JP6376748B2 - Teeth bleaching material composition and tooth bleaching method - Google Patents

Description

  The present invention relates to a tooth bleaching material composition for bleaching discolored or colored teeth by the action of a photocatalyst and a method for bleaching discolored or colored teeth using the tooth bleaching material composition. is there.

  In recent years, with the increasing demand for aesthetics of teeth, cases of tooth bleaching in clinical practice are increasing. Teeth bleaching is an effective means that can whiten teeth with little damage to the teeth, and various techniques have been proposed for this purpose.

  As a technique for bleaching teeth, a tooth bleaching material composition comprising a high concentration of hydrogen peroxide and anhydrous silicic acid has been proposed (Patent Document 1). Although this technique is excellent in the bleaching effect of teeth, there are problems such as giving a strong irritation to the gingiva and generating hypersensitivity.

  As another technique for bleaching teeth, a tooth bleaching material composition containing titanium dioxide having a photocatalytic action and a low concentration of hydrogen peroxide has been proposed (Patent Document 2). This technology uses a photocatalytic action caused by light irradiation to titanium dioxide to promote the decomposition of hydrogen peroxide, thereby obtaining a high bleaching effect, and because it uses a low concentration of hydrogen peroxide. Effective in reducing gingival irritation and hypersensitivity. However, although this technique can obtain a certain bleaching effect for teeth with relatively little discoloration or coloring, the bleaching effect is insufficient for teeth with significant discoloration or coloring.

  Patent Document 3 proposes a tooth bleaching material composition containing a compound of hydrogen and phosphorous and calcium having a photocatalytic action. In Patent Document 3, hydroxyapatite and fluorapatite are exemplified as suitable phosphorus and calcium compounds, but there is no exemplification of oxyapatite which is an essential component of this patent. Moreover, it has been shown that the phosphorus-calcium compound (including apatite) described in Patent Document 3 is produced by precipitating a phosphorus-calcium compound in a simulated body fluid. However, in this production method, apatite having a photocatalytic action cannot be mass-produced, and the production cost becomes high. Therefore, a tooth bleaching material could not be provided at a low cost.

  On the other hand, Patent Document 4 discloses a photocatalyst that can be applied to uses such as an oxidation catalyst, an antibacterial material, a sterilizing material, an ionic conductor, a solid electrolyte fuel cell member, an exhaust gas purifying agent, a semiconductor substrate oxidizing agent, a solar cell member, and a semiconductor. An oxyapatite having an action and a method for producing the same have been proposed. However, Patent Document 4 does not show application of oxyapatite to tooth bleaching. Furthermore, there is no suggestion that a tooth bleaching material composition containing oxyapatite and a compound that generates hydrogen peroxide in an aqueous solution is excellent in tooth bleaching effect.

JP-A-5-320033 Japanese Patent No. 3030380 Japanese Patent No. 4280812 JP 2007-91582 A

  The present invention eliminates the above-described problems of the prior art, is excellent in safety to the human body, exhibits a high bleaching effect in a short processing time, and can be manufactured at a low cost, and the tooth It is an object of the present invention to provide a method for bleaching teeth using a bleaching material composition.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have focused on apatite that is excellent in adsorptivity of organic substances such as pigments and affinity for tooth substance. Among them, it has a photocatalytic action and is easy to manufacture. By combining oxyapatite with a compound that generates hydrogen peroxide in an aqueous solution, it is possible to obtain a dental bleaching material composition that is highly safe for the human body and exhibits a high bleaching effect in a short processing time. As a result, the present invention has been completed. Furthermore, the tooth bleaching material composition of the present invention can be provided at low cost because it uses oxyapatite which is easy to produce.

  That is, the present invention is a tooth bleaching material composition comprising a photocatalytic oxyapatite and a compound that generates hydrogen peroxide in water, and a tooth that is excellent in applicability to teeth by further adding a thickener. Bleaching material composition. Further, the present invention is a method for bleaching a tooth, characterized in that the tooth bleaching material composition is applied to a discolored or colored tooth surface, and the coated part is irradiated with light to bleach the tooth.

  ADVANTAGE OF THE INVENTION By this invention, it becomes possible to provide the dental bleaching material composition and the tooth bleaching method which can bleach a discolored or colored tooth safely in a short processing time.

  Hereinafter, the present invention will be described in detail.

  The present invention applies a tooth bleaching material composition containing a photocatalytic oxyapatite and a compound that generates hydrogen peroxide in an aqueous solution to a discolored or colored tooth surface, and irradiates the applied portion with light. The present invention relates to a tooth bleaching material composition and a method for bleaching teeth using the tooth bleaching material composition. The oxyapatite contained in the tooth bleaching material composition of the present invention acts on surrounding oxygen and water when irradiated with light to generate active oxygen. In addition, oxyapatite irradiated with light accelerates decomposition of a compound that generates hydrogen peroxide in an aqueous solution, and generates more active oxygen. Thereby, the bleaching material composition for teeth of this invention expresses a high bleaching effect in a short processing time.

  The photocatalytic oxyapatite used in the present invention is a compound that can be represented by the following formula (1).

M ₁₀ (PO ₄ ) ₆ O ₂ (1)
(M in the formula represents at least one element of Ca, Mg, Sr, Ba, Fe, Co, Ni, Cu, Zn, Ag, Al, La, Cr, Y, Sm, and Nd.)
The oxyapatite used in the present invention is not particularly limited as long as it is a compound satisfying the above requirements. However, since it is easy to produce, Ca ₈ La ₂ (PO ₄ ) ₆ O ₂ , Ca ₈ Y ₂ (PO ₄ ) ₆ O ₂ , Ca _{8 A} 1 ₂ (PO ₄ ) ₆ O ₂ , Ca ₈ Sm ₂ (PO ₄ ) ₆ O ₂ , Ca ₈ Nd ₂ (PO ₄ ) ₆ O _{2 and the} like are suitable. These can be used alone or in admixture of two or more.

  The shape of the oxyapatite used in the present invention is not particularly limited, and may have pores. Moreover, it is preferable that the particle diameter of an oxyapatite is 0.1-100 micrometers. The amount of oxyapatite is preferably 1 to 90% by weight, more preferably 10 to 60% by weight, and still more preferably 30 to 60% by weight. If the blending amount is less than 1% by weight, a sufficient tooth bleaching effect cannot be obtained, and if it exceeds 90% by weight, the light transmittance is deteriorated and the tooth bleaching effect is lowered. In addition, in this application, "weight%" shows the weight% of each compounding component when a dental bleaching material composition is 100 weight%.

  The oxyapatite used in the present invention can be easily synthesized by an ordinary solid phase reaction method. That is, it can be synthesized by mixing and firing oxides, carbonates, hydroxides, chlorides, fluorides, phosphates, nitrates, sulfates, etc. of each metal element in formula (1). . However, the production method is not particularly limited as long as oxyapatite having a photocatalytic action can be produced.

The compound that generates hydrogen peroxide used in the present invention is at least one selected from the group consisting of hydrogen peroxide, percarbonate, perborate, perphosphate, persulfate, and urea peroxide. A compound can be mentioned. Specific examples include hydrogen peroxide, sodium peroxide, sodium perborate, potassium persulfate, sodium persulfate, sodium percarbonate, sodium perphosphate, calcium peroxide, magnesium peroxide, and urea peroxide. it can. Among them, since it is excellent in storage stability when blended in a tooth bleaching material composition, among the compounds that generate hydrogen peroxide, compounds other than hydrogen peroxide, that is, peroxide salts (percarbonate Salt, perborate, perphosphate, persulfate) and urea peroxide. Furthermore, peroxide salts (percarbonate, perborate, perphosphate, persulfate) are more preferable from the viewpoint of reducing the influence on the human body and improving the sustainability of the bleaching effect. These can be used alone or in admixture of two or more. Here, the “peroxide salt” is a salt of a peroxo acid coordinated with O ₂ ^2- and an alkali metal or alkaline earth metal.

  The amount of the compound that generates hydrogen peroxide in the aqueous solution is preferably 1 to 35% by weight, more preferably 1 to 25% by weight. If the blending amount is less than 1% by weight, a sufficient tooth bleaching effect cannot be obtained. On the other hand, when the amount exceeds 35 parts by weight, a large amount of hydrogen peroxide is generated, which is not preferable from the viewpoint of biological harm such as giving a strong stimulus when adhering to the gingiva or generating hypersensitivity.

  The tooth bleaching material composition of the present invention is preferably further blended with a thickener in order to impart retention on the tooth surface and more efficiently bleach the tooth. As the thickener used in the present invention, either an inorganic thickener or an organic thickener can be used. Examples of inorganic thickeners include fumed silica, calcium carbonate, calcium silicate, magnesium silicate, and clay minerals such as saponite, montmorillonite, beidellite, vermiculite, soconite, stevensite, hectorite, smectite, nectite and sepiolite. It is done. Organic thickeners include methylcellulose, hydroxyethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, carboxymethylcellulose calcium, carboxypolymethylene, sodium alginate, propylene glycol ester alginate, sodium polyacrylate, starch, starch Examples include sodium glycolate, starch phosphate ester, polyvinylpyrrolidone, carboxyvinyl polymer, caraya gum, gum arabic, caraya gum, and guar gum. These can be used alone or in admixture of two or more.

  The blending amount of these thickeners varies depending on the blending amount of oxyapatite and the compound that generates hydrogen peroxide in the aqueous solution and the type of thickening agent, but preferably 0.1 to 30% by weight, More preferably, it is 0.1 to 10% by weight. If the blending amount of the thickener is less than 0.1% by weight, a sufficient thickening effect cannot be obtained. Moreover, when it exceeds 30 weight%, a viscosity will become high too much and the applicability | paintability to a tooth will fall.

  The tooth bleaching material composition of the present invention is prepared by liquidizing the tooth bleaching material composition with a solvent in order to bring the oxyapatite having photocatalytic action and a compound that generates hydrogen peroxide in an aqueous solution into contact with the tooth appropriately. Or it is preferable to use paste form. As the solvent for forming a liquid or paste, water or alcohol is preferable. Examples of alcohol include ethanol, 1-propanol, 2-propanol, 2-methyl-2-propanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, glycerin, polyglycerin, and the like. Can be mentioned. These can be used alone or in admixture of two or more. The amount of the solvent used in the present invention is preferably 5 to 90% by weight. If the blending amount is less than 5% by weight, the applicability to the tooth surface tends to be poor, and if it exceeds 90% by weight, the retention on the tooth surface will flow badly, so the bleaching effect cannot be sufficiently obtained, Moreover, since the danger which adheres to a gum increases, it is not preferable.

  As one aspect of the tooth bleaching material composition of the present invention, oxyapatite, a compound that generates hydrogen peroxide in an aqueous solution, and if necessary, a thickener is mixed with a solvent to form a liquid or paste. Can do. In another embodiment, oxyapatite and, if necessary, a thickening agent mixed with a solvent to form a liquid or paste-like first component, a compound that generates hydrogen peroxide in an aqueous solution, and an increase as necessary. It is also possible to prepare a second component in a liquid or paste form by mixing a sticky agent with a solvent, and to mix and use the first component and the second component immediately before use. As another aspect, when the compound that generates hydrogen peroxide in an aqueous solution is solid, a powder material component in which oxyapatite and a compound that generates hydrogen peroxide in an aqueous solution are mixed, a solvent, and if necessary It is also possible to prepare a liquid material component mixed with a thickener and mix and use the powder material component and the liquid material component immediately before use.

  The tooth bleaching material composition of the present invention may further contain additives such as buffers, preservatives, stabilizers, sweeteners, pigments, and fragrances as long as the bleaching effect is not lowered.

  In order to bleach a tooth using the tooth bleaching material composition of the present invention, first, the tooth bleaching material composition of the present invention is applied onto the tooth surface using a brush or the like. Further, the tooth bleaching material composition of the present invention is filled in a mouth tray made of a light-transmitting resin, and the tooth bleaching material composition of the present invention is brought into contact with the tooth surface by attaching this to a tooth. There is also a method. After applying the tooth bleaching material composition of the present invention to the tooth by any of the above methods, the tooth is bleached by irradiating the application site with light. The light irradiation time when the tooth is bleached using the tooth bleaching material composition of the present invention is the composition of the oxyapatite having photocatalysis and the compound that generates hydrogen peroxide in an aqueous solution, or the discoloration or coloring of the tooth to be bleached What is necessary is just to adjust suitably according to a degree. Further, as a light source of a light irradiator used for bleaching a tooth using the tooth bleaching material composition of the present invention, an incandescent lamp, a fluorescent lamp, a black light, a halogen lamp, a metal halide lamp, a xenon lamp, a light emitting diode ( LED), mercury lamp, UV lamp, semiconductor laser and the like. As the wavelength region of the light irradiator, it is preferable to use visible light of 380 nm to 500 nm from the viewpoint of safety to the human body. Further, a series of operations for bleaching these teeth may be repeated a plurality of times depending on the discoloration or coloring degree of the teeth. The applied tooth bleaching composition of the present invention can be easily washed away with water.

  The tooth bleaching material composition and the bleaching method using the tooth bleaching material composition of the present invention can be applied to both myelinated and unmedulled teeth.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not restrict | limited at all by the following Examples.

[Evaluation of bleaching performance 1]
A colored model was prepared by dipping a 10 × 10 × 2 mm hydroxyapatite sintered body (APP-100, PENTAX) in a 1000 ppm methylene blue aqueous solution for one week and then drying. The bleaching material composition was applied to the surface of the colored model, and the coated surface was immediately irradiated with a halogen lamp (550 mW / cm ² , PLH-75, PHILIPS) for 1 minute, and then the bleaching material composition was removed by washing with water. The distance between the coloring model and the light source was fixed at 5 mm, and the bleaching process was performed three times. The color tone of the colored model surface before and after bleaching is measured with a simple colorimeter Shade Eye NCC (Matsukaze Co., Ltd.) in the color display: CIE 1976 L ^* a ^* b ^* color system, and the color differences ΔE and ΔL ^* , Δb ^* Bleaching performance was evaluated from ^* .

Delta] E = {(a bleached L ^* - before bleaching L ^{*) 2} + (after bleaching a ^* - before bleaching a ^{*) 2} + (after bleaching b ^* - before bleaching b ^{*) 2} 1 / 2}
ΔL ^* = after bleaching L ^* - before bleaching L ^*
Δb ^* = after bleaching b ^* - before bleaching b ^*
[Evaluation of bleaching performance 2]
After embedding human extracted teeth (molars, anterior teeth), only the crown portion was cut horizontally to cut out a 0.5 mm thick section, and immersed in physiological saline to obtain a horizontal section for bleaching. The bleaching material composition was applied to the surface of the horizontal slice for bleaching, and the coated surface was immediately irradiated with a halogen lamp (550 mW / cm ² , PLH-75, PHILIPS) for 5 minutes, and then the bleaching material composition was removed by washing with water. . The distance between the bleaching horizontal section and the light source was fixed at 5 mm, and the bleaching process was performed three times. The color tone of the surface of the horizontal section for bleaching before and after bleaching was measured using a micro-spectral color difference meter (VSS-400, Nippon Denshoku Industries Co., Ltd.) in color display: CIE 1976 L ^* a ^* b ^* color system, The bleaching performance was evaluated from the color differences ΔE, ΔL ^* , and Δb ^* .

[Synthesis of oxyapatite]
7.62 g of calcium pyrophosphate, 3.26 g of lanthanum oxide and 2.00 g of calcium carbonate were mixed in ethanol, and the mixture was baked in an electric furnace (Marusho Electric Co., Ltd.) at 1400 ° C. for 4 hours under atmospheric pressure. . The obtained fired product was pulverized in an agate mortar and passed through a 200 mesh sieve. The powder after sieving was analyzed by XDR and confirmed to be Ca ₈ La ₂ (PO ₄ ) ₆ O ₂ .

<Example 1>
0.25 g of oxyapatite and 0.25 g of 5% hydrogen peroxide water were uniformly mixed to prepare a tooth bleaching material composition. The bleaching performance of the obtained tooth bleaching composition was evaluated according to [Evaluation 1 of bleaching performance]. The results are shown in Table 1.

<Example 2>
0.25 g of oxyapatite and 0.25 g of 15% hydrogen peroxide water were uniformly mixed to prepare a tooth bleaching material composition. The bleaching performance of the obtained tooth bleaching composition was evaluated according to [Evaluation 1 of bleaching performance]. The results are shown in Table 1.

<Example 3>
0.25 g of oxyapatite and 0.25 g of 25% hydrogen peroxide water were uniformly mixed to prepare a tooth bleaching material composition. The bleaching performance of the obtained tooth bleaching composition was evaluated according to [Evaluation 1 of bleaching performance]. The results are shown in Table 1.

<Example 4>
0.25 g of oxyapatite and 0.25 g of 35% hydrogen peroxide solution were uniformly mixed to prepare a tooth bleaching material composition. The bleaching performance of the obtained tooth bleaching composition was evaluated according to [Evaluation 1 of bleaching performance]. The results are shown in Table 1.

<Example 5>
0.25 g of oxyapatite and 0.25 g of sodium percarbonate were mixed uniformly to prepare a tooth bleaching material composition. Prior to the bleaching treatment, 0.5 g of the tooth bleaching material composition was kneaded with 0.25 g of distilled water to make a paste before use. The bleaching performance of the obtained tooth bleaching composition was evaluated according to [Evaluation 1 of bleaching performance]. The results are shown in Table 1.

<Comparative example 1>
Visible light-responsive titanium dioxide (0.25 g) and 5% hydrogen peroxide water (0.25 g) were uniformly mixed to prepare a tooth bleaching material composition. The bleaching performance of the obtained tooth bleaching composition was evaluated according to [Evaluation 1 of bleaching performance]. The results are shown in Table 1.

<Example 6>
The bleaching performance of the tooth bleaching material composition of Example 1 was evaluated according to [Evaluation of bleaching performance 2]. The results are shown in Table 2.

  In the evaluation using the coloring models of Examples 1 to 5, the tooth bleaching material composition of the present invention was compared with the tooth bleaching material composition comprising visible light responsive titanium dioxide and hydrogen peroxide solution of the prior art. High bleaching effect. Although specific test results are not shown, the peroxide salt such as sodium percarbonate used in Example 5 is more stable than the hydrogen peroxide solution used in Examples 1 to 4. It has been confirmed that the effect on the human body is extremely small in terms of reactivity, reactivity, and the sustainability of the bleaching effect is good. Also in the evaluation using the human extracted tooth of Example 6, the tooth bleaching material composition of the present invention showed a high bleaching effect.

  ADVANTAGE OF THE INVENTION According to this invention, it contains the oxyapatite which has a photocatalytic action, and the compound which generate | occur | produces hydrogen peroxide in water, It is excellent in the safety | security to a human body, and also exhibits the high bleaching effect, The bleaching material composition for teeth Can be provided.

Claims (3)

Contains oxyapatite with photocatalytic activity and a compound that generates hydrogen peroxide in aqueous solution,
The oxyapatite is Ca ₈ La ₂ (PO ₄ ) ₆ O ₂ ;
The compound that generates hydrogen peroxide in the aqueous solution is a peroxide salt,
A tooth bleaching material composition comprising 30 to 60% by weight of the oxyapatite and 1 to 35% by weight of a compound that generates hydrogen peroxide in an aqueous solution.   Furthermore, the tooth | gear bleaching material composition of Claim 1 containing 0.1-30 weight% of thickeners. The tooth bleaching material composition according to claim 1 or 2 is applied to a tooth surface,
A method for bleaching a tooth, characterized in that the tooth is bleached by irradiating light onto a portion of the tooth surface coated with the tooth bleaching material composition.