JPH0586366B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention treats teeth, especially dentin, to form a dense coat layer on the dentin surface and prevent factors that stimulate the dental pulp (bacteria, chemicals, changes in hydrostatic pressure, etc.) The present invention relates to a tooth surface treatment agent for blocking dentin penetration, protecting the dental pulp, and firmly adhering dental restorative materials such as metal castings and dental composite resins to dentin. (Conventional technology) In recent years, with the advancement of adhesive technology, dental crown restorative materials (hereinafter referred to as restorative materials) such as metal castings and dental composite resins have been made with polymerizable monomers having acidic groups and initiators. A treatment method that uses an adhesive to fix the tooth to the tooth has become popular. Such adhesives are
JP-A-53-69494, JP-A-54-11149, JP-A-58-
21607 and Japanese Patent Application Laid-Open No. 60-69010. On the other hand, research has been conducted with the aim of increasing caries resistance by applying titanium tetrafluoride as a fluorinating agent to the tooth surface in the form of an aqueous solution [for example, Journal of the Oral Hygiene Society 31 Volume 63-78, 1982
Year: Caries Res. vol. 17,
pp. 412-418, 1983]. (Problems to be Solved by the Invention) As dental treatment methods using adhesives as described above have become widespread, clinical problems arising from incomplete adhesion between teeth and restorative materials, such as filling materials, Although the fallout of crown prosthesis, marginal discoloration, and occurrence of secondary caries have been significantly reduced, this does not mean that all clinical problems have been resolved. For example, when the synthetic resin adhesives and composite resins currently used in dentistry polymerize and harden within the cavity, unpolymerized monomers, catalysts, and various additives elute from the cured product and penetrate the dentin. It is thought that this may have an adverse effect on the dental pulp. Furthermore, under the harsh oral environment, the bonding interface between the repair material and the tooth may break down, allowing bacteria to invade the tooth substance through minute gaps, causing pulpitis. It is also said that changes in the oral environment, such as changes in hydrostatic pressure, are transmitted to the tooth substance through the gap and stimulate the dental pulp through the dental tubules. Current technology involves cleaning the cut and ground dentin surface with an aqueous solution of phosphoric acid or organic acid to dissolve and remove the shavings before bonding, in order to strengthen the adhesive force between the dentin and the restorative material. However, since acid cleaning causes the dental tubules to open widely, once a gap occurs at the bonding interface, the above-mentioned problems may be exacerbated. Therefore,
The problem to be solved by the present invention is to firmly adhere a restorative material to tooth tissue such as dentin, and to prevent polymerizable monomers and bacteria from penetrating into the dental pulp through the dentinal tubules. (Means for solving the problem) This problem can be solved by providing a tooth surface treatment agent consisting of a combination of a titanium tetrafluoride solution and an adhesive containing a polymerizable monomer having an acidic group. . That is, after treating the dentin surface with a titanium tetrafluoride solution included in the surface treatment agent, a restorative material is adhesively fixed to the tooth with an adhesive containing a polymerizable monomer having an acidic group. resolved. The present inventors focused on the phenomenon in which a water-resistant and acid-resistant film called a "glaze" is formed on the enamel surface coated with a titanium tetrafluoride aqueous solution, and applied a similar treatment to dentin to create a "glaze". When we started basic research on the formation state of ``glazes'' and the adhesive strength between such ``glazes'' and adhesives containing the aforementioned polymerizable monomers having acidic groups, we discovered unexpected facts and developed the present invention. Reached. In other words, titanium tetrafluoride treatment forms a dense titanium compound coating (“glaze”) on the dentin surface, and this coating allows chemical components such as unpolymerized monomers and bacteria to be absorbed into the dentin, that is, the dentinal tubules. It has been discovered that it has the ability to prevent infiltration into the interior of the body, and also strongly adheres to adhesives containing polymerizable monomers having acidic groups. The concentration of the titanium tetrafluoride solution used in the present invention is
The amount is required to be 0.05% by weight (based on the solution) (the following percentages represent weight%), preferably 0.2% or more.
If the concentration is too low, the formation of the "glaze" will be incomplete and the above-mentioned desired effect will not be fully expressed. Further, the upper limit of the concentration is allowed up to the saturation solubility of titanium tetrafluoride, but since there is no particular advantage of a high concentration, it is usually used within a concentration range of 20%. Suitable solvents include water, ethanol, methanol, and mixed solvents thereof, and among these, an aqueous solution is preferable. The time for which the titanium tetrafluoride solution is left in contact with the dentin, that is, the time it is left to stand after application, is required to be at least 5 seconds.The lower the concentration, the longer the time required. It takes more than a minute. After the required time has elapsed after application, remove the titanium tetrafluoride solution on the dentin surface by washing with water, dry the surface using an air syringe, etc., and apply 0.1
~100% polymerizable monomer with acidic groups and 99.9~
An adhesive solution consisting of 0% copolymerizable monomer is applied. The acidic group referred to in the present invention is

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[Formula] (where X is halogen), etc. As a polymerizable monomer having such an acidic group, a general formula having an ethylenic double bond is used.

[Chemical formula] (However, R ₁ , R ₂ , R ₃ are hydrogen or organic groups;
R ₄ is an organic group; m and n are integers from 1 to 4;
is an integer satisfying 3n≧≧1; A is an acidic group) A polymerizable monomer is used, and the following (meth)acrylate monomers are usually preferably used.

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[ka] (n is an integer from 2 to 40)

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[Chemical] These acidic group-containing monomers are usually copolymerizable monomers as diluents, such as (meth)acrylate monomers, and more specific examples include methyl (meth)acrylate, lauryl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,10-decane Diol di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerin di(meth)acrylate, bisphenol A
Di(meth)acrylate, 2,2-bis[(meth)
Acryloyloxyethoxyphenyl]propane, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane, trimethylolpropane tri(meth)acrylate, etc. are added to form the adhesive solution. be done. The effective concentration of the monomer having an acidic group is 0.1% or more, preferably 0.5% or more, based on the total polymerizable monomer (monomer having an acidic group + copolymerizable monomer). Note that if the monomer having an acidic group is liquid at room temperature, it can be used at 100% concentration without adding a diluent. The adhesive solution further contains a polymerization initiator (a room temperature curing redox initiator,
A photopolymerization initiator), a diluent such as ethanol, isopropanol, and ethyl acetate, a filler such as silica powder, glass powder, and alumina powder, and other various additives may be added if necessary.
Such adhesives include the above-mentioned Japanese Patent Application Laid-Open No. 53-69494,
Any of those disclosed in Nos. 54-11149, 58-21607, 60-69010, etc. can be used. Such an adhesive is applied to the surface of dentin treated with titanium tetrafluoride, and then bonded to a metal casting or composite resin. (Function) When a titanium tetrafluoride solution is applied to dentin, adhesion of the titanium compound occurs and a dense film is formed on the surface. Analysis by ESCA has shown that this film contains a large amount of titanium, but the details of its composition are unknown. This coating uniformly covers the dentin surface and can occlude the dentinal tubules, and is strongly bonded to the dentin and does not peel off easily. Therefore, it is presumed that various external stimuli are prevented from reaching the dental pulp through the dentin and dentinal tubules, and the dental pulp is protected. Furthermore, when an adhesive containing a monomer having an acidic group is applied onto this coating, it will firmly adhere to the coating, so it can be inferred that the dentin and the adhesive bond strongly through the coating. However, the details of the adhesion mechanism are not clear. (Effects) By using a combination of a solution containing titanium tetrafluoride and an adhesive containing a monomer with an acidic group, it has become possible to protect the dental pulp and strongly bond the dentin and the dental restorative material. For this reason, direct use of synthetic resin adhesives has traditionally been restricted, such as for sensitive patients, cavities close to the pulp, and abutment teeth with large exposed areas of dentin, without the need for a cement backing layer. It is judged that the use of synthetic resin adhesives is possible. (Example) (i) Preparation of tooth surface treatment agent A tooth surface treatment agent having the composition and combination shown in Table 1 was prepared and used in the experiments described in () below.

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[Table] (ii) Organic molecule blocking effect of titanium tetrafluoride treatment The following experiment was conducted to clarify the organic molecule blocking effect of the coating layer formed on the dentin surface by titanium tetrafluoride treatment. . The buccal or lingual side of a human molar was shaved parallel to the tooth axis to expose the dentin, and a band of wax was raised along the tooth axis at the center of the dentin surface to divide the surface into two. Spread 1 portion of 40% phosphoric acid aqueous solution on both divided sides.
After application for a few minutes and acid etching, washing with water and drying was performed according to a conventional method. Next, a 1% titanium tetrafluoride aqueous solution was applied to one side, and after 3 minutes, it was washed with water and dried. This tooth was immediately immersed in a 0.9% basic fuchsin aqueous solution, and after 2 hours, it was taken out and embedded in epoxy resin. Under water injection, the tooth was cut with a rotary cutter on a plane perpendicular to the tooth axis, and the penetration degree of the fuchsin dye was observed. From the dentin surface treated with titanium tetrafluoride (example), a very small amount of pigment penetration was observed only near the surface layer, but from the dentin surface that was not treated with titanium tetrafluoride (comparative example) A large amount of pigment penetrated into the tooth and reached the pulp cavity. Furthermore, when the dentin surface treated with titanium tetrafluoride was observed using a scanning electron microscope, it was found that it was covered with a dense coating layer and the dentinal tubules were occluded. (iii) Evaluation of bond strength 30 human molars were embedded in epoxy resin, the buccal or lingual side was scraped parallel to the tooth axis to expose the dentin, and the dentin surface was soaked with 40% phosphoric acid aqueous solution for 1 hour. The adherend sample was subjected to acid etching for one minute. Divide these into 6 groups of 5 items, A to E in Table 1.
A stainless steel disc (6 mm
φ×3mm) or acrylic disc (6mmφ×3
mm, used only for surface treatment agent D) was adhered. Ten minutes after bonding, each sample was immersed in water at 37°C, and 24 hours later, the shear bond strength between the dentin and the stainless steel or acrylic disc was measured.
All fractures occurred at the dentin-adhesive interface or within the dentin. The results are shown in Table 2.

[Table] (iv) Adhesive strength durability test The samples bonded under the conditions of Example 3 and Comparative Example 2 were immersed in 37°C water for 24 hours, and then placed in water baths at 4°C and 60°C for 1 minute alternately. A heat shock test of 10,000 immersions was conducted to compare the durability of the adhesive strength.
Table 3 shows the shear adhesive strength after heat shock 1000 times, 2500 times, and 10000 times.

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Claims (1)

[Claims] 1 (a) A solution containing 0.05% by weight or more of titanium tetrafluoride (based on the solution) and (b) 0.1 to 100% by weight of a polymerizable monomer having an acidic group and 99.9 to 0% by weight of the monomer. A tooth surface treatment agent made in combination with an adhesive made of a monomer that is copolymerizable with the polymer.