JPH0471551A - Denture attachment - Google Patents

Abstract

PURPOSE:To surely fix a holding plate at the preset position in a die, eliminate a drift between a metal cap and a holding plate, and secure them with an excellent suction force by providing a handle on the holding plate when the holding plate is cast to the metal cap. CONSTITUTION:The spacer 13 of a denture attachment 1 is made of a corrosion- proof nonmagnetic alloy and arranged at the center on the metal cap side of a magnetic substance 10, and a pair of yokes 11 made of a corrosion-proof soft magnetic alloy are erected toward the metal cap 93 on both sides to pinch the spacer 13. A magnet 12 is inserted between the yokes 11 and arranged on the spacer 13. A cap 14 is made of a corrosion-proof nonmagnetic alloy, the spacer 13, yokes 11, 11 and magnet 12 are combined into an integrated body, which is covered on the whole periphery except the lower face faced to the metal cap 93. When the holding plate 96 is to be stuck on the magnetic substance side of the metal cap 93 by casting, the holding plate 96 with a handle 97 is fixed at the preset position of a metal cap-shaped wax pattern, and the surrounding is fixed with a backup casting material to mold a die 98. The wax pattern is removed, then melted metal is filled through a pouring gate 99 to cast the metal cap 93, and the holding plate 97 is cast.

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. and a magnetic material embedded in the denture base, and relates to a denture attachment that has excellent adsorption force and corrosion resistance, and has little misalignment between the root plate and the retaining plate during casting.

[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. Therefore, this denture part 95 has a denture base 94 made of plastic or the like below, and the denture base 9.
1 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,
An 8-ring (samarium)-〇〇 (cobalt) rare earth magnet with 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. Low force compared to 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 covered with a case made of a non-magnetic alloy equivalent to stainless steel for rust prevention, as in the above 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.

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 II tooth 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. Unfortunately, poor flow of wax can leave gaps and make the seal incomplete, and corrosion progresses through these gaps. Furthermore, since the strength of the brazing filler metal is low, the joint 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. Can not.

On the other hand, without the cap, the entire attachment is made of gold,
There is a method of applying silver or nickel plating, but with this method, the plating tends to peel off and it is difficult to maintain the anticorrosion effect over 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 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 the denture attachment which is a magnetic material, the gist is that a handle is attached to the retainer plate when the retainer 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.

Thereby, the denture attachment can have a suction force of about 500 g or more. Such rare earth magnets include S-〇-based alloys such as SmCo5.5sCO+y, 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 a soft magnetic alloy that can be bent. In addition, Figures 5 and 6
The figure shows the relationship between saturation magnetic flux density, maximum energy product, and attractive force.

The size and shape of the handle to which the retaining plate is attached should be such that the retaining plate can be securely fixed in the casting.
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).
), the handle may be attached to the center or side of the upper surface of the retaining plate; however, this handle is removed after 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 should be Q, Q2 mm or more and not more than the height of the spacer. This is because if the penetration depth of welding the joint is less than 0.02+a+s, 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.
Spacer height is preferably 0.05+
If the spacer height exceeds 1.0 am, 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 The suction power is not sufficient.

In addition, in order to improve the corrosion resistance of the joint, the yoke has a weight ratio of C of 0.03% or less, Cr of 11 to 30%, MO
; Use a corrosion-resistant soft magnetic alloy of 4% or less, and use Ti or Ti alloy for the spacer and cap; C: 0.03°
Preferably, 7m magnetic stainless steel under GCI is used. Note that it is also possible to add Nb or T1 to the corrosion-resistant soft magnetic alloy as necessary.

[Function] The holding plate that is joined to the root plate of the denture attachment of the present invention has a handle attached to it when it is cast-welded to the root plate, so it can be securely fixed at a predetermined position in the mold, and the holding plate and the root plate can be securely fixed. There is no slippage of the plates, ensuring excellent suction power.

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.

In addition, the strength of the joint is higher than that of soldering, there is no damage due to mechanical stress, and there is no risk of joint wear.The joint has excellent durability and can be used for a very long time. Corrosion resistance is stable and there is no risk of 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. The magnet 12 is connected to 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 retaining plate 96 is bonded to the magnetic body side of the magnetic body by casting.

To weld the retaining plate 96 to the base plate 93, fix the retaining plate 96 with the handle 97 attached to the base plate shape in a predetermined position on the shidarou model, and use the surrounding area as a backup as shown in Fig. 1. The mold material is solidified to form a mold 98. 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 the present invention @A to C, three dimensions, magnetic properties, and materials of each part were selected 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 without a handle 97 attached to the holding plate 93 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 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
Show it 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 those with no discoloration and those with O1 discoloration were marked with an x.

Regarding abrasion resistance, the condition of the attachment side surface after rubbing the root plate and the magnetic material 1000 times with a load of 500 g was evaluated as follows, and those with excellent abrasion resistance and no change were rated O, For those with missing parts: ×
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. The cases in which the holding plate was not displaced and the welding was successful were marked with an x, and the cases in which the O5 holding plate was displaced and the welding was not successful were marked with an x. 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 casting welding of the retaining plate to the root plate, so the chain contact 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.

In the welding state, 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 the handle attached, so there was no displacement of the retaining plate. It was not possible to weld properly.

[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, 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 the welding process when a retaining plate is welded to the base plate according to an example of the present invention, and Fig. 2 (a), (b), and (e) are examples of how the handle is attached. FIG. 3 is a cross-sectional view of a 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 saturation magnetic flux density and maximum energy. 7 and 8 are cross-sectional views explaining the basic structure of a conventional denture attachment. FIG. 9 is a cross-sectional view of a conventional denture attachment.
The figure 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・alveolar, 93...root plate, 94
... denture base, 95... denture part, 96... retaining plate,
97...Handle, 8...Magnetic material of conventional denture attachment No. 9112 No. 10U2 Fig. 1 5J Fig. 2 (a) (b) (c) Fig. 5 Is 20 25 Saturation magnetic flux density (to G) Maximum energy product (MGOe) Fusuma 3 diagram? A4 drawing 712 8th drawing group 931

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.