JPH05230154A - Acrylic copolymer for tooth surface treatment and its use - Google Patents

Abstract

PURPOSE:To provide the title copolymer which comprises the units from an alkyl (meth)metacrylate and the units from styrenesulfonic acid derivative at a specific ratio and is excellent in adhesion to the teeth and teeth-repairing compositions as a surface-treating agent. CONSTITUTION:The objective copolymer comprises (A) the recurring units derived from an alkyl (meth)acrylate (preferably methyl methacrylate) and (B) the recurring units derived from a styrenesulfonic acid derivative (preferably p-styrenesulfonic acid) at an A:B 85/15 to 99/1 molar ratio preferably at A:B 86/14 to 95/5 molar ratio. When it is utilized as a teeth-surface-treating agent, the copolymer is preferably dissolved in water or a water-alcohol mixed solvent so that the concentration is adjusted to 0.7 to 12wt.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an acrylic copolymer for surface treatment of teeth having excellent affinity and a surface treatment agent for teeth which is a hydroxyapatite structure.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Conventionally, a (meth) acrylic curable resin (acrylic resin) has been used as a restorative agent for repairing a hydroxyapatite structure such as tooth structure. In such applications, the adhesive strength between the acrylic resin and the tooth surface does not change over a very long period of time, and it is necessary that the adhesive strength be high. Therefore, for example, when the tooth structure is to be repaired with a resin composition for repair using an acrylic resin as an adhesive component, the surface of the tooth structure is previously roughened with an etching agent such as an acid, and then the resin composition for repair is prepared. The method of filling is adopted.

However, during such a surface roughening treatment, an etching agent such as an acid may penetrate deep into the adherend, which may damage the hydroapatite structure itself. Further, when the hydroxyapatite structure is dentin, the penetrated etching agent may stimulate nerves and cause severe pain during repair.

In order to solve the above-mentioned problems of conventional tooth treatment agents, the applicant of the present invention uses tooth treatment as a tooth surface treatment agent in order to restore the tooth surface without roughening treatment. It has been proposed to use a resin in which a group having a bondability to the surface is introduced (Japanese Patent Application No. 171024/1985 (Japanese Patent Application Laid-Open No. 62-1024).
-33109 publication)).

[0005] This specification discloses a treating agent containing a polymer having a sulfonic acid group introduced as a group having a bondability to the surface of tooth. Specifically, for example, with a methacrylic acid ester such as methyl methacrylate
It is a polymer prepared by dissolving a copolymer with a sulfonic acid group-containing monomer such as p-styrene sulfonic acid in a solvent such as ethanol and copolymerizing it. When a solution in which such a polymer is dissolved is applied to the tooth surface, the solvent is removed and a treatment layer of this polymer is formed on the tooth surface. This copolymer layer (polymer treated layer)
Because the sulfonic acid group is bonded to the calcium component in the tooth structure, it adheres very strongly to the tooth structure, and this copolymer has repeating units derived from methyl methacrylate. Coated on layers (meta)
It also shows good compatibility with tooth filling materials containing acrylic curable resin as the main adhesive component. Therefore, by using this treatment agent, the tooth filling material is firmly adhered to and integrated with the tooth substance via the treatment layer, so that a good adhesion state is exhibited and this state is maintained for a long time. It In addition, since the treatment agent has a large molecular weight, it hardly penetrates deep into the dentin and stimulates the nerve less.

The present applicant has already applied for an invention of a method for treating tooth structure using a treating agent containing such a copolymer (see Japanese Patent Application No. 1-83348). .. Based on such a background, the present inventor has repeatedly studied the relationship between the content ratio of sulfonic acid groups in the copolymer and the adhesive strength. In the treatment layer of such a copolymer, it is generally considered that the calcium content in the tooth substance and the sulfonic acid group are bonded to each other to develop the adhesive strength between the treatment layer and the tooth substance surface. It is expected that the adhesive strength between the treatment layer and the tooth substance will increase with a certain correlation with the increase in the content of sulfonic acid groups in the copolymer. Therefore, considering only the adhesive strength between the treatment layer and the tooth structure, it is desirable that the content of the sulfonic acid group in the copolymer is high. However, the restoration agent composition which is filled on the treatment layer and restores the tooth structure has a methacrylic acid-based resin as a main component, and the treatment layer formed on the tooth surface has good adhesion with the restoration agent composition. Must have. The adhesive strength between the treatment layer and the restorative composition is largely due to the affinity between the treatment agent and the restorative composition, and in order to develop the affinity between them, it is used as a tooth surface treatment agent. The content of the methacrylic acid-based component unit in the copolymer must be above a certain level.

Therefore, in determining the composition of the tooth surface treatment agent, a methacrylic acid-based monomer is used so that the affinity between the treatment layer and the restorative composition can be maintained, and the affinity is maintained. Generally, the content of the sulfonic acid group in the copolymer is determined so that the adhesive strength between the tooth structure and the treatment layer is as high as possible.

Further, when such an acrylic copolymer is used as a tooth treatment agent, water or water.
Used with alcohol etc. When treating the tooth surface with a tooth treatment agent used in such a solution state, the more uniformly treated it is, the better the adhesive state can be developed, so in order to achieve a more uniform treatment state. It is considered advantageous to use a solution in which the acrylic copolymer as described above is completely dissolved in a solvent such as water. The solubility of the acrylic copolymer in water or a water / alcohol mixed solvent increases as the content of the sulfonic acid group in the copolymer increases, so that a copolymer solution having good solubility is prepared. In order to achieve this, a method of increasing the content of sulfonic acid groups in the copolymer is adopted. According to the study of the present inventors, when the content of the repeating unit having a sulfonic acid group in the copolymer is low to some extent (for example, lower than 30 mol% in a 3% solution), the solution containing the copolymer is There is a tendency to become cloudy and insoluble matter may be mixed. Comparing the case of using such a treatment liquid and the case of using a transparent treatment liquid in which the copolymer is completely dissolved, the treatment of the dentin surface is better in the case of using the treatment liquid which becomes cloudy. Since it is unlikely that it can be carried out more uniformly, the content of sulfonic acid groups in the copolymer is adjusted so that a transparent solution can be obtained.
It is generally set higher.

For the above reason, in the acrylic copolymer used for the treatment of the tooth surface, the content of the repeating unit having a sulfonic acid group is set to be high, and the (meth) acrylic repeating unit is used. It is a general method for determining the composition to keep the content of the unit relatively low.For example, as a copolymer for treating the surface of teeth, an acrylic resin having a composition such that it becomes cloudy in water or insoluble matter is mixed. It is the actual situation that the characteristics, especially the adhesive strength, of the system copolymers are not specifically known.

[0010]

The object of the present invention is to provide a tooth structure and a restorative agent among the copolymers comprising a repeating unit derived from a conventional alkyl (meth) acrylic acid ester and a repeating unit derived from a styrenesulfonic acid derivative. It is an object of the present invention to provide an acrylic copolymer showing particularly excellent adhesiveness to both of the compositions and a tooth surface treating agent using the acrylic copolymer.

[0011]

SUMMARY OF THE INVENTION The acrylic copolymer for surface treatment of teeth of the present invention comprises a repeating unit derived from an alkyl (meth) acrylate and a repeating unit derived from a styrenesulfonic acid derivative of 85: It is characterized by having a molar ratio of 15 to 99: 1.

The tooth surface treating agent of the present invention comprises a repeating unit derived from an alkyl (meth) acrylate and a repeating unit derived from a styrenesulfonic acid derivative in an amount of 85:15 to 99: 1. It is characterized by being composed of an acrylic copolymer having a molar ratio and water and / or alcohol.

The acrylic copolymer for surface treatment of teeth of the present invention is a copolymer based on poly (meth) acrylic acid alkyl ester and has a repeating unit content derived from a styrenesulfonic acid derivative. Is a copolymer having a specific range. With such a composition, adhesive strength that is several times that of conventional treatment agents or more is exhibited. Such an increase in the adhesive strength cannot be explained by the conventionally-considered adhesion theory, and can be achieved only by combining the combination of the resin of the present invention and the content rate.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Next, the acrylic copolymer for tooth surface treatment and the tooth surface treatment agent of the present invention will be specifically described.

First, the acrylic copolymer for surface treatment of teeth of the present invention will be described. The acrylic copolymer for tooth surface treatment of the present invention is a copolymer composed of a repeating unit derived from an alkyl (meth) acrylate and a repeating unit derived from a styrenesulfonic acid derivative.

The repeating unit derived from the (meth) acrylic acid alkyl ester forming the acrylic copolymer of the present invention can be represented by the following formula [I].

[0017]

[Chemical 1]

However, in the above formula [I], R ¹ is
It is a hydrogen atom or a methyl group. In particular, R ¹ is preferably a methyl group. R ² is usually an alkyl group having 1 to 5 carbon atoms, and examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group and a pentyl group. Especially R ²
Is preferably a methyl group.

Such a repeating unit can be derived from the compound represented by the formula [Ia] described below.

[0020]

[Chemical 2]

[I-a] However, in the formula [I-a], R ¹ and R ² have the same meaning as in the above formula [I]. In the present invention, the formula [I-a]
Examples of preferred compounds represented by are methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, butyl (meth) acrylate and pentyl (meth) acrylate. Of these, methyl methacrylate is particularly preferable.

The repeating unit derived from the styrene sulfonic acid derivative forming the acrylic copolymer of the present invention can be represented by the following formula [II].

[0023]

[Chemical 3]

However, in the above formula [II], R ³ is
It represents any one of H ⁺ , an alkali metal ion (eg, Li ⁺ , K ⁺ , Na ⁺ etc.), NH ₄ ⁺ and a lower alkyl group such as a methyl group and an ethyl group. Further, R ⁴ represents a hydrogen atom or a methyl group. Also, -SO ₃ R ^3, which may be attached to any position, preferably bonded in the para position relative to for example, vinyl.

This repeating unit has, for example, the following formula [II-a]
It can be derived from the compound represented by

[0026]

[Chemical 4]

[II-a] However, in the above formula [II-a], R ³ and R ⁴ have the same meanings as the above-mentioned [II].

Specific examples of the compound represented by the above formula [II-a] include p-styrene sulfonic acid, α-methyl p-styrene sulfonic acid, sodium p-styrene sulfonate,
Mention may be made of sodium α-methyl p-styrenesulfonate. Of these compounds, p-
Styrene sulfonic acid is particularly preferred.

In the present invention, the repeating unit derived from the styrene sulfonic acid derivative may be obtained by polymerizing styrene in addition to the method of copolymerizing the monomer in which the sulfonic acid is introduced in advance as described above. Alternatively, a method of introducing a sulfonic acid group or the like can be used.

The acrylic copolymer of the present invention comprises a repeating unit derived from the above (meth) acrylic acid alkyl ester and a repeating unit derived from a styrenesulfonic acid derivative in a molar ratio of 85:15 to 99: 1. Have in ratio. That is, the acrylic copolymer of the present invention is a copolymer having a lower content of sulfonic acid groups than the acrylic copolymer which has been conventionally proposed as a tooth surface treating agent and whose properties have been specifically examined. Is. Despite the low content of sulfonic acid groups, the copolymer of the present invention has significantly higher adhesive strength than conventional ones.

For example, Comparative Examples 1 to 3 which will be described later are acrylic copolymers having composition ratios which have been conventionally considered for use. Adhesive force to tooth structure was measured using these, and comparison was made. As shown in Examples 4 to 6, the maximum value of the adhesive strength is exhibited when the content of the repeating unit having a sulfonic acid group is about 30 to 40 mol%. That is, the copolymer having such a composition has a good balance between the adhesiveness due to the bond between the tooth substance (hydroxyapatite structure) and the sulfonic acid group and the affinity between the tooth treatment layer and the restorative composition. Is taken,
The adhesive strength of about 20 Kgf / cm ² is exhibited. Then, when the content of the repeating unit having a sulfonic acid group is decreased, the adhesive strength tends to be slightly decreased. However, when the content of the repeating unit having a sulfonic acid group was further reduced, the adhesive strength began to sharply increase at the time when the content of the repeating unit derived from the styrenesulfonic acid derivative was 15 mol%. As shown in (3), when the concentration of the repeating unit having a sulfonic acid group is 13 mol%, an adhesive strength of about 80 Kgf / cm ² is exhibited. This adhesive strength is almost maintained until the content of the repeating unit derived from the styrenesulfonic acid derivative is 1%. And in the acrylic copolymer of the present invention,
When the molar ratio of the repeating unit derived from the (meth) acrylic acid alkyl ester to the repeating unit derived from the styrenesulfonic acid derivative is 86:14 to 99: 1, particularly 86:14 to 95: 5. Higher adhesive strength.

The acrylic copolymer having the above-mentioned properties is usually a copolymer having a number average molecular weight of 10000 or more, and often 10 ⁵ to 10 ⁸ . Then, such an acrylic copolymer becomes a cloudy solution when added to water. FIG. 1 shows an example of the turbidity of an aqueous solution at 25 ° C. containing the acrylic copolymer of the present invention (copolymer of methyl methacrylate (MMA) and styrene sulfonic acid) at a content of 3% by weight. 12V, 50W to measure this turbidity
A colorimetric color difference meter (Z-Σ80 type, manufactured by Nippon Denshoku Industries Co., Ltd.) equipped with a halogen lamp of No. 1 was used. As is clear from the example shown in FIG. 1, the content of the repeating unit derived from styrenesulfonic acid in the copolymer is 30 mol% or more (the content of the MMA repeating unit is 70 mol% or less).
The turbidity of the aqueous solution containing methyl methacrylate is 1-3.
The turbidity rises rapidly as the content of repeating units derived from styrene sulphonic acid decreases, while it is almost constant in%. An acrylic copolymer having a turbidity of a 3% by weight aqueous solution of 10% or more, preferably 15 to 99%, more preferably 20 to 95% exhibits extremely high adhesive strength.

A clear theory has not been established as to why the acrylic copolymer of the present invention has excellent adhesive strength as described above. However, the present inventor has determined that the acrylic copolymer of the present invention has the following characteristics due to the types of repeating units, the content and properties of sulfonic acid groups, and the phenomenon that the copolymer becomes cloudy in water as described above. We believe that inferences such as those shown in can be made.

That is, when the surface of the tooth structure is treated with a conventional acrylic copolymer having a sulfonic acid group, the calcium component in the tooth structure reacts with the sulfonic acid group as described above.
Then, by reacting in this way, the acrylic copolymer becomes insoluble in water, a treatment layer insoluble in water is formed on the surface of the tooth structure, and adhesive strength is developed between this layer and the tooth structure. However, it is considered that not all of the sulfonic acid groups present in the copolymer are bound during such a reaction, but some of them remain in an unreacted state. Since the conventional acrylic copolymer has a high content of sulfonic acid groups, the amount of sulfonic acid groups remaining in an unreacted state is inevitably large. Since such unreacted sulfonic acid groups increase the affinity of the acrylic copolymer for water, the hydrophilic properties of the treated layer formed from the conventional acrylic copolymer are increased by the residual sulfonic acid groups. Acts to reduce the adhesive strength of the treatment layer,
As a result, the adhesive strength between the treatment layer and the tooth structure does not improve beyond a certain level.

On the other hand, in the acrylic copolymer of the present invention, the solubility of the copolymer in water is suppressed by controlling the sulfonic acid group content within a specific range. The copolymer itself does not dissolve transparently in water but becomes cloudy and dispersed. When the tooth surface is treated with an acrylic copolymer having such characteristics, the sulfonic acid group reacts with the calcium component, and the solubility of the treated layer (acrylic copolymer) in water is further reduced. It is considered that there is an unreacted sulfonic acid group that is not bonded to the calcium component in such a treated layer, and this sulfonic acid group acts as a water-immersive group. The reactive sulfonic acid groups are so small that they do not render the treated layer (ie the copolymer itself) hydrophilic. Therefore, by using the acrylic copolymer of the present invention, the tendency of the treated layer formed by the copolymer to become hydrophilic due to unreacted sulfonic acid groups is effectively prevented. That is, the adhesive strength between the tooth substance and the acrylic copolymer is essentially expressed by the bond between the sulfonic acid group and the calcium component. In the acrylic copolymer of the present invention, the adhesive strength thus expressed is shown. Is not reduced by the hydrophilization of the treated layer caused by the unreacted sulfonic acid groups.

Furthermore, in the acrylic copolymer of the present invention, the content of the (meth) acrylic component unit is high, and the repeating unit having a sulfonic acid group is also the (meth) acrylic component in the main chain portion. Since the structure is similar to that of the unit, the affinity between the treatment layer and the restoration agent composition is also good.

Therefore, it is considered that by using the (meth) acrylic copolymer of the present invention, a very high adhesive strength, which cannot be achieved by the conventional treating agents, is exhibited.

Although the above reasoning has been described as the bond strength between the treatment layer and the tooth substance being expressed by the bond between the sulfonic acid group and the calcium component, this bond strength naturally leads to the treatment layer and the tooth substance. It is considered that the physical adhesiveness of the treated layer also contributes, and the hydrophilicity of the treated layer by the above-mentioned unreacted sulfonic acid group is considered to act equally with respect to such physical adhesiveness. ..

The acrylic copolymer of the present invention is a copolymer formed only of a repeating unit derived from an alkyl (meth) acrylate and a repeating unit derived from a styrenesulfonic acid derivative. Although preferable, other monomers may be copolymerized as long as the characteristics of the copolymer are not impaired.

When the acrylic copolymer of the present invention is used as a surface treating agent for a tooth substance which is a hydroxyapatite structure, the acrylic copolymer is used by adding it to water or a water / alcohol mixed solvent. .. When a water / alcohol mixed solvent is used, a lower alcohol can be used as the alcohol, but ethanol is preferably used in consideration of toxicity. The concentration of ethanol in this mixed solvent is usually 90% by weight or less, preferably 50% by weight or less.

The concentration of the copolymer in the treatment liquid for the tooth surface treatment agent is usually 0.1 to 20% by weight, preferably 0.5 to 15% by weight, particularly preferably 0.7 to 12% by weight. It can be prepared by adding the acrylic copolymer of the present invention within the range of%. In the treatment liquid containing the acrylic copolymer thus prepared, the acrylic copolymer is not completely dissolved and at least a part thereof is in a dispersed state. Therefore, the turbidity of the treatment liquid of the present invention having the copolymer concentration as described above is
It will usually be in the range of 5-99, and often 15-95. With a treatment liquid having such a concentration, a remarkable increase in viscosity is not seen, and it can be used in the same manner as a conventional treatment liquid, and although some acrylic copolymers are in a dispersed state, A very uniform treatment layer can be formed.

Further, such a tooth surface treating agent includes
You may make it contain a metal ion. By blending such a metal ion, the dispersion state of the acrylic copolymer in the treatment liquid is stabilized, and at the same time, the restoration agent composition (dental composite, composite Adhesion with acrylic resin represented by resin) tends to be good. As such a metal ion, monovalent metal ions such as sodium ion and potassium ion can be used, but polyvalent metal such as calcium ion, iron ion, copper ion, nickel ion, aluminum ion and chromium ion. It is preferable to mix ions. Further, among these polyvalent metal ions, calcium ion, iron ion, copper ion, and aluminum ion are particularly preferable.

The metal ion as described above can be contained in the treatment liquid by adding a salt capable of generating the metal ion, for example, a compound such as sulfate or hydrochloride to the treatment liquid.

Such a metal ion has a sulfonic acid group in the acrylic copolymer of the present invention is usually 50
% Or more, preferably 30% or more, particularly preferably 10 to
It is blended so that 20% or more of the acid remains.

The tooth surface treatment agent as described above is applied to the tooth surface to react the calcium component in the tooth structure with the sulfonic acid group. Then, the solvent is removed to form a treatment layer made of an acrylic copolymer on the tooth surface. The restorative composition (composite resin) is applied on the treatment layer thus formed and cured to give a tooth structure,
The treatment layer and the restorative composition (cured body) are integrated to restore the tooth structure.

The tooth surface treating agent of the present invention can be used not only for restoration of tooth structure as described above, but also for restoration of hydroxyapatite structure having the same composition as tooth structure. You can Examples of such a hydroxyapatite structure include bone and ivory. Further, the treating agent of the present invention contains a substance containing calcium carbonate (eg, calcite, gneiss, aragonite, limestone, marble, chalk, shells, etc.), substance containing calcium phosphate (eg, phosphorus lime), calcium sulfate. It can also be used to restore plaster and the like.

[0047]

The acrylic copolymer for treating tooth surface of the present invention is a copolymer based on poly (meth) acrylic acid alkyl ester, which comprises a repeating unit derived from a styrenesulfonic acid derivative. It is a copolymer having a content within a specific range. By specifying the content of the sulfonic acid group in the copolymer in this manner, adhesive strength that is several times that of the conventional treating agent or more is exhibited.
Such an increase in the adhesive strength cannot be explained by the conventionally-considered adhesion theory, and can be achieved only by combining the combination of the resin of the present invention and the content rate.

[0048]

EXAMPLES Next, the present invention will be specifically described with reference to examples, but the present invention should not be construed in a limited manner by these examples.

[0049]

Example 1 [Synthesis of acrylic copolymer (A)] 36.0 g (0.36 mol) of methyl methacrylate and 8.3 g (0.04 mol) of sodium p-styrenesulfonate were mixed with 520 ml of water. -0.6 g (1% by weight) of azobisisobutronitrile in an ethanol mixed solution (mixing weight ratio = 10: 1.0) solvent
/ Monomer) at 70 ° C. for 17 hours.
The reaction solution was poured into a large amount of acetone to precipitate a polymer. It was dried under reduced pressure. The obtained polymer was dissolved in water to give a 5% solution, and the resulting polymer was passed through a column packed with 1.5 Kg of an ion exchange resin (Amberlite IR-118, manufactured by Organ) for desalting, and water was distilled off. An acrylic copolymer (A) was obtained.

The obtained polymer was analyzed by GPC using polystyrene of known molecular weight as a standard sample. As a result, the number average molecular weight of this polymer was 10 ⁵ or more, and the copolymerization molar ratio of the repeating unit derived from methyl methacrylate and the repeating unit derived from styrenesulfonic acid was determined from the quantitative value of sulfur by elemental analysis. It was 87:13 when calculated.

The resulting acrylic copolymer was dispersed at a concentration of 3% by weight in water at 25 ° C. to obtain an turbidity of 90.9%.
Met. The composition and properties are shown in Table 1.

[0052]

Example 2 [Synthesis of Acrylic Copolymer (B)] In the synthesis of the acrylic copolymer (A) in the above Example 1, the amount of methyl methacrylate used was 72.1 g (0.72 mol). ,
The amount of sodium p-styrenesulfonate used was 16.5 g.
A polymer was prepared in the same manner except that the amount was changed to (0.088 mol).

The number average molecular weight of the polymer was 10 ⁵ or more, and the copolymerization molar ratio of the repeating unit derived from methyl methacrylate and the repeating unit derived from styrenesulfonic acid was 91: 9 by elemental analysis. It was

Example 1 for this acrylic copolymer
The turbidity measured in the same manner as above was 89.0%. The composition and properties are shown in Table 1.

[0055]

Comparative Example 1 [Synthesis of Acrylic Copolymer (C)] In the synthesis of the acrylic copolymer (A) in Example 1, the amount of methyl methacrylate used was 11.3 g (0.11 mol). ,
The amount of sodium p-styrenesulfonate used was 23.2 g.
A polymer was prepared in the same manner except that the amount was changed to (0.11 mol).

The number average molecular weight of the polymer was 10 ⁵ or more, and the copolymerization molar ratio of the repeating unit derived from methyl methacrylate and the repeating unit derived from styrenesulfonic acid was 53:47 by elemental analysis. It was

Example 1 for this acrylic copolymer
The turbidity measured in the same manner as above was 1.0%. The composition and properties are shown in Table 1.

[0058]

Comparative Example 2 [Synthesis of Acrylic Copolymer (D)] In the synthesis of the acrylic copolymer (A) in Example 1 above, the amount of methyl methacrylate used was 21.0 g (0.21 mol). ,
The amount of sodium p-styrenesulfonate used was 18.6 g.
A polymer was prepared in the same manner except that the amount was changed to (0.09 mol).

The number average molecular weight of the polymer was 10 ⁵ or more, and the copolymerization molar ratio of the repeating unit derived from methyl methacrylate and the repeating unit derived from styrenesulfonic acid was 67:33 by elemental analysis. It was

Example 1 for this acrylic copolymer
The turbidity measured in the same manner as above was 7.5. The composition and properties are shown in Table 1.

[0061]

Comparative Example 3 [Synthesis of Acrylic Copolymer (E)] In the synthesis of the acrylic copolymer (A) in Example 1, the amount of methyl methacrylate used was 60 g (0.6 mol), p -The amount of sodium styrenesulfonate used was 27.6 g (0.
A polymer was prepared in the same manner except that the amount was changed to 15 mol).

The number average molecular weight of the polymer was 10 ⁵ or more, and the copolymerization molar ratio of the repeating unit derived from methyl methacrylate and the repeating unit derived from styrenesulfonic acid was 81:19 by elemental analysis. ..

Example 1 for this acrylic copolymer
The turbidity measured in the same manner as above was 5.7%. The composition and properties are shown in Table 1.

[0064]

Example 3 A tooth surface treatment liquid (A-1) was prepared by mixing 10 g of the acrylic copolymer (A) obtained as described above with 90 g of water.

The dentin surface treatment liquid (A-1) thus prepared had a turbidity of 90.3. The freshly extracted bovine tooth was ground with water-resistant emery paper ^# 600 under water until it reached the dentin, and the tooth surface treatment solution (A-
1) 40 ml was applied. After 60 seconds, by thoroughly washing with water, a treatment layer insoluble in water was formed on the surface of the extracted bovine tooth.

Next, the bovine extracted tooth on which the treatment layer was formed was blown with compressed air and dried, and then the surface area of the treatment layer was defined by a double-sided tape having a hole of 5.4 mm in diameter, and triethylene glycol and dimethacrylate were used. (TEGDMA), camphorquinone (CQ) and N-phenylglycine (NPG) photocurable resin (TEGDMA / Ca / NPG = 99 / 0.5)
/0.5) was applied in an amount of 10 μl, and light was irradiated for 60 seconds by Translux (manufactured by Kulzer). An acrylic length with an inner diameter of 6 mm and a height of 1 mm is placed here, and dental compolet resin Silux Plus (manufactured by Sumitomo 3M Ltd.) is filled.
Illuminated for a second. On top of this, metallic stainless steel (SUS 3
The sticks of No. 04) were bonded to each other using a commercially available super bond (manufactured by Sun Medical Co., Ltd.).

In this way, the bovine extraction tooth to which the metal is bonded is
After soaking in 7 ° C water for 24 hours, Autograph ^TM (Co., Ltd.)
Crosshead speed 2mm / mi using Shimadzu Corporation)
The adhesive strength was measured by n.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 82.3 ± 27.3 Kg.
Was / cm ² . The adhesive strength and turbidity are shown in Table 2.

[0069]

[Example 4] In the same manner as in Example 3, except that the acrylic copolymer (B) prepared in Example 2 was used instead of the acrylic copolymer (A), a tooth surface treatment agent ( B-1) was prepared.

The tooth surface treatment liquid thus prepared (B-
The turbidity of 1) was 91.2%. The treatment was performed in the same manner as in Example 3 except that this tooth surface treatment liquid (B-1) was used, and the adhesive strength was measured.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 83.7 ± 21.5 Kg.
Was / cm ² . The adhesive strength and turbidity are shown in Table 2.

[0072]

[Comparative Example 4] In the same manner as in Example 3, except that the acrylic copolymer (C) prepared in Comparative Example 1 was used in place of the acrylic copolymer (A), the tooth surface treatment agent ( C-1) was prepared.

The turbidity of the tooth surface treatment liquid (C-1) thus prepared was 4.5%. Treatment was carried out in the same manner as in Example 3 except that this tooth surface treatment liquid (C-1) was used,
The adhesive strength was measured.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 8.2 ± 3.6 Kg / c.
It was m ² . The adhesive strength and turbidity are shown in Table 2.

[0075]

[Comparative Example 5] In the same manner as in Example 3, except that the acrylic copolymer (D) prepared in Comparative Example 2 was used instead of the acrylic copolymer (A), a tooth surface treatment agent ( D-1) was prepared.

The tooth surface treatment liquid thus prepared (D-
The turbidity of 1) was 19.2%. The treatment was performed in the same manner as in Example 3 except that this tooth surface treatment liquid (D-1) was used, and the adhesive strength was measured.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 13.8 ± 5.8 kg /
It was cm ² . The adhesive strength and turbidity are shown in Table 2.

[0078]

[Comparative Example 6] In the same manner as in Example 3, except that the acrylic copolymer (A) prepared in Comparative Example 3 was used in place of the acrylic copolymer (A), the tooth surface treatment agent ( E-1) was prepared.

The tooth surface treatment liquid thus prepared (E-
The turbidity of 1) was 17.8%. The treatment was performed in the same manner as in Example 3 except that this tooth surface treatment liquid (E-1) was used, and the adhesive strength was measured.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 12.1 ± 3.4 Kg /
It was cm ² . The adhesive strength and turbidity are shown in Table 2.

[0081]

[0082]

[Example 5] In the same manner as in Example 3, except that the amount of the acrylic copolymer (A) used was changed to 5 parts by weight and the amount of water used was changed to 95 parts by weight, a tooth surface treatment agent (A- 2) was prepared.

The tooth surface treatment liquid thus prepared (A-
The turbidity of 2) was 90.9%. The treatment was performed in the same manner as in Example 3 except that this tooth surface treatment liquid (A-2) was used, and the adhesive strength was measured.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 54.8 ± 10.6 Kg.
Was / cm ² . The adhesive strength is shown in Table 3.

[0085]

Example 6 A tooth surface treating agent (A- was prepared in the same manner as in Example 3, except that the amount of the acrylic copolymer (A) used was changed to 3 parts by weight and the amount of water used was changed to 97 parts by weight. 3) was prepared.

The tooth surface treatment liquid thus prepared (A-
The turbidity of 3) was 90.9%. The treatment was carried out in the same manner as in Example 3 except that this tooth surface treatment liquid (A-3) was used, and the adhesive strength was measured.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 67.6 ± 36.3 Kg.
Was / cm ² . The adhesive strength is shown in Table 3.

[0088]

[Example 7] A tooth surface treating agent (A- was prepared in the same manner as in Example 3, except that the amount of the acrylic copolymer (A) used was changed to 1 part by weight and the amount of water used was changed to 99 parts by weight. 4) was prepared.

The tooth surface treatment liquid thus prepared (A-
The turbidity of 4) was 71.8%. The treatment was carried out in the same manner as in Example 3 except that this tooth surface treatment liquid (A-4) was used, and the adhesive strength was measured.

As a result, the adhesive strength between the photocurable resin and the bovine extracted tooth (dentin) was 80.3 ± 28.4 Kg.
Was / cm ² . The adhesive strength is shown in Table 3.

[0091]

[0092]

[Example 8] Dental surface treating agent (A) prepared in Example 3
To 100 parts by weight, 0.54 parts by weight of calcium chloride was added and dissolved. The adhesive strength was measured in the same manner except that this calcium ion-containing tooth surface treating agent (A-5) was used.

The results are shown in Table 4.

[0094]

Example 9 Dental surface treating agent (B) prepared in Example 4
To 100 parts by weight, 0.40 part by weight of calcium chloride was added and dissolved.

The adhesive strength was measured in the same manner except that this calcium ion-containing tooth surface treatment agent (B-5) was used. The results are shown in Table 4.

[0096]

[Comparative Example 7] Dental surface treating agent (C) prepared in Comparative Example 4
To 100 parts by weight, 1.57 parts by weight of calcium chloride was added and dissolved.

The adhesive strength was measured in the same manner except that this calcium ion-containing tooth surface treating agent (C-5) was used. The results are shown in Table 4.

[0098]

Comparative Example 8 Dental surface treatment agent (D) prepared in Comparative Example 5
To 100 parts by weight, 1.2 parts by weight of calcium chloride was added and dissolved.

The adhesive strength was measured in the same manner except that this calcium ion-containing tooth surface treatment agent (D-5) was used. The results are shown in Table 4.

[0100]

[Comparative Example 9] Dental surface treating agent (E) prepared in Comparative Example 6
To 100 parts by weight, 0.76 parts by weight of calcium chloride was added and dissolved.

The adhesive strength was measured in the same manner except that this calcium ion-containing tooth surface treating agent (E-5) was used. The results are shown in Table 4.

[0102]

[Brief description of drawings]

FIG. 1 is a graph showing an example of the turbidity of a solution containing an acrylic copolymer at a content of 3% by weight.

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Claims (4)

[Claims] 1. A repeating unit derived from a (meth) acrylic acid alkyl ester and a repeating unit derived from a styrene sulfonic acid derivative are prepared at 85: 15-9.
An acrylic copolymer for treating tooth surfaces, which has a molar ratio of 9: 1. 2. The acrylic copolymer for surface treatment of teeth according to claim 1, wherein the turbidity of an aqueous solution containing the acrylic copolymer at a content rate of 3% is 20% or more. Polymer. 3. A repeating unit derived from an alkyl (meth) acrylate and a repeating unit derived from a styrenesulfonic acid derivative are 85:15 to 99: 1.
A tooth surface treatment agent, comprising an acrylic copolymer having a molar ratio of: and water and / or alcohol. 4. The content of the acrylic copolymer is 0.
The tooth surface treatment agent according to claim 3, which is in the range of 1 to 20% by weight.