Retainer and method for manufacturing a retainer

Abstract

To provide a retainer capable of adjusting engagement, having excellent aesthetic property and durability, and capable of reliable retention of dentition after orthodontic treatment.SOLUTION: A retainer 100 for retention of dentition after orthodontic treatment is mounted, with occlusal surfaces T1 of respective teeth T being exposed, and includes: a front fitting part 10 mounted onto front surfaces of the respective teeth T from a lip and cheek side; and a rear fitting part 20 mounted to rear surfaces of the respective teeth T from a palatal side or a tongue side. The front fitting part 10 is transparent and also covers surfaces of respective gums A.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a retainer for maintaining the tooth alignment after orthodontic treatment and a method for manufacturing the retainer.

Background Art

[0002] First, before explaining the retainer, the underlying orthodontic treatment will be briefly described.

[0003] As a conventional orthodontic treatment, there is wire orthodontics in which teeth are gradually moved using a wire to align the tooth arrangement. However, this orthodontic method has drawbacks such as lacking aesthetic appeal and being difficult to clean the oral cavity because the wire cannot be removed during orthodontics.

[0004] Therefore, in recent years, there has been an increasing trend in aligner orthodontics that uses a transparent mouthpiece that is aesthetically pleasing and removable to align the tooth arrangement.

[0005] After such orthodontic treatment, if left untreated, the corrected tooth alignment tends to return to its original state, so it is necessary to use a retainer to maintain the tooth alignment.

[0006] As an existing retainer, there is a mouthpiece type called a press retainer. This retainer is molded entirely from a transparent resin and has the advantage of good aesthetic appeal. However, since it covers the occlusal surface of the teeth, it has the drawback that occlusal adjustment after orthodontic treatment cannot be performed.

[0007] Although it should be naturally understood by those skilled in the art, it is extremely important to perform occlusal adjustment after orthodontic treatment. This is because, as also advocated in occlusion studies, a poor occlusion state (malocclusion) causes uneven forces applied to the teeth, which can lead to various problems such as tooth cracks, dental caries caused by bacteria entering the cracks, and tooth deflection. Therefore, if occlusal adjustment cannot be properly performed even after orthodontic treatment, and the occlusal forces applied to each tooth are uneven, and large occlusal forces such as bruxism and tooth grinding, which are physiological phenomena, are applied at night, it can cause problems such as the tooth alignment regressing.

[0008] Therefore, as a retainer that can adjust the occlusion after orthodontic treatment, there are those that are worn with the occlusal surfaces of the teeth exposed. Specifically, there are those called wrap-around retainers and those called QCM retainers.

[0009] The former wrap-around retainer, as shown in Fig. 7, mainly uses a metal wire to fix the tooth alignment, and the wire is extended from the front teeth to the back teeth across the labial and buccal sides (Patent Document 1).

[0010] However, as described above, among the increasing trend of aligner orthodontics that emphasizes aesthetics, fixing with a wire after this aligner orthodontics does not follow the approximate trend, and in the first place, the wrap-around retainer is difficult to be actively accepted.

[0011] Moreover, although the wrap-around retainer has durability, there are problems such as the need for the technician's proficiency due to increased bending of the wire. Furthermore, compared to the above-mentioned press retainer, this wrap-around retainer also has problems such as a smaller contact area with the teeth and a weaker holding force for firmly fixing the tooth alignment after orthodontic treatment.

[0012] In contrast, as shown in Fig. 8, the latter QCM retainer has a transparent resin belt extending at least on the labial and buccal sides of the anterior teeth instead of a wire, which has better aesthetics than a wrap-around retainer and less wire bending.

[0013] However, it has a problem that its durability is extremely inferior to that of a wrap-around retainer and it needs to be replaced due to breakage. Moreover, compared with a press retainer, it has the same problem as a wrap-around retainer in that the contact area with the teeth is small, and the holding force for firmly maintaining the tooth alignment after orthodontic treatment is also weak.

[0014] Thus, each type of retainer has its own demerits. Therefore, there has been a proposal to use different types of retainers in combination to compensate for these demerits. Specifically, for example, a mouthpiece-type press retainer is used during the day and a wrap-around retainer is used during sleep.

[0015] However, in this case, when the tooth alignment that is retained with the occlusal surface of the teeth exposed by the wrap-around retainer during sleep is replaced with a press retainer that covers the occlusal surface of the teeth during the day, the tooth alignment tends to return slightly to its original state. That is, when different types of retainers are used in combination, the way of retention changes when each retainer is worn, and the intended retention function cannot be obtained.

Prior Art Documents

Patent Documents

[0016]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0017] Therefore, the present invention has been made to solve all kinds of demerits associated with existing various retainers at once, and its main object is to provide a retainer that can adjust the meshing, has excellent aesthetic properties and durability, and can firmly hold the tooth alignment after orthodontic treatment.

Means for Solving the Problems

[0018] That is, the retainer according to the present invention is a retainer for holding the tooth alignment after orthodontic treatment, and is a retainer that is worn with the occlusal surface of the teeth exposed, and has a front-side fitting portion that is worn on the surface of the teeth from the labial / buccal side, and a back-side fitting portion that is worn on the back surface of the teeth from the palate side or the lingual side. The front-side fitting portion is transparent and covers the surface of the gingiva.

[0019] According to the retainer configured in this way, since it is worn with the occlusal surface of the teeth exposed, the meshing can be adjusted after orthodontic treatment, and moreover, since the front-side fitting portion is transparent, it has excellent aesthetic properties. In addition, since the front-side fitting portion is worn on the surface of the teeth from the labial / buccal side and also covers the surface of the gingiva, it has excellent durability, and compared with existing wraparound retainers and QCM retainers, the contact area with the teeth is significantly increased, so that the tooth alignment after orthodontic treatment can be firmly held, and furthermore, secondary effects such as an unprecedented feeling of fit and difficulty in coming off can be obtained. In this way, the retainer according to the present invention has various advantages of existing retainers so to speak.

[0020] It is preferable that the front-side fitting portion and the back-side fitting portion are made of a thermoplastic resin. In this case, it has better durability than a QCM retainer using a resin belt and can be used continuously for at least two years.

[0021] Incidentally, the connecting portion between the inner side of the front fitting portion and the inner side of the back fitting portion is a portion that passes through a portion with a narrow clearance further inside than the rearmost tooth. Therefore, this connecting portion has to be made thin in terms of design, and if it is made of resin like the fitting portion, the mechanical strength cannot be ensured. Therefore, it is preferable to further provide a connector that is provided between the inner side of the front fitting portion and the inner side of the back fitting portion and has higher strength than these fitting portions. In this case, the strength of the connecting portion between the inner side of the front fitting portion and the inner side of the back fitting portion can be ensured.

[0022] It is preferable that the joint portion between the connector and the front fitting portion is located on the surface of the back teeth. In this case, even when the mouth is opened, the connector is hidden, so excellent aesthetics can be maintained.

[0023] Moreover, the retainer manufacturing method according to the present invention is a method for manufacturing a retainer for fixing the tooth alignment after orthodontic treatment, which creates a tooth mold including a plurality of simulated teeth and a simulated tooth root supporting them, creates a molding mold that is fitted to the tooth mold and has a gap interposed therebetween, and pours resin into the gap formed by fitting the tooth mold and the molding mold and hardens it, thereby creating a front fitting portion that is attached to the surface of the teeth from the labial and buccal sides and a back fitting portion that is attached to the back surface of the teeth from the palate side or the lingual side, and the front fitting portion is transparent and also covers the surface of the tooth root. According to such a retainer manufacturing method, the effects of the retainer described above can be achieved. That is, it is possible to provide a retainer that can adjust the occlusion, is excellent in aesthetics and durability, and can firmly fix the tooth alignment after orthodontic treatment.

Effects of the Invention

[0024] According to the invention of the present application configured as described above, it is possible to adjust the meshing, and moreover, it is possible to provide a retainer that has excellent aesthetic properties and durability and can firmly maintain the tooth alignment after orthodontic treatment, combining various advantages of existing retainers.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0026] Hereinafter, an embodiment of the retainer according to the invention of the present application will be described with reference to the drawings.

[0027] <Configuration> The retainer 100 according to the present embodiment is for maintaining the tooth alignment after orthodontic treatment, and as shown in FIG. 1, it is mounted on the tooth T with the occlusal surface T1 of the tooth T exposed. In the following, for convenience of explanation, the teeth and gums of a pre-prepared model will be described as the actual teeth T and gums A after orthodontic treatment.

[0028] Specifically, as shown in FIG. 1, this retainer 100 has a front fitting portion 10, a back fitting portion 20, and a pair of connectors 30 interposed between these fitting portions.

[0029] As shown in FIGS. 1 and 2, the front fitting portion 10 is mounted on the surface of the tooth T from the labial-buccal side.

[0030] This front fitting portion 10 has a shape along the labial-buccal surfaces (labial surface and buccal surface) of the tooth T after orthodontic treatment. In this embodiment, it is molded from the surface of the tooth alignment after orthodontic treatment.

[0031] More specifically, this front fitting portion 10 is made of a transparent resin and is continuously provided from the most posterior tooth T on one side through the anterior teeth to the most posterior tooth T on the opposite side. In this embodiment, it is made of a thermoplastic resin that can be used for a denture base, and is a colorless and transparent one mainly composed of, for example, an acrylic resin, a polyamide-based resin, or a polyester-based resin.

[0032] And, as shown in FIG. 1, this front fitting portion 10 is characterized by covering the surface of the tooth root A together with the surface of the tooth T.

[0033] That is, this front fitting portion 10 has a shape not only along the surface of the tooth T but also along the surface of the tooth root A. In this embodiment, it is molded from the surface of the tooth root A together with the surface of the tooth T.

[0034] More specifically, this front fitting portion 10 is continuously provided from the surface of the portion of the tooth root A that supports the most posterior tooth T on one side, through the surface of the portion that supports the anterior teeth, to the surface of the portion that supports the most posterior tooth T on the opposite side.

[0035] As shown in FIGS. 1 and 2, the back fitting portion 20 is mounted on the back surface of the tooth T from the palate side or the tongue side and is separate from the above-described front fitting portion 10.

[0036] This back fitting portion 20 has a shape along the palatal surface (palatal side) or the lingual surface (lingual side) of the tooth T after orthodontic treatment. In this embodiment, it is a mold of the back surface of the tooth alignment after orthodontic treatment.

[0037] More specifically, this back fitting portion 20 is made of a transparent resin and is continuously provided from the most posterior tooth T on one side through the anterior teeth to the most posterior tooth T on the opposite side. In this embodiment, it is made of a thermoplastic resin that can be used for a denture base, for example, a colorless and transparent one mainly composed of an acrylic resin, a polyamide-based resin, or a polyester-based resin, and here it is made of the same material as the above-described front fitting portion 10.

[0038] And as shown in FIG. 1, this back fitting portion 20 covers the back surface of the tooth root A together with the back surface of the tooth T.

[0039] That is, this back fitting portion 20 has a shape not only along the back surface of the tooth T but also along the back surface of the tooth root A. In this embodiment, it is a mold of the back surface of the tooth root A together with the back surface of the tooth T.

[0040] More specifically, this back fitting portion 20 is continuously provided from the back surface of the portion that supports the most posterior tooth T on one side of the tooth root A, through the back surface of the portion that supports the anterior teeth, to the back surface of the portion that supports the most posterior tooth T on the opposite side.

[0041] The connector 30 is bridged between the back side of the front fitting portion 10 and the back side of the back fitting portion 20 to connect these fitting portions 10 and 20. In this embodiment, it is passed further behind the most posterior tooth T.

[0042] This connector 30 is made of a material with higher strength than the front fitting portion 10 and the back fitting portion 20. Specifically, a metal wire is used.

[0043] One end of the connector 30 is a front-side joint portion 31 joined to the rear side of the front-side fitting portion 10, and the other end of the connector 30 is a rear-side joint portion 32 joined to the rear side of the rear-side fitting portion 20.

[0044] The front-side joint portion 31 is located on the surface of the innermost tooth, and more specifically, on the surface of the outermost tooth T or the surface of the tooth T one or two teeth in front of it, and is provided at a position that is not visible even when the mouth is open.

[0045] The rear-side joint portion 32 is located on the back surface of the innermost tooth, and more specifically, on the surface of the outermost tooth T or the back surface of the tooth T one or two teeth in front of it.

[0046] <Manufacturing method> Next, an example of the manufacturing method of the retainer 100 described above will be described.

[0047] First, as shown in the upper part of FIG. 3, a tooth mold 40 including a plurality of simulated teeth 41 imitating the teeth T after orthodontic treatment and simulated tooth roots 42 supporting them is prepared in advance, the tooth mold 40 is waxed up and buried in a flask 50.

[0048] Next, as shown in the lower part of FIG. 3, in order to create a molding die 60 that is one size larger than the tooth mold 40 described above, the tooth mold 40 is sprued using wax.

[0049] Then, as shown in the upper part of FIG. 4, by taking a mold of the surface of the sprued tooth mold 40 with plaster or the like, the molding die 60 described above is created as shown in the lower part of FIG. 4.

[0050] This molding die 60 is fitted to the tooth mold 40 from which the wax has been removed by dewaxing. As described above, since it is one size larger than the tooth mold 40, when it is fitted to the tooth mold 40, gaps are created between the surface of the simulated teeth 41, the back surface of the simulated teeth 41, the surface of the simulated tooth roots 42, and the back surface of the simulated tooth roots 42 that make up the tooth mold 40.

[0051] Therefore, as shown in the upper part of FIG. 5, for example, the connector 30 is attached in advance further inside the rearmost simulated tooth 41 of the tooth profile 40, and the molding die 60 shown in the lower part of FIG. 5 is fitted to this tooth profile 40, and resin is poured into the resulting gap and hardened.

[0052] As a result, as shown in FIG. 6, the prototype 70 of the front fitting portion 10 and the rear fitting portion 20 connected by the connector 30 is created.

[0053] After that, the prototype 70 of the front fitting portion 10 and the rear fitting portion 20 is polished or the like to manufacture the front fitting portion 10 and the rear fitting portion 20 into a desired shape.

[0054] <Function and effect> According to the retainer 100 configured as described above, since it is worn with the occlusal surface T1 of the tooth T exposed, the meshing can be adjusted after orthodontic treatment, and moreover, since the front fitting portion 10 is transparent, it has excellent aesthetics. Moreover, since the front fitting portion 10 is attached to the surface of the tooth T from the labial and buccal sides and also covers the surface of the gingiva A, it has excellent durability, and in addition, compared with existing wraparound retainers and QCM retainers, the contact area with the tooth T is significantly increased, so that the tooth alignment after orthodontic treatment can be firmly fixed, and furthermore, secondary effects such as an unprecedented feeling of fit and difficulty in coming off can be obtained. In this way, the retainer 100 of the present embodiment has various advantages of existing retainers so to speak.

[0055] In addition, since the front fitting portion 10 and the rear fitting portion 20 are made of a thermoplastic resin, they have better durability than QCM retainers using a resin belt and can be used continuously for at least two years.

[0056] Here, the connector 30 that connects the inner side of the front fitting portion 10 and the inner side of the back fitting portion 20 is, in this embodiment, a portion passing through a location with a narrow clearance further inside the rearmost tooth T, and in terms of design, it has to be made thin. If it is made of resin like the fitting portion, the mechanical strength cannot be ensured. On the other hand, in this embodiment, since a metal wire is used as the connector 30, the strength of the connecting portion between the inner side of the front fitting portion 10 and the inner side of the back fitting portion 20 can be ensured.

[0057] Moreover, since the front joining portion 31 joined to the front fitting portion 10 of the connector 30 is located on the surface of the back teeth, the connector 30 is hidden even when the mouth is open, and excellent aesthetics can be maintained.

[0058] <Other Embodiments> Note that the invention of the present application is not limited to the above-described embodiment.

[0059] For example, in the above-described embodiment, the front fitting portion 10 and the back fitting portion 20 are made of the same material as each other, but they may be made of different materials from each other.

[0060] Also, one or both of the front fitting portion 10 and the back fitting portion 20 are not limited to the colorless and transparent ones described in the above-described embodiment, and may be, for example, colored and transparent.

[0061] The connector 30 is, in the above-described embodiment, passed further inside the rearmost tooth T, but may be passed, for example, between the rearmost tooth T and the tooth T one before it.

[0062] Also, the connector 30 is not limited to a metal wire, and may be, for example, one using a reinforcing material such as glass fiber or carbon fiber.

[0063] The manufacturing method of the front fitting portion 10 and the back fitting portion 20 is not limited to the method described in the above-described embodiment, and they may be manufactured using a 3D printer.

[0064] In addition, the invention of the present application is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit thereof.

Explanation of Reference Numerals

[0065] T ··· Tooth T1 ··· Occlusal surface A ··· Tooth root 100 ··· Retainer 10 ··· Front fitting portion 20 ··· Back fitting portion 30 ··· Connector 31 ··· Front joint portion 32 ··· Back joint portion 40 ··· Tooth form 41 ··· Simulated tooth 42 ··· Simulated tooth root 50 ··· Flask 60 ··· Molding die 70 ··· Prototype

Claims

1. A retainer for maintaining the tooth alignment after orthodontic treatment, which is a retainer worn with the occlusal surfaces of the teeth exposed, comprising a front-side fitting portion attached to the front surface of the teeth from the labial / buccal side, and a back-side fitting portion attached to the back surface of the teeth from the palatal side or the lingual side, wherein the front-side fitting portion is transparent and covers the surface of the gingiva, and further comprising a connector provided only between the inner side of the front-side fitting portion and the inner side of the back-side fitting portion, the connector being arranged to reach from the inner side of the front-side fitting portion through the inner side of the tooth located most deeply to the inner side of the front-side fitting portion, and being formed of a wire having a higher strength than the fitting portion. A retainer characterized by this.

2. The retainer according to claim 1, characterized in that the front-side fitting portion and the back-side fitting portion are made of a thermoplastic resin.

3. The retainer according to claim 1 or 2, characterized in that the connector has a higher strength than each of the fitting portions.

4. The retainer according to claim 3, characterized in that the joint portion of the connector with the front-side fitting portion is located on the surface of the posterior teeth.

5. A method for manufacturing the retainer according to claim 1, comprising creating a dental model having a plurality of simulated teeth and simulated gingiva supporting them, creating a molding die that is fitted to the dental model with a gap interposed therebetween, and pouring and solidifying a resin into the gap formed by fitting the dental model and the molding die together to create the front-side fitting portion and the back-side fitting portion. A retainer manufacturing method characterized by this.

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