JPS5840523B2 - Dental primer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a primer composition for improving the adhesion of a dental composite resin to tooth structure, and a method for pre-treating tooth structure using the primer composition.

Many reports have already been introduced or put into practical use as dental composite resins, and it is now possible to obtain resins with considerably excellent performance as resins themselves.

For example, US Patent No. 3066112, US Patent No. 36291
No. 87 specifications, Jibun No. 48-11156, JP-A-48-103648, etc. contain aromatic polyfunctional acrylates or methacrylates or urethane modified products thereof as main components, and their degree of crosslinking and viscosity are described. A dental filling material containing aliphatic monofunctional or polyfunctional acrylate or methacrylate-1 monomer to adjust
Orthodontic adhesives or pit and fissure sealants are described.

These resins are cured by redox polymerization using catalysts and accelerators or by ultraviolet polymerization.

Recently, in the dental industry, instead of the conventional instant polymerization resin mainly composed of methyl methacrylate, there have been developed pit and fissure sealants and orthodontic adhesives containing the above-mentioned binder resin as the main component, as well as large amounts of inorganic fillers in the above-mentioned binder resin. Composite materials coated with chemicals are available as composite resins.

However, the above-mentioned composite resin generally has insufficient adhesion to the tooth structure, causing the restoration to fall off or leak around the bonded area, which causes secondary caries.

For this reason, many attempts have been made to bond composite resins to tooth structure, but at present no satisfactory results have been achieved.

That is, in many cases, the tooth surface is demineralized with an organic or inorganic acid to roughen the surface and expose the dental tubules.
In some cases, a pre-coating agent with a lower viscosity of the binder resin is applied in advance to prevent leakage into the tooth structure or penetration into the tooth tubules, but bonding using these methods is difficult. The bond between the tooth substance and the binder resin is mainly mechanical rather than chemical.

Therefore, in the hope of creating a chemical bond, a vinyl phosphoric acid compound such as vinyl phosphonic acid or vinyl benzyl phosphonic acid may be used as an undercoat after acid treatment, or it may be mixed with a binder resin in advance and the calcium in the tooth and vinyl phosphoric acid Some attempts have been made to bond the phosphate group of the compound and the vinyl group to bond by copolymerization between the double bonds of the binder resin and regulator monomer; The polymerization rate of the double bonds of the agent monomers and the copolymerization parameters are inconsistent, and this reaction does not occur under normal conditions.

Therefore, although this attempt seems to be effective at first glance, it cannot be said to be practical.

The present inventor has discovered that after etching the tooth substance and applying a specific phosphoric acid ester to the tooth substance prior to the pre-coating treatment or bonding of the composite resin as shown in the prior art, the pre-coating agent and composite resin The present invention was completed based on the discovery that the adhesion to tooth structure was significantly improved.

That is, the present invention provides a dental primer composition containing as an essential component an alkyl acid phosphate represented by the general formula: [wherein R represents an alkyl group having 1 to 13 carbon atoms which may have a side chain] and a dental primer containing said alkyl acid phosphate and a low boiling alcohol having a boiling point lower than that of water and optionally an organic peroxide.

The alkyl acid phosphate used in the present invention has an alkyl group having 1 to 13 carbon atoms, particularly 4 to 13 carbon atoms, and the alkyl group may be substituted or unsubstituted, linear or branched.

Generally, it is desirable for the alkyl group to have no unsaturated bond such as a vinyl group in terms of adhesiveness, odor, stability, etc.

Particularly preferred alkyl acid phosphates are mono- or dibutyl acid phosphate, mono- or di(
2-ethylhexyl) acid phosphate, etc.

Alkyl acid phosphates may be used alone or as a mixture of two or more.

Practically speaking, it is preferable to use the above-mentioned alkyl acid phosphate after diluting it with a low-boiling alcohol.

The dilution concentration is usually o, oi to 3.0% by weight, preferably 0
．． It is 5 to 20% by weight.

In the present invention, it is desirable that a monomolecular layer of alkyl acid phosphate be formed on the surface of the tooth in order to improve the adhesion of the precoating agent and composite resin to the tooth.

Therefore, if the amount of alkyl acid phosphate used is outside the above range, it is not preferable because it becomes difficult to form a monomolecular layer of the alkyl acid phosphate on the tooth surface.

The low boiling point alcohol is preferably an alcohol that has a boiling point lower than that of water, has low toxicity, and is less irritating to oral tissues such as dental pulp and mucous membranes, such as ethyl alcohol and isopropyl alcohol.

The alcohol serves not only as a diluent for the alkyl acid phosphate, but also as a disinfectant and drying aid for the tooth surface.

The primer composition comprising the above-mentioned alkyl acid phosphate and low-boiling alcohol may optionally contain an organic peroxide as a catalyst to accelerate the curing of the composite resin.
For example, benzoyl peroxide or the like may be added in an amount of 0.01 to 5.0% by weight.

Organic peroxides have traditionally been used by blending them into pre-coating agents, but depending on the type and amount of peroxide and pre-coating agent components, the storage stability (shelf life) of the pre-coating agent may be affected. There is a tendency to

Therefore, in the present invention, part or all of the organic peroxide may be transferred to the primer composition.

On the other hand, in the present invention, as will be made clear in the following examples, even if the pre-coating treatment is omitted, practically sufficient adhesion can be obtained between the composite resin and the tooth structure.

Next, a tooth pretreatment method using the above primer composition will be explained.

First, the area to be treated is cleaned, then the tooth surface is treated with an etching agent, for example, a 30% phosphoric acid aqueous solution, thoroughly washed with water, and then dried by blowing compressed air.

Etching conditions may be according to a conventional method and are not particularly limited.

Thereafter, the primer composition is applied onto the tooth surface to form a monomolecular layer of alkyl acid phosphate.

Volatilization of the alcohol component of the composition facilitates disinfection and drying of the tooth surface.

After applying the primer composition, if the composite resin is filled or injected into the designated area, the resin leaks or penetrates into the tooth structure better, and although the theoretical reason is not clear,
As a result, the adhesive strength between the tooth substance and the resin is increased.

Prior to applying the composite resin on the thin layer of alkyl acid phosphate, if desired, if a pre-coating agent is further applied on the thin layer, the adhesive strength between the tooth structure and the composite resin can be further increased.

The precoating agents are those conventionally used, such as aromatic polyvalent methacrylates or acrylates diluted with aliphatic polyvalent or partially methacrylates or acrylates to a viscosity of less than about 500 centipoise, and conventional catalysts or catalysts and promoters. What is necessary is just to mix|blend an agent suitably and to use it.

The pre-coating agent may be a two-component type, that is, a catalyst and a promoter are separately added to the diluted liquid and mixed together immediately before use, or a wave-type pre-coating agent, that is, a catalyst and a promoter are added to the diluted liquid and mixed together immediately before use. Those to which an accelerator is added are preferable because they do not require complicated mixing operations immediately before use and provide a sufficient adhesive curing effect.

- Although the wave-shaped precoating agent itself does not cause a noticeable curing reaction, when it is applied onto a thin layer of alkyl acid phosphate on the tooth substance and a composite resin is applied on top of it, it can be induced by the polymerization reaction of the resin. It is thought that it hardens due to the oxygen blocking effect (according to scanning electron microscopy, the liquid pre-coating agent was found to have penetrated several tens of micrometers into the tooth tubules exposed by the acid treatment and hardened).

). Composite resins applied on a thin layer of alkyl acid phosphate or on a pre-coating layer should still contain the same resins as are now commonly used in the field, i.e. aromatic polyfunctional acrylates or methacrylates or urethane modified versions thereof. It is possible to use a material containing an aliphatic monofunctional or polyfunctional acrylate or methacrylate monomer as the main component, and an appropriate inorganic filler (although there is no particular limitation).

According to the present invention, the adhesion between the dental composite resin and the tooth substance, which has been a problem in the past, is significantly improved, and therefore, the falling off of the restoration and the occurrence of leakage at the edges of the bonded area are effectively prevented.

EXAMPLES Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited to these Examples.

Examples 1 and 2 and Comparative Examples 1 to 3 Enameled tooth surface pretreated under various conditions shown in Table 1 and dental filling filled in the adapter (Shofu Composite Resin; manufactured by Shofu Tooth Manufacturing Co., Ltd.) 200
The adhesive was bonded under a load of
The adhesive strength was measured by tensile time.

The measurement results are shown in Table 1. As is clear from the measured values in Table 1, the effect of pretreatment is more pronounced for etching + primer (■) and etching + primer + precoating (■) than for etching (■) alone, and the effect of pretreatment is more pronounced when the primer treatment treatment (■) is omitted. Etching + precoating is inferior to other pretreatments, but the primer treatment of the present invention is extremely effective for adhesion.

Example 3 When using Shofu Composite Resin (manufactured by Shofu Tooth Manufacturing Co., Ltd.) according to its instruction manual, the area where the cavity was previously formed and its peripheral area were soaked with 30% phosphoric acid for 60 minutes.
After second etching, washing with water and drying, a primer of ethyl alcohol solution containing 0.1% butyl acid phosphate was applied and dried. 5 parts of methacrylate, 50 parts of methyl methacrylate,
10 parts of benzoyl peroxide, 0.0001 parts of hydroquinone
Immediately after applying the pre-coating agent consisting of 50% of the total amount of pre-coating agent, the above-mentioned Shofu composite resin kneaded product was filled.

The results of the adhesive strength test were shown in Table 1.

Example 4 When using Adabtiic (manufactured by Johnson & Johnson) according to the instructions for use, the area where the cavity was previously formed and the surrounding area were soaked with 30% phosphoric acid.
After etching for 0 seconds, washing with water, and drying, an ethyl alcohol liquid primer containing O, 3% 2-ethyl hexyl acid phosphate was applied, and after drying, the above adaptable kneaded product was filled.

Comparative Example 4 The results of the method in Examples 3 and 4 and the method of Examples 3 and 4 in which the treatment was performed without applying a primer were Table 2 shows the results of observing the adhesion between the filling and the tooth structure depending on the state of line of sight.

Example 5 In order to directly bond a plastic bracket or metal bracket, which is one of the orthodontic devices, to the tooth structure, the tooth structure was
After etching with % phosphoric acid for 60 seconds, washing with water and drying, applying an ethyl alcohol liquid primer containing 0.1% butyl acid phosphate and drying, press the bracket to the tooth surface using a mixture of Shofu composite resin. Then, remove the excess, wait for it to harden, and if you want it to last, cover the base of the bracket with a dental instant polymer resin using a brush stroke method, and after it hardens, attach the archwire.

Example 6 A primer was applied at the same time as Example 5, and after drying, a pre-coating agent consisting of 66 parts of a reaction product of bisphenol A and glycidyl methacrylate, 32 parts of methyl methacrylate, 1 part of benzoyl methyl ether, and 1 part of benzoyl peroxide was applied. The resin was cured by irradiation with an ultraviolet lamp, and while the surface was not completely cured, a dental instant polymer resin was piled up using the brush-and-build method, and the bracket was pressed against the bracket, the base of the resin was covered, the excess was removed, and the resin was allowed to cure.Example 5 An archwire was attached in the same way.

Example 7 The tooth surface at the corner of the occlusal surface where there is a pit and fissure to be sealed was cleaned, etched with 30% phosphoric acid for 60 seconds, washed with water and dried, then applied with the primer of Example 3 and dried. The pre-coating agent No. 3 was applied, and the Shofu composite resin mixed at a powder-liquid ratio of 3:2 was gently flowed in from one end of the pit and fissure.

Hardening ends after about 5 minutes.

Partial shedding was observed in those that were not subjected to primer treatment after 6 months, but no shedding occurred in those that were treated with primer.

Example 8 A composition in which 1.0 part of benzoyl peroxide in the pre-coating agent composition in Example 3 was transferred to the primer was used in the same manner as in Example 3, and as a result, the method of Example 3 in Table 2 was obtained. Almost the same results were obtained.

Further, in order to examine the shelf life, the primer and pre-coating agent of Example 3 and the primer and pre-coating agent of Example 8 were stored at room temperature, 37° C. and 50° C., and the number of days until abnormalities were observed was determined.

The results are shown in Table 3, and it is clear that the composition according to Example 8 is superior.

Furthermore, using the primer and pre-coating agent in Example 8, an adhesive strength test was conducted in the same manner as in Example 3.
kg/crtf1kg/cwt.

165 after 1 month

Claims (1)

[Scope of Claims] 1. A dental primer containing as an essential component an alkyl acid phosphate represented by the general formula: [wherein R represents an alkyl group having 1 to 13 carbon atoms which may have a side chain] Composition. Contains an alkyl acid phosphate represented by [wherein R represents an alkyl group having 1 to 13 carbon atoms which may have a side chain], a low boiling point alcohol having a boiling point lower than that of water, and optionally an organic peroxide. Dental primer composition. 3 Alkyl acid phosphate from 0.01 to 3.
2. The primer composition according to item 2, containing 0% by weight. 4. The primer composition according to item 3, containing 0.01 to 5.0% by weight of an organic peroxide.