JP5442279B2 - Partial denture - Google Patents

Description

  The present invention relates to a partial denture that overcomes the problems of a so-called non-clasp denture made of all-resin except for artificial teeth, is difficult to detach, and has a good wearing feeling.

To overcome the unpleasant discomfort caused by strong restraint such as caskets to the dental caries (maintenance teeth) due to the traditional clasp, the maintenance force is maintained by adhering the wing and large denture base to the alveolar ridge mucosa beyond the concept of clasp. Non-clasp dentures have been proposed (Non-Patent Documents 1 to 3). All of these non-clasp dentures stably maintain the wearing state by sandwiching the gum from the buccal side and the lingual side by the wing or denture base of thermoplastic resin rich in elasticity. As the thermoplastic resin, polycarbonate resin, polyester resin, nylon (polyamide) resin, or the like is used. An example of a non-clasp denture using a nylon resin is shown in FIG. Non-clasp dentures using polyester resin or polycarbonate resin have the same structure based on the same idea as shown in FIG. This is a partial denture that has already been put to practical use in the United States and is called by a name such as Valplast, Lucitone, or Polycarbonate (Non-Patent Documents 1 to 3).
As shown in FIG. 14, these partial dentures 150 are all made of a thermoplastic resin except for artificial teeth. As can be seen from FIG. 14, the tooth (life tooth) for obtaining the maintenance force is placed in the opening 161 h that is almost surrounded by the four circumferences, the wing W of the extended denture base 120, and the denture base The tooth and gum of a tooth decay are pinched | interposed with the lingual part. When the partial denture 150 is mounted, the tooth enters the opening 161h that is almost surrounded by the four circumferences, and about 90% or more of the circumference of the tooth is surrounded by the denture base 120.

Fig.15 (a) is the figure which attached the non-clasp partial denture 150 shown in FIG. 14 to the patient's plaster model, and looked at the left side part from the cheek side. It is a figure from the viewpoint which looks up from a little lower side. Here, two points are characteristic.
One is translucent and can be identified from the outside, but a protruding line Z in a non-clasp denture embedded in a concave bent portion that is a boundary between a tooth and a gum of a tooth is recognized. In FIG. 15A, this is indicated as a broken line Z. The protruding line Z fits into a concave bent portion that forms the boundary between the tooth and gum of the patient's tooth decay (life tooth). From the position of the protruding line Z in the wing W of the non-clasp denture 150, it is obvious that the wing W abuts not only on the tooth of the tooth decay but also on the root gum.
The second relates to end artificial teeth. The artificial teeth L ₅ and L ₆ are embedded and fixed in a denture base 120 made of thermoplastic resin. Not only the end artificial tooth but also the artificial tooth is provided with a T-shaped continuous hole, and a T-shaped resin wire is formed by filling the T-shaped hole with resin. Thus, the artificial tooth is fixed to the denture base. The artificial tooth facing the tooth is called an end artificial tooth. The artificial teeth L ₅ and L ₆ in FIG. 15A face the tooth L ₄ and L ₇ respectively, and both end artificial teeth. It is. In the non-clasp denture 150, in order to make the denture base 120 of the end artificial teeth L5 and L6 large and to take a large wing W for pinching the dental gum, the cheek of the denture base of the end artificial tooth the height B _e side is taken larger than the tooth portion T _e exposed from denture base end artificial teeth.
The above two points are true not only for the left side (L side) portion of the non-clasp denture 150 but also for the right side (R side) portion as shown in FIG. That is, in FIG. 15 (b), the has a protruding line Z seen through the wing W of the portion of鉤歯R _5, and buccal height denture base 120 of the end portion artificial teeth R6 facing the鉤歯R5 B _e is made larger than the height T _e of the tooth portion exposed from the denture base 120.

FIG. 16 is a view of the non-clasp denture 150 of FIG. 14 viewed from the back side. Note that in FIG. 16, in the opening 161 h into which the tooth enters, the gum contact surface on the gum side and the tooth contact surface on the tooth side are the same surface (same curved surface) with respect to the protruding line Z. It is in the point that the discrepancy is small and continuous as if it were on the top. This point will be described in detail with reference to FIGS. 17 and 18. Figure 17 is a view of the wing W of鉤歯R ₅ from the back. FIG. 18A is a sectional view taken along line XVIIIa-XVIIIa in FIG. FIG. 18B is a diagram showing lines on each contact surface that are orthogonal to the protruding line Z in FIG. 17 and 18 (a) and 18 (b), in the wing W of the non-clasp denture 150, the tooth contact surface and the gum contact surface continuous from the tooth contact surface to the root side have almost no crossing angle. without i.e. theta _N is formed to be close to 180 °. Strictly speaking, the angle formed by the line on each contact surface orthogonal to the projecting line Z does not coincide with the angle formed by the tooth contact surface and the gum contact surface, but is approximated instead. There is no problem. Further, the height Y of the central portion of the wing W is much larger than the thickness d of the central portion of the wing W, and the thickness d is about 20% or less of the height Y.

Here, the above features of the conventional non-clasp denture 150 are summarized.
(1) A tooth is put in the opening part 161h surrounded by the four circumferences. About 90% of the circumference is surrounded by the denture base.
(2) The wing W that contacts the tooth decay comes into contact with the tooth and gum of the tooth decay. In the wing W, a protruding line Z is formed corresponding to the concave boundary between the tooth of the tooth decay and the gum. The protruding line Z is located near the center of the wing.
(3) at the end the artificial tooth is an artificial tooth facing the鉤歯, height B _e denture base of the part is greater than the height T _e of the tooth portion exposed from the denture.
(4) In the wing W that contacts the toothed teeth, the tooth contact surface and the gum contact surface do not have a large crossing angle, and continue substantially like the same surface across the protruding line Z.
(5) The thickness d of the wing W is about 20% or less of the height Y of the wing W. The thickness d is about 1 mm or less, for example, and the height Y is about 6.5 mm.

The following can be said about maintaining the wearing state of the non-clasp denture.
(K1) The wing W is arranged on the cheek side, the tooth decay and its gum (gingiva) are sandwiched between the denture base on the lingual side, and the maintenance force is to be secured by the elastic force.
(K2) A large contact area between the large denture base (thermoplastic resin) 120 and the ridge mucous membrane is used to obtain a maintenance force.
(K3) As for the denture base, in the artificial tooth portion, the denture base is disposed so as to almost completely cover the ridge mucosa. For this reason, the denture base is made thin, and in particular, the thickness of the denture base on the buccal side is made thin and wide. It is customary to have a cherry or pink denture base that is cosmetically implied.
According to the partial denture 150 described above, the burden on the maintenance teeth is reduced and the wearing feeling is improved as compared with the restraint by the conventional bowl-shaped metal clasp. In addition, since no metal clasp is used, aesthetics can be improved if the color of the thermoplastic resin is a healthy food such as cherry. In addition, since a metal clasp is not used, a partial denture can be easily manufactured by injecting a molten thermoplastic resin into a mold in which artificial teeth are arranged, cooling, removing the mold, and adjusting. . That is, the number of processes can be reduced and the production can be performed efficiently.

Valplast Japan website http://www.valplast-japan.com/ Kyoyukai Co., Ltd. website http // www.kyoyukai.co.jp / Arte International website http // www.pi-touch.co.jp

  However, the above-described non-clasp denture gradually loosens with use, and causes “rattle” in the vertical direction. For this reason, there is an opinion that there are many problems in actually using it for biting and chewing food. However, it is very effective when the main purpose is not to give the other person an impression of missing teeth during a conversation or chat. That is, it is very useful when used as a partial denture for showing the completeness of teeth when not occluded. However, the above non-clasp denture is also a large swing for the purpose of maintaining the integrity of the teeth at the time of non-occlusion only to show, and the wing W is closely attached from the tooth of the tooth decay to the gum (the cervical part). Because it is covered, the feeling of cramping or breathing is great.

  The present invention is a thermoplastic resin part that overcomes the drawbacks of the above-mentioned non-clasp denture that it is easy to produce shakiness or lacks durability while taking advantage of an efficient production method that reduces the number of steps. The purpose is to provide dentures.

The partial denture of the present invention is a partial denture having an artificial tooth, a denture base on which the artificial tooth is provided, and a concave fitting portion that is fitted so as to be applied to a toothed tooth. This partial denture has no clasp or metal fitting part anywhere, and is formed by integral injection molding of thermoplastic resin, including the concave fitting part. The concave fitting part does not include a rest. It is a fitting part that exerts a fitting force only on the tooth part of the tooth.The denture base is regarded as a curved plate-like body, and the plate-like body is formed in a concave shape so that it fits into the part corresponding to the tooth. The inner peripheral surface along the inner periphery of the concave fitting portion is standing so as to intersect the back surface of the denture base, and the bottom side is limited by the back surface of the denture base, and the denture base A metal reinforcing wire is embedded in 50% or more of the total length of the steel.

According to the above configuration, the concave fitting portion is securely fitted only on the tooth of the toothed tooth, particularly on the root of the tooth (the tooth on the root side from the ridge) from the lateral direction (horizontal direction). It is possible to obtain a structure that is applied with a resultant force. The C-shape (concave fitting portion) is substantially flat, and the flat surface has a relationship orthogonal to the tooth axis of the toothed tooth. The horizontal direction or the horizontal direction is an in-plane direction of a plane on which the C-shaped (concave fitting portion) is placed. According to the configuration of the present invention described above, the concave fitting portion does not exert a fitting force on the gums or gums.
The inner peripheral surface of the concave fitting portion is limited by the back surface on the bottom side so that it does not extend wildly toward the gum side. If the concave fitting part is configured so that the fitting force is applied only to the tooth part, it will be pressed against the gingiva side when chewing food, but it will be stopped by the tooth ridges even if it repels, Etc. and does not leave easily.
On the other hand, when the concave fitting part abuts against the gingival part forming a mountain-shaped slope and exerts pressure, the thermoplastic resin is highly elastic, so when food is chewed, it is pressed against the slope and slides down. Then, when the occlusal pressure disappears, the slope of the denture base part of the gingival slope is easily lifted up and enters the state of separation. For this reason, in the conventional non-clasp denture, since a large portion such as a wing provided for the purpose of increasing the maintenance force hits the gingival slope, it acts in the direction of promoting separation.
As a result of the configuration of the present invention described above, it is possible to reliably prevent detachment from the mounted state while obtaining advantages such as an improvement in economy by reducing the number of steps by a manufacturing method by integral injection molding of a thermoplastic resin. Furthermore, since a wing corresponding to a gum is not used, a comfortable wearing feeling can be obtained except for a cramped feeling.
In addition, since said concave fitting part is formed with thermoplastic resin by integral injection molding process with a denture base etc., it can be regarded as the extension part of a denture base. For this reason, the back surface of the concave fitting portion may be referred to as the back surface of the denture base extension, or the back surface of the denture base when the concave fitting portion is formed in the vicinity of the denture base. Moreover, what kind of thermoplastic resin may be sufficient as said thermoplastic resin.

  The angle formed by the inner peripheral surface facing the opening and the inner peripheral surface and the back surface can be in the range of (right angle −30 °) to (right angle + 60 °). Here, about the back surface of a concave fitting part, the above-mentioned description that it can be regarded as the back surface of a denture base is applied. By setting the angle formed between the inner peripheral surface and the back surface to be a right angle or within a predetermined angle range from the right angle, the inner peripheral surface can be reliably fitted only to the tooth portion. If the above-mentioned angle is close to 180 °, it becomes a concave fitting part that may come into contact with the gums continuously from the tooth part, and tends to have a shape that promotes removal from the mounted state. When the angle formed between the inner peripheral surface and the back surface exceeds 150 ° (right angle + 60 °), there is a possibility that pressure is applied to the gums on the back surface as described above. In other words, the inner peripheral surface is not clearly limited by the back surface on the bottom side, but extends to the gums and exerts pressure. More preferably, the angle is 120 ° (right angle + 30 °) or less. Further, if the angle is less than 60 ° (right angle −30 °), a portion where the concave fitting portion is thinned locally occurs, and the rigidity of the concave fitting portion is lowered, which is not preferable. Therefore, it is good to set it as 60 degrees or more. In addition, the concave portion may not be formed with a planar portion that can be said to be the back surface. This is the case for curved surfaces with a small radius of curvature. In particular, in the case of having a buccal side extending portion, which will be described later, such a concave fitting portion structure tends to be obtained. In such a case, the back surface of the denture base close to the concave fitting portion is viewed macroscopically and is regarded as the above back surface.

  On the inner peripheral surface facing the opening, there can be no protruding line corresponding to the concave bent portion at the boundary between the tooth portion of the toothed portion and the gum portion. As a result, the height (width in the direction of the tooth axis) of the inner peripheral surface of the concave fitting portion is rounded down so as not to be applied to the gums of the tooth decay so that the above-mentioned protruding line is not formed. As a result, the fitting of only the tooth portion of the tooth is ensured.

  The height of the buccal denture base, which is the buccal side of the denture base of the end artificial tooth, is determined from the denture base of the end artificial tooth. The height of the exposed cheek side tooth portion, which is the exposed cheek side tooth portion, can be made smaller. Accordingly, a thermoplastic resin portion that fits only to the tooth portion and does not touch the gum can be formed with a gentle slope continuously from the buccal side portion of the denture base of the end artificial tooth to the concave fitting portion. . In other words, the height of the buccal denture base of the end artificial teeth is small and small, so it is gently (without sharply rounding up) and fits only on the tooth part of the tooth without touching the gingiva. A mated thermoplastic resin buccal portion can be formed.

  A metal reinforcing wire is embedded in 50% or more of the total length. The thermoplastic resin is rich in elasticity, and when a denture base is formed only with the thermoplastic resin, a state of undulation in the dentition direction occurs. For example, in the case of a partial denture of the lower jaw, when stiff food is bitten by the right back tooth, it is compressed at the right back tooth part and is likely to generate a wave that floats near the front tooth. Such undulations along the dentition are also considered to promote separation from the conventional non-clasp denture wearing state. By embedding the reinforcing wire over 50% or more as in this configuration, it is possible to increase the rigidity of the entire denture base and suppress the occurrence of waviness. By using such a metal reinforcing wire, it is possible to keep the mounting state stable only with a concave fitting portion fitted only to a tooth without using a rest or a wing while using a thermoplastic resin rich in elasticity. it can.

  The concave fitting portion can be prevented from contacting more than 65% of the periphery of the tooth. Thereby, the cramped feeling at the time of wearing can be further eased while obtaining the above-mentioned advantages.

The concave fitting portion may include a buccal side extending portion that extends to the buccal side of the toothed tooth at a portion where the plate-like body is recessed . Thereby, it can be set as the concave fitting part which has a cheek side extension part made from a thermoplastic resin according to the state of a patient's remaining tooth. The lingual side may be constituted by a tongue side extending portion, or may be constituted by a wall-like portion of the denture base. A partial denture that is optimal for the patient can be formed in combination with a concave fitting portion that is formed by only the wall-shaped portion of the denture base that will be described later. Here, the buccal side extending portion and the lingual side portion are defined by dividing the concave fitting portion by the center line of the dentition of the artificial tooth, the buccal side portion being the buccal side extending portion, and the opposite side being the lingual side portion. .

  In the center of the cheek side extending portion of the concave fitting portion, the thickness of the central portion can be set to 30% or more of the height of the portion. As a result, the extended portion on the cheek side can have a relatively large rigidity, and can be fitted to the tooth surface with a considerable force. That is, the fitting to the toothed hook can be made more stable by the thick clasp rather than the thin planar contact portion (wing). The durability against long-term use can also be improved.

  The buccal side extending portion can be prevented from coming into contact with more than 50% of the tooth surface buccal side portion which is a half of the periphery of the tooth. Thereby, the uncomfortable feeling by seeing the cheek side extension part made of a thermoplastic resin can be suppressed. The above-described non-clasp denture uses a wing that covers the dental gingiva, and therefore intentionally covers almost 100% of the buccal portion of the tooth surface, which is a half of the circumference of the dental caries. However, in the partial denture of the present invention, since it does not fit into the gingiva, the user's true gum is exposed and the tooth on it is partially hidden by the buccal extension. For this reason, it is preferable in terms of aesthetics that the extended portion on the cheek side is also short. By making it into the range which does not exceed the above 50%, the uncomfortable feeling is small and the aesthetics are ensured. It is also effective in reducing the tightness when worn.

  As described above, when there is no protruding part on the buccal side and the tongue side, the concave fitting part is formed in a concave shape in the wall-like part of the denture base, and the wall-like part is brought into contact with the tongue side of the dental caries. The tongue side part, the mesial side part in contact with the mesial side, and the centrifugal side part in contact with the distal side can be configured. Thereby, according to the state of the patient's remaining teeth, an appropriate concave fitting part can be formed in combination with the concave fitting part that has a protruding part on the cheek side.

  At least two concave fitting portions are provided, the first concave fitting portion is fitted to the first toothed hook from the first direction, and the second concave fitting portion is fitted to the second hooked tooth, It is possible to adopt a structure that is fitted from a second direction different from the first direction. As a result, it is mounted by the two concave fitting portions having different detachment directions, so that a reliable mounting state can be maintained even if the food is chewed and chewed. In addition, said 1st direction and 2nd direction belong to the in-plane direction of the plane orthogonal to tooth-axis directions, such as a toothed hook.

  The partial denture manufacturing method given as a reference example manufactures a partial denture having an artificial tooth, a denture base on which the artificial tooth is provided, and a concave fitting portion to be fitted so as to be applied to the tooth. This method includes (1) a step of producing a plaster model of a tooth of a user's oral cavity, and (2) an integral injection of a thermoplastic resin including a concave fitting portion using the plaster model. (3) After covering the plaster model with occlusal paper, attach the partial denture on it, and depending on the concentration of the colorant of the occlusal paper transferred to the plaster model, the partial denture It is characterized by adjusting and adjusting.

  The occlusal paper is originally used to wear a partial denture to the user, bite the occlusal paper with the upper and lower teeth, and see how the teeth mesh with the tint of the colorant transferred from the occlusal paper. It is done. However, it can be used for the production of partial dentures as in the present invention, and in particular, in the case of partial dentures produced by integral injection molding of thermoplastic resin, the concave fitting part does not contain a metal clasp, so the color of the occlusal paper It is possible to easily grind the portion where the agent is deeply transferred, and the efficiency of adjustment can be greatly improved. That is, the partial denture of the present invention does not include a metal clasp and is made of a soft material, so that loosening occurs in low-accuracy grinding, causing a problem. By using the occlusal paper in the above-described manner, it is possible to accurately grasp a portion to be cut with respect to the marked portion, and to realize high-precision cutting. By this adjustment, the partial denture can be smoothly detached and secured, and all of maintenance, support and gripping can be ensured. By using the occlusal paper as described above, the shape of the unevenness or the like of the portion where the inner surface of the partial denture is difficult to see becomes clear. Such an effect cannot be obtained by other means. In particular, the above manufacturing method is extremely useful for the partial denture of the present invention which does not include a metal clasp in the concave fitting portion and is likely to loosen by adjustment with low accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the partial denture of a thermoplastic resin which overcame the fault of being easy to detach | leave from a mounting state in a non-clasp denture can be obtained.

It is a perspective view which shows the state which mounted | wore the gypsum model with the partial denture in Embodiment 1 of this invention. It is a perspective view which shows the partial denture of FIG. It is a figure of the concave fitting part C1 of the partial denture of FIG. 1, (a) is the figure seen from the toothed side, the back side, (b) is sectional drawing which follows the IIIb-IIIb line | wire of (a), (c ) Is a view as seen from the side of the toothed tooth and the front side, and (d) is a side view as seen from the cheek side. (A) is a top view of the concave fitting part C1 of the state fitted to the toothed hook, (b) is sectional drawing which follows the IVb-IVb line | wire in (a). It is an enlarged view of the concave fitting part C2, C3 of the partial denture of FIG. It is the figure which looked at concave fitting part C2, C3 from the lingual side and denture base back side. It is the top view which looked at the state which fitted the concave fitting part C2, C3 to the toothed hook from the tooth crest part side. The state which fits the concave fitting part of the partial denture of this Embodiment to the toothed hook is shown, (a) is sectional drawing in the case of the concave fitting part C1, (b) is concave fitting part C2, C3. It is sectional drawing in the case. It is sectional drawing which shows a wing part when the conventional non clasp denture is mounted | worn. It is process drawing which shows the manufacturing process of the partial denture in Embodiment 1 of this invention. It is a figure which shows the process of adjustment of the manufacturing process n belly of FIG. It is a perspective view which shows the partial denture in Embodiment 2 of this invention. It is an enlarged view of the concave fitting part C2 of the partial denture of FIG. It is a perspective view which shows the conventional non-clasp denture. The state which mounted | wore the gypsum model with the conventional non-clasp denture is shown, (a) is a left wing vicinity, (b) is a figure which shows the right wing vicinity. It is the figure which looked at the conventional non-clasp denture from the back side. It is the figure which looked at the opening part of the right side of the conventional non-clasp denture from the back side. (A) is sectional drawing which follows the XVIIIa-XVIIIa line | wire of FIG. 17, (b) is a figure for demonstrating the angle which the tooth contact surface and gum contact surface which pinch | interposes a protruding line make.

(Embodiment 1)
FIG. 1 is a perspective view showing a state in which a partial denture 10 according to Embodiment 1 of the present invention is mounted on a plaster model M. FIG. The partial denture 10 is for the upper jaw, and includes a denture base 20, a resin artificial tooth 31, and concave fitting portions C ₁ , C ₂ , and C ₃ for tooth decay (maintenance teeth). The remaining teeth are the three teeth R ₅ , R _3, and L ₇ , and the following concave fitting portions are fitted to the respective teeth.
鉤歯L7: concave mating part _{C 1}
Tooth R5: concave fitting part C ₂
鉤歯R3: concave mating part _{C 3}
FIG. 2 is a perspective view of the partial denture 10 of FIG. 1 viewed from the front side. The inner peripheral surface F in the concave fitting portion C1 is fitted only to the tooth portion of the tooth. The inner peripheral surface F is a tooth contact surface of the toothed tooth. The concave fitting portion C ₁ and the concave fitting portions C ₂ and C ₃ have different shapes as follows, as shown in FIG.
(Concave fitting part C ₁ ):
It is composed of a buccal side extending portion 11 that extends to the buccal side of the tooth decay and a tongue side extending portion 21 that extends to the lingual side of the tooth decay. About the lingual side part, you may be formed by the wall-shaped part instead of the extension part. A concave fitting portion of a type having the buccal side extending portion 11 is referred to as an “extending structure fitting portion” or simply “an extending structure”.
(Concave fitting portions C ₂ and C ₃ ):
It is composed of the denture base wall-like portions 33, 34, and 35 which are in contact with the lingual side of the tooth decay and the mesial side and the distal side of the tooth decay. This type of concave fitting portion is referred to as a “wall-like structure fitting portion” or simply “wall-like structure”.

A metal reinforcing wire 29 is embedded in the denture base 20. The metal reinforcing wire 29 extends over 50% of the total length of the denture base. In this partial denture 10, the denture base 20, the concave fitting portions C ₁ , C ₂ , C ₃ , the metal reinforcing wire 29 and the artificial teeth are integrally formed by integral injection molding of a thermoplastic resin. The metal reinforcing wire 29 and the artificial tooth are not, of course, a thermoplastic resin, but when the molten thermoplastic resin is injected into the mold, by placing it in the mold in advance, after cooling the thermoplastic resin, It is integrated with the thermoplastic resin. For this reason, the portion exposed on the surface other than the artificial teeth is formed only of the thermoplastic resin. Therefore, since there is no conventional metal clasp, it is excellent in aesthetics, and restraint on the tooth decay can be eliminated.
In addition, the partial denture 10 of the present invention does not require a rest or the like, and a retaining force is generated by the concave fitting portions C ₁ , C ₂ , and C ₃ . 1 will be described later in relation to the stability of the mounting state, as well as terms such as the mounting method and the keys and locks related to the concave fitting portions C ₁ , C ₂ , and C ₃ .
In FIG. 1, the concave fitting portion C ₁ is fitted from the horizontal direction or the horizontal direction, and the concave fitting portions C ₂ and C ₃ are fitted from the vertical direction or the vertical direction. Here, it should be noted that the direction of fitting and detaching is not a simple vertical direction or vertical direction, but is fitted and detached while drawing a complicated trajectory. In this respect, it is greatly different from the conventional method of attaching and removing partial dentures. Then, the one concave fitting direction fitting the mating portion C _1, the other and are different directions mating concave mating portion C _2, C ₃ is important. One is called a key and the other is called a lock. Depending on the state in the oral cavity of the user, the horizontal direction is the fitting direction, but both directions are different in the horizontal plane. In the partial denture in the embodiment of the present invention, the attachment / detachment direction is described as the vertical direction, the horizontal direction, etc., with emphasis on simplicity of explanation, but the actual situation has a complicated trajectory as described above in all partial dentures. Draw.

FIG. 3 is an enlarged view of the concave fitting portion C1, (a) is a view of the back surface side with the denture base back surface 20b facing upward, and (b) is along the line IIIb-IIIb in (a). It is sectional drawing, (c) is the figure seen from the surface side of the denture base 20, and (d) is the figure seen from the cheek side. In Fig.3 (a), the internal peripheral surface F is formed as a side end surface of the concave fitting part C1, and stands so that it may cross | intersect with the back surface 20b of a denture base. The intersection angle theta _N is less than 120 °. That is, the limit of the root side of the inner peripheral surface F that is fitted only to the tooth portion is determined by the denture base back surface 20b. As a result, the inner peripheral surface F is reliably prevented from fitting into the gums.
A significant difference in structure from the conventional non-clasp denture is that the inner peripheral surface F can determine the limit on the root side by the denture base back surface 20b. Like the wing W of the non-clasp denture 150 shown in FIGS. 17 and 18, the angle formed by the tooth contact surface F and the surface continuous to the root side (gum contact surface B _v ) is almost 180 °. is there. That is, the portion F that contacts only the tooth portion is not limited to the limit on the root side, but rather extends to the root side. As an extended portion, a gum contact portion _Bv is provided. Only the tooth section continuously from the portion contacting F, to extend continuously in contact with portions B _v gums corresponds to the concave bent portion of the boundary between the tooth portions and gum portion of鉤歯projecting A line is inevitable. Therefore, the wing W of the conventional non-clasp denture 150 is provided with a protruding line Z as shown in FIGS. In the partial denture 10 of the present invention, there is of course no protruding line Z. The partial denture 10 of the present embodiment is basically different in structure from the non-clasp denture 150 so that a maintenance force can be generated only at the top side of the protruding line.

It is to be common to the concave mating portion C ₁ -C ₃ of the present embodiment, alignment fitted to鉤歯is the denture base 20 is regarded as a curved plate-like body, the plate-like body in a concave It is formed by punching (see FIG. 3C). Thus, mating portion C ₁ -C ₃ This recessed fitting has a high rigidity, is combined firmly fitted into鉤歯. When the concave portion is fitted to the tooth portion of the toothed tooth from the horizontal direction or the vertical direction, the mounting state can be stably maintained even when subjected to occlusal pressure, detachment force, or the like due to this high rigidity. In the conventional non-clasp denture 150, a thin sheet of thermoplastic resin is sandwiched from the lingual side and the cheek side, including the tooth and gum of the tooth decay, to obtain a maintenance force. At this time, in the non-clasp denture 150, it is pushed from above the toothed teeth in the up-and-down direction and tries to obtain a maintenance force by sandwiching with the above-mentioned planar body. For this reason, the partial denture 10 of the present embodiment and the conventional non-clasp denture 150 are greatly different in structure.

With reference to FIG. 3 (d), the end artificial tooth facing the tooth of the artificial tooth will be described. The partial denture 10 in the present embodiment, the height B _e buccal denture part is buccal portion of the denture base end artificial teeth L ₆ is exposed from the denture base of its ends artificial teeth L ₆ the height of the buccal exposed tooth portion is a tooth portion of the buccal to T _e, less than. Thus, the cheek-side portion of the denture base end artificial teeth L _6, over the recessed mating portion C _1, fit only the tooth portion of the鉤歯, and extend out buccal thermoplastic resin not applied to the gums The portion 11 can be formed with a gentle slope. That is, the height of the buccal denture base of the end artificial teeth is small and small, so as it is gently (without sharply rounding up), the thermoplastic resin that fits only on the tooth portion of the tooth decay A cheek-side extended portion can be formed.
In contrast, in the conventional non clasp denture 150, FIG. 15 (a), the (b), the end artificial teeth _{L 5,} L 6, cheeks a buccal portion of the denture base of _{R 6} The height B _e of the side denture base is larger than the height T _e of the buccal side exposed tooth part, which is the buccal tooth part exposed from the denture base of each end artificial tooth. In the non-clasp denture 150, this is a result of increasing the wing W so as to contact both the tooth and the gum of the tooth decay and also swinging the denture base 120. It can be said that this is one of the structural features representing the difference between the concept of the partial denture 10 in the present embodiment and the concept of the non-clasp denture 150.

Figure 4 is a view of the concave mating portion C ₁ of the extending out structure from the top side of the鉤歯L _7. Concave mating portion C ₁ is surrounding the periphery of鉤歯L _7, it does not exceed 65% be 65% or less of the circumferential length of鉤歯L _7. Further, the circumference of the buccal extension 11 is 50% or less of the tooth cheek side circumference. Moreover, since the circumference of the toothbrush cheek side is half of the tooth circumference, the circumference of the buccal extension 11 is 25% or less of the circumference of the tooth. Such limitation of the circumferential length is greatly different from the opening 161h for the toothed teeth of the conventional non-clasp denture 150 shown in FIG. Part denture 10 of the present embodiment, the concave mating portion C ₁ is not fitted so as to cover from above, fitted as Ategau from the lateral direction crossing the axis of the tooth. For this reason, the limitation of the circumference as described above is inevitable. If the circumference is not limited, the concave fitting portion cannot be fitted to the toothed hook from the lateral direction. Since even a thermoplastic resin is uncomfortable, such a limitation on the circumference is effective for alleviating the uncomfortable feeling of the mounted body.
FIG. 4B is a cross-sectional view taken along line IVb-IVb in FIG. This cross-sectional position is near the center of the buccal extension 11. According to this cross-sectional view, it is clear that the thickness d is 30% or more of the height (width) Y of the portion. Thereby, the buccal side extending portion 11 can have a large rigidity, and the fitted state can be stably maintained. That is, the fitting to the toothed hook can be made more stable by the thick concave fitting portion rather than the thin planar contact portion (wing). The durability against long-term use can also be improved.
Here, as shown in FIG. 4B, the cheek-side extension portion 11 of the concave fitting portion C1 does not have a planar portion that can be said to be a back surface, and is curved toward the side surface. In the buccal side extension part, it is easy to have the structure of the concave fitting part of the form which may be said that there is no such back surface. In this case, the back surface 20b of the denture base adjacent to the buccal side extending portion 11 can be regarded as the above-mentioned back surface when viewed macroscopically (see FIG. 3A). The angle formed between the denture base back surface 20b and the inner peripheral surface F of the buccal side extending portion 11 as seen from a macro view may be within a range of 60 ° to 150 °. The angle is clearly within this angular range.

FIG. 5 is a perspective view of the concave fitting portions C ₂ and C ₃ of the wall-like structure as seen from the cheek side and the tooth crest side. FIG. 6 is a perspective view of the concave fitting portions C ₂ and C ₃ as viewed from the denture base back surface 20b side. FIG. 7 is a plan view of the concave fitting portions C ₂ and C ₃ as viewed from the top of the tooth with the partial denture attached to the gypsum model. The metal reinforcing wire is omitted because the figure becomes complicated. 5 to 7 confirm the following.
(1) The concave fitting portions C ₂ and C ₃ of the wall-like structure type are formed of a toothed tongue side portion 33, a mesial side portion 34, and a centrifugal side portion 35. This structure is different from the extended fitting type concave fitting portion C1.
(2) The inner peripheral surface F of the concave fitting portions C ₂ and C ₃ of the wall-like structure is defined (limited) on the denture base back surface 20b on the root side, and intersects the denture base back surface 20b. Standing. If the denture base 20 is regarded as a curved plate-like body by changing the way of viewing, the inner peripheral surface F can be regarded as a side end surface formed by punching the plate-like body into a concave shape. The angle formed between the inner peripheral surface F and the back surface of the concave fitting portion or the denture base back surface 20b is close to a right angle and is clearly in the range of (right angle -30 °) to (right angle + 60 °). This was true even mating portion C ₁ fitted concave extending out structure.
(3) The inner peripheral surface F has a short width (height direction), and has no protruding line corresponding to the concave bent portion at the boundary between the tooth of the tooth and the gum. This is also the same as mating portion C ₁ fitted concave extending out structure.
(4) As shown in FIG. 7, the concave fitting portions C ₂ and C ₃ are fitted to 65% or less of the circumference around the toothed teeth R ₃ and R ₅ , respectively. The circumferential length limitation is also the same as the mating portion C ₁ fitted concave extending out structure.
(5) end the artificial teeth R _2, R _6, the height T _e buccal exposed portion of the end portion artificial teeth is greater than the height B _e buccal denture portion of the base side. That is, T _e > B _e is satisfied. This structure is also the same as the mating portion C ₁ fitted concave extending out structure.
As described in (1) above, the concave fitting portions C ₂ and C ₃ of the wall-like structure are different in shape from the concave fitting portion C ₁ of the extended structure, but the structural feature (2 ) To (5) are the same. Naturally, the effects of the structures (2) to (5) are the same.

-Stability of wearing condition-
(Partial denture 10 of the present embodiment):
(1) FIG. 8 is a diagram showing a wearing state and the like when the partial denture 10 according to the present embodiment is worn on a patient, (a) is a concave fitting portion C ₁ , and (b) is a concave fitting. The joining parts C ₂ and C ₃ are shown. In FIG. 8A, both the buccal side extending portion 11 and the lingual side extending portion 21 are fitted only to the tooth portion of the toothed tooth L7 and are not fitted to the gingiva or gum. With the exception of a very special condition in the patient's oral cavity, the partial denture 10 of the present embodiment is mounted along a direction (lateral direction or horizontal direction) intersecting the tooth axis. The occlusal pressure applied when food is occluded is basically borne by the alveolar mucosa through the denture base of the portion where the artificial teeth are located. Even if the occlusal pressure is applied to the partial denture 10, the positions of the concave fitting portions C ₁ , C ₂ , and C ₃ hardly change. And, for the force opposite to the occlusal pressure (detachment force), since the fitting is performed from the prominent part of the tooth decay to the root side, there is a taper that expands the cross section on the apex side of the tooth decay, Withdrawal is prevented.
The concave bent portion K is located at the boundary between the tooth and the gum, but the concave fitting portions C ₁ , C ₂ , and C ₃ are fitted only to the teeth above the concave bent portion K.
(2) In the above concave fitting structure, mounting is performed from the horizontal direction to the root of the toothed teeth. The attachment and detachment are performed along a direction (lateral direction or horizontal direction) different from the detachment direction, which effectively works to prevent the detachment. Moreover, a concave mating portion C _1, and the concave mating portion C _2, C _3, has a structure that is also mounted from different directions at the same horizontal plane.
FIG. 1 shows the mounting direction of the concave fitting portion C ₁ and the concave fitting portions C ₂ and C ₃ . When the partial denture 10 is mounted, first, the concave fitting portion C ₁ (first concave fitting portion) is moved to the toothed tooth L ₇ in the horizontal direction or the lateral direction (first direction) and loosely fitted. . Then, this was a concave mating portion C ₁ as a fulcrum, the entire portion denture 10, the vertical direction also in along a longitudinal direction (second direction), the concave mating portion C _2, C 3 _(second concave The fitting portion) is fitted to the toothed teeth R ₃ and R ₅ . The first direction and the second direction are different. As described above, the first concave mating portion C ₁ is referred to as the key, the second concave mating portion C _2, C ₃ is referred to as a lock. Only one second concave fitting portion is sufficient. The key cannot be removed unless it is unlocked. Since the lock release direction is a direction that follows the second mounting direction (lateral direction or horizontal direction) in the reverse direction, the vertical release force shown in FIG. 8 does not release at all. The names “key” and “lock” are not general. As described above, there are two or more concave fitting portions and two or more different fitting directions. This is because the mounting direction of the conventional non-clasp denture 150 to be described later is from the tooth crest to the root. This is a great difference from mounting by moving in one direction.
In addition, depending on the state in the user's oral cavity, the fitting direction of C ₁ may be the vertical direction, and the fitting direction of C ₂ and C ₃ may be the horizontal direction. When C ₂ and C ₃ are first fitted and then C ₁ is fitted, C ₂ and C ₃ are keys and C ₁ is locked.
(Non-clasp denture 150):
FIG. 9 is a diagram illustrating a wearing state, a wearing direction, and the like when a conventional non-clasp denture 150 is worn on a patient. In the non-clasp denture 150, the tooth is inserted in the opening portion 161h, and is mounted in the vertical direction from the top to the bottom along the tooth axis from the top side of the tooth. With this attachment, the teeth and gums of the tooth decay are sandwiched from the lingual side and the cheek side. It is intended to keep the wearing state stable by sandwiching this. However, when the denture base 120 and the wing W of the non-clasp denture are in contact with the gingival portion that forms a convexly curved slope, and the pressure is applied, the thermoplastic resin is rich in elasticity. When the occlusal pressure disappears, the slope is easily lifted and separated by the repulsive force of the denture base of the gingival slope. By repeating this, loosening occurs with use, rattling occurs, and it is considered that it becomes easy to separate. In the conventional non-clasp denture, since a large portion such as a wing provided for the purpose of increasing the maintenance force hits the gingival slope, it is considered that it acts in the direction of promoting separation. In addition, although the protruding line Z is inserted into the concave bent portion K at the boundary between the tooth and the gum, the tooth side recedes and the gingival side protrudes. Therefore, almost no anchor effect can be expected.

  As a result of the configuration of the present invention described above, it is possible to reliably prevent detachment from the mounted state while obtaining advantages such as economy by a manufacturing method by integral injection molding of a thermoplastic resin (described later). Furthermore, since a wing corresponding to a gum or a large denture base is not used, a comfortable wearing feeling can be obtained except for a feeling of cramping.

FIG. 10 is a process diagram showing an example of a method for manufacturing the partial denture 10 in the present embodiment. First, the patient's impression is taken and then manufactured according to the following steps.
Plaster model → wax denture production (metal parts such as metal reinforcement wires, artificial teeth, etc. are placed on the old denture) → wax denture primary burial (in the lower flask) → secondary burial (in the upper flask) → flow wax → upper and lower flasks Separation → Mold maintenance → High temperature and high temperature injection of thermoplastic resin into the mold → Natural cooling (about 1 hour) → Removal In the process up to removal, there is no need to manufacture a metal clasp in the partial denture of this embodiment. Accordingly, the manufacturing process can be omitted. Further, after the thermoplastic resin is injected into the mold at a high pressure and high temperature and then naturally cooled, it is naturally cured to a product state. In contrast, in the case of a partial denture of a conventional denture base made of resin, it takes about one day to keep the temperature high and then slowly cool and take it out. Therefore, the process can be shortened compared with the case where a resin-made denture base is used.

After removal, the adjustment can be easily performed by the adjustment method shown in FIG. The occlusal paper is originally used to attach a partial denture to a user, occlude the occlusal paper with upper and lower teeth, and check the occlusion by the density of the colorant transferred from the occlusal paper. However, as shown in FIG. 11, it can be used for the adjustment process in the manufacture of a partial denture. The occlusion paper is thinly coated with a colorant, and transfers the colorant to the contact object according to the contact pressure level. This occlusal paper is placed on the plaster model, the occlusal paper can be crumpled, the occlusal paper is sandwiched between the plaster model, and a partial denture is attached. The occlusal paper is rolled and rolled and is flat, but is pushed into the plaster model by the partial denture, so that it is sandwiched between the plaster model and the partial denture in a crumpled state. At this time, a high pressure is applied to the occlusal paper at the portion of the partial denture that protrudes inconveniently, and the colorant is darkly transferred. This darkly transferred portion is ground with a grinding tool.
In the case of partial dentures manufactured by integral injection molding of thermoplastic resin, since the metal clasp is not included in the concave fitting part, it is possible to easily grind and adjust the part where the colorant of the occlusal paper is darkly transferred. The efficiency of can be greatly improved. Grinding is performed by attaching a replaceable grinding tool (such as a carborundum point) to the tip of a dental electric drill, and is commonly used. Any occlusion paper may be used, but Okklusions-Foile (thickness: 12 μm, color: red) REF480032 of HANEL, Germany may be used. The color may be red but blue. Since it is better that the colorant is transferred to the partial denture and the colorant is not transferred to the plaster model, it is preferable to use an occlusal paper coated with the colorant only on one side. In the case of this occlusal paper coated on one side of the colorant, it is naturally arranged so that the colorant directly hits the partial denture 10.

(Embodiment 2)
FIG. 12 is a perspective view showing a partial denture 10 according to Embodiment 2 of the present invention. This partial denture 10 is for the lower jaw and includes concave fitting portions C ₁ and C ₂ for the toothed teeth. The patient lacks the lower jaw left 5-7 and the right 6-7, and the partial denture 10 compensates for the missing portion. The connecting portion that connects the resin portion that fixes the right artificial tooth and the resin portion that fixes the left artificial tooth is usually composed of a large metal connector. However, as shown in FIG. Then, this part is also formed of a thermoplastic resin. However, the metal reinforcement line is buried. In order to make the structure of the drawing easier to see, the metal reinforcing wire is omitted. The concave fitting portions C ₁ and C ₂ both have the following shape.
(Concave fitting part C1, C2):
It is composed of a buccal side extending portion 11 that extends to the buccal side of the tooth decay and a wall-like portion 21 formed on the tongue side of the tooth decay. As described above, since there is an extended portion on the cheek side, the concave fitting portions C ₁ and C ₂ are of an extended structure type. The two concave fitting portions C ₁ and C ₂ have almost the same structure although there is a difference between left and right.

FIG. 13 is an enlarged view of the concave fitting portion C1. As for the two concave fitting portions C ₁ and C ₂ , the following structure can be given as in the concave fitting portion of the partial denture of the first embodiment.
(1) The inner peripheral surface F is demarcated (limited) to the denture base back surface 20b on the root side, and stands so as to intersect the denture base back surface 20b. The angle formed between the inner peripheral surface F and the back surface of the concave fitting portion or the denture base back surface 20b is close to a right angle, clearly in the range of (right angle -30 °) to (right angle + 60 °).
(2) The inner peripheral surface F has a short width (in the height direction), and there is no projecting line corresponding to the concave bent portion at the boundary between the tooth of the tooth and the gum.
(3) The concave fitting portions C ₁ and C ₂ are clearly fitted to 65% or less of the circumference around the toothed teeth.
(4) The end artificial teeth L _5, the height T _e buccal exposed portion of the end portion artificial teeth is greater than its base side cheek side height B _e denture base. That is, T _e > B _e is satisfied.
(5) One of the concave fitting portions C ₁ and C ₂ (first concave fitting portion) is loosely fitted in the horizontal teeth in the horizontal direction, and is rotated in the horizontal direction using that as a fulcrum, and the other (second The concave fitting part) is fitted to the toothed teeth. If the first fitting portion is a key, the second fitting portion is a lock. The key cannot be removed unless it is unlocked. It does not deviate from the separation force along the tooth axis direction of the tooth.

  The partial denture 10 of the present embodiment includes the structural features (1) to (5) above. For this reason, the mounting state can be kept stable even if it is not provided with a metal clasp, together with the simplicity of manufacturing by forming by integral injection molding of a thermoplastic resin. Moreover, the improvement of the aesthetics by not providing a metal clasp can be acquired. Furthermore, the discomfort in the oral cavity can be eliminated by the small concave fitting portion and the small denture base.

  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.

  The partial denture of the present invention can overcome the disadvantage of non-clasp dentures that are easily disengaged from the wearing state, and can further eliminate discomfort in the oral cavity.

DESCRIPTION OF SYMBOLS 10 Partial denture, 11 Buccal side extension part, 20 Denture base, 20b Denture base back surface, 21 Tongue side part (lingual side extension part, tongue side wall-shaped part), 29 Metal reinforcement line, 31 Artificial tooth, 33 Tongue side part (Of concave fitting part of wall-like structure), 34 mesial side part (of concave fitting part of wall-like structure), 35 centrifugal side part (of concave fitting part of wall-like structure), 120 non-clasp denture denture, 150 non clasp denture, openings contains the 161h鉤歯, B backside (concave mating part or denture), B _e end tooth exposed portion of the height of the artificial tooth, B _v non clasp denture gums those contact surface, d buccal extends out of the center of the thickness, F inner circumferential surface, a concave bent portion of the boundary between the teeth and gums of K鉤歯, T _e end buccal height of denture base of artificial teeth, Y Height (width) of the center of the buccal extension, W Non-clasp dent Over wing, Z projecting lines (non clasp denture), theta _N inner peripheral surface and the back surface and the angle formed.

Claims (10)

A partial denture comprising an artificial tooth, a denture base provided with the artificial tooth, and a concave fitting portion to be fitted so as to be applied to a tooth;
The partial denture is not provided with a clasp or metal fitting part anywhere, including the concave fitting part, and is formed by integral injection molding of a thermoplastic resin,
The concave fitting portion is a fitting portion that does not include a rest and exerts a fitting force only on the tooth portion of the toothed tooth , and regards the denture base as a curved plate-like body, and passes the plate-like body into a concave shape. as formed, standing the is intended to fit into corresponding portions鉤歯, as the inner circumferential surface along the inner circumference of the concave mating part, crossing the rear surface of the front Symbol denture The partial denture is characterized in that the bottom side is limited by the back surface of the denture base and a metal reinforcing wire is embedded in 50% or more of the total length of the denture base.   The partial denture according to claim 1, wherein an angle formed between the inner peripheral surface and the inner peripheral surface and the back surface is in a range of (right angle -30 °) to (right angle + 60 °).   3. The partial denture according to claim 1, wherein the inner peripheral surface has no protruding line corresponding to a concave bent portion at a boundary between a tooth portion and a gum portion of the tooth decay. 4.   Among the artificial teeth, in the end artificial tooth facing the tooth decay, the height of the buccal denture base which is the buccal side portion of the denture base of the end artificial tooth is the height of the end artificial tooth. The partial denture according to any one of claims 1 to 3, wherein the partial denture is smaller than a height of a buccal side exposed tooth portion which is a buccal side tooth portion exposed from the denture base.   The partial denture according to any one of claims 1 to 4, wherein the concave fitting portion does not contact more than 65% around the toothed teeth. The said concave fitting part is equipped with the buccal side extension part extended to the cheek side of the said tooth decay in the part by which the said plate-shaped body was dented in the concave shape , The any one of Claims 1-5 characterized by the above-mentioned. Partial denture according to item.   The partial denture according to claim 6, wherein a thickness of the central portion of the concave fitting portion is 30% or more of a height of the portion at the center of the extended portion on the cheek side.   The partial denture according to claim 6 or 7, wherein the buccal side extending portion does not contact more than 50% of the buccal periphery which is half of the periphery of the tooth decay.   The concave fitting portion is formed in a concave shape in the wall-shaped portion of the denture base, and the wall-shaped portion is a lingual side portion that contacts the lingual side of the toothed tooth, a mesial side portion that contacts the mesial side, The partial denture according to any one of claims 1 to 5, wherein the partial denture is configured by a centrifugal side portion that comes into contact with the centrifugal side.   The concave fitting portion includes at least two concave fitting portions, the first concave fitting portion is fitted to the first toothed hook from the first direction, and the second concave fitting portion is fitted to the second hooked tooth. The partial denture according to any one of claims 1 to 9, wherein the partial denture is fitted from a second direction different from the first direction.

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