JP3277503B2 - 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 a soft lining material has 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 (A) 100 parts by weight of an organopolysiloxane, and (B) 0.0% of an organic peroxide.
A soft dental lining material comprising 5 to 15 parts by weight and (C) 5 to 300 parts by weight of polyorganosilsesquioxane fine particles.

The component (A) organopolysiloxane used in the present invention, which is used in ordinary silicone rubbers, may be linear or branched, and may be a mixture thereof. There may be. The organic group bonded to the silicon atom in the diorganosiloxy unit, which is a repeating unit, is a methyl group, an ethyl group, a propyl group, a butyl group, an alkyl group such as an octyl group, a vinyl group, an allyl group,
Examples thereof include an alkylene group such as 1-butenyl group, an aryl group such as phenyl group, a substituted alkyl group such as chloromethyl group and 3,3,3-trifluoropropyl group. From the viewpoint of maintaining good physical properties after curing, a methyl group, a vinyl group or a mixture thereof is preferred. Further, in the triorganosiloxy unit which is a terminal unit of the organopolysiloxane, the organic group bonded to the silicon atom may be any combination of the above-mentioned organic groups, but dimethylvinylsiloxy is preferred because of easy synthesis and crosslinking reaction. Units and trimethylsiloxy units are preferred.

The number of siloxy units of the organopolysiloxane of the component (A), that is, the average degree of polymerization, is preferably in the range of 50 to 5,000, particularly 100 to 2,000. When the average degree of polymerization is less than 50, it is difficult to obtain sufficient elasticity, elongation and mechanical strength after curing. In addition, if it exceeds 5,000, the viscosity becomes too high and not only the operability before the effect is hindered, but also
After the effect, it tends to be difficult to obtain sufficient mechanical strength.

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

[0013]

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(However, Ph represents a phenyl group). The bonding order of the repeating structural units in the compounds used in the compounds and the examples and comparative examples described below is completely arbitrary, and the number of the repeating structural units shown in the structural formula simply indicates the average total amount of each structural unit. Not just.

The component (B) organic peroxide used in the present invention is a vulcanizing agent used for crosslinking and curing the organopolysiloxane of the component (A). It is a known vulcanizing agent. Examples of the organic peroxide include acyl peroxides such as benzoyl peroxide and p-chlorobenzoyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t- Non-acyl peroxides such as butylperoxy) hexane and dicumyl peroxide. These organic peroxides can be used alone or as a mixture of two or more. The compounding amount of the organic peroxide of the component (B) is selected from the range of 0.05 to 15 parts by weight based on 100 parts by weight of the organopolysiloxane of the component (A). Component (B)
When the amount of the organic peroxide is less than 0.05 part by weight, vulcanization is not sufficiently performed, and when the amount exceeds 15 parts by weight, not only is there no particular effect, but also the physical properties of the obtained silicone rubber elastic body are adversely affected. It is not preferable because it may give.

The component (C) polyorganosilsesquioxane fine particles used in the present invention serve as a reinforcing material for silicone rubber.

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. 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 fluorocarbon resin powders such as polytetrafluoroethylene and povinylidene fluoride, which have a small reinforcing effect on silicone rubber and have a low compatibility between fluorocarbon resin and silicone rubber. However, the matrix / filler interface does not blend in, voids are formed, and a coloring component penetrates into the gaps, so that the coloring amount is large despite the low hydrophilicity of the filler.

However, in the present invention, the component (C)
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 the filler of the 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 diameter 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 compounding amount of the fine particles is required to be 5 to 300 parts by weight based on 100 parts by weight of the organopolysiloxane of the component (A). If the amount is less than 5 parts by weight, sufficient mechanical strength cannot be obtained for the cured elastic body, and if it exceeds 300 parts by weight, it is difficult to mix the compound into the 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.

The soft dental lining material of the present invention may optionally contain a filler other than polyorganosilsesquioxane fine particles as needed, as long as the 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,
Fluorocarbon resin powder such as polytetrafluoroethylene, povinylidene fluoride, carbon black,
Examples include glass fiber, pulverized polymer, powder 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. Examples of such additives include a reaction inhibitor, an ultraviolet absorber, a plasticizer, a pigment, an antioxidant, and an antibacterial agent.

The soft dental lining material of the present invention comprises the necessary components from among fillers and additives other than organopolysiloxane, organic peroxide, fine particles of polyorganosilsesquioxane, and fine particles of polyorganosilsesquioxane. Is weighed in an appropriate amount and kneaded by a general kneading machine such as a kneader or planetary until it becomes uniform, whereby a paste-like composition can be obtained.

The method of using the soft dental lining material of the present invention is as follows.
A known indirect lining method can be employed.

[0030]

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.

[0031]

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 organopolysiloxanes used in the following Examples and Comparative Examples.

[0033]

[Table 1]

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 a sample paste is taken, and the diameter is 9 mm × length 12 mm.
And filled under a predetermined condition. After curing, remove from mold, 37
After standing in air at 24 ° C. for 24 hours, it is measured by a Shore A hardness tester.

(2) Tensile Strength and Elongation A required amount of a sample paste was taken, filled in a stainless steel mold having a hole having a shape of a required dumbbell-shaped test piece and having a thickness of 2 mm, and cured under predetermined conditions. 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) Coloring A required amount of the sample paste is taken and 10 mm × 10 mm × 2 m
It was filled in a stainless steel mold having a hole of m and cured under predetermined conditions. After curing, remove from the mold, 3
After standing in air at 7 ° C. for 24 hours, L ^* , a ^* and b ^* before coloring are measured by a color difference meter. After that, the test piece was
immersed in a t% curry aqueous solution and stirred at 40 ° C for 24 hours.
Save time. After storage, wash with water, dry, and measure again with a colorimeter.
^* , A ^* , and b ^* are measured, and the difference, ΔL ^* , Δa ^* , Δb ^*
Then, the coloring amount (ΔE ^* ) is obtained using the following equation.

ΔE ^* = (ΔL ^{* 2} + Δa ^{* 2} + Δb ^{* 2} ) ^1/2 (4) Cutability test A required amount of a sample paste is taken, and the diameter is 9 mm × length 12 mm.
And filled under a predetermined condition. After curing, remove from mold, 37
After standing in air at 24 ° C. for 24 hours, the cutting property was evaluated using a carbide bar and a 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. Example 1 100 parts by weight of the compounds shown in Table 1 and an organic peroxide As a catalyst, 2 parts by weight of benzoyl peroxide (hereinafter abbreviated as BPO) and 100 parts by weight of a polyorganosilsesquioxane having a particle diameter of 2 μm are put into a planetary, and kneaded until uniform, to obtain a sample paste. This sample paste is filled in a required mold, fixed with a clamp via a glass plate, and immersed in boiling water for 1 hour. Then, after taking out and leaving it to stand in the air at 37 ° C. for 24 hours, each physical property was measured according to the above-mentioned test method. Table 3 shows the results.

Examples 2 to 7 and Comparative Examples 1 to 4 Materials having the respective compositions shown in Table 2 were kneaded with a kneader to prepare pastes. Create a cured body using each paste,
The test was performed according to the above evaluation method. Table 3 shows the results.

[0041]

[Table 2]

[0042]

[Table 3]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-301609 (JP, A) JP-A-61-191355 (JP, A) JP-A-58-201707 (JP, A) JP-A-55-2017 38172 (JP, A) JP 44-5516 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61K 6/00 CA (STN)

Claims (1)

(57) [Claims] 1. An organic peroxide (B) containing 0.05 to 15 parts by weight of an organic peroxide and (C) 5 to 300 parts by weight of polyorganosilsesquioxane fine particles, based on 100 parts by weight of an organopolysiloxane. A soft dental lining material characterized by comprising: