JPS62126115A - Dentifrice - Google Patents

Abstract

PURPOSE:A dentifrice, obtained by incorporating an N-type semiconductor capable of initiating photocatalytic reaction in a dentifrice ingredient consisting of a polishing agent and additive which are respectively inorganic compounds and having bacterial plaque decomposing action and germicidal effect on carious pathogenic germs at the same time. CONSTITUTION:A dentifrice obtained by incorporating <=20wt%, preferably 5-10wt% N-type semiconductor powder, e.g. titanium dioxide, capable of initiating photocatalytic reaction in a dentifrice ingredient consisting of a polishing agent of an inorganic compound, e.g. calcium hydrogenphosphate or calcium carbonate, and additive of an inorganic compound. The secondary treatment of the surface of the N-type semiconductor powder selected from supporting of platinum, reducing with hydrogen and sensitizing with a dyestuff further enhances the photocatalytic reaction. The germicidal action by OH radicals generated by irradiation of the N-type semiconductor powder with light in a state of contact with water in the oral cavity can be effectively enhanced by removing organic compounds.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a dentifrice, and more particularly to a dentifrice having a bactericidal effect against germs.

[Conventional technology]

The applicant discovered that N-type semiconductor has a decomposing effect on dental plaque, and would like to first propose a toothpaste containing N-type semiconductor powder (Japanese Patent Application No. 58-119955 "Toothpaste"). The agent is ``tsuchi'' (tooth decay).

Although it has a remarkable effect on decomposing the plaque that promotes dental plaque, Streptococcus mutans (Streptococcus mutans), the pathogenic bacteria that generates plaque,
In some respects, it was not necessarily sufficient from the perspective of directly attacking the Mutans.

The reason for this is that the ingredients contain organic substances, so even if N-type semiconductor powder is contained, the energy acts on the organic substances in the dentifrice ingredients during the photocatalytic reaction, reducing the effect by half. It is thought that

[Problems to be Solved by the Invention] Therefore, in this invention, the N-type semiconductor powder is contained to have a plaque decomposition effect, and the N-type semiconductor powder is exposed to light while in contact with the moisture in the oral cavity. The present invention aims to provide a toothpaste with a novel composition that allows the O1l radicals generated upon irradiation to exert a sufficient bactericidal action to destroy and kill the Streptococcus mutans bacteria.

[Means for Solving the Problems] In order to achieve the above technical problem, the present invention provides a dentifrice that effectively activates the photocatalytic reaction of N-type semiconductor powder by removing organic compounds, particularly A dentifrice is provided, which is characterized in that it contains a mixture of a powdered abrasive that is an inorganic compound, a powdered additive that is an inorganic compound, and an N-type semiconductor powder.

The abrasive described above must be an inorganic compound, and specifically may be conventional calcium hydrogen phosphate, heavy or light calcium carbonate, or a mixture thereof.

The above-mentioned additives include any auxiliary agent that enhances the preservability of the dentifrice, or enhances its plaque-degrading action or bactericidal action against the Streptococcus mutans bacteria, with the exception of inorganic compounds,
is appropriate.

If the content of the N-type semiconductor powder exceeds 20% by weight, the light energy conversion efficiency of the N-type semiconductor powder will deteriorate. Therefore, an N-type semiconductor powder content within the range of about 1 to 20% by weight is preferred, and even more preferably about 5 to 10% by weight.
The composition contains N-type semiconductor powder within a range of % by weight.

In addition, by performing a secondary treatment on the surface of the N-type semiconductor powder, platinum can be removed by suspending the semiconductor powder in a chloroplatinic acid aqueous solution that has been subjected to PLL adjustment, and irradiating it with light under a nitrogen atmosphere. The catalytic effect can be improved by supporting platinum using a photoelectric refraction method in which it is deposited on a semiconductor, a kneading method in which a semiconductor powder is kneaded with platinum black, or the like. Furthermore, by attaching a dye such as metal phthalocyanine to the semiconductor powder, the usable absorption wavelength range of the semiconductor can be expanded to include the absorption wavelength range of the dye, and it is possible to measure the light energy conversion efficiency by dye sensitization. In addition to these treatment methods, hydrogen reduction at high temperature under hydrogen gas ventilation creates oxygen defects and hydrogen incorporation within the crystal lattice, which can transform it into a higher quality semiconductor and further enhance the photocatalytic reaction. will be strengthened.

[For production]

When the N-type semiconductor powder contained in the dentifrice of this invention is irradiated with natural light or artificial light while in contact with saliva in the oral cavity or water used for tooth brushing, for example, when the N-type semiconductor powder is When titanium is used, (1) a genuine tag and excited electrons are generated on the surface of titanium dioxide by the second reaction. (h゛ indicates a hole.) Ti02+hC+h"+e-・-(1) The holes generated on the surface of titanium dioxide are formed by an oxidation reaction that takes electrons from the water in saliva, as shown in equation (2). OH radical (・01
1) is generated.

)1□0+h3→・0t”2 ・・・・・・(2) On the other hand, the electrons that reached the titanium dioxide surface through the diffusion process undergo a reduction reaction in the presence of dissolved oxygen, and are converted to I as shown in equation (3).
OH radicals are generated via O□ radicals.

(3) It is presumed that dextran, which is the main component of dental plaque, is decomposed and solubilized by OH radicals as shown in the following equation (4).

It was confirmed through a culture test that the 011 radical described above exhibits a bactericidal effect on the Streptococcus mutans bacteria. Details of this test are as follows. That is, by using physiological saline instead of the culture solution, we will set up an environment in which Streptococcus mutans does not grow, and examine how the amount of bacteria will change with or without semiconductor powder.

A. Experimental procedure (1) Preculture in a test tube using a conventional method.

(2) Add an appropriate amount of preculture solution to the medium (BIII 3.7W/V
Collect into XSucrose 5W/Vχ) 100n+42 and culture anaerobically at 37°C.

(3) pH and O, D of the above culture solution (540 nm)
Measure.

(4) Prepare two containers, one container contains 100ml of physiological saline, and the other container contains physiological saline Loo.
m 1 contains N-type Hane body powder 0. Add IWHaχ.

(5) Collect 0.5 mff of a 10-fold dilution of the culture solution whose pH and O, D (540 nm) were measured earlier into two containers, and divide into 15 mA portions each.

After preparing the sample in this way, (6) put the sample (1) into a desiccator (2) as shown in FIG. 2 and bring it into an anaerobic state. Also, the liquid temperature should be 37°C, and 1
Irradiation is performed with a 00W-mercury lamp (3).

(7) Collect 0.5 mβ from the sample every hour and culture on agar plate on a petri dish for about 48 hours.

Number (4) in Figure 2 is the mercury lamp (3) and desiccator (2)
The number (5) is a star which maintains the sample (1) in a stirring state within the desiccator (2).

B. Test results: Two representative examples are shown below.

Test results I (a) Culture conditions: After 24 hours of preculture, 0.5 m# of a 10-fold dilution of the preculture solution was collected and cultured for 27 hours.

0, D (540nm) 0.212pH4
,55 Number of viable bacteria per 0.5ml 38 X 10' (7,50) (
b) Changes in bacterial species over time were as shown in Table 1 below.

P10υ [1 (a) Culture conditions: Preculture was carried out under conditions different from test result I.
After 5 hours, add 0.5 m of a 103-fold dilution of the preculture solution.
A was collected and cultured for 23 hours.

0, D (540nm) 0.180p H
4,55 Number of viable bacteria per 0.5 mf 42 X 10' (8,62) (
b) Changes in the amount of bacteria over time were as shown in Table 2 below.

Table 1 The value in parentheses is the logarithm of the bacterial amount.

No colonies were formed in the chapters even in the undiluted solution.

Table 2 The value in parentheses is the logarithm of the bacterial amount.

No colonies were formed in the book even in the undiluted solution.

When the above Tables 1 and 2 are illustrated, the graphs are shown in FIGS. 3 and 4, respectively.

As described above, it is clear that the N-type semiconductor powder exerts a remarkable bactericidal effect on the Streptococcus mutans when irradiated with a mercury lamp. One of the characteristics of the dentifrice according to the present invention is that it is composed only of inorganic compounds, and its excellent effects will be described later.

〔Effect of the invention〕

According to this invention, the light energy irradiated to the N-type semiconductor powder is effectively used to generate OH radicals in saliva etc. that are in contact with the powder, and these radicals have a plaque decomposition effect and a bactericidal effect. Since a dentifrice composition is provided that allows this to occur, it is possible to achieve a high level of dental hygiene that cannot be achieved using conventional oral cleaning methods. This is because by directly exterminating the Streptococcus mutans bacteria that produce dental plaque, the subsequent growth of dental plaque is inhibited, and the existing dental plaque is removed by the decomposition action described above.

What should be particularly noted here is that the dentifrice of the present invention is composed only of inorganic compounds, and the OH radicals are organic compounds in conventional dentifrices, such as humectants such as glycerin, lauryl sulfate, etc. There is no risk of unnecessary consumption of foaming agents such as sodium, flavoring agents such as peppermint, or sweeteners such as saccharin. In other words, substantially all of the OH radicals are effectively utilized for decomposing dental plaque and destroying cell membranes of the Streptococcus mutans, for example.

When using the powdered dentifrice of the present invention, there are no particular restrictions on how it can be used, as long as care is taken to avoid its use in combination with any organic compounds. Used as a water dentifrice (
(using a toothbrush), applying it in powder form to areas with a lot of plaque and rubbing it with your fingertips, or, of course, applying it to the bristles of a toothbrush and using it like a conventional powdered toothpaste. Everything is possible. Of course, it is also possible to use it by mixing it into a transparent jelly-like substance.

〔Example〕

Below, several examples of the present invention are shown in Tables 3 to 9.

(1) The composition of the dentifrice of Example 1 is shown in Table 3.

Table 3 Example 1 (2) Examples 2 to 7 are shown in Tables 4 to 9, respectively.

Example 2 differs from Example 1 in the content of titanium dioxide,
Example 3 differs from Example 1 in the proportions of components other than titanium dioxide.

Example 4 is the same as Example 1 except that iron sesquioxide (FezO:+), which is harmless to the human body, is used instead of titanium dioxide as the N-type semiconductor powder.

In Examples 5 to 7, the proportions of all the components in Example 1 were changed, and in particular, purified water was added to Examples 6 and 7.

Table 4 Example 2 Table 5 Example 3 Table 6 Example 4 Table 7 Example 5 Table 8 Example 6 Table 9 Example 7 Any of the above examples also has the above-mentioned advantages. The effect was obtained.

[Brief explanation of drawings]

The drawings are for explaining this invention. Figure 1 shows the mechanism by which N-type semiconductor powder (titanium dioxide) generates OI (radicals), and Figure 2 shows a partial cutaway of an apparatus for testing its bactericidal action. The front view and FIGS. 3 and 4 are graphs showing test results of bactericidal activity.

Claims (8)

[Claims] (1) A dentifrice containing an N-type semiconductor powder that causes a photocatalytic reaction in a dentifrice component consisting of an inorganic compound abrasive and an inorganic compound additive. (2) The toothpaste according to claim (1), wherein the N-type semiconductor powder is obtained by subjecting it to a secondary treatment selected from platinum loading, hydrogen reduction, and dye sensitization. agent. (3) The dentifrice according to claim (1) or (2), wherein the content of the N-type semiconductor powder is about 20% or less by weight. (4) The dentifrice according to claim (3), wherein the content of the N-type semiconductor powder is about 5 to 10% by weight. (5) The dentifrice according to any one of claims (1) to (4), wherein the target dentifrice is in the form of a toothpaste. (6) The dentifrice according to any one of claims (1) to (4), wherein the target dentifrice is in the form of a semi-toothpaste. (7) The dentifrice according to any one of claims (1) to (4), wherein the target dentifrice is in the form of powder toothpaste. (8) The dentifrice according to any one of claims (1) to (4), wherein the target dentifrice is in the form of a liquid dentifrice.