JP3040297B2 - Dental soft lining material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicone-based soft dental lining material used for a mucosal surface of a resin denture base.

[0002]

2. Description of the Related Art Many denture patients, particularly complete dentures, are elderly patients, and the alveolar ridge generally has a remarkable bone resorption, and the occlusal force per unit area increases. Since the alveolar ridge mucosa is also thinned by senile atrophy, the impact of occlusal and mastication pressures is transmitted directly to the alveolar bone without being reduced. Further, the thin mucous membrane sandwiched between the hard resin denture base and the hard alveolar bone is squeezed every time it bites, and is damaged, causing damage.

[0003] In such difficult cases, if a resin denture base is manufactured using only a commonly used methyl methacrylate resin, good results cannot be obtained in maintaining, stabilizing and supporting the denture. Therefore, it is necessary to cover the resin denture base mucous membrane surface with a soft material and a soft dental lining material to compensate for the lost viscoelasticity of the ridge ridge mucous membrane and to provide cushioning to alleviate the impact during occlusion. In other words, the purpose of lining with a soft material is to overcome various obstacles caused by the hard material of the denture base pressing on the mucosa below the floor.

[0004] Conventionally, soft dental lining materials used clinically include (meth) acrylate polymers,
There are fluorine resin, polyolefin resin, silicone rubber and the like. For temporary use, denture stabilizers (so-called denture stabilizers) are used.

However, a soft material such as a (meth) acrylic acid polymer lacks chemical stability in the oral cavity, and hardens or becomes brittle within a few months, and cannot be used for a long period of time. Fluorine-based lining materials are also poor in viscoelasticity, and a sufficient cushioning effect is not expected. The polyolefin-based lining material has many practical problems because it has a high melting temperature and may cause deformation of the resin denture base, and requires a plurality of adhesives and a dedicated heater to complicate the operation. Although the silicone rubber-based lining material is a relatively stable material, it is not sufficient in durability and operability, for example, it cannot be colored or cut. In particular, the soft lining material currently used in clinical practice has a problem in that it has almost no machinability and cannot be corrected once cured.

[0006] As for the denture stabilizer, the longer the period of use, the higher the consistency and the lower the plasticity. As a result, the purpose of improving the maintenance, stability and support of the denture base by improving the compatibility and marginal sealing properties of the incompatible denture cannot be sufficiently fulfilled, and in many cases the oral tissue is damaged. In addition, since the compression stress is small and the elasticity is poor, the cushioning effect against the occlusal pressure is not sufficient, and this has caused the recurrence of pain in the oral mucosa.

[0007]

As described above, the soft lining materials for dental prostheses provided so far for the denture base have a reduced use property in a short period of use, and the use period in the oral cavity is short. Not only did there not exist a material that exhibited a satisfactory cushioning effect, but the use was complicated and many were not suitable for practical use. For this reason, a soft dental lining material that has appropriate viscoelasticity, does not cause deterioration in physical properties, and is excellent in operability, particularly, has cutting properties has been desired. Particularly with the aging society, such soft dental lining materials have been strongly demanded.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems of the prior art, and as a result, by using silicone rubber as a matrix and polyorganosilsesquioxane fine particles as a filler, the durability has been improved. This led to the development of a soft dental lining material that is excellent in operability and operability and can be used for a long period of time.

That is, the present invention relates to (B) a method in which (B) a silicon atom is bonded to a silicon atom in a molecule with respect to 100 parts by weight of an organopolysiloxane having at least two organic groups having a terminal unsaturated bond in the molecule. (A) an organohydrogenpolysiloxane having at least three hydrogen atoms
The amount of the hydrogen atom to be 0.5 or more relative to one unsaturated bond in the component (C).
And 0.1 to 1000 ppm based on the total amount of component (B),
And (D) polyorganosilsesquioxane fine particles 5
A soft dental lining material comprising 300 parts by weight.

The component (A) used in the present invention comprises an organopolysiloxane having at least two organic groups having terminal unsaturated bonds in the molecule (hereinafter abbreviated as unsaturated bond-containing silicone). It is a main component which is crosslinked by an organohydrogenpolysiloxane (hereinafter abbreviated as SiH siloxane) to become a rubber elastic body.

The unsaturated bond-containing silicone of the component (A) is not limited in the structure of other organic groups as long as it is an organopolysiloxane having at least two organic groups having terminal unsaturated bonds in one molecule. It may be linear or branched, and may be a mixture thereof.

Examples of the organic group having a terminal unsaturated bond include a vinyl group, an allyl group, and a 1-butenyl group. A vinyl group bonded to a silicon atom is most advantageous because of its ease of synthesis. . These organic groups having a terminal unsaturated bond may be present at either the terminal or the middle of the molecular chain of the organosiloxane, or may be present at both of them. In order to have the property, it is preferable that at least one exists at the terminal.

The organic group bonded to the silicon atom other than the organic group having a terminal unsaturated bond includes a methyl group, an ethyl group,
Propyl group, butyl group, alkyl group such as octyl group, aryl group such as phenyl group, chloromethyl group, 3,
Examples thereof include a substituted alkyl group such as a 3,3-trifluoropropyl group. Of these, a methyl group is most preferable because it is easy to synthesize and maintains good physical properties after curing.

Further, in order to use the material as a soft dental lining material, it is necessary to provide a material suitable for the soft lining material, in particular, to have an appropriate hardness after curing, and to obtain sufficient elongation and mechanical strength. 50 to 5000 siloxane units consisting of only an organic group having no terminal unsaturated bond between siloxane units consisting of an organic group having an unsaturated bond, particularly 100 to 100
It is preferable that 2,000 of them are included continuously. 5 siloxane units having only an organic group having no terminal unsaturated bond
If the number is less than 0, it is difficult to obtain sufficient elongation, elasticity and mechanical strength after curing. When the number of siloxane units having only an organic group having no terminal unsaturated bond exceeds 5,000, not only the viscosity becomes too high, but the operability before curing is impaired,
It tends to be difficult to obtain sufficient hardness after curing.

[0015] Representative examples of the unsaturated bond-containing silicone used in the present invention are as follows.

[0016]

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(However, Ph represents a phenyl group). In addition, the bonding order of each repeating structural unit in the compounds used in the compounds and Examples and Comparative Examples described later is completely arbitrary, and the number of repeating structural units shown in the structural formula is simply the total amount of each structural unit. It only shows the average value.

The SiH siloxane of the component (B) in the present invention is a component having a function of crosslinking the above-mentioned unsaturated bond-containing silicone into a rubber elastic body. In order to react with the unsaturated bond-containing silicone to form a crosslinked structure, at least three hydrogen atoms bonded to the silicon atom are required in the molecule. If the number is less than 3, a crosslinked structure is not obtained and a rubber elastic body cannot be obtained.

Examples of the organic group bonded to a silicon atom other than a hydrogen atom include those similar to the organic group having a terminal unsaturated bond and the organic group having no terminal unsaturated bond in the aforementioned component (A). However, a methyl group is most preferred because it is easy to synthesize and retains good physical properties after curing. Such SiH silicone may be linear, branched or cyclic, and may be a mixture thereof.

Specific examples of the SiH siloxane used in the present invention are as follows.

[0021]

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And the like. In the SiH siloxane used in the above and below examples and comparative examples,
Like the unsaturated bond-containing silicone, the bonding order of each repeating structural unit in the molecule is completely arbitrary, and the number of repeating structural units shown in the structural formula merely indicates the average total number of each structural unit.

The unsaturated bond-containing silicone of the present invention and S
Although the amount of each iH siloxane varies greatly depending on its molecular weight, usually, one or more unsaturated bonds in the unsaturated bond-containing silicone have at least 0.5 hydrogen atoms bonded to silicon atoms in the SiH siloxane, Preferably, they may be blended in a ratio of 1 to 5. If this ratio is too small, the curability becomes insufficient, and if it is too large, the elastic body obtained tends to become brittle or the stability over time of the elastic body decreases due to the remaining hydrogen atoms bonded to excess silicon atoms. is there.

In addition, a hydrogen atom bonded to a silicon atom by an organohydrogenpolysiloxane having at least three hydrogen atoms bonded to a silicon atom in a molecule is used for one unsaturated bond in the unsaturated bond-containing silicone. If it is 0.5 or more, an organohydrogenpolysiloxane containing only two or one hydrogen atom bonded to a silicon atom in the molecule may be further added.

As the component (C) platinum catalyst used in the present invention, any of those used in ordinary hydrosilation reactions can be used.
Examples thereof include chloroplatinic acid, an alcohol-modified product thereof, and a vinylsiloxane complex of platinum. In order to enhance the storage stability, a material having a small amount of chloro, such as a vinyl siloxane complex of platinum, is preferable.

The amount of the platinum catalyst may be in the range of 0.1 to 1000 ppm based on the total weight of the unsaturated bond-containing silicone and SiH siloxane in terms of platinum atoms. When the amount is less than 0.1 ppm, the crosslinking reaction between the unsaturated bond-containing silicone and the SiH siloxane does not proceed sufficiently. When the amount is more than 1000 ppm, the cured product becomes yellow due to precipitation of platinum black, or black when it is severe. Problems such as coloring and difficulty in controlling the crosslinking reaction occur.

The component (D) polyorganosilsesquioxane fine particles used in the present invention function as a reinforcing material for the silicone rubber obtained from the components (A), (B) and (C). .

As a reinforcing material for silicone rubber, silica-based powders such as crushed quartz, fused silica, wet silica and dry silica are generally considered to be effective, but they are not suitable for use as soft dental lining materials. These have the disadvantage that they have high hydrophilicity due to silanol groups remaining in the particles and / or on the surface of the particles, and therefore have a large amount of coloring (hereinafter abbreviated as coloring amount) due to penetration of coloring components of the elastic body after curing. Having. In addition, fine particles such as wet silica and dry silica cannot provide sufficient rigidity to the cured elastic body due to their small particle size, and therefore have no machinability. Examples of fillers having low hydrophilicity include polytetrafluoroethylene and fluorocarbon resin powders such as povinylidene fluoride.
These have a small reinforcing effect on silicone rubber, and have poor compatibility between the fluorocarbon resin and silicone rubber, so that the matrix / filler interface does not blend in, voids are formed, and the coloring component penetrates here, so that the hydrophilicity of the filler is low. Nevertheless, the amount of coloring is large.

However, in the present invention, component (D)
The filler, i.e., polyorganosilsesquioxane fine particles, has a higher hydrophobicity than the above-mentioned silica-based powder, and has a Si--O bond, a Si--CH ₃ bond, etc. Good familiarity,
In addition, the effect of reinforcing the silicone rubber is large, so that the cured elastic body has a sufficient mechanical strength and a small amount of coloring. Further, by selecting a material having an appropriate particle size, it is possible to fill at a high filling rate, and it is possible to give a sufficient rigidity to the cured elastic body. Therefore, the hardened elastic body can be provided with machinability.

As the polyorganosilsesquioxane fine particles in the present invention, known ones can be used. As the organic group of the polyorganosilsesquioxane fine particles,
Alkyl groups such as methyl group, ethyl group, propyl group, butyl group and octyl group; alkylene groups such as vinyl group, allyl group and 1-butenyl group; aryl groups such as phenyl group, chloromethyl group; A substituted alkyl group such as a 3,3-trifluoropropyl group; a hydrogen atom; and the like. Among them, a methyl group or a methyl group is preferable because these groups are easily synthesized and maintain good physical properties after curing. Those in which a methyl group and a part thereof are substituted by the above-mentioned organic group are preferably used.

Typical examples of the polyorganopolysiloxane used in the present invention are as follows: polymethylsilsesquioxane, poly (50 mol% methyl + 50 mo)
1% phenyl) silsesquioxane, poly (99mol
% Methyl + 1 mol% hydrogen) silsesquioxane.

The use of the polyorganosilsesquioxane microparticles, particularly polymethylsilsesquioxane microparticles, as a filler in a silicone rubber composition is described in JP-A-61-159450. Japanese Patent Application Laid-Open No. 61-159450 only mentions the releasability and the releasability as its effects, and merely discloses the use as a release material and a release material. However,
The present inventors have found that the composition is excellent in coloring resistance, has sufficient strength, and has machinability, and has considered using the composition as a soft dental lining material.

The polyorganosilsesquioxane fine particles are obtained by hydrolyzing and condensing an organotrialkoxysilane or one or more of its hydrolysis and condensation products in an aqueous solution of ammonia or amines. These are preferably free from impurities such as chlorine atoms, alkaline earth metals and alkali metals, and are spherical in shape.

The average particle size of the polyorganosilsesquioxane fine particles is 0.1 to 100 μm, preferably 0.1 to 100 μm.
20 μm is used. If it is less than 0.1 μm, it is difficult to manufacture, and it is difficult to fill a necessary amount as a soft dental lining material. If it exceeds 100 μm, it is difficult to obtain a necessary reinforcing effect, and the soft dental lining material is difficult to obtain. It tends to be difficult to obtain the necessary reinforcing effect as a material.

The amount of the fine particles is 5 to 300 parts by weight per 100 parts by weight of the unsaturated bond-containing silicone of the component (A).
Parts by weight are required. If the amount is less than 5 parts by weight, sufficient mechanical strength of the cured elastic body cannot be obtained, and if it exceeds 300 parts by weight, it is difficult to mix the compound into a system and hardly form a paste. Further, the rubber elasticity of the elastic body after curing is poor, and not only loses the reinforcing effect but also deteriorates the mechanical strength.

If necessary, the soft dental lining material of the present invention may optionally contain a filler other than polyorganosilsesquioxane fine particles as long as its physical properties are not significantly reduced. If representative examples are specifically shown, crushed quartz, fused silica, wet silica, silica-based powder such as dry silica,
Examples thereof include fluorocarbon resin powders such as polytetrafluoroethylene and polyvinylidene fluoride, carbon black, glass fiber, pulverized polymer, powdered polymer, and composite filler (pulverized composite of inorganic oxide and polymer).

Further, other additives may be added as long as the physical properties are not significantly reduced. Such additives include non-reactive silicones, reaction inhibitors, UV absorbers,
Examples include a plasticizer, a pigment, an antioxidant, and an antibacterial agent.

[0038] The soft dental lining material of the present invention generally comprises an unsaturated bond-containing silicone, a filler containing polyorganosilsesquioxane fine particles as a main component, a platinum catalyst and, if necessary, an instep. And a two-pack type comprising a filler containing SiH siloxane and polyorganosilsesquioxane fine particles as main components and, if necessary, an unsaturated bond-containing silicone and additives. Is generally used as a mixture.

The method of preparation includes unsaturated bond-containing silicone,
An appropriate amount of necessary components is measured from fillers and additives other than SiH siloxane, polyorganosilsesquioxane fine particles, platinum catalyst, and polyorganosilsesquioxane fine particles, and the mixture is kneaded by a general kneader such as a kneader or a planetary. By kneading until uniform, a paste-like composition can be obtained.

The method for using the soft dental lining material of the present invention is as follows.
It can be used by a known direct lining method. That is, just before use, two types of pastes of the former and the latter are weighed and kneaded in an appropriate amount, put on the back of the denture, and held until fully cured in the oral cavity of the patient. After curing, remove from the oral cavity and remove excess part.

[0041]

The soft dental lining material obtained by the present invention has an appropriate elasticity after curing, becomes an elastic body excellent in coloring resistance, and is a soft dental lining material having machinability. It is preferably used.

[0042]

EXAMPLES The present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Table 1 shows the unsaturated bond-containing silicones used in the following Examples and Comparative Examples, and Table 2 shows the SiH siloxanes.
Shown in

[0044]

[Table 1]

[0045]

[Table 2]

In the examples and comparative examples, the evaluation of the dental soft lining material was performed by the following method, and the same sample was measured or evaluated three times and the average value was recorded.

(1) Shore A Hardness A required amount of each of the pastes A and B is taken, kneaded, and filled into a polytetrafluoroethylene (hereinafter abbreviated as PTFE) mold having a hole having a diameter of 9 mm and a length of 12 mm. At 37 ° C. in air. After curing, the resin is taken out of the mold, left in the air at 37 ° C. for 24 hours, and measured with a Shore A hardness meter.

(2) Tensile strength, elongation A required amount of each paste and each paste are mixed, and after kneading, a PT having a thickness of 2 mm and having a hole having a shape of a required dumbbell-shaped test piece is obtained.
The mold was filled in an FE mold and sufficiently cured in air at 37 ° C. After curing, the resin was taken out of the mold, allowed to stand in the air at 37 ° C. for 24 hours, and then subjected to an autograph (manufactured by Shimadzu Corporation) at a crosshead speed of 10 mm / min. Measure the tensile strength and elongation at cutting. The size of the parallel part of the dumbbell-shaped test piece is 10 mm in length and 5 mm in width.

(3) Amount of coloring Take the required amount of each of the pastes A and B, and after kneading,
It was filled in a PTFE mold of mm × 10 mm × 2 mm and sufficiently cured in air at 37 ° C. After curing, the resin is taken out of the mold and left in the air at 37 ° C. for 24 hours, and then L ^* , a ^* and b ^* before coloring are measured by a color difference meter. Thereafter, the test piece is immersed in a 20 wt% curry aqueous solution and stored at 40 ° C. for 24 hours with stirring. After storage, wash and dry, then measure L ^* , a ^* , b ^* again with a color difference meter,
From L ^* , △ a ^* , △ b ^* , the coloring amount (△
E ^* ).

ΔE ^* = (ΔL ^{* 2} + Δa ^{* 2} + Δb ^{* 2} ) ^1/2 (4) Cutability test Take the required amount of paste for each of A and B, and after kneading, 9 mm diameter x length It was filled in a PTFE mold having a hole of 12 mm in thickness, and was sufficiently cured in air at 37 ° C. After curing, the mold was taken out of the mold and allowed to stand in the air at 37 ° C. for 24 hours, and then cutability was evaluated using a carbide bar and silicone point using a micro engine for dental technology. The evaluation points were evaluated from A to D according to the following criteria.

A: The surface part can also be removed. B: The peripheral part can be removed but the surface part cannot be removed. C: Scratches can be removed but cannot be removed. D: Cannot be removed at all.
Compound of platinum vinylsiloxane complex, amount of fine particles of polyorganosilsesquioxane 100 having a particle diameter of 2 μm such that platinum is 200 ppm based on the total amount of the compound.
Put the parts by weight in the planetary, knead until uniform,
Paste was used.

The compounds shown in Table 1 were each 50 parts by weight, the compounds shown in Table 2 were 4 parts by weight, and the particle diameter was 2
100 parts by weight of fine particles of polymethylsilsesquioxane of μm were put into a planetary and kneaded until the mixture became uniform to obtain a paste B.

The two types of pastes, A and B, were kneaded at a mixing ratio of 1: 1 and evaluated according to the evaluation method described above. Table 4 shows the results.

Examples 2 to 11, Comparative Examples 1 to 5 Materials having the respective compositions shown in Table 3 were kneaded by planetary in the same manner as in Example 1 to prepare pastes. The same platinum catalyst as that used in Example 1 was used.

A test was carried out using each paste in accordance with the above evaluation method. Table 4 shows the results.

[0056]

[Table 3]

[0057]

[Table 4]

[0058]

[Table 5]

From the results shown in Table 4, the soft dental lining material of the present invention (Examples 1 to 11) has moderate hardness, sufficient tensile strength and elongation, a small amount of coloring and good machinability. You can see that. On the other hand, in the comparative example, if the number of hydrogen atoms bonded to the silicon atoms in the component (B) is less than 3 (Comparative Example 1), the paste will not cure, and the polyorganosilsesquioxane powder is used as a filler. When not used (Comparative Example 2), the coloring amount is large and there is no machinability. When the compounding amount of the polyorganosilsesquioxane powder is less than 5 parts by weight (Comparative Example 3), sufficient mechanical strength is obtained. When the number of hydrogen atoms bonded to silicon atoms in the component (B) is less than 0.5 with respect to one unsaturated bond in the component (A) (Comparative Example 4), the paste cannot be obtained. When the compounding amount of the polyorganosilsesquioxane powder which is not sufficiently cured is 300 parts by weight or more (Comparative Example 5), no paste is formed, and in all cases of Comparative Examples, it is favorable as a soft dental lining material. It turns out that it does not show the property.

[0060]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-38172 (JP, A) JP-A-1-301609 (JP, A) JP-A-61-159450 (JP, A) JP-A-63-163 15849 (JP, A) JP-A-2-298550 (JP, A) JP-A-6-135814 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61C 13/01-13 / 23 A61K 6/00-6/093

Claims (1)

(57) [Claims] (A) An organopolysiloxane having at least two organic groups having a terminal unsaturated bond in a molecule.
(B) an organohydrogenpolysiloxane having at least three hydrogen atoms bonded to a silicon atom in the molecule per 100 parts by weight of the hydrogen atom to one unsaturated bond in the component (A). Is 0.5 or more,
(C) 0.1 to 1000 ppm of a platinum catalyst based on the total amount of component (A) and component (B) in terms of platinum atom, and (D) 5 to 30 fine particles of polyorganosilsesquioxane.
A soft dental lining material comprising 0 parts by weight.