JP5457657B2 - Partial denture - Google Patents

Description

  The present invention is a partial denture that has been improved with respect to a partial denture having a clasp that is fitted so as to be applied to a tooth, and has a high durability and a high degree of stable mounting. It is about.

  The partial denture is an artificial tooth that replaces the missing tooth, a denture base that fixes the artificial tooth and adheres closely to the ridge, and is fixed to the denture base, and is freely detachably fitted to the remaining tooth (tooth decay). It consists of a clasp and a rest formed integrally with the clasp. The partial denture must have three actions: (A1) support action that resists occlusal pressure, (A2) maintenance action that resists withdrawal force, and (A3) grip action that resists horizontal force applied to the denture. is there.

  The problems of the traditional partial denture are listed in order. As shown in FIGS. 25 (a) and 25 (b), the conventional clasp has a three-dimensional constraining arm 109 located on the front side of the fixing portion 108 fixed to the artificial tooth side, on the artificial tooth side (left side in the figure). It extends from the upper part to the obliquely lower part and grips the toothed teeth 103 to restrain them. FIG. 25A is a front view when the state in which the clasp is attached is viewed from the cheek side (front side), and FIG. 25B is a top view.

  The three-dimensional constraining arm 109 is configured to three-dimensionally grip the toothed teeth 103 from the side and the upper part so that a contact portion with the toothed teeth 103 becomes large, and thus places a heavy burden on the toothed teeth 103. In FIG. 25 (a), the rest 110 protrudes upward from the previous base point 111 of the fixing portion 108, and holds down the crown top of the tooth decay from above, and the tooth bump ridge (overhanging portion) obliquely downward from the base point 111. The three-dimensional constraining arm 109 that passes through the undercut portion or the tooth neck portion constrains the toothed teeth 103. This constraint can be compared to a three-dimensional casket. That is, in the conventional partial denture, the tooth 103 is constrained by the three-dimensional restraining arm 109 which goes around the tooth diagonally from the top side of the tooth and reaches the root while being pressed from above by the rest 110. Regardless of the material of the clasp, it is the same whether it is made of cast metal or metal wire, in that a heavy burden is placed on the tooth decay.

  In the case where the rest 110 is provided, it is necessary to provide a groove-like rest pit for storing the rest on the top of the toothed teeth 103 by tooth removal. If this tooth is removed, cold water pain and pulpitis may be induced. In addition, when there is a problem in fitting the rest 110 to the rest fossa, the denture base does not sufficiently contact the ridge mucosa (the part after the restored missing tooth) and has a gap. The gap between the ridge mucosa and the bottom of the denture base is difficult to recognize clearly. Even if there is a gap, the denture appears to be stably fixed, and the mounting is continued as it is. Food residues, particulates, etc. may enter the gaps, damaging the ridge mucosa and causing ulcers.

  In terms of a feeling of wearing or a feeling of use, in the case of an old partial denture, it is natural that a feeling of discomfort resulting from the above three-dimensional restriction occurs. Furthermore, when food is chewed with a partial denture having an old clasp as described above, the base point 111 of the three-dimensional constraining arm 109 (the connecting portion between the three-dimensional constraining arm 109 and the rest 110) is positioned at the upper end of the toothed tooth 103. According to the lever principle, the three-dimensional restraining arm 109 is swung with the vicinity of the base point 111 as a fulcrum, and the toothed teeth 103 are swung. For this reason, the case where a pain arises in a ridge mucosa or a partial denture comes off arises. In addition, since the occlusal pressure is properly received at the rest, damage may occur, and problems such as swallowing the damaged object may occur. Further, the three-dimensional restraining arm 109 often comes into contact with the tongue, lips, cheek mucous membrane, and the like, resulting in an uncomfortable feeling and often cannot provide a good feeling of use.

  Further, as shown in FIGS. 25A and 25B, in the partial denture using the old clasp, the three-dimensional constraint arm is greatly exposed on the front side. For this reason, the solid constraining arm 109 is conspicuous, and there is a problem in terms of aesthetics, particularly in the front tooth portion.

In order to overcome the above problem, a C-shaped or semicircular arc-shaped concave portion including two metal arms 64a and 64b as shown in FIGS. An improved partial denture provided with at least one semicircular arc-shaped recess that fits the toothed teeth 63 to the roots of the toothed teeth 63 has been proposed by the same inventors as the present invention (Patent Documents 1 and 2). According to this improved partial denture, the semicircular arc-shaped concave portion including the two metal arms 64a and 64b branched from the fixed portion 62 is fitted so as to be fitted only to the tooth root of the toothed teeth 63. There is almost no restraint to 63, and the force which inclines with respect to a toothed hook does not act in any state, As a result, the burden on a toothed hook can be reduced epoch-makingly. Further, since the planar portions of the metal arms 64a and 64b are fitted so as to be applied to the tooth root of the toothed teeth 63, even the weak toothed teeth 63 are reinforced by the semicircular arc-shaped recesses, and even the case where the vitality is restored. Has also been confirmed. For this reason, if there is one wobble that is wobbled, it is possible to provide a partial denture that can be applied to the root of the tooth and fitted together to extend the entire life including the tooth. Further, since the length of the cheek side (front side) arm of the two metal arms is shortened, it is excellent in aesthetics. In the following description, the partial dentures shown in FIGS. 26A and 26B are referred to as prototype partial dentures and are cited. The present invention is an invention realized by adding a new component to the prototype partial denture.
Revised Osborne Partial Denture Ishiyaku Publishing Co., Ltd., July 1977, p.166 Japanese Patent No. 3928102 WO2006 / 131969 A1

  In the prototype partial denture clasp, one of the two metal arms extends to the lingual side and the other extends to the buccal side. With this partial denture, except for special remaining teeth, the lingual arm is made longer than the buccal arm to improve aesthetics. That is, in most cases, from the viewpoint of aesthetics, the cheek-side arm is shortened, and the lingual-side arm is lengthened correspondingly to ensure the maintenance force and the gripping force. However, the lingual arm and the buccal arm are subjected to an open bending stress each time they are attached and detached, but the long extending lingual arm receives a large bending moment. And since the length is long, the tip end of the lingual arm is small and large bending deformation concentrates repeatedly. In many cases, the patient does not follow the attachment / detachment route as instructed by the doctor, and in such a case, distortion is concentrated in a larger and weaker part. By repeated attachment and detachment, the lingual arm does not return to its original state, and strain remains in the entire lingual arm. As a result, the tip of the lingual arm is opened, loosening is caused in the fitting of the clasp, and the maintenance action, the gripping action and the support action may be reduced.

  An object of the present invention is to provide a partial denture that does not loosen even after repeated desorption, has high durability, and can always obtain a highly stable wearing state.

The partial denture of the present invention includes a plurality of artificial teeth, a denture base that holds the artificial teeth, and one or more clasps that are attached to the denture base and are maintained by the toothed teeth. In this partial denture, the clasp has a lingual arm along the lingual side of the toothed tooth and a buccal arm along the cheeked side of the toothed tooth, and the lingual arm is a toothed tooth that is applied around the toothed tooth A toothed portion, a toothed portion applied to the tooth adjacent to the toothed hook, and a continuous portion that is located between the toothed toothed portion and the toothed tooth assigned portion and is continuous ; continuous unit, is added to the tip of鉤歯Ategai portion and reinforces the tip of該鉤tooth Ategai unit, the鉤歯Ategai portion and the adjacent tooth Ategai unit, protruding at the tooth surface intersect in a continuous portion The corners are formed so that the corners enter between the teeth of the toothed teeth and the adjacent teeth, and the corners in the continuous part are ridged or ridged at the part that enters between the teeth . The adjacent toothed part and the toothed part are concave from the ridgeline or ridge to both sides, Tooth Ategai portion may not extend from the portion facing the inter-teeth are limited to a portion facing the inter-teeth forming the ridge or ridges.

According to said structure, it has the effect | action of following (E1) and (E2).
(E1): As in the present invention, when the adjacent toothed portion is formed at the tip of the lingual arm with a continuous portion having a cross-sectional area of a predetermined level or more, rigidity is increased at the distal end portion of the toothed portion, Bending deformation does not concentrate during the above attachment / detachment. Rather, the tip of the lingual arm is more rigid and difficult to deform near the tip.As a result, when attaching or detaching, the entire clasp or partial denture rotates around the adjacent tooth with the adjacent tooth assigned portion as a fulcrum. On the other hand, it is a movement to attach and detach while elastically deforming other parts. As a result, the opening of the lingual arm and the slack of the clasp do not occur, and a high maintenance force, gripping force and supporting force can be maintained. Since the buccal arm is short and does not loosen, it can maintain a high gripping action in cooperation with the lingual arm. Moreover, about holding | maintenance of a high supporting force is as follows. The partial dentures of the present invention or prototype bear on average most occlusal pressure by the alveolar mucosa through the denture base. As a result of the above-mentioned high maintenance force and gripping force, the position of the partial denture is stably and firmly maintained, so that the occlusal pressure can be steadily and stably averaged and can be borne by the alveolar mucosa. Also, the drop due to loosening can be prevented.
(E2): In the partial denture clasp of the present invention, in principle, the lingual arm is applied to the root side from the raised portion of the tooth decay. This also applies to the toothed teeth and adjacent toothed parts of the lingual arm, where the toothed parts are on the root side of the toothed ridge, and the toothed part is the raised tooth of the next tooth. It is applied to the root side of the department. Even if the tooth is not clearly recognized as a bulge, there is a recess or recess in the root of the tooth, and the toothed part is applied to the root. . Here, it is assumed that a force (force in the direction of the top of the tooth) is applied in the direction in which the clasp is detached from the tooth.
(E2-i) In the lingual arm of the partial denture of the present invention, an increase in resistance to detachment can be obtained by increasing the contact area between the applied surface and the tooth surface (applied tooth surface). The applied surface of the lingual arm is a rough surface. For this reason, there is a high deviation resistance due to surface contact. By increasing the contact area, not only the maintenance force but also the gripping force can be improved by the orientation of the surface.
(E2-ii) The adjacent tooth assigned portion is positioned at the tip of the toothed tooth assigned portion, and is applied to the adjacent tooth to interpose a continuous portion having a secured cross section, thereby reinforcing the tip of the toothed tooth assigned portion. do. The adjacent toothed portion acts on the adjacent tooth as a scaffold, and acts to prevent displacement and deformation of the toothed toothed portion in the direction of the tooth crest and horizontal force. Since the cross-sectional area of the continuous portion has a predetermined level or more, the blocking action is not weakened by the continuous portion and can be directly applied to the toothed portion. As a result, compared with the prototype lingual arm, it is possible to reinforce the blocking force against opening deformation at the front side portion. As a result, not only the maintenance force but also the gripping force can be strengthened. The effect of the above (E2) is independent of (E1).
(Summary): The prototype partial denture by the inventor does not have a rest, and the solid restraint arm is substituted by two arms having a C-shape. In this prototype partial denture, there is a case where a rest or a three-dimensional restraining clasp is not provided due to the looseness of the clasp caused by the above-described repeated attachment and detachment, resulting in insufficient maintenance force and gripping force. The above-mentioned “toothed tooth fitting part + neighboring tooth fitting part + continuous part having a cross-sectional area of a predetermined value or more” prevents loosening that is the cause of insufficient maintenance force and gripping force by the above (E1). The maintenance force and the gripping force are reinforced by itself (E2). As a result, the partial denture of the present invention can enhance the maintenance force and the gripping force without impairing the advantages of the prototype partial denture that provides the above-mentioned comfortable wearing feeling. The clasp according to the present invention does not place a burden on the teeth at the time of occlusion and is almost free, and when the maintenance force and the gripping force are exerted, only the contact from the lower part to the middle part occurs on the tooth surface on the root side of the tooth . Thereby, a comfortable wearing feeling can be obtained similarly to the prototype partial denture.
The rest and the three-dimensional restraint clasp place a very large burden on the tooth decay. Tooth-applying portion + continuous portion having an average cross-sectional area of a predetermined level or more ”can be substituted.
In the above effects (E1) and (E2), it is important to secure an average cross-sectional area of the continuous portion. The average cross-sectional area of the continuous portion may be at least half the average cross-sectional area of the central portion of the toothed portion, but more preferably, the average cross-sectional area is equal to or greater than that of the central portion of the toothed portion. .

  In the above clasp, any material, for example, a casting or a metal wire, may be used, but at least the lingual arm is preferably an integral casting. As a result, the weak portion of the prototype partial denture at the tip side of the toothed portion can be replaced with a continuous integral casting of the continuous portion and the adjacent toothed portion to be strengthened. Further, the lingual arm can be easily formed by the integral casting.

The above continuous portion, angled (excessive) Ategai face each other in鉤歯Ategai portion and Tonariha Ategai portion intersect, you shaped to form a Ategai plane crossing angle (excessive) portion. According to such a shape, corresponding to the deep depth between the teeth on the lingual side, the tooth-tooth-applying surface and the adjacent tooth-applying surface project a large intersection angle. For this reason, the average cross-sectional area of the continuous portion is large. The toothed part, which is the main part of the lingual arm, receives the force in the direction of the top of the tooth against the force in the withdrawal direction, but it is applied to the root side, so it moves beyond the ridge. Needs to be deformed to increase the radius of curvature of the toothed portion, and the deformation requires a predetermined force. Similarly, a force for increasing the radius of curvature is also required for the adjacent tooth assignment portion. The area near the crossing corner of the fitting surface has a cross-sectional area or rigidity of a predetermined level or more, does not easily deform, and becomes a great resistance against the above deformation. That is, in the lingual arm of the partial denture according to the present invention, not only the addition of the adjacent toothed portion, but also a large cross-sectional area that forms the intersecting surface crossing angle portion is made large and solid, so that the toothed portion. It is possible to increase the deterrence against the detachment deformation at both of the adjacent tooth placement portions.
However, when taking the shape where the above-mentioned crossing-intersection corner part protrudes greatly, the attachment stability of the partial denture becomes so high that the attachment / detachment becomes difficult. In particular, when two partial clasps are provided on the partial denture and both of them are formed on the lingual arm with the above-mentioned adjacent tooth application portion or the like, it becomes difficult to attach and detach. In such a case, it is preferable to shorten the protruding length by deleting the front end portion of the above-mentioned crossing corner portion. In this case, the tooth surface side is not a ridge line shape but a width and a surface shape.

  A raised surface part that rises in a convex shape through the continuous part to the lower part (the part on the root side of the tooth) of the applied part of the toothed part and the adjacent toothed part. Can be provided. When the gap between the teeth at the root of the tooth is large, by forming a raised surface portion that fits between the large teeth, the engagement between the tooth and the lingual arm can be realized, and the maintenance force can be enhanced. For example, even if the front teeth have no distinct ridges on both the tooth and the adjacent teeth, some patients may have a similar inclination at the base of the front teeth at the bottom of the ridge (inclinations that recede toward the root, or indentations) There is a wide interdental part with a slope. In the case of such a patient, the above-described rising surface portion greatly contributes to strengthening the maintenance force.

  A large connector connected to the denture base can be provided. By using a large connector, it is possible to widen the oral cavity, suppress the covering of the ridge mucosa, and improve comfort. A large connector is a metal structure that connects denture bases that are separated from each other in the dentition, or a denture base and a maintenance device, and is often formed in an arch shape so as to contact the gingiva. Called a plate. In the case of the upper jaw, it is a paratal bar, a paratal plate or the like, and in the lower jaw, it is called a lingual bar or a lingual plate.

  A hook that extends so as to intersect the large connector and that is locked between the crown tops of two consecutive remaining teeth can be provided. According to this configuration, the partial denture can greatly improve the maintenance action and the gripping action by the clasp and the hook. The hook contacts between the crowns of successive remaining teeth, and is locked between the crown tops by the locking portion, so that the partial denture is inclined, the horizontal displacement, in particular, the lingual or posterior escape, and A shift along the dentition direction can be reliably prevented and a highly stable gripping action can be obtained.

  According to the present invention, even if desorption is repeated, loosening does not occur, durability is high, and a highly stable wearing state can always be obtained.

(Embodiment 1)
FIG. 1 is a diagram showing a partial denture 10 according to Embodiment 1 of the present invention. This partial denture 10 is a partial denture for the upper jaw, and is for patients lacking the left 5th to 7th and the right 5th to 7th. Artificial teeth L5, L6, L7 and R5, R6, R7 are fixed to the denture base 31. The denture base 31 is divided into two left and right parts, and is connected by a paratal bar 32 (a front surface 32a and a back surface 32b). Two clasps 11 and 21 are fixed to the denture base 31. The clasp 21 having the right fourth tooth is the same as the prototype partial denture clasp by the inventor. The clasp 11 having the left fourth tooth is formed with a buccal arm 12 applied to the cheek side peripheral surface of the tooth and a lingual arm applied to the lingual peripheral surface of the tooth. . The lingual arms 13, 14, and 15 are composed of the following parts.
(Rodent application part 13): The main part of the lingual arm is applied to the tooth decay.
(Neighboring tooth application part 14): It comes out from the tip and is applied to the adjacent tooth located next to the tooth decay.
(Continuous portion 15): In the continuous portion 15 of the lingual arm shown in FIG. 1, the fitting surface of the toothed tooth fitting portion 13 and the fitting surface of the adjacent tooth fitting portion 14 are closely intersected to form a corner portion. In particular, the continuous portion 15 is an assigned plane intersection angle portion. In the present embodiment, the “assignment plane intersection angle portion” is used in the same meaning as the “continuous portion”. The projecting crossing corner portion formed by intersecting the two mating surfaces in the mating surface intersecting corner portion 15 extends along the tooth axis direction on the tooth surface side, and is linear (ridgeline). Or it is a band-like part with a little width. When the gap between the tooth roots of the toothed teeth and the adjacent teeth is wide, the tooth side of the crossing corner is not a line but a band like a gentle ridge. If the continuous portion 15 has the shape of the above-mentioned intersection crossing corner and the extent of the protrusion is large, it may be difficult to attach and detach so much that the stable mounting state passes. In such a case, the protruding portion may be deleted, and the above-mentioned ridgeline tooth surface side may be retracted to form a belt-like or planar tooth surface side (see FIG. 11). By this deletion, the tooth surface side of the continuous part is separated from the teeth (toothed teeth and adjacent teeth), but the above-described effects of the present invention can be obtained as long as the adjacent tooth applying surface is applied to the adjacent teeth.

  FIG. 2 is a view of the clasp 11 as viewed from above. The toothed hook portion 13 has a semi-cylindrical cross section, and has a fitting surface 13b that contacts the toothed tooth and a rounded surface 13a with a metallic luster. Further, the adjacent tooth applying portion 14 also has an assigning surface 14b in contact with the adjacent tooth and a rounded surface 14a with metallic luster. The angle formed by the intersection of the tooth-tooth-applying surface 13b and the adjacent tooth-applying surface 14b is slightly smaller than 90 ° macroscopically, but is smaller and sharper because it intersects the concave and concave surfaces. In the clasp 11, at least the lingual arm is preferably made of an integral casting, but may be made of a metal wire or the like. When the lingual arm is manufactured by a single casting, the entire clasp including the buccal arm 12 and the like is preferably a single casting. In the case of a monolithic casting, a normal metal used for a clasp can be used, but it is preferable to use a platinum alloy in terms of strength, elasticity, durability, and the like.

FIG. 3 is a diagram showing the clasp 11 viewed almost horizontally, and FIG. 4 is a diagram showing the clasp 11 viewed from below. FIG. 5 is an enlarged view of the portion of the intersection surface intersection corner 15.
The tooth surface side 15b in the assigned surface crossing corner 15 is easy to identify. However, the portion on the surface side corresponding to the tooth surface side 15b, the core portion, and the like are unclear because there is a width in the line drawing during the clasp design. For this reason, the continuous part is defined as follows. As shown in FIG. 5, the width of the tooth surface side 15b is set to 1 mm, and it extends to the surface 13a, 14a side of the lingual arm and takes a cross section of 1 mm width. The width of the tooth surface side 15 b of the continuous portion 15 can be regarded as the thickness of the continuous portion 15. This plate-like part having a thickness of 1 mm is defined as a continuous part (see FIG. 7C). The surface of the plate-like portion (parallel upper and lower surfaces) is taken to be substantially orthogonal to the central axis (curve) of the toothed portion. Even when the width of the tooth surface side 15b is narrower or wider than 1 mm, the plate-like portion is defined as the continuous portion 15 with a width of 1 mm centered on the tooth surface side 15b. The average cross-sectional area of the continuous portion is an average value in the thickness direction of the 1 mm thick plate-like portion. In addition, when there is an arbitrary method for taking the 1 mm wide plate-like portion, a plurality of 1 mm-wide plate-like portions are taken in the optionality, and the cross-sectional area of the above-described continuous portion is a plurality of plate-like portions. The minimum value in the partial average cross-sectional area is taken. Arbitraryness in the way of taking the plate-like portion should be a problem when the average cross-sectional area greatly fluctuates within the range of the arbitraryness, and may be ignored if there is no significant difference. The cross-sectional area and the like of the continuous portion should not be limited to the detailed interpretation of terms, but should be understood in accordance with the spirit of the present invention.

As described above, the tooth surface side 15b of the fitting surface crossing corner portion 15 of the clasp 11 is located at a large protruding portion, which indicates that the depth between the tooth of the patient's tooth and the adjacent tooth is deep. . The toothed teeth facing surface 13b is concave along the peripheral surface of the toothed teeth, and the adjacent toothed tooth facing surface 14b is concave along the peripheral surface of the adjacent teeth, and both intersecting points are along the direction of the height h. It is the tooth surface side (ridgeline) 15b. The tooth surface side 15b has a width. As in this embodiment, like the ridge line, when the position of the tooth surface side 15b protrudes greatly and the radius of curvature of the concave surface of the adjacent tooth application surface 14b is equal to or less than a predetermined value, the tooth application portion 13 is Even if it tries to open the tip beyond the ridges from the root side, the contact between the adjacent tooth-facing surface 14b and the adjacent tooth becomes the opening stick, and the opening is prevented. When such a protruding tooth surface side 15b is provided in two clasps, it is necessary to pay attention to the difficulty of attachment / detachment as described above. This point will be described in the partial denture of FIG.
As shown in FIG. 4, the clasp 11 is fixed at substantially the same height as the roots of the tooth portions of the artificial teeth L5 and L6. The denture base 31 is arranged so as to straddle the ridge lining mucosa (not shown), and comes into contact with the ridge lining mucosa on the back surface 31b. The paratal bar 32 is fixed by embedding the embedded portion in the meat portion between the front surface 31 a and the back surface 31 b of the denture base 31. Since the paratal bar 32 is made of metal, it is thin and narrow and has sufficient strength. For this reason, a tongue feeling becomes favorable. When the denture base is extended along the lingual side of the ridge without using the paratal bar 32, the volume of the denture base increases, the free movement of the tongue is inhibited, and the tongue feeling deteriorates.

FIG. 6 is a perspective view showing a state in which the partial denture 10 is mounted on a gypsum model M of a patient. The clasp 11 of the partial denture 10 uses the upper left fourth tooth L4 as a tooth, and the left third tooth L3 as an adjacent tooth. The clasp 21 is a prototype clasp, but the right fourth tooth R4 is a toothed hook. The denture base 31 is divided into left and right parts, and is connected by a large connector paratal bar 32. The paratal bar 32 is arranged along the palate away from the teeth R4 to R1 and L1 to L4 toward the palate. For this reason, the remaining teeth (living teeth) are spaced apart from the clasps 11 and 21. For this reason, there is no pressure feeling applied to the remaining teeth.
FIG. 7 (a) shows the toothed tooth L4 and the adjacent tooth L3 of the patient's plaster model, FIG. 7 (b) shows the prototype lingual arm 64b, and FIG. 7 (c) shows the present embodiment. It is a figure which shows the lingual arm 11. FIG. As shown in FIG. 7A, the toothed teeth L4 and the adjacent teeth L3 form deep interdental teeth and are in close contact at the center. If the prototype lingual arm 64b is used, the pointed tip shown in FIG. By the way, the toothed tooth L4 is clearly formed with a rounded taper surface that recedes (recesses) toward the ridge 5 and the root 7 below. That is, the taper surface has a slope such that the radius of curvature is small on the root side and the radius of curvature has a maximum value at the ridge. Such a ridge is a characteristic characteristic of the fourth tooth. Further, the adjacent tooth L3 also has a taper having an inclination similar to the taper formed from the bumpy part of the fourth tooth to the root part (inclination that recedes toward the root) as far as the root part is concerned.
The prototype lingual arm 64b can secure a sufficiently large maintenance force and gripping force by the tapered surface having the above-mentioned inclination by placing the tooth-tooth-applying surface on the root portion 7 of the tooth-tooth L4. In the case of the lingual arm 64b shown in FIG. 7B, the distance (thickness) in plan view between the surface of the toothed portion and the applied surface is made slightly thicker in order to secure a large maintenance force and a gripping force. This is an example. When the thickness of the toothed portion is increased, the tongue touches the thickness or level difference, and the tongue feeling is lowered. However, no matter how much the thickness is increased to prevent the opening deformation, the prototype lingual arm 64b extends to the interdental portion of the toothed tooth L4 and has no further length. The tip of the prototype lingual arm 64b tapers to zero thickness with a taper in thickness and width. For this reason, as described above, the distal end portion of the lingual arm 64b is easily deformed.
On the other hand, in the lingual arm 11 in the partial denture of the present embodiment, the continuous part / adjacent toothed part is provided at the tip of the toothed part, and the cross-sectional area of the continuous part is secured at a predetermined level or more. Deformation is reliably prevented. In addition, since the adjacent toothed portion is also applied to the adjacent tooth and has a scaffolding strung in a different direction from the toothed tooth assigned portion, it is effective in enhancing the maintenance force, the gripping force, and the supporting force. Furthermore, when attaching and detaching the partial denture, the adjacent tooth assigned portion becomes a fulcrum for attachment and detachment due to the high rigidity described above. As a result, when the partial denture is attached or detached, a large strain does not occur at the distal end of the toothed teeth portion / continuous portion / the adjacent tooth portion. As a result, even if the attachment and detachment are repeated, the lingual arm does not open, and a highly stable wearing state can be obtained.

FIG. 8 is a view showing a state in which the lingual arm 11 is applied to the toothed teeth L4 and the adjacent teeth L3. Both the tooth-tooth-applying surface 13b and the adjacent tooth-assigning surface 14b extend to the back of the interdental portions of the teeth L4 and L3 to be applied. As a result, the tooth surface side 15b of the fitting surface crossing corner 15 enters into the back of the interdental space 3 in FIG.
FIG. 9 is a view showing a cross section taken along line IX-IX in FIG. That is, it is sectional drawing of the toothed hook part 13 of the state applied to the toothed hook L4. The toothed portion 13 is in close contact with the toothed surface 13b, which has a taper that is inclined backward from the ridge 5 to the root. A taper surface having the same inclination is formed at the root portion of the adjacent tooth L3 on the interdental portion 3 side, and the application surface 14b of the adjacent tooth application portion 14 is in close contact therewith. Consider a case where a force in the detachment direction acts on the lingual arm 11 of the partial denture 10 mounted in such a form.
When a force in the detachment direction is applied, the toothed portion 13 of the lingual arm 11 does not detach if it does not open in the direction of the arrow K shown in FIG. In order for the toothed portion 13 to rise beyond the ridge 5 shown in FIG. 8, it is necessary to open in the direction K to a large radius of curvature corresponding to the ridge 5. However, as shown in FIG. 8, the adjacent tooth L3 and the adjacent tooth-assigning surface 14b are in close contact with each other, and a part of the concave surface that has entered the back of the interdental area with respect to the opening in the direction K of the toothed tooth-attaching portion 13 It becomes a stick and prevents this opening. As a result, the opening of the toothed portion 13 in the K direction is strongly prevented, and as a result, the maintenance force can be further strengthened.
The above-mentioned action of the sticking rod is such that the tooth surface side 15b of the fitting surface crossing corner portion 15 protrudes greatly, and the interdental back surface of the adjacent tooth fitting surface 14b accompanies the displacement of the tooth fitting portion 13 in the K direction. Some movements are limited to structures that are blocked by adjacent teeth. Such a structure does not always occur even when the continuous portion 15 forms the crossing corner portion. However, when the requirements of the above structure are satisfied, a strong maintenance force enhancing action can be achieved. In this case, it goes without saying that the gripping force and the supporting force are also strengthened.
As described above, the structure as described above may result in excessively stable mounting, which may result in difficulty in attaching and detaching. Therefore, it is necessary to pay attention by adjusting by grinding or the like.

  FIG. 10 is a diagram illustrating a modification of the partial denture 10 according to the first embodiment of the present invention. In this modification, the two clasps 11 and 21 of the partial denture 10 are both provided on the lingual arm with the toothed teeth applying portions 13 and 23, the adjacent tooth applying portions 14 and 24, and the assigned surface crossing angle portion 15, 25. Accordingly, the two clasps 11 and 21 both have durability that will not be deformed even if they are repeatedly attached and detached while strengthening the maintenance force. As described above, when such a protruding tooth surface side 15b is provided in two clasps, it is necessary to pay attention to the difficulty of attachment / detachment as described above. In such a case, as shown in FIG. 11, one or both of the clasps 11 and 21 are preferably retracted from the back of the interdental space by deleting the protruding tooth surface side. If the adjacent tooth-assigning portion 14 is applied to the adjacent tooth and the average cross-sectional area of the continuous portion is equal to or higher than a predetermined level, the adjacent tooth-assigning portion 14 is attached / detached even if the tooth surface side 15b of the continuous portion 15 is retracted. Acts as a fulcrum and prevents opening or loosening of the lingual arm. In addition, as long as the adjacent teeth applying portion 14 is applied to the adjacent teeth and the average cross-sectional area of the continuous portion is ensured, the above-mentioned struts can maintain sufficient maintenance force and gripping force. The continuous part may be actually thicker, but is defined as a 1 mm thick plate-like part as described above.

(Embodiment 2)
FIG. 12 is a diagram showing a partial denture 10 according to Embodiment 2 of the present invention. In this Embodiment, the partial denture 10 provided with the clasp 11 which makes a front tooth a toothed hook and an adjacent tooth | gear is illustrated. The partial denture 10 is for the upper jaw, and the remaining teeth are only the two left and right first teeth. The clasp 11 uses the left first tooth L1 as a tooth and the right first tooth R1 as a neighboring tooth. The clasp 21 is a prototype clasp, and the right first tooth R1 is a toothed tooth. The denture base 31 is divided into right and left and connected by a paratal bar 32.

FIG. 13 is a view of the clasp 11 looking up slightly from the side of the toothed teeth. In FIG. 13, the clasp 11 shows the concave surfaces of the assigning surfaces 13b and 14b, and a raised surface portion G that rises in a convex shape is formed below the assigning surfaces. Moreover, about the paratal bar, the non-glossy back surface is visible.
FIG. 14 is an enlarged view of the application surfaces 13 b and 14 b of the clasp 11 and the tooth surface 15 b of the continuous portion 15. In this lingual arm, the tooth surface side 15b of the continuous portion 15 which continues the tooth-applying surface 13b and the adjacent tooth-applying surface 14b faces the teeth with a certain width. As shown in FIGS. 5 and 7C, the continuous portion 15 can also be determined by a plate-like portion having a thickness of 1 mm with the ridge line portion positioned at the thickness center on the tooth surface side 15b.

FIG. 15 is a diagram illustrating a state in which the partial denture 10 according to the present embodiment is mounted on a gypsum model of a patient. The two front teeth L1 and R1 are the toothpaste and adjacent teeth of the clasp 11. The clasp 21 uses the right first tooth R1 as a toothed hook. The position, shape, action, and the like of the paratal bar 32 are the same as those in the first embodiment.
FIG. 16 is a view of the two front teeth of the patient as viewed from the lingual side. Although there is no ridge, a taper with an inclination that becomes narrower toward the root side is recognized between the teeth 3 at the root of the tooth. That is, in the left and right first teeth L1 and R1, the portion 5 facing the interdental 3 of the root of the tooth protrudes, and the lower portion 7 recedes or is recessed. FIG. 17 is a view of the state in which the clasp 11 is mounted on the lingual side.
FIG. 18 is a cross-sectional view including the teeth L1, R1 and the clasp 11 in the clasp wearing state shown in FIG. 18A is a cross-sectional view of the interdental side of the toothed tooth L1, FIG. 18B is a cross-sectional view of the interproximal side of the adjacent tooth R1, and FIG. 18C is a cross-sectional view of the continuous portion 15 between the teeth. is there. According to these figures, the raised surface portion G is fitted into a depression in the lower portion of the interdental side of the toothed teeth L1 and the adjacent teeth R1, and an engagement is formed between the teeth and the clasp 11.
In addition to the effects of (E1), (E2-i) and (E2-ii) described above, by forming an engagement relationship with the tooth by the raised surface portion G on the application surfaces 13b, 14b, 15b, The maintenance force and the gripping force can be further enhanced.

(Embodiment 3)
FIG. 19 is a diagram showing a partial denture 10 according to Embodiment 3 of the present invention. The partial denture 10 is characterized in that a hook 51 is provided in addition to the clasp 11 having the adjacent tooth-assigning portion 14 and the like unique to the present invention. In the partial denture 10, a hook 51 is formed integrally with the lingual bar 32 so as to extend from the lingual bar 32.
FIG. 20 is a view showing a state in which the partial denture 10 of FIG. 19 is mounted on a patient's plaster model. The partial denture 10 is for the lower jaw, and the clasp 11 has the right third tooth R3 as a tooth and the right fourth tooth R4 as a neighboring tooth. The hook 51 is hung between the crowns of the left fourth tooth L4 and the fifth tooth L5. Further, the prototype clasp 21 has a left third tooth L3 as a toothed hook. It can be said that the shape, position and action of the lingual bar 32 are the same as those in the first embodiment.

  FIG. 21 is a view of the toothed tooth R3, the adjacent tooth R4, and the interdental part 3 to which the clasp 11 is applied as viewed from the lingual side. The interdental part 3 is deep, and the continuous part 15 protrudes greatly from the assigned crossing corner, corresponding to the partial denture in the first embodiment. A cross-sectional view of the clasp 11 with the lingual arm applied is shown in FIGS. FIG. 22 is a cross-sectional view at a position from between the teeth of the toothed tooth R3, and FIG. 23 is a cross-sectional view at a position from between the teeth of the adjacent tooth R4. In both cases, the facing surfaces 13b and 14b are assigned to the tooth surface that recedes from the ridge 5 to the root side. As a result, for the clasp 11 having the adjacent toothed portion 14 and the continuous portion 15, the clasp of the partial denture according to the first embodiment, apart from the reinforcing action of the maintenance force due to the shape factor peculiar to the partial denture according to the first embodiment. 11 can be obtained.

FIG. 24 is an enlarged view of the hook 51, (a) is a side view of the hook 51, and (b) is a view seen from the side of the remaining teeth. From FIG. 24, the following structures can be clearly identified for the hook and the curved portion.
The hook 51 is formed by a portion 51 a extending from the lingual bar 32, a portion 51 b contacting between the crowns of the two remaining teeth therefrom, and a crown top portion 51 c extending between the crown tops therefrom. . The crown top portion 51c extends from the lingual side of the remaining tooth to the cheek side. The locking portion of the hook 51 is formed by a crown top portion 51c, and the projection Z at the tip portion is provided to be hooked with a fingertip or the like at the time of attachment / detachment. There is little possibility that the locking portion of the hook 51 will harm aesthetics.
The crown 51b of the hook 51 is provided with a convex portion Y that fits into a concave formed near the boundary between the crowns of the two remaining teeth. According to said convex part Y, the hook 51 fits the convex part Y in the recessed part produced between the crowns of two adjacent remaining teeth, and greatly improves the gripping action, particularly the gripping action in the dentition direction. In addition, the fitting action of the concave portions between the crowns of the convex portions Y improves the maintenance action. Therefore, in the hook 51, not only the locking portion but also the crown portion 51b plays a large role in improving the gripping action, the maintenance action and the support action.
By providing the clasp 11 having the hook 51 and the adjacent tooth placement portion 14 and the like, the partial denture 10 in the present embodiment can realize stable mounting over a long period of time.

(Summary of partial dentures of the present invention)
1. By adding the adjacent toothed portion and the continuous portion to the lingual arm of the prototype, it is possible to prevent repetitive opening deformation from accumulating at the tip of the lingual arm during attachment and detachment. This is realized by having the adjacent tooth-assigning portion as a fulcrum for attachment and detachment.
2. Maintenance action, gripping action and support action can be enhanced. In the present invention, the enhancement of these actions can be realized by the above-described very simple mechanism.
(I) Originally, even in the prototype partial denture, the buccal arm and the lingual arm, in particular the lingual arm, holds the toothed teeth on the root side, that is, the undercut part on the root side from the holy part, The contact between the ridge and the lingual arm exerts a deterrent against the tooth axis direction separation. In addition, since there is no rest, the occlusal pressure is applied only to the artificial tooth, and the occlusal pressure is borne by the alveolar mucosa and the gingiva via the denture base and the large connector. The partial denture which concerns on this invention is equipped with this effect (2. (i)).
(Ii) Furthermore, in the partial denture of the present invention, a strong detachment preventing force can be obtained particularly by adding the adjacent tooth applying portion and the continuous portion to the lingual arm. In addition, the gripping force of the lingual arm can be strengthened by adding the adjacent toothing portion 14 and the like, and movements such as tilt, rotation, and displacement are prevented.
From the above, (A1) Supporting action resisting occlusal pressure, (A2) Maintenance action resisting detachment force, and (A3) Horizontal force applied to the denture, which are basically required for partial dentures It can be seen that the gripping action to resist is ensured without any problem.
Regarding the partial denture clasp 11 of the present invention, as described above, the characteristics of the partial denture of the prototype (comfortable wearing feeling, aesthetics, etc.) are not changed, and the lack of the characteristics of the prototype is compensated. It is further promoted.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  By using the partial denture of the present invention, there is provided a partial denture that has a good feeling of use, has almost no burden on maintenance teeth, is excellent in aesthetics, is easy to attach and detach, and can maintain a highly stable wearing state. Can be expected to contribute greatly to this field.

It is a perspective view which shows the partial denture in Embodiment 1 of this invention. It is the perspective view which looked at the clasp of the main component part of the partial denture of FIG. 1 from the top. It is the perspective view which looked at the clasp of the main welfare part of the partial denture of FIG. 1 horizontally. It is the perspective view which looked up the clasp of the main welfare part of the partial denture of FIG. 1 from the bottom. It is an enlarged view of said clasp. It is a perspective view which shows the state which mounted | wore the gypsum model with the partial denture of FIG. (A) is a tooth and a neighboring tooth, (b) is a lingual arm of a prototype clasp, and (c) is a diagram showing a lingual arm of the clasp of FIG. It is a figure which shows the state which applied the lingual arm to the tooth and the adjacent tooth. It is sectional drawing which follows the IX-IX line of FIG. It is a perspective view which shows the modification of the partial denture of FIG. 1, and shows the partial denture of embodiment of this invention. It is a figure for demonstrating the shape which removed the tooth surface side of the continuous part of a lingual arm, in order to ensure the detachability of a partial denture. It is a perspective view which shows the partial denture in Embodiment 2 of this invention. It is the perspective view which looked at the clasp which is the main components of the partial denture of FIG. 12 from the toothed side. It is an enlarged view of the clasp of the main component part of the partial denture of FIG. It is a perspective view which shows the state which mounted | wore the gypsum model with the partial denture of FIG. It is the figure which looked at the tooth decay and the adjacent tooth | gear with respect to the said clasp from the lingual side. It is a figure which shows the state which applied the lingual arm to the tooth and the adjacent tooth. (A) is the XVIIIA-XVIIIA line of FIG. 17, (b) XVIIIB-XVIIIB line, (c) is sectional drawing which follows the XVIIIC-XVIIIC line. It is a perspective view which shows the partial denture in Embodiment 3 of this invention. It is a perspective view which shows the state with which the partial denture of FIG. 19 was mounted | worn with the gypsum model. It is the figure which looked at the tooth and the adjacent tooth | gear with respect to the clasp of the main component part of the partial denture of FIG. 20 from the lingual side. It is sectional drawing containing the toothed hook part of the state applied to the toothed hook. It is sectional drawing containing the adjacent tooth assignment part of the state applied to the adjacent tooth. It is a figure of the hook with which the partial denture of FIG. 19 is equipped, (a) is a side view, (b) is the front view seen from the tooth | gear side to be latched. It is a figure which shows the state which mounted | wore the maintenance tooth | gear with the conventional partial denture clasp, (a) is the front view seen from the cheek side, (b) is a top view. It is a figure which shows the state which mounted | wore the maintenance tooth with the clasp of the prototype partial denture improved about the conventional clasp, (a) is the front view seen from the cheek side, (b) is a top view.

3 Interproximal part, 5 Hoyu part or overhang part, 7 Lower part of Hoyu part (retracted surface part or dent), 10 Partial denture, 11 Clasp, 12 Buccal arm, 13 Tooth part of lingual arm, 13a Tooth Surface of the assigned portion, 13b Back surface (toothed tooth-assigned surface), 14 Adjacent tooth-assigned portion, 14a Surface of the adjacent tooth-assigned portion, 14b Back surface (adjacent tooth-assigned surface), 15 continuous portions (assigned surface crossing angle portion), 15b continuous Attached face part (crossing angle part), 21 clasp, 22 buccal arm, 23 lingual arm, 24 adjacent tooth assigning part, 25 continuous part (assigning face crossing angle part), 31 denture base, 32 large connector (paratalbar) , Lingual bar), 51 hook, 51a hook root portion, 51b hook crown side portion, 51c hook crown top portion, G raised surface portion, 62 fixing portion, 63 tooth decay, 64a cheek Arms, 64b lingual arm, M plaster model, the convex portion to fit into the recess in the vicinity of the boundary of Y crown, projections for hooking at Z desorption.

Claims (4)

A partial denture comprising a plurality of artificial teeth, a denture base that holds the artificial teeth, and one or more clasps attached to the denture base and maintained by a dental caries,
At least one of the clasps has a lingual arm along the lingual side of the tooth decay and a buccal arm along the cheek side of the tooth decay;
The lingual arm has a toothed part assigned to wrap around the toothed teeth, an adjacent toothed part applied to a tooth adjacent to the toothed tooth, the toothed tooth assigned part and the toothed tooth assigned And a continuous part that is located between and continuous with the part,
The adjacent toothed portion and the continuous portion are added to the distal end of the toothed portion and the distal end of the toothed portion is reinforced,
Wherein A鉤歯Ategai portion and the adjacent tooth Ategai portion, corner portion angled portion so as to project in the intersecting tooth surface at the continuous portion to between the teeth of the adjacent teeth of the adjacent and鉤歯To enter,
The corner portion in the continuous portion is a ridge line shape or a ridge shape at a portion that enters between the teeth, and the adjacent tooth application portion and the toothed tooth application portion form a concave surface from the ridge line or the ridge to both sides, The adjacent denture portion is limited to a portion facing the teeth forming the ridge line or ridge and does not extend from a portion facing the teeth.   In the fitting surface of the toothed tooth fitting portion and the adjacent tooth fitting portion, a lower surface portion of the fitting surface is provided with a raised surface portion that rises in a convex shape through the continuous portion. The partial denture according to claim 1.   The partial denture according to claim 1, further comprising a large connector connected to the denture base.   The partial denture according to claim 3, further comprising a hook that extends so as to intersect the large connector and is locked between the crown tops of two consecutive remaining teeth.

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