JP2008081479A - Denture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a denture having a lining material firmly fixing to a denture base. <P>SOLUTION: The denture 1 comprises artificial teeth, the denture base 2 comprising a poly(methyl methacrylate) for supporting the artificial teeth and the lining material installed to a surface of the denture base fixed to a human body. The lining material is silicone rubber 9 prepared by adding ethylene dimethacrylate to silicone 8 expressed by the general formula (wherein m+n=50-2,000) and performing gel polymerization. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a denture.

Japanese Patent No. 3779530

  Conventionally, for denture users, the impact that occurs when chewing hard food is accompanied by unbearable severe pain. It was. This is mainly because the denture base that is in close contact with the oral mucosa is a hard resin made of polymethylmethacrylate. This is because it is inevitable that a slight gap is generated between the denture base and the oral mucosa when the denture is mounted.

  As one of the countermeasures for solving such dissatisfaction, there is a method in which the patient himself purchases a commercially available denture stabilizer and wears a denture applied on the surface in contact with the oral mucosa in the mouth. Although this will surely chew hard food without feeling pain, and a comfortable wearing feeling can be obtained, such an effect lasts only for about 4 to 5 days, and is also troublesome and economical for the patient. Since the burden is large, the fundamental solution has not been reached.

  Under such circumstances, recently, there is an increasing demand for dentures that can be chewed with food comfortably without rattling after wearing. Therefore, in the field of dental technicians, the development of dentures with a polyvinyl silicone resin-based lining material fixed has been promoted, and some of them have been put to practical use, such as Dentax's Moroplast B (registered trademark). . However, the pain when chewing a hard object is somewhat relieved than when the denture base touches the oral mucosa directly, and since the backing resin is relatively hard, the pain is not completely eliminated. Since deterioration with time such as discoloration and alteration of the lining material was remarkable, there was still a problem that the life of the denture was short, it was easy to come off and a stable wearing feeling could not be obtained.

  On the other hand, by using biomedical silicone rubber, which is used in the medical field for human substitutes and prosthetics, as a denture lining material, physiological compatibility between the denture and the oral mucosa is achieved and a buffering action Although it is expected to prevent rattling of dentures, it has been difficult to secure a sufficient adhesive force. Therefore, at present, development of dentures using biomedical silicone rubber as a backing material has not been realized.

In order to solve such a situation, a denture shown in Patent Document 1 has been proposed.
The present invention can provide a product (denture) obtained by strongly adhering silicone rubber having improved adhesion to an adherend of a denture base by adding methyl methacrylate.
Regarding the mechanism, in the polymerization process of silicone rubber, MMA (methyl methacrylate) that does not mix uniformly with silicone is polymerized in a form that is ejected to the outside, so that PMMA (polymethyl methacrylate) is formed near the surface of the silicone rubber. It was considered that the adhesion to the adherend was dramatically improved since a thin layer of was formed. That is, with the polymerization of silicone containing a small amount of MMA, MMA is polymerized near the surface, so the methyl group of the PMMA layer on the surface of the silicone rubber produced by the polymerization, the denture and the methyl group of the PMMA resin which is this material It was considered that the silicone rubber was firmly bonded to the denture base without using any adhesive because of the van der Waals interaction.
The adhesive force between the denture base and the silicone rubber as the backing material depends on van der Waals force as described above, and does not have a chemical bonding force. Inventors of the present application have thought over the years whether the silicone rubber could be fixed to the denture base with a mechanism different from the invention of Patent Document 1 regarding the adhesive force between the denture base and the silicone rubber as the lining material. .
Further, as in the invention of Patent Document 1, when the MMA solvent enters, the silicone rubber easily accumulates dirt. This is because the surface of the silicone rubber becomes porous (a large number of undulations can be formed on the surface) when the MMA solvent is added.
For this reason, the inventor of the present application has conducted earnest research for the purpose of improving silicone rubber, which is a lining material for a denture base, by a meganism different from that of Patent Document 1.

  The object of the present invention is to improve the adhesion of dentures by a mechanism different from that of the above-mentioned Patent Document 1.

A first invention of the present application is a denture provided with an artificial tooth, a denture base that supports the artificial tooth and has polymethyl methacrylate as a main component, and a lining material provided on the surface of the denture base that is fixed to the human body. The following configuration is provided.
That is, the above lining material has the general formula
A silicone rubber obtained by gel polymerization by adding ethylene dimethacrylate to silicone represented by (m + n = 50 to 2000).

  A second invention of the present application provides the denture according to the first invention of the present application, wherein the gel further comprises a crosslinking agent and a catalyst.

  A third invention of the present application provides the denture according to the first or second invention of the present application, wherein the ratio of the ethylene dimethacrylate to the silicone is 0.05 to 1% by volume.

In the implementation of the first to third inventions of the present application, the adhesive force between the denture base (resin) and the silicone rubber as the lining material was remarkably improved by a mechanism different from that of the silicone rubber added with MMA.
Further, since MMA is not required and the solvent is not required, the surface of the silicone is smooth, and the porosity of the surface generated when MMA (solvent) is used is remarkably improved. For this reason, the contamination of the silicone rubber was greatly reduced.
Specifically, unlike the one of Patent Document 1 in which ethylene dimethacrylate is added to silicone and polymerized to add SMMA to silicone rubber (as a surface layer) by adding MMA, the produced silicone rubber is The component composition is uniformly dispersed and the surface is smooth, and it is firmly fixed to the denture base of SMMA by chemical bonding, not intermolecular force.
As a result, the use of silicone rubber for dentures, which is flexible, has a good fit, has a high affinity with the living body, and has a low burden on the living body, facilitates the long-term use of dentures.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The manufacturing process of the denture of the present invention is shown in FIGS.
1 (A) to 1 (D) are cross-sectional views illustrating the flow of a manufacturing process for a denture according to the present invention. FIG. 2 is a cross-sectional view showing an example of a state in the mouth of a patient wearing the denture according to the present invention. FIG. 3 is a cross-sectional view showing an example of a state in the mouth of a patient wearing the denture according to the present invention. FIG. 4 is a cross-sectional view showing an example of a state in the mouth of a patient wearing the denture according to the present invention.

First, the manufacturing procedure of the silicone rubber according to the present invention will be described. Hydrogen gel polysiloxane having a general formula represented by the following “Chemical Formula 3” as a crosslinking agent and ethylene dimethacrylate may be added to the silicone gel represented by the following “Chemical Formula 2”. After stirring, the mixture is sealed in a polymerization container having a rectangular parallelepiped shape, etc., and left at low temperature or at room temperature.
The hydrogen polysiloxane is added in a ratio of 10% by volume to 100% by volume of silicone gel (total 110% by volume).
The ethylene dimethacrylate is added at a ratio of 0.05 to 1% by volume with respect to 100% by volume of the silicone gel (total 100.05 to 101% by volume / total 110.05 to the above hydrogen polysiloxane). 111% by volume). In particular, ethylene dimethacrylate is preferably added at a ratio of 0.1 to 0.6% by volume with respect to 100% by volume of silicone gel (total 100.1 to 100.6% by volume).
If the amount of ethylene dimethacrylate added to the silicone is less than 0.05% by volume, the peel strength is extremely lowered, and it becomes difficult to fix the silicone rubber to the denture base. On the other hand, when the amount of ethylene dimethacrylate added to the silicone exceeds 1.0% by volume, the silicone rubber becomes too soft to lose its self-supporting property and cannot be used as a backing material.

  As a result, the polymerization (crosslinking) reaction of the silicone proceeded using the platinum compound contained in the silicone as a catalyst, and a test piece of silicone rubber having a smooth surface and elasticity was obtained.

(M + n = 50-2000)
(R is a methyl group or hydrogen, k + 1 = 8 to 98)

Next, the manufacturing method of the denture which backed the denture base with the silicone rubber which concerns on this invention is demonstrated with reference to FIG.
As shown in FIG. 1A, the following steps are performed on a denture (semi-finished product) including an artificial tooth 100 and a denture base 2 made of PMMA resin (resin) in which the artificial tooth 100 is implanted. .
First, the denture 1 in which the paraffin wax 3 is applied with a predetermined thickness on the surface of the denture base 2 made of PMMA resin on the human body is placed in the lower flask 5 so that the application surface of the paraffin wax 3 is exposed. Secure with gypsum 6. Then, as shown in FIG. 1 (B), while pouring gypsum 6 'serving as a model into the upper space including the application surface of paraffin wax 3, the upper flask 4 in which the lower gypsum layer 7 is hardened in advance is placed below. Cover the flask 5 and leave it for a while to wait until the gypsum 6 'is completely solidified.

  Next, as shown in FIG. 1C, the upper and lower flasks 4 and 5 are opened, and the paraffin wax 3 is washed away with a suitable solvent and removed. Thereby, when the upper and lower flasks 4 and 5 are closed, a space having a shape corresponding to the portion where the paraffin wax 3 was present is secured. Then, the surface of the denture base 2 from which the paraffin wax 3 has been removed is dried.

Then add hydrogen polysiloxane crosslinker (10% by volume with respect to silicone as described above), ethylene dimethacrylate (0.05 to 1.0% by volume with respect to silicone as described above) and platinum catalyst and mix. Silicone 8 is poured from above the denture base 2. Thereafter, as shown in FIG. 1 (D), the upper flask 4 is put on, sealed with a bolt 14, and housed in a pressure cooker (not shown), and is kept at 100 ° C. under a pressure of 1.2 to 3.5 atm. Heat at ~ 130 ° C for about 15-25 minutes. Thereby, the silicone 8 is polymerized and cured into a soft rubber shape so as to match the cavity shape of the portion where the paraffin wax 3 (FIG. 1B) was present.
At this time, the silicone rubber 9 is bonded to the surface of the denture base 2 on the side to be mounted on the human body.

  Then, the upper and lower flasks 4 and 5 are opened again, the denture 1 is dug from the plaster 6 and the surrounding burrs and the like are removed. Thereby, the denture 1 by which the silicone rubber 9 was lined on the surface by the side of the denture base 2 attached to the human body is obtained.

  2-5 is sectional drawing which shows the mode in the patient's mouth which mounted | wore with the denture produced as mentioned above. FIG. 2 is an example in which the entire portion of the denture base 2 that touches the oral mucosa 10 is covered with a silicone rubber 9, and this type of denture is mainly used for teeth that chew hard objects such as lower molars. By doing so, the impact can be greatly reduced.

  3 and 4 are examples in which silicone rubber 9 is lined on a part of the part of the denture base 2 that touches the oral mucosa 10 (part to which direct force is applied), and FIG. FIG. 4 shows the case of the upper front teeth. According to this, since a small amount of silicone rubber 9 is sufficient to reduce the impact transmitted to the oral mucosa 10, the manufacturing cost of the denture can be reduced.

  FIG. 5 is an example of a denture for a patient in which a portion of the maxillary sinus 11 penetrates to the nasal cavity 12 side due to a cleft palate or the like, and the insertion portion 2 a of the denture base 2 formed to be inserted into the affected area 13. Silicone rubber 9 is provided locally. As a result, the affected area 13 is completely covered with the flexible silicone rubber 9 without any gaps, so that air leakage is prevented and sound clarity is ensured, and beverages and the like are prevented from flowing into the nasal cavity 12. Can do.

  Next, an Example and a comparative example are shown about adhesion | attachment between the resin which is a denture base of the denture based on this invention, and said silicone rubber which is a lining material.

(Example 1)
Silicone rubber 100% by volume
Ethylene dimethacrylate 0.05% by volume
Total 100.05% by volume

(Example 2)
Silicone rubber 100% by volume
Ethylene dimethacrylate 0.1% by volume
Total 100.1% by volume

(Example 3)
Silicone rubber 100% by volume
Ethylene dimethacrylate 0.2% by volume
Total 100.2% by volume

Example 4
Silicone rubber 100% by volume
Ethylene dimethacrylate 0.5% by volume
Total 100.5% by volume

(Example 5)
Silicone rubber 100% by volume
Ethylene dimethacrylate 0.6% by volume
Total 100.6% by volume

(Example 6)
Silicone rubber 100% by volume
Ethylene dimethacrylate 1.0% by volume
Total 101.0% by volume

(Comparative example)
Silicone rubber 100% by volume
Methyl methacrylate 0.3% by volume
Total 100.3% by volume

A peeling test was performed on the above-described Examples and Comparative Examples. As a test piece of each example / comparative example, the silicone of each of the examples and comparative examples having a lateral width of 30 mm and a thickness of 1.5 mm is similarly applied to a small piece formed of a resin having a lateral width of 30 mm and a thickness of 1.5 mm. A laminate of small pieces made of rubber was used. That is, a 180 degree peel adhesion strength test was performed on these test pieces. Specifically, for this test piece, an end portion where both small pieces overlap was pulled at an angle of 180 degrees in the longitudinal width direction using an Instron universal material testing machine 5582 type. The crosshead speed (tensile speed) was 200 mm / min. The temperature of the test environment is 23 ° C. and the humidity is 50% RH.
The test pieces of Examples 1 to 6 were prepared by the manufacturing method shown in FIG. 1 (although the shape differs from that of the denture), and in each of the steps shown in FIG. The atmospheric pressure was 3.5 atmospheric pressure, and heating was performed at 115 ° C. for 15 minutes. Moreover, also about the comparative example, it was the same as that of the said Example about conditions other than an additive.
For each of the examples and comparative examples, the following four samples are prepared, and the component blending ratios of the samples are all as described above, and each sample is subjected to a peel test to obtain an average value. It was set as the test result of an Example and a comparative example.
Specifically, Nissin's natural resin (trade name) is used as the resin resin, Factor II's Real Stick A-588-2 (trade name and product number) is used as the silicone rubber, and CG Corporation is used as the resin resin. A sample using the above-mentioned real stick A-588-2 for silicone rubber, and Metadent (registered trademark / trademark holder: Mitsui Chemicals) of Sun Medical Co., Ltd. for the resin resin. Using the above-mentioned sample using Dow Corning's SILASTIC MDX4-4210 (registered trademark and product number) as the silicone rubber, using the above metadent as the resin resin, and using the EVA Touch Super ( A sample using Evatouch / registered trademark) was prepared.
The result (average value) was as follows.

(Example 1)
When a tensile force of 22.8 N was applied, the resin piece and the silicone rubber piece began to peel. Neither the resin piece nor the silicone rubber piece was broken.

(Example 2)
When a tensile force of 30 N was applied, the resin piece and the silicone rubber piece began to peel. Neither the resin piece nor the silicone rubber piece was broken.

(Example 3)
When a tensile force of 58.3 N was applied, the resin piece and the silicone piece began to peel. A piece of silicon rubber was cut off.

Example 4
When a tensile force of 64 N was applied, the resin piece and the silicone rubber piece began to peel. A piece of silicon rubber was cut off.

(Example 5)
When a tensile force of 18.2 N was applied, the resin piece and the silicone piece began to peel. Softening of the silicone rubber pieces occurred.

(Example 6)
When a tensile force of 15.3 N was applied, the resin piece and the silicone piece began to peel. Softening of the silicone rubber pieces occurred.

(Comparative example)
When a tensile force of 23 N was applied, the resin piece and the silicone piece began to peel. Both pieces peeled off without breaking.

  As described above, it can be confirmed that any of Examples 1 to 5 of the present invention has a peel strength of 15 N or more, and is practical. In particular, in Examples 2 to 4, the peel strength is 30 N or more in the range of 0.1% to 0.6% by volume of ethylene dimethacrylate added to 100% by volume of silicone rubber. It turns out that it exceeds 23N of an example. In particular, when Example 3 and Example 4 are seen, the amount of ethylene dimethacrylate added to 100% by volume of silicone rubber ranges from 0.2% by volume to 0.6% by volume. It turns out that it has gained strength.

   FIG. 6A shows a 1000-fold image of the surface of the test piece of Example 4 using a scanning electron microscope (SEM). FIG. 6B shows a 1000-times image of the surface of the test piece of the comparative example by SEM, and FIG. 7 shows an image of the surface of the test piece of the comparative example by 1500 times by SEM. For each SEM image of FIG. 6 and FIG. 7, in order to make it easy to see the undulations on the surface, the surface of the test piece is not viewed from the front but is taken from a diagonal view.

When FIG. 6A is compared with FIG. 6B, the test piece surface (FIG. 6A) of Example 4 of the present invention is more on the test piece surface of the comparative example (FIG. 6B). It can be seen that it is smoother (with less undulations). Even when the magnification of the SEM is further increased to 1500 times, as shown in FIG. 7, the surface of the test piece of the comparative example still has many surface undulations compared to the surface of the test piece of Example 4. 6B and FIG. 7, it can be seen that a large amount of dust a adheres to the undulation dent on the surface of the test piece of the comparative example. As shown in FIG. 6A, no such dust is seen on the surface of the test piece of Example 4.
Each test piece of the example and the comparative example is subjected to ultrasonic cleaning after formation, and is further prepared to remove surface deposits that are usually performed to obtain an SEM image. The dust attached before observation remains. Thus, it can be seen that in the comparative example, dirt is easily attached due to the undulation of the surface, and once attached dirt is not easily removed.

FIG. 8A shows an SEM image obtained by enlarging the vicinity of the boundary between the resin layer (resin piece) x1 and the silicon gob layer (silicone rubber piece) y1 on the surface of the test piece of Example 4 by 500 times. B) shows an SEM image obtained by enlarging the vicinity of the boundary between the resin layer (resin piece) x2 and the silicon gob layer (silicone rubber piece) y2 on the surface of the test piece of the comparative example by 500 times. 8A and 8B are both front views of the test piece surface.
As seen in FIG. 8B, the boundary line kk between the resin layer x2 and the silicone rubber layer y2 appears linearly on the surface of the test piece of the comparative example, and the boundary between both layers is clear. On the other hand, as can be seen in FIG. 8A, on the surface of the test piece of Example 4, the boundary line kk between the resin layer x1 and the silicone rubber layer y1 is complicated, and the boundary between the two layers becomes ambiguous. Yes. This indicates that both layers are chemically bonded.
From this, it can be seen that the present invention firmly fixes the lining material to the denture base by a mechanism different from the invention of Patent Document 1.

(A)-(D) are sectional drawings explaining the flow of the manufacturing process of the denture based on this invention. It is sectional drawing which shows an example of the mode in the patient's mouth equipped with the denture based on this invention. It is sectional drawing which shows an example of the mode in the patient's mouth equipped with the denture based on this invention. It is sectional drawing which shows an example of the mode in the patient's mouth equipped with the denture based on this invention. It is sectional drawing which shows an example of the mode in the patient's mouth equipped with the denture based on this invention. (A) is explanatory drawing which shows a 1000 times SEM image of the test piece surface of Example 4 of this invention, (B) is explanatory drawing which shows a 1000 times SEM image of the test piece surface of a comparative example. It is explanatory drawing which shows the 1500 times SEM image of the test piece surface of the said comparative example. (A) is explanatory drawing which shows a 500 times SEM image of the test piece surface of Example 4 of this invention, (B) is explanatory drawing which shows a 500 times SEM image of the test piece surface of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Denture 2 Denture base 3 Paraffin wax 4 Upper flask 5 Lower flask 6,6 'Gypsum 8 Silicone 9 Silicone rubber 10 Oral mucosa 11 Maxillary sinus 12 Nasal cavity

Claims (3)

In a denture comprising an artificial tooth, a denture base that supports the artificial tooth and has polymethyl methacrylate as a main component, and a lining material provided on a surface to be fixed to the human body of the denture base,
The above lining material is a general formula
A denture characterized by being a silicone rubber obtained by adding ethylene dimethacrylate to gel represented by (m + n = 50 to 2000) and gel polymerization.   The denture according to claim 1, wherein the gel further comprises a crosslinking agent and a catalyst.   The denture according to claim 1 or 2, wherein the ratio of the ethylene dimethacrylate to the silicone is 0.05 to 1% by volume.