JPS5838407B2 - dental etching agent - Google Patents

Description

[Detailed description of the invention] The present invention relates to a dental etching agent.

Composite resins consisting of a resin and an inorganic filler are used as dental restoration materials, but since none of these resins actually adheres to the tooth structure, the sealing properties and retention of the resin within the cavity are improved. Various methods have been developed to do this.

Traditionally, it has been known that a very effective method is to etch the enamel wall of the cavity with acid before filling it with resin, and aqueous solutions of citric acid, phosphoric acid, etc. in various concentrations are recommended as etching agents. There is.

However, because the viscosity of conventional etching solutions is low, the solution spreads to areas other than the intended location, causing problems such as corroding healthy teeth and causing unnecessary pain to patients.

As a method to improve these drawbacks, adding a water-soluble polymer such as polyvinyl alcohol, polyvinylpyrrolidone, etc. to the acid aqueous solution may be considered, but either method had a low thickening effect and did not form into a paste.

Therefore, the present inventors investigated ways to eliminate such drawbacks and found that among water-soluble polymers, carboxymethylcellulose sodium salt has a very thickening effect (10% by weight), unlike other polymers. It has been found that by adding aqueous acid solution), the solution becomes paste-like, and the etching effect does not deteriorate, and only the target area can be etched.

Further, the same effect was obtained by adding highly dispersible silica to the acid aqueous solution in the same amount.

That is, the present invention is a dental etching agent prepared by adding carboxymethyl cellulose sodium salt and/or highly dispersible silica to an acid aqueous solution to form a paste.

In the present invention, as the acid aqueous solution, conventionally known aqueous solutions such as citric acid and phosphoric acid are used.

The concentration of acid in the acid aqueous solution is 10% by weight (based on the acid aqueous solution)
Above, preferably 30 to 70% by weight.

The acid aqueous solution includes not only acid diluted with water as mentioned above, but also water-soluble polyhydric alcohol (
For example, glycerol, pentaglycerol, etc.) may be added.

The carboxycellulose sodium salt used in the present invention is generally referred to as CMC, and is a sodium salt obtained by partially converting the hydroxyl groups in the cellulose molecule into carboxymethyl ether.

Usually, as carboxymethyl cellulose sodium salt, the degree of etherification is 0.4 to 1.2, and the degree of polymerization is 500 to 10.
00 are commercially available, and any of these can be used in the present invention.

The highly dispersible silica used in the present invention is also referred to as white carbon, which is artificially produced ultrafine particles of silicic acid or silicate.

These can be obtained by rapid decomposition of gas or liquid silicic acid sources. They are fine particles of silicic acid or silicate with an amorphous structure.

Examples of typical commercially available highly dispersible silica include Aerosil (manufactured by Nippon Aerosil, Degussa), Cab
O Sil (Godfrey ('01)j
inc. ), Hi-Sil (Pitt)
sburgh Plate GlassCo. (manufactured by),
Durosil (FGllstoffGesells
Haft Marquard), Nipushial (Nippon Silica), Toxil (Tokuyama Soda), etc.
Any of these can be used in the present invention.

The amount of carboxymethyl cellulose sodium salt and highly dispersible silica to be added to the acid aqueous solution is necessary to make the liquid paste-like, and is usually 3% by weight or more, preferably 7% by weight or more.

The amount added is appropriately selected depending on the acid used and its concentration.

On the other hand, if the amount added is too large, the viscosity of the paste will become too high, making such an etching agent inconvenient for application to tooth cavities.

There are no particular restrictions on the method of mixing carboxymethyl cellulose sodium salt and highly dispersible silica, and a predetermined amount of carboxymethyl cellulose sodium salt or highly dispersible silica powder may be added to an acid aqueous solution or dissolved or dispersed in water in advance. Adding a predetermined amount of carboxymethyl cellulose sodium salt or highly dispersed silica,
Just stir.

Furthermore, the same effect can be obtained by adding both carboxymethyl cellulose sodium salt and highly dispersible silica together.

Other additives such as dyes may also be added.

As described above, in the present invention, by adding carboxymethyl cellulose sodium salt and/or highly dispersible silica to the acid aqueous solution, the acid aqueous solution becomes paste-like.

Therefore, when the acid aqueous solution is applied to the tooth cavity, the acid aqueous solution does not spread to areas other than the intended location, and the tooth can be effectively treated.

Hereinafter, the present invention will be explained in further detail with reference to Examples.

Example 1 10% by weight of highly dispersible silica (manufactured by Nippon Aerosil ■, trade name Aerosil 380) was added to an aqueous phosphoric acid solution (concentration 50% by weight) and thoroughly stirred to obtain a paste-like composition.

The resulting composition was placed in a test tube and left upside down overnight, but the composition did not fall, confirming that the composition had been thickened.

A cavity with a diameter of 3 mm and a depth of 3 mTrt was formed in the extracted human tooth using a dental air turbine, spanning the enamel and dentin.

When the obtained composition was applied to the enamel part of this cavity, only the desired enamel part could be etched without dripping.

Furthermore, if a phosphoric acid aqueous solution of the same composition without the addition of highly dispersed silica is used, even if you try to apply it to the enamel part of the cavity, the solution will easily drip and reach the dentin, making it impossible to etch only the enamel part. It was possible.

Applying this phosphoric acid aqueous solution to the dentin is
If it is close to tooth decay, it causes irritation and is clinically undesirable.

The degree of etching was evaluated by scanning electron microscopy based on the degree of texture of the enamel surface, and there was no difference between those with and without high-dispersion silica. No decrease in the etching effect was observed.

Example 2 One portion of sodium carboxymethyl cellulose (manufactured by Kishida Chemical Industries, reagent) was added to an aqueous phosphoric acid solution (concentration, 50% by weight).
0% by weight was added and stirred well to obtain a paste-like composition.

The resulting composition was placed in a test tube and left upside down overnight, but the composition did not fall out.

When the composition was applied to the tooth enamel and etched, only the desired area was etched without dripping as in Example 1, and the degree of etching was the same as when sodium carboxymethyl cellulose was not added. Ta.

Therefore, the etching agent of the present invention was very effective in etching only the target area.

Claims (1)

[Claims] 1. A dental etching agent made into a paste by adding carboxymethyl cellulose sodium salt and/or highly dispersible silica to an acid aqueous solution.