JPH0454957A - Artificial tooth attachment - Google Patents

Abstract

PURPOSE:To obtain an excellent attractive force eliminating a deviation between a root face plate and a holding plate with improvement in strength and durability by mounting a knob on the holding plate while border faces of a cap, a yoke and a spacer of a magnetic body on the side of the root face plate are joined by welding in a cast welding of the holding plate on the root face plate. CONSTITUTION:At the joint of a cap 14, a yoke 11 and a spacer 13 and at a joint of the yoke 11 and the space 13, two members to be put together are joined by welding so as to make both the members melt into each other completely. As a result, the elimination of the border faces allows the preventing of saliva from infiltration com pletely to protect the material from corrosion perfectly. A holding plate 96 is welded on the side of a magnetic body of a root face plate 93 by cast welding. To cast weld the holding plate 96 on the root face plate 93, the holding plate 96 with a know 97 mounted thereon is fixed at a specified position of a wax model formed in a shape of the root face plate and the perimeter thereof is solidified with a mold material as backup to make a cast mold 98. After a dewaxing of the wax model, a molten metal is poured into the mold at an inlet 99 to cast the root face plate while the holding plate 97 is cast welded, thereby accomplishing a cast welding successfully without deviation of the holding plate.

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 made of a magnetic material embedded in the denture base, has excellent adsorption power and corrosion resistance, and has less misalignment between the root plate and the retaining plate during microscopic examination.

[Prior art] Conventionally, as a denture using magnetic attraction force, for example,
What is shown in FIGS. 62-231653 has been proposed.

This denture is provided with a denture portion 95 facing a root plate 93 made of a magnetic material and embedded in a root 92 in an alveolus 91. However, this denture part 95 has a denture base 94 made of plastic or the like below, and the denture base 9
4 has a magnetic body 8 at a position facing the base plate 93.

As shown in FIG. 10, the magnetic body 8 has a protrusion 83 on the upper part.
A magnet 82 is placed inside a stainless steel case 81 having a diameter. However, as the magnet 82,
Ss (samarium)-Co (cobalt)-based rare earth magnets having strong magnetic force are used.

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

In addition, since magnets are easily eaten by skin in the oral cavity, if the rare earth magnet is exposed in the oral cavity, the magnet will rust and the attractive 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 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 increased.

By the way, the retaining plate is usually bonded to the base plate by casting. That is, the retaining plate is fixed at a predetermined position within the mold, the base plate is cast, and the retaining plate is welded. However, there is a problem in that the retaining plate tends to move within the mold, making it difficult to weld it in an accurate position. If the holding plate shifts during welding in this way, the suction force of the denture attachment will decrease.

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 Vanavia), 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 suction force may be reduced due to the displacement of the retaining plate, and at the joints between the cap, yoke and spacer, and the joints between the yoke and spacer. This was developed in view of the problems mentioned above.It is small, has high suction power, completely seals against corrosion caused by saliva, has excellent strength and durability, and is excellent in that there is no misalignment between the root plate and the retaining plate. The purpose of the present invention is to provide a denture attachment that has a suction force.

[Means for Solving the Problems] In order to solve the above-mentioned problem, the inventors have conducted extensive studies on how to securely fix the retaining plate to the mold when casting the retaining plate to the base plate, and have developed a method for fixing the retaining plate to the mold. The present invention was conceived based on the idea of attaching a handle during casting as a means of fixing the handle.

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 metal metal sandwiching the spacer and standing upright toward the root plate side;
The spacer includes a magnet having an S pole and an N pole facing the yokes on the length plate side of the spacer, and a cap covering the magnet, the pair of yokes, and the spacer except for the root plate side. In the denture attachment which is a magnetic material, the gist is that a handle is attached to the front retaining plate when the retaining plate is cast-welded to the root plate.

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.

As a result, a denture attachment having a suction force of about 500 g or more can be obtained1. Such rare earth magnets include S mc Os, 5IICo1. 5sC such as
There are o-based alloys, Nb-Fe-B-based alloys, etc.

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 size and shape of the handle to which the holding plate is attached may be such that the holding plate can be securely fixed within the mold.

Furthermore, the handle may be attached to the side surface of the holding plate as shown in Fig. 2(a), or may be attached to the side of the holding plate as shown in Fig. 2(b) and (c).
), it may be placed along the center or side of the upper surface of the holding plate. Note that this handle is removed after casting.

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 is 0.02 m or more, and the height of the spacer is The following is preferable. This is because if the weld penetration depth of the joint is less than 0.02 mm, 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 005 to 1.
It is preferable to set it to 0+m. Spacer height is 0.05
If it is less than mm, it is difficult to ensure sufficient wear resistance, and therefore, sufficient sealing performance and sufficient strength of the joint cannot be obtained. However, the spacer height is 1. If the OI is exceeded, the magnetic attraction force will not be 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%, Mo.
; 4% or less corrosion-resistant soft magnetic alloy is used, and the spacer and cap are made of Ti or Ti alloy or C:O, O3
% or less of non-magnetic stainless steel is preferably used.

Note that Nb or Ti may be added to the corrosion-resistant soft magnetic alloy as necessary.
It is also possible to add.

[Function] The holding plate of the denture attachment of the present invention, which is joined to the root plate, has a handle attached when it is cast-welded to the root plate, so it can be securely fixed at a predetermined position within the casting area, and the holding plate can be firmly fixed to the root plate. There is no displacement of the holding plate, and excellent suction power can be ensured.

The magnetic material of the denture attachment of the present invention is made by welding the joints of the cap, caulk, and spacer, and the joints of the yoke and spacer by completely melting the two adjoining members, so that 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] An example of the present invention will be explained together with a conventional example 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 cross-sectional view of a denture attachment to which the present invention is applied, and Fig. 4 is an exploded perspective view of a magnetic material.
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 connected to a pair of yokes 11.11
Nf! is arranged on the spacer 13 so that the S 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 1.
2 are combined to form a single body, which covers the entire circumference except for the lower surface facing the root plate. In addition, root plate 9
A retaining plate 96 is bonded to the magnetic material side of 3 by casting.

To weld the retainer plate 96 to the base plate 93, the retainer plate 96 with the handle 97 attached is fixed in a predetermined position on the base plate-shaped wax model, and the surrounding area is molded as a backup as shown in FIG. The material is solidified and a mold 98 is formed. After removing the wax model, pour molten metal through the sprue 99 and attach the base plate 9.
At the same time as casting 3, the retaining plate 97 is cast-welded.

Regarding the denture attachment having the above configuration, as shown in Tables 1 to 3 as Examples A to C of the present invention, the dimensions, magnetic properties, and materials of each part were selected in three ways and 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 ε without a handle 97 attached to the holding plate 93 was 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 (conventional examples E and F) with different structures and materials can be bonded with dental adhesive according to the dimensions, magnetic properties, and materials of each member shown in Tables 5 and 6. Na. In addition, conventional example E
The magnetic material of the denture attachment is as shown in Figure 7.
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. 8, 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.

Regarding the denture attachments of the present invention example, comparative example, and conventional example prepared as described above, corrosion resistance, abrasion resistance,
Measure the welding condition and suction force, and submit the measurement results to the seventh
Shown in the table.

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 for those that did not change color, those that showed O5 discoloration were indicated as ×.

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 500 g. Those with excellent abrasion resistance and no change were rated O, 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 welding condition was evaluated based on the position of the retaining plate after welding. Cases in which the holding plate did not shift and the welding was successful were marked with an ○, and cases in which the holding plate did not shift and the welding was not successful were marked with a ×. In addition, in Conventional Examples E and F, there is no part corresponding to the retaining plate in the present invention, and there is no need to consider the welding of the retaining plate to the base plate, so the welding state was not evaluated.

(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 welding condition, all of the invention examples A to C were successfully welded without any displacement of the retaining plate, but the comparative example was welded without attaching the handle, so the retaining plate was displaced and the welding was successful. Cast welding was not possible.

[Effects of the Invention] The present invention arranges a magnet body of 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, when the retainer plate is cast-welded to the root plate, a handle is attached to the retainer plate, and the magnetic cap, yoke, and spacer are The feature is that the boundary surface on the side of the root plate is joined by welding, and as there is no displacement of the holding plate, a stable attraction force between the root plate and the magnetic material is obtained, and furthermore, the attraction of each member of the magnetic material is The joint is melted so that the boundary completely disappears, resulting in complete waterproofing and protecting the magnet from corrosion. In addition, the joint has excellent corrosion resistance, sufficient strength, and excellent wear resistance.

[Brief explanation of the drawings] Fig. 1 is a sectional view of a mold when a retaining plate is cast-welded to a base plate according to an example of the present invention, and Fig. 2 (a), (b), and (c) show an example of how the handle is attached. 3 is a sectional view of the denture attachment to which the present invention is applied, FIG. 4 is an exploded perspective view of the magnetic material shown in FIG. 1, and FIGS. 5 and 6 show the saturation magnetic flux density and maximum energy. Diagram showing the relationship between product and attraction force, 7th
8 and 8 are cross-sectional views explaining the basic structure of conventional denture attachments, FIG. 9 is a sectional view of conventional denture attachments, and FIG.
FIG. 0 is a cross-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... Alveolus, 93... Root plate, 94... Denture base, 95... Denture part, 96...
Holding plate, 97...Handle, 8...Magnetic material of conventional denture attachment Fig. 9 Fig. 10 Fig. 1 %J3 Fig. 2 (a) (b) (c) Fig. 5 Saturation magnetic flux density ( G) Maximum energy product (MGOe)? A3 drawing, 4th drawing, 7112, 8th drawing, 96

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 a handle is attached to the retaining plate when the retaining plate is cast-welded to the root 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.