JP4916624B2 - Tooth bleaching method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for bleaching and removing a pigment (colored, discolored) deposited on a tooth.
[0002]
[Prior art]
In recent years, in dental practice, there has been an increasing demand for tooth bleaching as an improvement in aesthetics. As a tooth bleaching, there is a method using hydrogen peroxide of several 30%. For example, it is described in the bleaching method by Matsukaze Highlight (trade name), the improved Mackines bleaching method, the walking bleach method, etc., and in JP-A-8-143436, JP-A-5-320033, and JP-A-8-113520. There is a bleaching method.
[0003]
As a new bleaching method that is excellent in safety and simplicity and has a remarkable effect on both myelinated and non-medullary teeth in a short period of time, the present inventors have used photocatalytic titanium dioxide and low-concentration hydrogen peroxide solution. A method to be used in combination is presented (Japanese Patent Laid-Open No. 11-92351). Furthermore, an effective tooth bleaching material has been found by using titanium dioxide and an inorganic or organic thickener.
[0004]
Here, in the various bleaching methods described above, the present inventors tried bleaching discolored teeth without pretreatment. Depending on the teeth, a difference in the bleaching effect may occur, and a sufficient bleaching effect may not be obtained. I found many times.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for cleaning a tooth before tooth bleaching that solves the above-described problems and enhances the tooth bleaching effect easily and stably.
[0006]
[Means for Solving the Problems]
As a result of intensive studies on a pretreatment method for bleaching with a tooth bleaching material, the present inventors have found that the bleaching effect can be stably improved by washing with a condensed phosphate aqueous solution, and have reached the present invention. That is, the present invention relates to a discolored tooth bleaching method characterized by pretreatment with a condensed phosphate aqueous solution when a tooth is bleached using a tooth bleaching material.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the tooth is washed with a condensed phosphate aqueous solution before the tooth bleaching material is used. Specifically, a phosphate aqueous solution is soaked in absorbent cotton, gauze, etc., and the tooth surface is directly wiped using this. Subsequently, it is washed with water, dried and bleached with a tooth bleaching material.
[0008]
Examples of the condensed phosphate to be used include potassium salts such as pyrophosphoric acid, tripolyphosphoric acid, and tetraphosphoric acid, sodium salts, and the like, and tetrasodium pyrophosphate is particularly preferable. These may be used alone or in admixture of two or more. These aqueous solutions preferably have a pH of 4.0 or more and less than 12.0. If the pH is 12.0 or more, the oral mucosa is affected. Moreover, there exists a possibility that the enamel of a tooth | gear may be melt | dissolved as it is pH 4.0 or less.
[0009]
The density | concentration of condensed phosphate aqueous solution is 0.01 to 30 weight% normally, More preferably, it is 0.1 to 10 weight%. If it is too thin, there will be no difference in effect from washing with water, and if it is too thick, it will be difficult to prepare a solution, and salt will precipitate during use.
[0010]
The main action of the condensed phosphate of the present invention can include a builder effect of the condensed phosphate. As a result, many of the dirt materials on the tooth surface, particularly inorganic substances that are not easily decomposed by the tooth bleaching material, are washed away. Further, tooth discoloration substances that cannot be washed with condensed phosphate are decomposed and bleached with a tooth bleaching material. By these two operations, a stable and high bleaching effect can be obtained.
[0011]
The tooth bleaching material used after the pretreatment of the present invention is not particularly limited, and tooth bleaching materials containing various hydrogen peroxides mentioned in the prior art can be used. A bleaching material using titanium dioxide having a photocatalytic action and hydrogen peroxide proposed by the present inventors can also be used suitably. Examples of the components of the bleaching material include titanium dioxide, hydrogen peroxide, phosphoric acid, tetrasodium pyrophosphate and a thickener.
[0012]
As the titanium dioxide, any form and property can be used as long as it is a titanium dioxide that produces a photocatalytic action. Preferably, it is any one of anatase type, rutile type and brookite type, and rutile type is particularly preferable. Further, it is also possible to use an anatase type, rutile type or brookite type titanium dioxide whose surface has improved affinity with the tooth surface by coating with calcium phosphate. In addition, it is possible to use a material in which platinum is supported on titanium dioxide to improve the photocatalytic activity, or a material that exhibits photocatalytic action in response to light in the visible light region by performing plasma treatment or the like on titanium dioxide. .
[0013]
The titanium dioxide may be in a powder state or in a sol state dispersed in a medium such as water. The particle diameter of titanium dioxide is preferably 1 to 500 nm, more preferably 5 to 200 nm. The effect is sufficiently obtained even if the amount of titanium dioxide is small, specifically 0.001 to 10% by weight, preferably 0.01 to 1% by weight, more preferably 0.01 to 0%. .1% by weight. If the blending amount is too small, it may take a long time to obtain a favorable result depending on the degree of discoloration of the tooth, and if it is too large, the light transmission property of titanium dioxide itself is not good and the bleaching effect is lowered. Sometimes.
[0014]
The content of hydrogen peroxide is 35% by weight or less, preferably 1 to 10% by weight. Even if the content is higher than this range, there is no significant difference in the bleaching effect, and it is not advantageous from the viewpoint of safety. Phosphoric acid and condensed phosphates are used as stabilizers and bleach accelerators. As phosphoric acid, orthophosphoric acid is preferable. Examples of the condensed phosphate include potassium phosphate such as pyrophosphoric acid and tripolyphosphoric acid which are condensed phosphoric acid, sodium salt, etc., preferably tetrasodium pyrophosphate.
[0015]
The addition amount of phosphoric acid is 0.1 to 10% by weight, preferably 0.2 to 2% by weight. When the amount is less than this range, the effect is small. When the amount is large, the acidity of the bleaching composition becomes strong, causing problems such as adversely affecting the tooth surface. Moreover, the addition amount of condensed phosphate is 0.1 to 10 weight%, Preferably it is 0.5 to 5 weight%. When the amount is less than this range, the effect is small, and when the amount is large, the liquidity of the bleaching composition becomes alkaline, and the stability of hydrogen peroxide decreases.
[0016]
As the thickener, either inorganic or organic can be used. However, organic thickeners that are difficult to decompose by photocatalysis are preferred. As the inorganic thickener, an inorganic clay mineral, more preferably a layered structure type inorganic clay mineral is used. In general, inorganic clay minerals are composed of a fibrous structure type (for example, sepiolite, apatalite, etc.), an amorphous structure type (for example, allophane, etc.), a mixed layer structure type (for example, kaolinite, montmorillonite, etc.) and the above layered structure. Broadly divided into types. The layered structure type inorganic clay mineral utilizes the property of swelling water molecules between unit layers in its structure and realizes that hydrogen peroxide existing in the system is held in contact with the discolored tooth. It is. In the present invention, it is preferable to use a layered structure type inorganic clay mineral having the property of swelling in the presence of water.
[0017]
Even if inorganic clay minerals are fibrous structure type and amorphous structure type clay minerals, it is possible to realize a swollen state by stirring with a high speed stirring device after adding water, but layered structure type Clay minerals have the advantage of not requiring such special equipment.
[0018]
Inorganic clay minerals include dicalite, nacrite, kaolinite, anoxite, halloysite, metahalosite, chrysotile, lizardite, serpentine, antigolite, beidellite, montmorillonite, sauconite, stevensite, nontronite, saponite, hectorite. , Vermiculite, smectite, sepiolite, nectite, illite, sericite, marine stone-montmorillonite, rholite-montmorillonite, chlorite-vermiculite, illite-montmorillonite, halloysite-montmorillonite, kaolinite-montmorillonite and the like.
[0019]
Among the above-mentioned inorganic clay minerals, the layered structure type clay mineral particularly preferably used in the present invention includes montmorillonite, saconite, smectite, stevensite, beidellite, nontronite, saponite, hectorite, vermiculite, nectite and sepiolite. . These may be natural products or synthetic products. Synthetic products include synthetic sodium magnesium silicate lithium (Laponite) and the like. A mixture of two or more of these can also be used.
[0020]
As the organic thickener, a water-soluble polymer is used, and a thickener for food additives is preferably used from the viewpoint of safety. Particularly preferred food additive thickeners for use in food additives include sodium alginate, propylene glycol alginate, sodium carboxymethylcellulose, sodium starch glycolate, sodium starch phosphate ester, methylcellulose, sodium polyacrylate and the like.
More preferably, sodium polyacrylate, methyl cellulose, or sodium carboxymethyl cellulose having excellent storage stability is used. These may be natural products or synthetic products, and a mixture of two or more of these may be used.
[0021]
The blending amount of these thickeners is preferably 0.01 to 10% by weight, more preferably 0.1 to 5% by weight. The blending amount of the thickening agent is selected so that the viscosity of the tooth bleaching material is 0.001 to 10 Pa · s, preferably 0.002 to 0.10 Pa · s. When the viscosity is within this range, the bleaching material does not sag even when applied to the tooth surface having an angle of 45 degrees with respect to the horizontal plane.
[0022]
The tooth bleaching material is used by directly applying to the tooth surface and repeating the treatment of irradiating light one or more times, preferably a plurality of times. The light to be irradiated is preferably light having a wavelength that can be absorbed by titanium dioxide and cause photocatalytic action, and has a wavelength that has little adverse effect on the human body. As such a wavelength, light including a wavelength of 300 nm or more, more preferably light including a wavelength of 380 to 500 nm is used. Examples of the light source used include exothermic lamps, fluorescent lamps, halogen lamps, black lights, metal halide lamps, xenon lamps, mercury lamps, UV lamps, LEDs (light emitting diodes), and semiconductor lasers. What is necessary is just to make the light from these light sources into a predetermined wavelength by cutting an unnecessary wavelength through an appropriate filter.
[0023]
The number of times of application of the bleaching material and light irradiation can be appropriately adjusted according to the degree of discoloration. When performing the application | coating operation of a bleaching material, what is necessary is just to apply | coat normally about every 15 minutes-20 minutes, and the space | interval and frequency can be suitably set according to the state of a tooth. The bleaching material is effective for bleaching both non-medullary teeth and pulped teeth.
[0024]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention does not receive a restriction | limiting at all to a following example.
[0025]
Example 1
Purified water to 35% by weight of hydrogen peroxide 10.0 g, phosphoric acid 0.60 g, pyrosodium pyrophosphate 10 hydrate 2.00 g, rutile titanium dioxide (MT-150A manufactured by Teika) 0.06 g, laponite 1.50 g Using the aqueous solution with a total amount of 100 g as a bleaching material, the discolored teeth (extracted teeth) were bleached by the following procedure.
1) As a preparation, plaque, tartar, tar, etc. were removed with an ultrasonic scaler.
2) As a pretreatment, the tooth surface was washed with a 2.0% by weight aqueous solution of tetrasodium pyrophosphate, washed with water and dried.
3) Simple moisture-proofing was performed.
4) A bleaching material was applied to the tooth surface and irradiated with light having a wavelength of 380 nm or more.
5) One irradiation time was set to 5 minutes, and the operation was repeated 4 times by applying new bleaching agent and light irradiation each time.
As a result, the initial color change degree F3.5 became the color change degree F1.5 after bleaching.
[0026]
Comparative Example 1
Bleaching was performed in the same manner as in Example 1 except that the washing was not performed with the aqueous solution of 4 sodium pyrophosphate in 2). As a result, the initial color change degree F3.5 became the color change degree F2.0 after bleaching.
[0027]
Comparative Example 2
Only the discolored teeth (extracted teeth) were washed with a tetrasodium pyrophosphate aqueous solution. As a result, the initial color change degree F3.5 became the color change degree F2.5.
[0028]
In the above bleaching test, the classification of the degree of discoloration of the discolored teeth (extracted teeth) used was as follows.
F1: The whole crown is uniformly colored with pale yellow, brown, and gray, and no stripe pattern is seen.
F2: Darker than F1, the entire crown is uniformly colored, and no striped pattern is seen.
F3: Dark gray, bluish gray with stripes.
F4: Remarkably dark purple, grayish purple, and the entire crown portion is discolored.
[0029]
【Effect of the invention】
According to the present invention, remarkable effects such as (1) simple operation, (2) enhanced tooth bleaching effect, and (3) stabilized tooth bleaching effect can be obtained.

Claims (7)

When the tooth bleaching is performed by applying a treatment including irradiating light having a wavelength of 300 nm or more after the tooth bleaching material is applied, pretreatment with a condensed phosphate aqueous solution is performed.
The discolored tooth bleaching method, wherein the tooth bleaching material contains titanium dioxide having a photocatalytic action and hydrogen peroxide as main components. The method according to claim 1, wherein the concentration of the condensed phosphate aqueous solution is 0.01 to 30% by weight. One or more aqueous solutions wherein the condensed phosphate aqueous solution is selected from the group consisting of sodium tripolyphosphate 0.1 to 10% by weight, sodium pyrophosphate 0.1 to 10% by weight and 4 potassium pyrophosphate 0.1 to 10% by weight The method of claim 2 , wherein The method according to claim 3 , wherein the aqueous condensed phosphate solution is an aqueous solution containing 0.1 to 10% by weight of tetrasodium pyrophosphate. The method according to any one of claims 1 to 4, phosphoric acid and condensed phosphoric acid salt to the tooth bleaching material is added. The method according to any one of claims 1 to 5, wherein the condensed phosphoric acid salt is tetrasodium pyrophosphate. The method according to any one of claims 1 to 6 , wherein a thickener is added to the tooth bleaching material.