JP7292736B2 - CLASP DESIGN METHOD, LOCAL DENTURE MAKING METHOD, AND GAUGE - Google Patents

Description

TECHNICAL FIELD The present invention relates to a clasp design method, a partial denture manufacturing method based on the clasp design method, and a gauge used in the clasp design method.

Surveyor is used as dental laboratory equipment for designing and fabricating partial dentures. In other words, by measuring, determining, and recording the maximum protuberance and undercut of the remaining teeth (abutment teeth) on the dental model taken from the patient, the clasp of the local denture can be determined and recorded. A design is performed (see, for example, Patent Literature 1).

JP-A-2003-159263

In conventional clasp design, it has been considered to place the hook point at a position recessed from the maximum protuberance by a predetermined undercut amount to generate a retaining force for the local denture. However, when the partial denture is attached or detached, if the force exerted by the hooked arm of the clasp is uneven in the direction orthogonal to the attachment/detachment direction, stress is applied to the remaining teeth (abutment teeth) in a direction different from the attachment/detachment direction. may occur. Remaining teeth (abutment teeth) for patients who require local dentures are valuable teeth that must maintain their functionality as abutments for wearing local dentures over a long period of time. There is a demand for a design of partial dentures that minimizes the generation of stress in directions different from the direction of attachment and detachment.

The present invention has been made in view of the above circumstances,
A method for designing a clasp that reduces the occurrence of stress in a direction different from the direction of attachment and detachment to an abutment tooth when attaching and detaching a partial denture, a method for fabricating a partial denture based on the clasp design method, and the clasp design method An exemplary problem is to provide a gauge for use in

In order to solve the above problems, the present invention has the following configurations.
(1) A first hooked arm running on one side of the abutment tooth and having a first hooked point, and a second hooked arm running on the other side of the abutment tooth and having a second hooked point. and a clasp design method for designing a clasp comprising
The first height position of the first hooked point in the attachment/detachment direction of the clasp is on the root side of the maximum protuberance on the one side of the abutment tooth, and the attachment/detachment is performed by a predetermined undercut amount. an undercut height determination step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction orthogonal to the direction;
As the first height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the first height position of the first hooked point is set on the other side of the abutment tooth an undercut height recording step for recording;
The second height position of the first hooked point in the attachment/detachment direction of the clasp is closer to the crown than the maximum protuberance on the one side of the abutment tooth, and is the undercut amount. an overbulge cut height determining step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction perpendicular to the attaching/detaching direction;
As the second height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the second height position of the first hooked point is set on the other side of the abutment tooth an overbulge cut height recording step for recording;
When the clasp is attached to the abutment tooth after being detached from the abutment tooth, a second height position of the first hook point and a second height of the second hook point and a clasp designing method for determining the position of the first hook and the position of the second hook such that the height positions are substantially the same height position.

(2) a first hooked arm running on one side of the abutment tooth and having a first hooked point and a second hooked arm running on the other side of said abutment tooth and having a second hooked point; and a method of making a partial denture comprising designing a clasp comprising:
The first height position of the first hooked point in the attachment/detachment direction of the clasp is on the root side of the maximum protuberance on the one side of the abutment tooth, and the attachment/detachment is performed by a predetermined undercut amount. an undercut height determination step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction orthogonal to the direction;
As the first height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the first height position of the first hooked point is set on the other side of the abutment tooth an undercut height recording step for recording;
The second height position of the first hooked point in the attachment/detachment direction of the clasp is closer to the crown than the maximum protuberance on the one side of the abutment tooth, and is the undercut amount. an overbulge cut height determining step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction perpendicular to the attaching/detaching direction;
As the second height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the second height position of the first hooked point is set on the other side of the abutment tooth an overbulge cut height recording step for recording;
When the clasp is attached to the abutment tooth after being detached from the abutment tooth, a second height position of the first hook point and a second height of the second hook point a hook point position determining step of determining the position of the first hook point and the position of the second hook point so that the height positions are substantially at the same height position.

(3) Used in the clasp design method of (1),
a rod-shaped portion extending from a tip portion, which is one end portion, to a rear end portion, and having a contact portion, which is a portion that contacts the abutment tooth, between the tip portion and the rear end portion;
an undercut height protrusion projecting in a direction orthogonal to the extension direction of the rod-shaped portion at the tip, and a direction orthogonal to the extension direction of the rod-shaped portion between the contact portion and the rear end of the rod-shaped portion and at least one of the overbulge cut height projections projecting into the gauge.

Further objects or other features of the present invention will be made clear by preferred embodiments described below with reference to the accompanying drawings.

According to the invention,
A method for designing a clasp that reduces the occurrence of stress in a direction different from the direction of attachment and detachment to an abutment tooth when attaching and detaching a partial denture, a method for fabricating a partial denture based on the clasp design method, and the clasp design method We can provide gauges used for

Schematic diagram showing how the clasp is worn Schematic diagram showing the movement of the hook tip when the clasp is attached Schematic diagram showing the procedure flow of the clasp design method according to the first embodiment Sectional view showing a design based on the clasp design method according to the second embodiment Sectional view showing a design based on the clasp design method according to Embodiment 3 Sectional view showing a design based on the clasp design method according to the fourth embodiment Schematic diagram showing an example of a gauge Schematic diagram showing a gauge according to Embodiment 7

[Embodiment 1]
A clasp design method according to Embodiment 1 is a method for designing a clasp including a first hooked arm running on one side of the abutment tooth and a second hooked arm running on the other side of the abutment tooth. be. The clasp design method includes an undercut height determination process, an undercut height recording process, an overbulge cut height determination process, an overbulge cut height recording process, and a hook position determination process. Hereinafter, the clasp design method according to the first embodiment will be described in order with reference to the drawings. First, the action of the clasp 10 manufactured based on the clasp design method according to the first embodiment will be described.

FIG. 1 is a schematic diagram showing how a clasp is worn. FIG. 1( a ) shows a state in which the clasp 10 of the local denture 1 is attached to the abutment tooth 2 and the first hooked arm 11 is running on one side of the abutment tooth 2 . Although not depicted in FIG. 1( a ), a second hooked arm 12 runs on the other side of the abutment tooth 2 on the other side. FIG. 1(b) shows a state in which the clasp 10 is attached to the abutment tooth 2 from a state in which the clasp 10 is detached from the abutment tooth 2. As shown in FIG.

In FIG. 1(b), the hooked point 11a of the first hooked arm 11 (first hooked point 11a) and the hooked point 12a of the second hooked arm 12 (second hooked point 12a) are attached to the abutment tooth 2. It shows the state of being in contact with At this time, it is preferable that the cusps 11 a and 12 a contact the abutment tooth 2 on the crown 21 side of the maximum protuberance 25 .

Here, the one side of the abutment tooth 2 can be, for example, the lingual side or buccal side of the abutment tooth 2, and the other side of the abutment tooth 2 is the opposite side of the lingual side. It can be buccal or lingual as opposed to buccal. One side of the abutment tooth 2 may be the lingual side or the buccal side, and can be appropriately determined according to the ease of putting on and taking off the partial denture 1, the wearing feeling, and the like.

The attachment/detachment direction D of the clasp 10 is a design concept of the partial denture, and can be appropriately determined from the viewpoints of reduction of stress generation to the abutment tooth 2, ease of attachment/detachment of the partial denture, and the like. The attachment/detachment direction D can be, for example, a direction parallel to the tooth axis of the abutment tooth 2 or a direction parallel to a straight line connecting the center of gravity of the crown 21 portion and the center of gravity of the root 23 portion.

FIG. 2 is a schematic diagram showing the movement of the hook when the clasp is attached. FIG. 2 shows a cross section in a plane passing through the first hooked point 11a and the second hooked point 12a, and the abutment tooth 2 is depicted in its cross section. In addition, the positions of the first hooked point 11a and the second hooked point 12a, except for the height position in the attachment/detachment direction D, are determined by a conventionally known design method so that the clasp 10 can exert the function of maintaining the local denture 1. can be determined as appropriate based on That is, the positions of the first hooked point 11a and the second hooked point 12a can be uniquely determined by determining the height positions in the attachment/detachment direction D determined by each step described later.

2(a) shows a state corresponding to FIG. 1(b), that is, a state where the first hooked point 11a and the second hooked point 12a are in contact with the abutment tooth 2. FIG. In FIG. 2(a), the first hooked point 11a is at the height of the overbulge cut height Ho, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by an undercut amount C. It is in contact with the abutment tooth 2 at the closed position. In FIG. 2(a), the second hooked point 12a is in contact with the abutment tooth 2 at the height position of the overbulge cut height Ho. At this time, it is preferable that the abutment tooth 2 is not biased by the clasp 10 , that is, the first hooked arm 11 and the second hooked arm 12 in a direction different from the attaching/detaching direction D of the clasp 10 . Here, the overbulge cut height Ho means that when the clasp 10 is attached to the abutment tooth 2 from a state detached from the abutment tooth 2, the first hook point 11a is attached to the abutment tooth 2. This is the height position (second height position) at which the momentum is started.

In FIG. 2(b), as the partial denture 1 is worn and the clasp 10 is pushed toward the tooth root 23 in the attachment/detachment direction D, the protruded portion of the abutment tooth 2 pushes the first hook arm 11. and a state in which the second hook arm 12 is pushed and spread in a direction substantially perpendicular to the attachment/detachment direction D. As shown in FIG. At this time, the abutment tooth 2 is biased in a direction substantially orthogonal to the attachment/detachment direction D by the first hooked arm 11 and the second hooked arm 12 . However, the urging forces of the first hooked arm 11 and the second hooked arm 12 are designed to cancel each other out as much as possible, and stress generation in the abutment tooth 2 in a direction different from the attachment/detachment direction D is reduced. . In particular, at the portion where the biasing by the first hooked arm 11 and/or the second hooked arm 12 starts, the biasing by the first hooked arm 11 and the biasing by the second hooked arm 12 By designing to cancel out each other as much as possible, the stress generated in the abutment tooth 2 can be effectively reduced, and the load on the abutment tooth 2 when the local denture 1 is attached or detached can be reduced.

In FIG.2(c), the state with which the local denture 1 was mounted|worn is shown. In FIG. 2(c), the first hooked point 11a is at the height of the undercut height Hu, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by the undercut amount C. It is in contact with the abutment tooth 2 in position. In FIG. 2(c), the second hooked point 12a is in contact with the abutment tooth 2 at the height position of the undercut height Hu. At this time, the first hooked point 11 a and the second hooked point 12 a are in contact with the abutment tooth 2 , but the abutment tooth 2 is attached by the first hooked arm 11 and the second hooked arm 12 . not encouraged. Here, the undercut height Hu is the height position (first height position) of the first hook point 11a when the clasp 10 is attached to the abutment tooth 2 .

Next, each step of the clasp design method according to Embodiment 1 will be described in order with reference to the drawings. FIG. 3 is a schematic diagram showing the procedure flow of the clasp design method according to the first embodiment. In FIG. 3, as in FIG. 2, a cross section along a plane passing through the first hooked point 11a and the second hooked point 12a is shown, and the section of the abutment tooth 2 is drawn. In FIG. 3, it is assumed that the undercut height Hu and the overbulge cut height Ho are measured and recorded using a surveyor (not shown) on a dental model taken from a patient. In FIG. 3, the gauges 5 and 6 are attached to the surveyor so that the extending directions of the bar-shaped portions 51 and 61 are parallel to the attachment/detachment direction D of the partial denture 1 . The details of the gauges 5 and 6 such as the bar-shaped portions 51 and 61 (see FIG. 7) will be described later.

<Undercut height determination step M1>
In the undercut height determination step M1, the undercut height Hu, which is the height position (first height position) of the first hooked point 11a when the clasp 10 is attached to the abutment tooth 2, is determined.

FIG. 3(a) shows a state in which the contact portion 53 of the gauge 5 is brought into contact with the maximum protuberance portion 25 of the abutment tooth 2. FIG. The gauge 5 has an undercut height projecting portion projecting in a direction perpendicular to the extending direction of the rod-shaped portion 51 at its tip portion 52 . The undercut height protruding portion includes the undercut height measuring portion 55 that protrudes by the undercut amount C, and the undercut height measuring portion 55 that protrudes in a direction different from that of the undercut height measuring portion 55 and in a direction perpendicular to the extension direction of the bar-shaped portion 51. and a recording unit 56 (see FIG. 7). Details of the gauge 5 will be described later. The gauge 5 can be moved parallel to the attachment/detachment direction D while being in contact with the maximum protuberance 25 of the abutment tooth 2 by the function of the surveyor.

FIG. 3(b) shows a state in which the undercut height measuring portion 55 of the gauge 5 is brought into contact with the abutment tooth 2 by moving the gauge 5 parallel to the attaching/detaching direction D from the state of FIG. 3(a). ing. Here, the undercut height measuring portion 55 of the gauge 5 protrudes by a predetermined undercut amount C in a direction perpendicular to the extending direction of the bar-shaped portion 51 of the gauge 5 . As a result, the width of the abutment tooth 2 in the direction perpendicular to the attachment/detachment direction D is narrowed by a predetermined undercut amount C on the root 23 side of the maximum protuberance portion 25 on one side of the abutment tooth 2. can be located. Let the height position of the said position be undercut height Hu.

<Undercut height recording process M2>
In the undercut height recording step M2, the height position of the undercut height Hu is recorded on the other side of the abutment tooth 2 as the height position of the second hooked point 12a.

FIG. 3(c) shows the height position of the undercut height measuring portion 55 of the gauge 5 while maintaining the extension direction of the bar-shaped portion 51 of the gauge 5 parallel to the attachment/detachment direction D from the state of FIG. 3(b). is maintained, the gauge 5 is moved to the other side of the abutment tooth 2. By bringing the undercut height recording portion 56 of the gauge 5 into contact with the abutment tooth 2 , the undercut height Hu can be recorded on the other side of the abutment tooth 2 .

The method of recording the undercut height Hu on the abutment tooth 2 is not particularly limited, but a method of contacting the abutment tooth 2 with a recording material such as ink adhered to the undercut height recording portion 56, Carbon paper or the like is sandwiched between the undercut height recording portion 56 and the abutment tooth 2, and the undercut height recording portion 56 is brought into contact with the abutment tooth 2 to adhere the carbon paper component to the abutment tooth 2. and the like.

<Over bulge cut height determination step M3>
In the overbulge cut height determination step M3, when the clasp 10 is attached to the abutment tooth 2 after being detached from the abutment tooth 2, the first hooked point 11a is biased against the abutment tooth 2. determines the overbulge cut height Ho, which is the height position (second height position) at which to start.

FIG. 3(d) shows a state in which the contact portion 63 of the gauge 6 is brought into contact with the maximum protuberance portion 25 of the abutment tooth 2. FIG. The gauge 6 has an over-bulge cut height projecting portion that projects in a direction perpendicular to the extending direction of the rod-shaped portion 61 between the contact portion 63 and the rear end portion 64 of the rod-shaped portion 61 . The over-bulge cut height protruding portion is a different direction from the over-bulge cut height measuring portion 67 that protrudes by the undercut amount C and the over-bulge cut height measuring portion 67, and protrudes in a direction orthogonal to the extension direction of the rod-shaped portion 61. and an overbulge cut height recording section 68 (see FIG. 7). Details of the gauge 6 will be described later. The gauge 6 can be moved parallel to the attachment/detachment direction D while being in contact with the maximum protuberance 25 of the abutment tooth 2 by the function of the surveyor.

FIG. 3(e) shows a state in which the overbulge cut height measuring portion 67 of the gauge 6 is in contact with the abutment tooth 2 by moving the gauge 6 parallel to the attachment/detachment direction D from the state of FIG. 3(d). showing. Here, the overbulge cut height measuring portion 67 of the gauge 6 protrudes by a predetermined undercut amount C in a direction perpendicular to the extending direction of the bar-shaped portion 61 of the gauge 6 . As a result, the width of the abutment tooth 2 in the direction perpendicular to the attachment/detachment direction D is narrowed by a predetermined undercut amount C, which is closer to the crown 21 than the maximum protuberance 25 on one side of the abutment tooth 2 . position can be specified. Let the height position of the said position be over bulge cut height Ho.

<Over bulge cut height recording step M4>
In the overbulge cut height recording step M4, the height position of the overbulge cut height Ho is recorded on the other side of the abutment tooth 2 as the height position of the second hooked point 12a.

FIG. 3(f) shows the height of the overbulge cut height measuring portion 67 of the gauge 6 while maintaining the extension direction of the rod-shaped portion 61 of the gauge 6 parallel to the attachment/detachment direction D from the state of FIG. 3(e). It shows a state in which the gauge 6 is moved to the other side of the abutment tooth 2 while maintaining its position. By bringing an over-bulge cut height recording portion 68 of the gauge 6 projecting in a direction different from the over-bulge cut height measuring portion 67 and in a direction orthogonal to the extending direction of the rod-shaped portion 61 to the abutment tooth 2, The overbulge cut height Ho can be recorded on the other side of the abutment tooth 2 .

The method for recording the overbulge cut height Ho on the abutment tooth 2 is not particularly limited, but the same method as the method for recording the undercut height Hu on the abutment tooth 2 can be used.

<Cut Point Position Determining Step M5>
In the hook point position determination step M5, when the clasp 10 is attached to the abutment tooth 2 from the state in which the clasp 10 is detached from the abutment tooth 2, the second height position of the first hook point 11a and the second height position of the clasp 10 are adjusted. The position of the first hooked point 11a and the position of the second hooked point 12a are determined so that the second height position of the hooked point 12a of No. 2 is substantially the same height position as the overbulge cut height Ho. . In the hooked point position determination step M5, the first height position of the first hooked point 11a and the first height of the second hooked point 12a are determined when the clasp 10 is attached to the abutment tooth 2. The positions of the first hooked point 11a and the second hooked point 12a can also be determined so that the positions are substantially at the same height as the undercut height Hu.

By determining the positions of the first hooked point 11a and the second hooked point 12a in the hooked point position determination step M5, the state where the clasp 10 is attached (the state shown in FIG. 1(a)) and the clasp 10 as the abutment When attached to the abutment tooth 2 from a state detached from the tooth 2, the first hooked point 11a is about to start biasing against the abutment tooth 2 (state in FIG. 1(b)). In both states, the height positions of the first hooked point 11a and the second hooked point 12a can be substantially the same as the undercut height Hu and the overbulge cut height Ho, respectively. As a result, it is possible to reduce stress generated in the abutment tooth 2 in a direction different from the detachment direction D when attaching the local denture 1 while maintaining the retaining function of the clasp 10 .

[Embodiment 2]
The clasp designing method according to the second embodiment includes, in addition to each step of the clasp designing method according to the first embodiment, deletion for forming a plane parallel to the attachment/detachment direction D by removing the protruding portion 26 of the abutment tooth 2. A partial determination step M6 is further included. Hereinafter, in the description of the clasp designing method according to the second embodiment, the description of the configurations common to the clasp designing method according to the first embodiment will be omitted, and the same reference numerals will be used.

<Deleted Portion Determining Step M6 (Embodiment 2)>
In the deletion portion determination step M6 in the second embodiment, the portion of the protruding portion 26 that protrudes to the other side of the abutment tooth 2 from the position of the second hooked point 12a recorded in the undercut height recording step M2 is selected. Determine the part to be deleted.

FIG. 4 is a cross-sectional view showing a design based on the clasp design method according to the second embodiment. In FIG. 4, the portions determined to be deleted in the deletion portion determining step M6 are indicated by dashed lines. In FIG. 4, of the protruding portion 26, the portion that protrudes to the other side of the abutment tooth 2 from the position of the undercut height Hu recorded in the undercut height recording step M2 is shown as a portion to be removed.

FIG. 4(a) shows a state in which the first hooked point 11a and the second hooked point 12a are in contact with the abutment tooth 2. FIG. In FIG. 4(a), the first hooked point 11a is at the height of the overbulge cut height Ho, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by an undercut amount C. It is in contact with the abutment tooth 2 at the closed position. In FIG. 4(a), the second hooked point 12a is in contact with the abutment tooth 2 at the height position of the overbulge cut height Ho. At this time, the abutment tooth 2 is not biased by the clasp 10 , that is, the first hooked arm 11 and the second hooked arm 12 in a direction different from the attaching/detaching direction D of the clasp 10 . This is achieved by removing the protuberant portion 26 projecting to the other side of the abutment tooth 2 from the position of the second hooked point 12a at the height position of the undercut height Hu. This is because the second hooked arm 12 can be in a state where it does not bias the abutment tooth 2 also in the position.

In FIG.4(b), the state with which the local denture 1 was mounted|worn is shown. In FIG. 4(b), the first hooked point 11a is at the height of the undercut height Hu, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by the undercut amount C. It is in contact with the abutment tooth 2 in position. In FIG. 4(b), the second hooked point 12a is in contact with the abutment tooth 2 at the height position of the undercut height Hu. At this time, the first hooked point 11 a and the second hooked point 12 a are in contact with the abutment tooth 2 , but the abutment tooth 2 is attached by the first hooked arm 11 and the second hooked arm 12 . not encouraged.

[Embodiment 3]
The clasp designing method according to the third embodiment includes, in addition to each step of the clasp designing method according to the first embodiment, deletion for forming a plane parallel to the attachment/detachment direction D by removing the protruding portion 26 of the abutment tooth 2. A part determination step M7 is further included. In the clasp design method according to the third embodiment, the second hook arm is designed as a plate 13 formed parallel to the extending direction of the plane formed by the removed portion determination step M7 (see FIG. 5). The plate 13 is formed so as to be in contact with the abutment tooth 2 together with the first hooked point 11a at least at the height position of the overbulge cut height Ho. Hereinafter, in the description of the clasp designing method according to the third embodiment, the description of the configurations common to the clasp designing method according to the first embodiment will be omitted, and the same reference numerals will be used.

<Deleted Portion Determining Step M7 (Embodiment 3)>
In the deletion portion determination step M7 in the third embodiment, the portion of the protruding portion 26 that protrudes to the other side of the abutment tooth 2 from the position of the second hooked point 12a recorded in the overbulge cut height recording step M4. is determined as the part to be deleted.

FIG. 5 is a cross-sectional view showing a design based on the clasp design method according to Embodiment 3. FIG. In FIG. 5, the portions determined to be deleted in the deletion portion determining step M7 are indicated by dashed lines. In FIG. 5, of the protruding portion 26, the portion that protrudes to the other side of the abutment tooth 2 from the position of the over-bulge cut height Ho recorded in the over-bulge cut height recording step M4 is shown as a portion to be removed. there is

FIG. 5( a ) shows a state in which the first hooked point 11 a and the plate 13 as the second hooked arm are in contact with the abutment tooth 2 . In FIG. 5(a), the first hook tip 11a is at the height of the overbulge cut height Ho, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by an undercut amount C. It is in contact with the abutment tooth 2 at the closed position. In FIG. 5(a), the plate 13 is in contact with the abutment tooth 2 in the plane formed by the cutout determination step M7. At this time, the abutment tooth 2 is not biased by the clasp 10 , that is, the first hooked arm 11 and the plate 13 in a direction different from the attachment/detachment direction D of the clasp 10 .

In FIG.5(b), the state with which the local denture 1 was mounted|worn is shown. In FIG. 5(b), the first hooked point 11a is at the height of the undercut height Hu, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by the undercut amount C. It is in contact with the abutment tooth 2 in position. In FIG. 5(b), the plate 13 is in contact with the abutment tooth 2 in the plane formed by the cutout determination step M7. At this time, the first hooked point 11 a and the plate 13 are in contact with the abutment tooth 2 , but the abutment tooth 2 is not biased by the first hooked arm 11 and the plate 13 .

[Embodiment 4]
The clasp design method according to the fourth embodiment includes, in addition to each step of the clasp design method according to the first embodiment, deletion for forming a plane parallel to the attaching/detaching direction D by removing the protruding portion 26 of the abutment tooth 2. A partial determination step M8 is further included. In the clasp design method according to the fourth embodiment, the second hooked arm is designed as the plate 14 formed parallel to the extending direction of the plane formed by the removed portion determination step M8. The plate 14 is formed to contact the abutment tooth 2 together with the first hooked point 11a at both height positions of the overbulge cut height Ho and the height position of the undercut height Hu. Hereinafter, in the description of the clasp design method according to the fourth embodiment, the description of the configurations common to the clasp design method according to the first embodiment will be omitted, and the same reference numerals will be used.

<Deleted Portion Determination Step M8 (Embodiment 4)>
In the deletion portion determination step M8 in the fourth embodiment, the position of the abutment tooth 2 is higher than the position of the second hook tip 12a recorded in the undercut height recording step M2 and the overbulge cut height recording step M4. In addition to the portion projecting to the other side of the abutment tooth 2, the portion extending from the other side of the abutment tooth 2 to one side by a predetermined length is determined as the portion to be deleted. Further, a rest 27 substantially orthogonal to the attachment/detachment direction D may be provided on the tooth root 23 side of the portion to be removed.

FIG. 6 is a cross-sectional view showing a design based on the clasp design method according to the fourth embodiment. In FIG. 6, the portions determined to be deleted in the deletion portion determining step M8 are indicated by dashed lines. In FIG. 6, of the protruding portion 26, the portion protruding to the other side of the abutment tooth 2 from the position of the second hook point 12a recorded in the undercut height recording process M2 and the overbulge cut height recording process M4. In addition, a portion extending from the other side of the abutment tooth 2 to one side by a predetermined length is shown as a removed portion.

FIG. 6( a ) shows a state in which the first hooked point 11 a and the plate 14 as the second hooked arm are in contact with the abutment tooth 2 . In FIG. 6(a), the first hooked point 11a is at the height of the overbulge cut height Ho, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by an undercut amount C. It is in contact with the abutment tooth 2 at the closed position. In FIG. 6(a), the plate 14 is in contact with the abutment tooth 2 in the plane formed by the cutout determination step M8. At this time, the abutment tooth 2 is not biased by the clasp 10 , that is, the first hooked arm 11 and the plate 14 in a direction different from the attachment/detachment direction D of the clasp 10 .

In FIG.6(b), the state with which the local denture 1 was mounted|worn is shown. In FIG. 6(b), the first hooked point 11a is at the height of the undercut height Hu, and the abutment tooth 2 is thinner than the maximum protuberant portion 25 of the abutment tooth 2 by the undercut amount C. It is in contact with the abutment tooth 2 in position. In FIG. 6(b), the plate 14 is in contact with the abutment tooth 2 in the plane formed by the cutout determination step M8. At this time, the first hooked point 11 a and the plate 14 are in contact with the abutment tooth 2 , but the abutment tooth 2 is not biased by the first hooked arm 11 and the plate 14 .

[Embodiment 5]
A partial denture manufacturing method according to the fifth embodiment includes each step of the clasp design method according to the first embodiment. That is, the partial denture manufacturing method according to Embodiment 5 includes the undercut height determination step M1, the undercut height recording step M2, the overbulge cut height determination step M3, the overbulge cut height recording step M4, and the hook tip of Embodiment 1. This method includes each step of the positioning step M5 and fabricates the partial denture 1 based on the clasp design method including each of these steps.

[Embodiment 6]
A gauge according to the sixth embodiment is a gauge used in the clasp design method according to the first embodiment. A gauge according to the sixth embodiment will be described below with reference to the drawings. In the description of the gauge according to the sixth embodiment, the description of the parts common to the clasp design method according to the first embodiment will be omitted, and the same reference numerals will be used.

FIG. 7 is a schematic diagram showing an example of a gauge. 7(a) shows an example of the gauge 5, and FIG. 7(b) shows an example of the gauge 6. As shown in FIG. The gauge 5 is a bar-shaped portion extending from a tip portion 52, which is one end, to a rear end portion 54, and having a contact portion 53, which is a portion that contacts the abutment tooth 2, between the tip portion 52 and the rear end portion 54. 51 , and an undercut height protrusion that protrudes in a direction orthogonal to the extension direction of the bar-shaped portion 51 at the tip portion 52 . The undercut height protruding portion is an undercut height measuring portion 55 that protrudes by an undercut amount C, and a direction different from that of the undercut height measuring portion 55, and the undercut height measurement is performed in a direction orthogonal to the extending direction of the bar-shaped portion 51. It has an undercut height recording portion 56 projecting larger than the portion 55 . In FIG. 7, the bar-shaped portion 51 is partially omitted in its extension direction, and actually is longer in the extension direction than the illustrated shape. The omitted portion is indicated by a wavy line in FIG. It should be noted that the display of the omitted portion is the same in the illustration of each gauge.

The gauge 6 is a rod-shaped portion that extends from a tip portion 62 as one end to a rear end portion 64 and has a contact portion 63 that is a portion that contacts the abutment tooth 2 between the tip portion 62 and the rear end portion 64. 61 , and an over-bulge cut height projecting portion that projects in a direction perpendicular to the extending direction of the rod-shaped portion 61 between the contact portion 63 and the rear end portion 64 of the rod-shaped portion 61 . The over-bulge-cut height protruding portion is in a different direction from the over-bulge-cut height measuring portion 67 that protrudes by the undercut amount C, and the over-bulge-cut height measuring portion 67. It has an over bulge cut height recording portion 68 that protrudes more than the bulge cut height measuring portion 67 .

The undercut height measuring portion 55 and the overbulge cut height measuring portion 67 protrude from the rod-shaped portions 51 and 61 by the undercut amount C, and are thinner than the maximum protuberant portion 25 by the undercut amount C in the abutment tooth 2. position can be measured. The undercut height recording portion 56 and the overbulge cut height recording portion 68 protrude more than the undercut height measuring portion 55 and the overbulge cut height measuring portion 67, respectively. Undercut height Hu or overbulge cut height Ho can sometimes be recorded even when the bulging portion on the other side protrudes more than the other side. Here, the undercut amount C is not particularly limited as long as it is constant in the undercut height measurement unit 55 and the overbulge cut height measurement unit 67, but is, for example, 0.25 mm (0.010 inch), 0.50 mm (0 .020 inches).

The distance from the tip portion 62 of the over-bulge-cut height measuring portion 67 and the over-bulge-cut height recording portion 68 is not particularly limited, but is longer than the length from the maximum protuberant portion 25 of the general abutment tooth 2 to the crown 21. Long is preferred. Moreover, as shown in FIG. 7(c), an over-bulge-cut height measuring unit 77 and an over-bulge-cut height recording unit 78 have a gauge 7 whose distance from the tip 72 is longer than that of the gauge 6. A plurality of gauges with different distances to the bulge cut height protrusion may be used. Further, the gauge may be a gauge in which the distance from the tip portion to the overbulge cut height projection portion is variable.

A gauge according to the sixth embodiment may have both an undercut height protrusion and an overbulge cut height protrusion like a gauge 8 shown in FIG. 7(d). In the gauge 8, ellipsoidal protrusions whose centers are eccentric with respect to the central axis in the extending direction of the bar-shaped portion 81 are formed as the undercut height protrusion and the overbulge cut height protrusion. In the gauge 8, the portion protruding most from the rod-shaped portion 81 is the undercut height recording portion 86 or the overbulge cut height recording portion 88, and the portion on the opposite side of the recording portion sandwiching the rod-shaped portion 81 is the undercut amount. These are the measuring portions (the undercut height measuring portion 85 and the overbulge cut height measuring portion 87) projecting by C. FIG. In the gauge 8, the undercut height recording portion 86 and the overbulge cut height recording portion 88 protrude in different directions.

As a gauge according to the sixth embodiment, like a gauge 9 shown in FIG. It may have a plurality of measuring parts protruding into. The gauge 9 is formed with four different measuring portions (an undercut height measuring portion 95 and an overbulge cut height measuring portion 97).

[Embodiment 7]
The gauge according to the seventh embodiment is, like the gauge according to the sixth embodiment, a gauge used in the clasp design method according to the first embodiment. A gauge according to the seventh embodiment will be described below with reference to the drawings. In the description of the gauge according to the seventh embodiment, the description of the parts common to the clasp design method according to the first embodiment and the gauge according to the sixth embodiment will be omitted, and the common reference numerals will be used.

FIG. 8 is a schematic diagram showing a gauge according to Embodiment 7. FIG. 8A and 8B are views of the gauge 15 according to Embodiment 7 as seen from the front and from the right side, respectively. 8(c) and 8(d) are views of the gauge 16 according to Embodiment 7 as seen from the front and the right side, respectively. As shown in FIG. 8(a), the gauge 15 has a bar-shaped undercut height measuring portion 155 having a screw thread with a predetermined pitch. Further, as shown in FIG. 8C, the gauge 16 has a bar-shaped overbulge cut height measuring portion 167 having a screw thread with a predetermined pitch. 8(a) and 8(c), the undercut height measuring portion 155 and the overbulge cut height measuring portion 167 are shown by dashed lines as they pass through the bar portions 151 and 161, respectively.

In the gauges 15 and 16, through-holes having grooves of a predetermined pitch are formed in the bar-shaped portions 151 and 161 in accordance with the threads of a predetermined pitch of the undercut height measuring portion 155 and the overbulge cut height measuring portion 167, respectively. The undercut height measuring portion 155 and the overbulge cut height measuring portion 167 are inserted into the through holes. With this configuration, by rotating the undercut height measurement unit 155 or the over bulge cut height measurement unit 167, the undercut height measurement unit 155 or the over bulge cut height measurement unit 167 can be moved in the respective extension directions. .

The undercut height measuring unit 155 and the overbulge cut height measuring unit 167 rotate the undercut amount adjusters 156 and 166 connected thereto in the directions of the arrows (rotational directions) shown in FIGS. 8(b) and 8(d). ), it can be moved in each extension direction. For example, when the undercut amount adjuster 156 of the gauge 15 is rotated clockwise in the rotational direction in FIG. Rotate clockwise. This rotation causes the undercut height measuring section 155 to move leftward in the extension direction of the undercut height measuring section 155 (the direction of the arrow shown in FIG. 8A) relative to the bar-shaped portion 151 . That is, by adjusting the amount of rotation of the undercut amount adjuster 156 in the rotation direction, the amount of movement of the undercut height measuring section 155 in the extension direction can be adjusted. This configuration is the same for the overbulge cut height measuring portion 167 of the gauge 16 as well.

Although the gauges 15 and 16 do not have an undercut height recording section and an overbulge cut height recording section, the undercut height measuring section 155 and the overbulge cut height measuring section 167 can perform their functions. That is, the undercut height measuring unit 155 and the over bulge cut height measuring unit 167 measure the undercut amount C, and then indicate the height position using the undercut height measuring unit 155 or the over bulge cut height measuring unit 167. , can be recorded. When the height position of the abutment tooth 2 cannot be recorded due to the small amount of protrusion of the undercut height measuring unit 155 or the overbulge cut height measuring unit 167, the undercut amount adjusters 156 and 166 adjust the protrusion amount. You should adjust the amount.

In the gauges 15 and 16, the contact portions 153 and 163 are formed as plate-like portions projecting from the rod-like portions 151 and 161, respectively. Here, the contact portions 153 and 163 are located on the side opposite to the undercut amount adjusters 156 and 166 with respect to the bar portions 151 and 161 along the extension direction of the undercut height measuring portion 155 or the overbulge cut height measuring portion 167. protrudes to That is, when the gauges 15 and 16 are used, the contact portions 153 and 163 projecting from the rod-shaped portions 151 and 161 come into contact with the abutment tooth 2 .

The undercut height measurement unit 155 and the over bulge cut height measurement unit 167 adjust the amount of movement in the extension direction, respectively, so that the undercut height measurement unit 155 and the over bulge cut height measurement unit 155 and the over bulge cut height measurement unit 155 and the over bulge cut height measurement unit 155 with respect to the contact portions 153 and 163, respectively. It is possible to adjust how much the tip of 167 protrudes. That is, the amount of undercut C can be measured by the amount by which the undercut height measuring portion 155 protrudes from the contact portion 153 in the extension direction of the undercut height measuring portion 155 . Further, the amount of undercut C can be measured by the amount of protrusion of the over-bulge-cut height measuring portion 167 from the contact portion 163 in the extension direction of the over-bulge-cut height measuring portion 167 .

The undercut amount adjusters 156 and 166 need only be fixedly connected to the undercut height measuring section 155 and overbulge cut height measuring section 167, respectively, at least in the rotational direction, and the shape thereof is not particularly limited. For example, as shown in FIG. 8, the undercut amount adjusters 156, 166 can be disc-shaped. Further, as shown in FIGS. 8(b) and 8(d), the disk surfaces of the undercut amount adjusters 156 and 166 are graduated, and the undercut height measuring section 155 and the overbulge cut height measuring section 167 are marked. It is possible to easily grasp the amount of protrusion of.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these, and various modifications and changes are possible within the scope of the gist thereof. For example, the present invention includes the following gists.

(Purpose 1) The clasp design method includes a first hooked arm that runs on one side of the abutment tooth and has a first hooked point, and a first hooked arm that runs on the other side of the abutment tooth and has a second hooked point. and a clasp designing method for designing a clasp comprising a second hooked arm having a first height position of the first hooked point in the attaching/detaching direction of the clasp, the one side of the abutment tooth The undercut height determination step of determining the height position of the position where the width of the abutment tooth in the direction orthogonal to the attachment/detachment direction is narrower by a predetermined undercut amount than the maximum protuberance portion in and, as the first height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the first height position of the first hooked point is set to the other side of the abutment tooth and an undercut height recording step of recording the second height position of the first hooked tip in the attachment/detachment direction of the clasp on the crown side of the maximum protuberance on the one side of the abutment tooth. and an overbulge cut height determination step of determining the height position of the position where the width of the abutment tooth in the direction perpendicular to the attachment/detachment direction is narrowed by the undercut amount; An overbulge cut height that records the same height position as the second height position of the first hook tip on the other side of the abutment tooth as the second height position of the second hook tip. a second height position of the first hook point and a second height position of the second hook point when the clasp is attached to the abutment tooth from a state in which the clasp is detached from the abutment tooth; and a hook point position determining step of determining the position of the first hook point and the position of the second hook point such that the second height position is substantially the same height position. and

According to this, when the partial denture is attached and detached, a method for designing a clasp that reduces the generation of stress in a direction different from the direction of attachment and detachment to the abutment tooth, a method for manufacturing a partial denture based on the clasp design method, And the gauge used in the clasp design method can be provided.

(Purpose 2) In the clasp design method, the undercut height recording step or the overbulge Even if it further includes a deletion portion determination step of determining a portion that protrudes to the other side of the abutment tooth from the position of the second hooked point recorded in the cut height recording step as a portion to be deleted. good.

(Purpose 3) A partial denture manufacturing method includes a first hooked arm that runs on one side of an abutment tooth and has a first hooked point, and a second hook that runs on the other side of the abutment tooth. A method of making a partial denture comprising designing a clasp comprising: a second hooked arm having a point;
The first height position of the first hooked point in the attachment/detachment direction of the clasp is on the root side of the maximum protuberance on the one side of the abutment tooth, and the attachment/detachment is performed by a predetermined undercut amount. an undercut height determination step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction orthogonal to the direction;
As the first height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the first height position of the first hooked point is set on the other side of the abutment tooth an undercut height recording step for recording;
The second height position of the first hooked point in the attachment/detachment direction of the clasp is closer to the crown than the maximum protuberance on the one side of the abutment tooth, and is the undercut amount. an overbulge cut height determining step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction perpendicular to the attaching/detaching direction;
As the second height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the second height position of the first hooked point is set on the other side of the abutment tooth an overbulge cut height recording step for recording;
When the clasp is attached to the abutment tooth after being detached from the abutment tooth, a second height position of the first hook point and a second height of the second hook point and a hook point position determining step of determining the position of the first hook point and the position of the second hook point so that the height positions are substantially at the same height position.

(Purpose 4) The gauge is used in the clasp design method, extends from the tip, which is one end, to the rear end, and is in contact with the abutment tooth between the tip and the rear end. a rod-shaped portion having a certain contact portion; an undercut height projection projecting in a direction perpendicular to the extending direction of the rod-shaped portion at the tip portion; It is intended to have at least one of the overbulge cut height protrusions that protrude in a direction orthogonal to the extending direction of the rod-like portion.

(Purpose 5) The gauge has an undercut height measuring portion that protrudes by the undercut amount, and a direction different from the undercut height measuring portion and perpendicular to the extension direction of the rod-shaped portion. an undercut height recording portion that protrudes larger than the undercut height measurement portion in a direction to the direction of the over bulge cut height measurement portion, and the over bulge cut height protrusion portion is an over bulge cut height measurement portion that protrudes by the undercut amount; It may have an over-bulge-cut height recording section projecting larger than the over-bulge-cut height measuring section in a direction different from that of the bulge-cut height measuring section and perpendicular to the extending direction of the rod-shaped section.

(Purpose 6) In the gauge, the undercut height measuring part and/or the overbulge cut height measuring part has a plurality of measuring parts with different undercut amounts and protruding in different directions. may

(Purpose 7) When the gauge has both the undercut height protrusion and the overbulge cut height protrusion,
The undercut height recording portion and the overbulge cut height recording portion may protrude in different directions.

1: partial denture 10: clasp 11: first hooked arm 11a: first hooked point 12: second hooked arm 12a: second hooked point 13, 14: plate 2: abutment tooth 21: crown 23: tooth root 25: maximally protruding portion 26: protruding portion 27: rests 5, 6, 7, 8, 9, 15, 16: gauges 51, 61, 71, 81, 91, 151, 161: bar-shaped portions 52, 62, 72, 82, 92, 152, 162: tip portions 53, 63, 73, 83, 93, 153, 163: contact portions 54, 64, 74, 84, 94, 154, 164: rear end portions 55, 85, 95 , 155: undercut height measuring units 56, 86, 96: undercut height recording units 67, 77, 87, 97, 167: over bulge cut height measuring units 68, 78, 88, 98: over bulge cut height recording unit 156 , 166: Undercut amount adjuster C: Undercut amount D: Attachment/detachment direction Hu: Undercut height Ho: Over bulge cut height

Claims (6)

A first hooked arm running on one side of the abutment tooth and having a first hooked point, and a second hooked arm running on the other side of the abutment tooth and having a second hooked point. A clasp design method for designing a clasp comprising
The first height position of the first hooked point in the attachment/detachment direction of the clasp is on the root side of the maximum protuberance on the one side of the abutment tooth, and the attachment/detachment is performed by a predetermined undercut amount. an undercut height determination step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction orthogonal to the direction;
As the first height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the first height position of the first hooked point is set on the other side of the abutment tooth. an undercut height recording step of recording in
The second height position of the first hooked point in the attachment/detachment direction of the clasp is closer to the crown than the maximum protuberance on the one side of the abutment tooth, and is the undercut amount. an overbulge cut height determining step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction perpendicular to the attaching/detaching direction;
As the second height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the second height position of the first hooked point is set on the other side of the abutment tooth. an overbulge cut height recording step of recording in
When the clasp is attached to the abutment tooth after being detached from the abutment tooth, a second height position of the first hook point and a second height of the second hook point and a clasp designing method for determining the position of the first hook and the position of the second hook such that the height positions are substantially the same height position. In order to remove the bulged portion of the abutment tooth and form a plane parallel to the attachment/detachment direction, the bulged portion recorded in the undercut height recording step or the overbulge cut height recording step 2. The method of designing a clasp according to claim 1, further comprising a deletion portion determining step of determining, as a portion to be deleted, a portion that protrudes to the other side of the abutment tooth beyond the position of the second hooked point. A first hooked arm running on one side of the abutment tooth and having a first hooked point, and a second hooked arm running on the other side of the abutment tooth and having a second hooked point. A method of making a partial denture comprising designing a clasp comprising:
The first height position of the first hooked point in the attachment/detachment direction of the clasp is on the root side of the maximum protuberance on the one side of the abutment tooth, and the attachment/detachment is performed by a predetermined undercut amount. an undercut height determination step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction orthogonal to the direction;
As the first height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the first height position of the first hooked point is set on the other side of the abutment tooth. an undercut height recording step of recording in
The second height position of the first hooked point in the attachment/detachment direction of the clasp is closer to the crown than the maximum protuberance on the one side of the abutment tooth, and is the undercut amount. an overbulge cut height determining step of determining a height position of a position where the width of the abutment tooth is narrowed in a direction perpendicular to the attaching/detaching direction;
As the second height position of the second hooked point in the attachment/detachment direction of the clasp, the same height position as the second height position of the first hooked point is set on the other side of the abutment tooth. an overbulge cut height recording step of recording in
When the clasp is attached to the abutment tooth from a state detached from the abutment tooth, a second height position of the first hook point and a second height position of the second hook point a hook point position determining step of determining the position of the first hook point and the position of the second hook point so that the height positions are substantially at the same height position. Used in the clasp design method according to claim 1 or claim 2,
a rod-shaped portion extending from a tip portion, which is one end portion, to a rear end portion, and having a contact portion, which is a portion that contacts the abutment tooth, between the tip portion and the rear end portion;
an undercut height protrusion projecting in a direction orthogonal to the extension direction of the rod-shaped portion at the tip, and a direction orthogonal to the extension direction of the rod-shaped portion between the contact portion and the rear end of the rod-shaped portion and at least one of the overbulge cut height projections projecting into
The undercut height protruding portion includes an undercut height measuring portion protruding by the undercut amount, and a direction different from that of the undercut height measuring portion, and the undercut height protruding portion extends in a direction perpendicular to the extending direction of the bar-shaped portion. Having an undercut height recording part that protrudes larger than the measuring part,
The over-bulge-cut height protruding part is an over-bulge-cut height measuring part that protrudes by the undercut amount, and is in a different direction from the over-bulge-cut height measuring part, and is in a direction orthogonal to the extending direction of the rod-shaped part. A gauge having an over-bulge cut height recording part projecting larger than an over-bulge cut height measuring part . 5. The gage according to claim 4 , wherein the undercut height measuring portion and/or the overbulge cut height measuring portion has a plurality of measuring portions with different undercut amounts and protruding in different directions. when the gauge has both the undercut height projection and the overbulge cut height projection,
6. A gauge according to claim 4 or 5, wherein the undercut height recording portion and the overbulge cut height recording portion project in different directions.

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