnetic flux density of the soft magnetic alloy of the yoke and retaining plate is 20,000
When the force is greater than G, the suction force further increases. Pure iron is an example of such a soft magnetic alloy. Incidentally, FIGS. 5 and 6 show the relationship between the saturation magnetic flux density, the maximum energy product, and the attractive force.

The unevenness 97 attached to the side surface of the magnetic cap 14 is
As long as it prevents the denture from falling out, its shape and attachment method are not restricted.

For example, as shown in FIG. 1(a), foreign matter may be attached to the side surface of the cap, or as shown in FIG. 1(b), unevenness 97 may be simply provided on the side surface of the cap. As shown in FIG. 1(e), holes may be made by welding.

In addition, in the denture attachment of the present invention, laser welding or electron beam welding can be used to weld 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. This is because if the weld penetration depth of the joint is less than 0021, sufficient strength of the joint cannot be obtained and sealing performance 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 0°05 to 1
．． Spacer height is preferably 0.05
If the spacer height is less than 1.0 m, it is difficult to ensure sufficient wear resistance, and therefore sufficient sealing performance and joint strength cannot be obtained.However, if the spacer height exceeds 1.0-1, The magnetic attraction force is no longer sufficient.

In addition, in order to improve the corrosion resistance of the joint, the yoke has a weight ratio of C: 0.03% or less, cr: 11 to 30%, M
o; Use a corrosion-resistant soft magnetic alloy of 4% or less, and use Ti or Ti alloy or C; O, for the spacer and cap.
o It is preferable to use non-magnetic stainless steel with a 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.

[Operation] Since the side surface of the magnetic cap of the denture attachment of the present invention is provided with unevenness, when the magnetic material is embedded in the denture, the magnetic material is prevented from falling out from the denture.

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 wear of the joint. In addition, the joints have excellent durability, have stable corrosion resistance over a very long period of time, and are free from peeling.

[Example] Examples of the present invention will be described 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. 3 is a sectional view of a denture attachment to which the present invention is applied, and FIG. 4 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. Magnet] 2 is a pair of yokes 11.11
The spacer 13 is disposed on the spacer 13 so that the north pole is in contact with one yoke 11 and the south pole is in contact with the other yoke 11. The cap 14 is made of a corrosion-resistant non-magnetic alloy, and includes the spacer 13, the yoke 11.11 and the magnet 12.
are combined to form a single body, which covers the entire circumference except for the lower surface facing the root plate. In addition, the root plate 93
A holding plate 96 is bonded to the upper surface of the holding plate 96 by steel welding.

Regarding the denture attachment having the above configuration, as examples A to C of the present invention, unevenness 97 is provided on the side surface of the cap 14 with the unevenness shown in FIGS. 1(a), (b), and (c),
Three dimensions, magnetic properties, and materials of each part were selected as shown in Tables 1 to 3, and the parts were joined by laser welding.

In addition, as a comparative example, the structure is the same as the product of the present invention, but
A denture attachment without the unevenness 97 on the side surface of the cap 14 was also prepared by joining by laser welding according to the dimensions, magnetic properties, and materials of each part shown in Table 4.

Furthermore, as conventional examples, denture attachments with different structures and materials (Conventional Examples E and F) were bonded with dental adhesive according to the dimensions, magnetic properties, and materials of each member shown in Tables 5 and 6. . In addition, conventional example E
The magnetic material of the denture attachment 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.

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

The denture attachments of the present invention example, comparative example, and conventional example prepared as described above were measured for suction force, corrosion resistance, abrasion resistance, and degree of magnetic material falling off from the denture, and the measurement results are shown in Table 7. Indicated.

Regarding corrosion resistance, magnetic material was added to artificial saliva at 37°C for 1
The degree of discoloration after immersion for 000 hours was evaluated, and those with no discoloration and those with O1 discoloration were marked with an 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 with a load of 50 og. Those with excellent abrasion resistance and no change were marked ○, and those with no chipping were evaluated. For those whose parts were seen, ×
It was shown in

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

The degree of magnetic material falling out from the denture is determined by the cap (No.
A to D) or only the yokes (NoE and F) were made with unevenness on the side surface and adhered to a special jig, and a tensile test was conducted using a weight of 50 kg for evaluation. Those that did not fall off were marked with ○, and those that did fall off were marked with ×.

(Left below) As shown in the measurement results in Table 7, the conventional example E in Table 5 and the conventional example F in Table 6 have a low suction force of 200 to 300 g, and both joints are glued. Therefore, both corrosion resistance and abrasion resistance are inferior.

In contrast, invention examples A in Tables 1 to 3, which are examples of the present invention,
~C and comparative example have excellent corrosion resistance and wear resistance due to welding of the interface between the cap, yoke, and spacer on the root plate side, and the suction force is also 700 g.
The above is excellent.

Regarding the degree of magnetic material falling off from the dentures, Comparative Example D and Conventional Examples E and F did not have unevenness on the side surface, so the magnetic material fell off from the dentures, whereas the magnetic material fell off from the dentures in Comparative Example D and Conventional Examples E and F, which are the denture attachments according to the present invention. Inventive examples A to C had unevenness on the side surface of the cap, so no falling-off occurred in any of them, 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, unevenness is provided on the side surface of the magnetic material cap to prevent the magnetic material from falling off the denture. , the boundary surface of the yoke and the spacer on the root plate side are joined by welding, and the provided unevenness completely prevents the magnetic material from falling off the denture, and furthermore, each member of the magnetic material Since the joint is melted in such a way that the boundary part completely disappears, complete waterproofness 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 the drawing]

Figures 1 (a), (b), and (c) are perspective views showing an embodiment in which the side surface of the cap is provided with unevenness, Figure 2 is a cross-sectional view of a denture attachment to which the present invention is applied, and Figure 3 is the figure 2. Figures 4 and 5 are diagrams showing the relationship between saturation magnetic flux density, maximum energy product, and attraction force, Figures 6 and 7 are the basic structure of a conventional denture attachment. 8 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, 11
...Yoke, 12...Magnet, 13.Spacer, 14
...cap, 91...alveolar, 93...root plate,
94... Denture base, 95... Denture part, 96... Holding plate, 97... Irregularities, 8... Magnetic body #18 of conventional denture attachment Figure 1 Eye Figure 4 Saturation magnetic flux density (NiG) Maximum Energy Dan (MGOe) 7P! , Figure 2, Atsushi, Figure 3, Figure 6, Figure 7

Claims (2)

[Claims] (1) A denture attachment consisting of a retaining plate made of a soft magnetic alloy adhered to the magnetic side of a root plate embedded in the tooth root, and a magnetic substance 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, characterized in that a side surface of the cap of the magnetic material is provided with unevenness to prevent the magnetic material from falling off the denture. (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.