JPH0741411A - Soft lining material for dental use - Google Patents

Abstract

PURPOSE:To obtain a soft lining material for dental use having cuttability and giving an elastic material having proper elasticity and excellent coloration resistance after being cured. CONSTITUTION:This soft lining material for dental use contains (A) 100 pts.wt. of an organopolysiloxane having >=2 organic groups having terminal unsaturated bond of the molecule, (B) >=0.5mol (based on 1mol of the unsaturated bond in the component A) of an organohydrogen polysiloxane having 2 3 hydrogen atoms bonded to Si atom in the molecule, (C) 0.1-1,000ppm (in terms of platinum atom based on the sum of the components A and B) of a platinum catalyst such as platinum or vinylsiloxane complex of platinum and (D) 5-300 pts.wt. of fine particles of polyorganosilsesquioxane such as polymethylsilsesquioxane or poly(50mol% methyl + 50mol% phenyl)silsesquioxane.

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 backing material for use on the mucosal surface of a resin denture base.

[0002]

2. Description of the Related Art Many dentures, especially full dentures, are elderly patients, and alveolar ridges generally have significant bone resorption, and the occlusal force per unit area is large. Since the alveolar ridge mucosa also becomes thin due to senile atrophy, the impact of occlusion and masticatory pressure will be transmitted directly to the alveolar bone without being alleviated. In addition, the thin mucous membrane sandwiched between the hard resin denture base and the hard alveolar bone is squeezed and scratched each time it bites, causing damage.

In such a difficult case, if a resin denture base is manufactured only with a methylmethacrylate resin which is usually used, good results cannot be obtained in maintaining, stabilizing and supporting the denture. Therefore, it is necessary to line the mucosal surface of the resin denture base with a soft material or a soft dental lining material to compensate for the lost viscoelasticity of the alveolar ridge mucosa and provide a cushioning property to alleviate the impact during occlusion. In other words, it is the purpose of lining with a soft material to overcome various obstacles caused by the pressure of the submucosa by the hard material of the denture base.

As a soft dental backing material which has been conventionally used clinically, a (meth) acrylic acid ester polymer,
Fluorine-based resins, polyolefin-based resins, and silicone rubber-based resins are available. Further, denture stabilizers (so-called denture stabilizers) are used for temporary applications.

However, a soft material such as a (meth) acrylic acid polymer lacks chemical stability in the oral cavity and is hardened and weakened within a few months, making it impossible to use it for a long time. Fluorine-based lining materials also have poor viscoelasticity and are not expected to have a sufficient cushioning effect. 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, which complicates the operation. Although the silicone rubber-based lining material is a relatively stable material, it is not sufficient in terms of durability and operability such as coloring and not being cut. In particular, the soft lining material currently used clinically has little machinability, and there is a problem that it cannot be corrected once it is hardened.

With respect to the denture stabilizer, too, the viscosity increases and the plasticity decreases as the period of use increases. As a result, not only the purpose of improving the maintenance, stability and support of the denture base cannot be sufficiently achieved by improving the conformability and marginal sealing property of the incompatible denture, but also the oral tissue is often impaired. Moreover, since the compressive stress is small and the elasticity is poor, the cushioning effect against the occlusal pressure is not sufficient, which causes the recurrence of pain in the oral mucosa.

[0007]

As described above, the soft dental lining materials for denture bases that have been provided hitherto have a decrease in physical properties and the like within a short period of use, resulting in a short period of use in the oral cavity. In addition to the fact that there is no material that exhibits a satisfactory cushioning effect, many of them are not suitable for practical use because of complicated usage. Therefore, there has been a demand for a soft dental backing material that has appropriate viscoelasticity, has no deterioration in physical properties, and has excellent operability, and particularly has machinability. Especially, with the aging of society, there is a strong demand for such soft dental backing material.

[0008]

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

That is, according to the present invention, (A) 100 parts by weight of an organopolysiloxane having at least two organic groups having a terminal unsaturated bond in the molecule, (B) is bonded to a silicon atom in the molecule. Component (A) comprising an organohydrogenpolysiloxane having at least 3 hydrogen atoms
The amount of the hydrogen atom is 0.5 or more with respect to one unsaturated bond in the component (C), which is the component (A) of the platinum catalyst in terms of platinum atom.
And 0.1 to 1000 ppm with respect to the total amount of component (B),
And (D) polyorganosilsesquioxane fine particles 5
The soft dental lining material is characterized by containing 300 parts by weight.

The component (A) used in the present invention is an organopolysiloxane having at least two organic groups having a terminal unsaturated bond in the molecule (hereinafter abbreviated as unsaturated bond-containing silicone), which is the component (B). It is a main component that becomes a rubber elastic body by crosslinking with an organohydrogenpolysiloxane (hereinafter abbreviated as SiH siloxane).

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

Examples of the organic group having a terminal unsaturated bond include a vinyl group, an allyl group and a 1-butenyl group, but a vinyl group bonded to a silicon atom is most advantageous from the viewpoint of easy synthesis. . These organic groups having a terminal unsaturated bond may be present at either or both ends of the molecular chain of the organosiloxane, or both of them, but the cured elastic body has excellent physical properties. In order to have properties, it is preferable that at least one is present at the terminal.

Examples of the organic group bonded to a silicon atom other than the organic group having a terminal unsaturated bond include a methyl group, an ethyl group,
Alkyl groups such as propyl group, butyl group, octyl group, aryl groups such as phenyl group, chloromethyl group, 3,
Substituted alkyl groups such as a 3,3-trifluoropropyl group are exemplified, and among these, a methyl group is most preferable from the viewpoints of easy synthesis and keeping good physical properties after curing.

Further, in order to use it as a soft dental lining material, in order to obtain suitable properties, in particular, an appropriate hardness after hardening, and sufficient elongation and mechanical strength, a terminal end 50 to 5000, especially 100 to siloxane units having only an organic group having no terminal unsaturated bond between siloxane units having an organic group having an unsaturated bond
It is preferable that 2000 pieces are continuously contained. 5 siloxane units with only organic groups without terminal unsaturated bonds
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 5000, not only does the viscosity become too high and the operability before curing is impaired,
It tends to be difficult to obtain sufficient hardness after curing.

Typical examples of the unsaturated bond-containing silicone used in the present invention are as follows.

[0016]

[Chemical 1]

(However, Ph represents a phenyl group) and the like. The bonding order of the repeating structural units in the compounds and the compounds used in Examples and Comparative Examples described below 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 unsaturated bond-containing silicone to form 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 silicon atoms are necessary in the molecule. If the number is less than 3, a rubber elastic body cannot be obtained because of no cross-linked structure.

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 component (A). However, the methyl group is the most preferable because it is easy to synthesize and retains good physical properties after curing. The SiH silicone may be linear, branched or cyclic, and may be a mixture thereof.

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

[0021]

[Chemical 2]

And the like. Also in the SiH siloxane used in Examples and Comparative Examples described above and below,
Like the unsaturated bond-containing silicone, the bonding order of the repeating constitutional units in the molecule is completely arbitrary, and the number of repeating constitutional units shown in the structural formula merely indicates the average total number of the respective constitutional units.

The unsaturated bond-containing silicone and S in the present invention
The amount of each iH siloxane compounded varies greatly depending on its molecular weight, but normally, one unsaturated bond in the unsaturated bond-containing silicone contains 0.5 or more hydrogen atoms bonded to the silicon atom in the SiH siloxane, It is preferable to mix them in a ratio of 1 to 5. If this ratio is too small, the curability becomes insufficient, and if it is too large, the resulting elastic body becomes brittle or excess hydrogen atoms bonded to silicon atoms remain, so that the temporal stability of the elastic body tends to decrease. is there.

Further, the hydrogen atom bonded to the silicon atom by the organohydrogenpolysiloxane having at least three hydrogen atoms bonded to the silicon atom in the molecule is equivalent to 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 added.

As the component (C) platinum catalyst used in the present invention, any catalyst can be used so long as it can be used in a usual hydrosilylation reaction. For example, platinum,
Examples thereof include chloroplatinic acid, its alcohol-modified products, and platinum vinylsiloxane complexes. In order to improve the storage stability, a substance having a low chlorine content such as a platinum vinylsiloxane complex is preferable.

The content of the platinum catalyst may be in the range of 0.1 to 1000 ppm in terms of platinum atom based on the total weight of the unsaturated bond-containing silicone and SiH siloxane. If the blending amount is less than 0.1 ppm, the crosslinking reaction between the unsaturated bond-containing silicone and SiH siloxane does not proceed sufficiently, and if it is more than 1000 ppm, the cured product becomes yellow due to the 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 functions as a reinforcing material for the silicone rubber obtained from the components (A), (B) and (C). .

Silica powders such as crushed quartz, fused silica, wet silica, and dry silica are generally said to be effective as a reinforcing material for silicone rubber, but for use as a soft dental backing material, However, these have a high hydrophilicity because silanol groups remain in the particles and / or on the surface of the particles, and as a result, there is a large amount of coloring (hereinafter abbreviated as the coloring amount) due to the penetration of the coloring component of the elastic body after curing. Have. Further, fine particles of wet silica, dry silica or the like cannot give sufficient rigidity to the elastic body after curing because of its small particle size, and therefore have no machinability. As the filler having low hydrophilicity, there are fluorocarbon resin powders such as polytetrafluoroethylene and povinylidene fluoride.
These have a small reinforcing effect on the silicone rubber, and the compatibility between the fluorocarbon resin and the silicone rubber is poor, and the matrix / filler interface does not fit well, and voids are formed, and the coloring component penetrates there, so that the hydrophilicity of the filler is low. Nevertheless, the amount of coloring is large.

However, in the present invention, the component (D)
The filler mentioned above, that is, the polyorganosilsesquioxane fine particles have higher hydrophobicity than the above-mentioned silica-based powder and also have Si-O bond, Si-CH ₃ bond, etc. Familiar,
Furthermore, the reinforcing effect on the silicone rubber is great, and therefore the elastic body after curing has sufficient mechanical strength and at the same time has a small coloring amount. Further, by selecting a material having an appropriate particle diameter, it is possible to fill the material with a high filling rate, and it is possible to give the cured elastic body sufficient rigidity. Therefore, machinability can be imparted to the cured elastic body.

Known polyorganosilsesquioxane fine particles can be used in the present invention. 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, 3, Substituted alkyl groups such as 3,3-trifluoropropyl group; hydrogen atoms and the like are exemplified, but of these, a methyl group, or a methyl group, from the viewpoint of easy synthesis and maintaining good physical properties after curing. A methyl group and one in which a part of the methyl group is substituted with the above-mentioned organic group are preferably used.

Typical examples of the polyorganopolysiloxanes used in the present invention are shown in the following: polymethylsilsesquioxane and poly (50 mol% methyl + 50mo).
1% phenyl) silsesquioxane, poly (99 mol
% Methyl + 1 mol% hydrogen) silsesquioxane and the like.

The use of fine particles of polyorganosilsesquioxane, especially fine particles of polymethylsilsesquioxane, as a filler of a silicone rubber composition is described in JP-A-61-159450. In JP-A-61-159450, only the releasability and releasability are mentioned as its effect, and only the use as a releasant and a releasant is disclosed. However,
The present inventors have discovered that the composition has excellent coloring resistance, sufficient strength, and machinability, and has considered using it as a soft dental backing material.

The polyorganosilsesquioxane fine particles were obtained by hydrolyzing and condensing organotrialkoxysilane or a mixture of one or more of hydrolyzed and condensed products thereof in an aqueous solution of ammonia or amines. Those having almost no impurities such as chlorine atom, alkaline earth metal and alkali metal and having a spherical shape are preferable.

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

The amount of the fine particles blended is 5 to 300 with respect to 100 parts by weight of the unsaturated bond-containing silicone of the component (A).
Parts by weight are required. If it is less than 5 parts by weight, the cured elastic body cannot have sufficient mechanical strength, and if it exceeds 300 parts by weight, it is difficult to mix it into the system and it is difficult to form a paste. Further, the rubber elasticity of the cured elastic body is poor, and not only the reinforcing effect is lost but also the mechanical strength is deteriorated.

The soft dental backing material of the present invention may optionally contain a filler other than the polyorganosilsesquioxane fine particles, if necessary, as long as the physical properties thereof are not significantly deteriorated. Typical examples are silica powder such as crushed quartz, fused silica, wet silica, and dry silica,
Examples thereof include fluorocarbon resin powders such as polytetrafluoroethylene and polyvinylidene fluoride, carbon black, glass fibers, pulverized polymers, powder polymers, and composite fillers (composite of inorganic oxide and polymer are pulverized).

Further, other additives may be added as long as the physical properties are not significantly deteriorated. Such additives include non-reactive silicones, reaction inhibitors, ultraviolet absorbers,
Examples include plasticizers, pigments, antioxidants, antibacterial agents, and the like.

The soft dental backing material of the present invention is usually an unsaturated bond-containing silicone, a filler containing polyorganosilsesquioxane fine particles as a main component, a platinum catalyst and, if necessary, an upper agent. , And a package containing SiH siloxane, a filler containing polyorganosilsesquioxane fine particles as a main component, and optionally an unsaturated bond-containing silicone and an additive, if necessary, immediately before use. It is common to mix and use.

The preparation method is as follows: unsaturated bond-containing silicone,
SiH siloxane, polyorganosilsesquioxane fine particles, platinum catalyst, filler and additives other than polyorganosilsesquioxane fine particles are weighed in appropriate amounts, and then kneader, planetary, etc. By kneading until uniform, a paste composition can be obtained.

The method of using the soft dental backing material of the present invention is as follows.
It can be used by a known direct lining method. That is, just before use, two kinds of pastes of A and B are weighed and kneaded in an appropriate amount, spread on the back of the denture, and held in the patient's mouth until it is sufficiently cured. After curing, remove from the oral cavity and remove the excess.

[0041]

The soft dental backing material obtained according to the present invention is a soft dental backing material having an appropriate elasticity after curing, an elastic body excellent in coloring resistance, and cutting property. It is preferably used.

[0042]

EXAMPLES Examples will be shown to more specifically describe the present invention, but the present invention is not limited to these examples.

The unsaturated bond-containing silicones used in the following examples and comparative examples are shown in Table 1, and the SiH siloxanes are shown in Table 2.
Shown in.

[0044]

[Table 1]

[0045]

[Table 2]

In the Examples and Comparative Examples, the soft dental lining material was evaluated 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 paste of A and B is kneaded, and after kneading, filled in a mold made of polytetrafluoroethylene (hereinafter abbreviated as PTFE) having a hole of 9 mm in diameter and 12 mm in length. , Fully cured in air at 37 ° C. After curing, it is taken out of the mold, left standing in air at 37 ° C. for 24 hours, and then measured by a Shore A hardness meter.

(2) Tensile Strength, Elongation A, Required amount of each paste of A and B, and after kneading, 2 mm thick PT with holes in the shape of required dumbbell-shaped test piece
It was filled in a mold made of FE and sufficiently cured in air at 37 ° C. After curing, the molded product was taken out of the mold and left in the air at 37 ° C. for 24 hours, and then, using an autograph (manufactured by Shimadzu Corporation), a crosshead speed of 10 mm / min. Measure the tensile strength and elongation at break with. The size of the parallel part of the dumbbell-shaped test piece is 10 mm in length and 5 mm in width.

(3) Coloring amount The required amount of each paste of A and B is taken and after kneading, 10
It was filled in a PTFE mold of mm × 10 mm × 2 mm and sufficiently cured in air at 37 ° C. After curing, the product is taken out of the mold and left in air at 37 ° C. for 24 hours, and then L ^* , a ^* and b ^* before coloring are measured by a color difference meter. Then, the test piece is dipped in a 20 wt% curry aqueous solution and stored at 40 ° C. for 24 hours while stirring. After storage, it was washed with water and dried, and L ^* , a ^* , and b ^* were measured again with a color difference meter, and the difference, Δ
^{L *, △ a *, △} b * than, coloring amount using the following equation (△
E ^* ).

[Delta] E ^* = ([Delta] L ^{* 2} + [Delta] a ^{* 2} + [Delta] b ^{* 2} ) ^1/2 (4) Machinability test Take the required amount of each paste of A and B, and after kneading, diameter 9mm x length It was filled in a PTFE mold having a hole of 12 mm in diameter and sufficiently cured in air at 37 ° C. After curing, it was taken out from the mold and allowed to stand in air at 37 ° C. for 24 hours, after which the machinability was evaluated using a dental engine microengine and a carbide bar and silicone point. The evaluation points were evaluated according to the following criteria, from A to D points.

A: The surface part can also be scraped B: The peripheral part can be scraped but the surface part cannot be scraped C: Scratches but not scraped D: No scraping Example 1 50 parts by weight of each of the compounds shown in Table 1
Platinum vinyl siloxane complex is a compound, and polyorganosilsesquioxane fine particles 100 having a particle diameter of 2 μm and an amount such that platinum is 200 ppm with respect to the total amount of the compound.
Put parts by weight into the planetary, knead until uniform,
It was paste A.

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

The two kinds of pastes of the above A and B were kneaded at a mixing ratio of 1: 1 and evaluated according to the above-described evaluation method. The results are shown in Table 4.

Examples 2 to 11 and Comparative Examples 1 to 5 Materials having the respective compositions shown in Table 3 were kneaded by a 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 performed using each paste according to the above evaluation method. The results are shown in Table 4.

[0056]

[Table 3]

[0057]

[Table 4]

[0058]

[Table 5]

From the results shown in Table 4, the soft dental lining materials of the present invention (Examples 1 to 11) have appropriate hardness, sufficient tensile strength and elongation, a small amount of coloring and good machinability. I understand. On the other hand, in the comparative example, when the number of hydrogen atoms bonded to the silicon atom in the component (B) is less than 3 (Comparative Example 1), the paste does not cure, and the polyorganosilsesquioxane powder is used as the filler. When not used (Comparative Example 2), there is a large amount of coloring, 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. If the number of hydrogen atoms bonded to the silicon atom in component (B) is less than 0.5 with respect to one unsaturated bond in component (A) (Comparative Example 4), the paste is not formed. When the amount of the polyorganosilsesquioxane powder that does not cure sufficiently is 300 parts by weight or more (Comparative Example 5), it does not become a paste, and in all Comparative Examples, it is good as a soft dental backing material. It turns out that the property is not shown.

[0060]

Claims (1)

[Claims] 1. An organopolysiloxane (A) having at least two organic groups having a terminal unsaturated bond in the molecule (A).
100 parts by weight of (B) an organohydrogenpolysiloxane having at least 3 hydrogen atoms bonded to silicon atoms in the molecule, wherein the hydrogen atom is added to one unsaturated bond in the component (A). Is 0.5 or more,
(C) Platinum catalyst in terms of platinum atom, based on the total amount of component (A) and component (B), 0.1 to 1000 ppm, and (D) polyorganosilsesquioxane fine particles 5 to 30
A soft dental lining material, characterized by containing 0 parts by weight.