CN112156028A

CN112156028A - Novel tooth whitening gel and preparation method and application thereof

Info

Publication number: CN112156028A
Application number: CN202011174811.5A
Authority: CN
Inventors: 孙皎; 杨甦; 汪俊; 刘昕; 隋佰延
Original assignee: Ninth Peoples Hospital Shanghai Jiaotong University School of Medicine
Current assignee: Ninth Peoples Hospital Shanghai Jiaotong University School of Medicine
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2021-01-01

Abstract

The invention discloses a novel tooth whitening gel and a preparation method thereof. The preparation method of the novel tooth whitening gel comprises the steps of fully reacting a corresponding activator with an oxidant according to a certain mass ratio, adding a thickening agent, mixing, uniformly stirring, and standing to obtain the novel tooth whitening gel. The whitening gel containing oxygen free radicals is obtained by activating persulfate through phosphate, so that the degradation of pigments in hard tissues of teeth is realized, the whitening effect is achieved, and meanwhile, the demineralization on the surface of enamel and the bad stimulation on dental pulp cells can be effectively reduced.

Description

Novel tooth whitening gel and preparation method and application thereof

Technical Field

The invention relates to a novel persulfate-containing non-hydrogen peroxide whitening gel, and belongs to the technical field of tooth whitening.

Background

The desire of people seeking tooth whitening in the modern society is strong, and some psychological researches also show that people with bright and white teeth can obtain positive self-evaluation and good social attraction more easily. The existing tooth whitening gel mainly comprises Hydrogen Peroxide (HP) or Carbamide Peroxide (CP), and is accelerated to decompose by a catalyst or laser and the like to generate perhydroxyl anion and oxygen radical components, so that double bonds in staining groups in tooth tissues can be effectively destroyed, pigments in enamel and dentin shallow layers are decomposed to be changed into substances with smaller molecular weight, and absorption peaks are changed into ultraviolet light from visible light, and finally tooth whitening is realized. However, if the operation is careless, the gel is easy to cause damage to gingival epithelium and oral mucosa, and may cause demineralization of the hard tissue structure of teeth, reduction of surface hardness and the like, and meanwhile, hydrogen peroxide molecules are easy to pass through enamel and dentin to reach the pulp cavity, so that sensitive or pulp pain is frequently caused after bleaching in clinic.

The safe and effective whitening gel has good oxidation performance, can decompose dyeing groups positioned in the enamel or the dentin superficial layer, has controllable action range, and releases less oxidation components which penetrate into the dentin deep layer or pulp cavity, thereby avoiding the damage to pulp tissues. To achieve this goal, the present patent attempts to formulate new tooth whitening gels based on oxidizing systems that activate persulfates.

Common persulfates are classified into peroxomonosulfates and peroxodisulfates, which are compounds obtained by substituting one or two H atoms in hydrogen peroxide with a sulfonic acid group. The performance is stable at normal temperature, and the oxidability is not obvious. When activated under certain conditions, the oxidation performance is significantly improved. In particular, peroxymonosulfate has a unique asymmetric structure (shown in the following figure, the structure diagram of potassium peroxymonosulfate molecule) and is more easily excited and activated.

Researches show that the persulfate can be effectively activated by energy excitation modes such as ultraviolet irradiation, heat energy, ultrasound and the like, so that a peroxy bond of the persulfate is broken to generate a free radical. The transition metal can activate the persulfate at normal temperature and normal pressure, and in addition, the scholars adopt active methods such as active carbon, graphene, strong base and the like. However, it should be noted that the transition metals are expensive, too costly, and potentially biologically toxic; the strong alkaline condition has high requirements on instruments and equipment. In conclusion, the above activation techniques are high in energy consumption and harsh in technical conditions, and it is difficult to introduce persulfate oxidation systems into the field of dental applications.

In recent years, the scholars find that the organic dye can be effectively oxidized and degraded under the conditions of normal temperature and normal pressure by using the phosphate solution as the activator of the persulfate, no external energy is added, the reaction is mild, no secondary pollution is caused, and the method is suitable for the operation environment of oral clinic. The hydroxyl free radical, superoxide free radical, sulfate free radical and the like generated in the oxidation system have strong oxidizability, are favorable for decomposing pigment radicals in hard tissues of teeth, and achieve the whitening effect. Meanwhile, the oxygen free radical has strong activity, fast reaction and less effect of exceeding a long distance, so that the pulp tissue is not easy to be damaged theoretically.

Disclosure of Invention

Aiming at the adverse reactions and problems in the prior art, the invention provides the efficient and safe non-hydrogen peroxide tooth whitening gel by combining the advantages of a persulfate activation system, which realizes good tooth whitening effect, has higher biological safety and less stimulation to dental pulp tissues.

The technical scheme of the invention is as follows:

the tooth whitening gel comprises an oxidant, an activator, a thickener and water, and the components in parts by mass are as follows: 5-25% of oxidant, 10-35% of activator, 5-10% of thickener and 40-60% of water.

The further technical proposal is that the oxidant is peroxymonosulfate or peroxydisulfate.

The further technical proposal is that the peroxymonosulfate is potassium peroxymonosulfate, sodium peroxymonosulfate or combination thereof; the peroxydisulfate salt is potassium peroxydisulfate, sodium peroxydisulfate or a combination thereof.

The further technical scheme is that the activating agent is phosphate buffer solution, and the phosphate is one or a mixture of more of tripolyphosphate, pyrophosphate, hexametaphosphate, dihydrogen phosphate and dihydrogen phosphate.

The further technical proposal is that the tripolyphosphate comprises sodium tripolyphosphate, potassium tripolyphosphate or a combination thereof; the pyrophosphate comprises sodium pyrophosphate, potassium pyrophosphate or a combination; the hexametaphosphate comprises sodium hexametaphosphate, potassium hexametaphosphate or a combination; the dihydric phosphate comprises potassium dihydrogen phosphate, sodium dihydrogen phosphate or a combination thereof; the dibasic phosphate salts include dibasic potassium phosphate, dibasic sodium phosphate or combinations thereof.

The technical scheme is that the activating agent is used after monobasic phosphate and dibasic phosphate are dissolved into neutral buffer solution according to a certain proportion. For example, 2g of disodium hydrogen phosphate and 0.22g of potassium dihydrogen phosphate are dissolved in 100mL of deionized water, and the pH is adjusted to neutral.

The further technical scheme is that the pyrophosphate, the tripolyphosphate and the hexametaphosphate in the activating agent can be respectively or compositely dissolved in deionized water for subsequent use, and the mass ratio of the activating agent to the water is (0.03-0.3): 1.

preferably, the oxidizing agent is potassium peroxymonosulfate, the activating agent is potassium dihydrogen phosphate-disodium hydrogen phosphate buffer solution, and the mixture ratio by mass fraction is (0.04-0.16): 1. potassium monopersulfate is a green oxidant emerging in recent years, has stable properties in general states, and has no obvious oxidation effect when being reacted with organic matters alone. Belongs to peroxide with asymmetric structure, and researches show that the neutral phosphate anion buffer solution can effectively activate persulfate.

Preferably, the oxidant is potassium hydrogen peroxymonosulfate, the activator is sodium pyrophosphate solution, sodium tripolyphosphate solution or combination, and the mass fraction ratio is (0.06-0.25): 1. sodium pyrophosphate and sodium tripolyphosphate both belong to polyphosphate, the formed activating agent is alkaline solution containing phosphate radical ions, and persulfate can be effectively activated under the conditions of normal temperature and normal pressure.

The further technical scheme is that the thickening agent is one or more of silicon dioxide, sodium alginate or sodium carboxymethylcellulose, and accounts for 5% -10% by mass. The thickening agent gives the gel good rheological property, has a certain adhesion effect on the tooth surface, is beneficial to operation and avoids contact damage to gingival tissues or mucous membranes.

The tooth whitening gel provided by the invention is prepared according to the following steps: dissolving the corresponding phosphate in deionized water, fully dissolving by using a magnetic stirrer at the rotating speed of 300-350r/min, stirring for 5-10min to form an activating agent, and then performing reaction according to the formula (4-25): 1 and the oxidant, adding the thickening agent, mixing, stirring uniformly, and standing to obtain the catalyst.

Specifically, the tooth whiteness can be improved by coating the prepared tooth whitening gel on the surface of enamel for 45min after a single action. The action mechanism of the tooth whitening gel is that a large number of oxygen free radical components are generated by activating persulfate, dyeing groups are effectively degraded, and the whitening of teeth is realized. Compared with the prior art, the invention has the following advantages: the prepared whitening gel does not contain hydrogen peroxide substances, and can achieve good whitening effect and reduce irritation to dental pulp and damage to hard tissues of teeth.

Drawings

In order to more clearly illustrate the features of particular embodiments of the present invention, reference will now be made in brief to the accompanying drawings of embodiments. It is to be understood that the drawings described below are merely exemplary of the invention and that other similar drawings may be obtained by those of ordinary skill in the art without the exercise of inventive faculty.

FIG. 1 is a graph showing the results of experiments on degraded tea liquids of gel groups A to G in example 8;

FIG. 2 is a graph showing the results of experiments in which groups D-G of gels in example 9 degrade acid orange dye;

fig. 3 is a graph showing the whitening effect of the tooth whitening gel obtained in example 10 on tea-stained teeth;

fig. 4 is a graph showing color value changes of the tooth whitening gel obtained in example 10 after it is applied to tea-stained teeth;

FIG. 5 is a schematic view of a stent device for obtaining whitening gel permeate in example 11;

FIG. 6 is a graph showing a comparison of apoptosis rates of human dental pulp cells cultured in the tooth whitening gel obtained in example 11 and a commercially available hydrogen peroxide gel permeation solution, respectively;

fig. 7 is a scanning electron micrograph of the tooth whitening gel of example 12 after it has been applied to the enamel surface with a commercially available hydrogen peroxide gel.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. The experimental procedures used in the following examples are all conventional procedures unless otherwise specified. Materials, reagents and the like used in the following examples are commercially available unless otherwise specified. It is to be understood that the described embodiments are merely a few, but not all, applications of the invention. It should be understood that these examples are only for illustrating the characteristics of the present invention and are not intended to limit the scope of the present invention. All other embodiments obtained by a person skilled in the art without making any inventive step are within the scope of protection of the present invention.

Example 1.

Dissolving 2g of disodium hydrogen phosphate and 0.22g of potassium dihydrogen phosphate in 100mL of deionized water, fully dissolving by using a magnetic stirrer at the rotation speed of 300-350r/min, stirring for 5-10min, adjusting the pH value to 7.2-7.5 to obtain an activating agent, fully reacting 5mL of the activating agent with 0.8g of potassium hydrogen peroxymonosulfate, adding 0.4g of silicon dioxide, mixing, uniformly stirring, standing to obtain the gel A.

Example 2.

Dissolving 0.3g of sodium pyrophosphate in 5mL of deionized water, fully dissolving by using a magnetic stirrer at the rotating speed of 300-350r/min, stirring for 5-10min to form an activating agent, fully reacting with 1.2g of potassium hydrogen peroxymonosulfate, adding 0.4g of silicon dioxide, mixing, uniformly stirring, and standing to obtain the gel B.

Example 3.

Dissolving 1g of sodium tripolyphosphate in 5mL of deionized water, fully dissolving by using a magnetic stirrer at the rotating speed of 300-350r/min, stirring for 5-10min to form an activating agent, fully reacting with 1.2g of potassium hydrogen peroxymonosulfate, adding 0.8g of sodium alginate, mixing, uniformly stirring, and standing to obtain the gel C.

Example 4.

Dissolving 0.15g of sodium pyrophosphate and 0.7g of sodium tripolyphosphate in 5mL of deionized water, fully dissolving by using a magnetic stirrer at the rotation speed of 300-350r/min, stirring for 5-10min to form an activating agent, fully reacting with 1.2g of potassium hydrogen peroxymonosulfate, adding 0.4g of silicon dioxide, mixing, uniformly stirring, and standing to obtain the gel D.

Example 5.

Dissolving 0.2g of sodium pyrophosphate and 0.8g of sodium tripolyphosphate in 5mL of deionized water, fully dissolving by using a magnetic stirrer at the rotation speed of 300-350r/min, stirring for 5-10min to form an activating agent, fully reacting with 1.2g of potassium hydrogen peroxymonosulfate, adding 0.4g of silicon dioxide, mixing, uniformly stirring, and standing to obtain the gel E.

Example 6.

Dissolving 0.25g of sodium pyrophosphate and 0.9g of sodium tripolyphosphate in 5ml of deionized water, fully dissolving by using a magnetic stirrer at the rotation speed of 300-350r/min, stirring for 5-10min to form an activating agent, fully reacting with 1.2g of potassium hydrogen peroxymonosulfate, adding 0.4g of silicon dioxide, mixing, uniformly stirring, and standing to obtain the gel F.

Example 7.

Dissolving 0.3G of sodium pyrophosphate and 1G of sodium tripolyphosphate in 5mL of deionized water, fully dissolving by using a magnetic stirrer at the rotating speed of 300-350r/min, stirring for 5-10min to form an activating agent, fully reacting with 1.2G of potassium peroxymonosulfate, adding 0.4G of silicon dioxide, mixing, uniformly stirring, and standing to obtain the gel G.

Example 8.

Adding 5g of freshly prepared Keemun black tea into 250mL of deionized water, boiling for 5min, stopping heating, supplementing the solution to 250mL, cooling at room temperature, and filtering with filter paper with the aperture of 30-50mm to obtain a 2% tea solution for experiments.

The decolorization effect of the gel A-G group after 45min with 2% tea solution is shown in figure 1, and the better decolorization effect of the gel D-G group can be seen.

Example 9.

500ul of gel D-G was reacted with 0.30M acid orange solution to obtain the respective degradation kinetics curves, as shown in FIG. 2. This example illustrates that the prepared tooth whitening liquid gel can effectively oxidize and degrade the organic dye of acid orange, and further defines the preferable gel proportion, and fig. 2 shows that the degradation efficiency of gel G is the best.

Example 10.

Selecting fresh bovine incisors with complete shapes, normal enamel development, no caries, hidden cracks and defects, removing soft tissues, dental calculus and pigments, preparing an enamel intrinsic block with the length and width of about 6mm and the thickness of about 3-4mm by a hard tissue cutting machine, soaking the enamel intrinsic block in the 2% tea solution for 10 days, and polishing the surface of the enamel intrinsic block by pumice to obtain 40 tea-dyed tooth blocks which are respectively put into a gel G group and a commercially available HP gel group (Opalescence Boost 38% hydrogen peroxide gel).

The gel of each group was coated on the enamel surface of the tea-stained tooth mass for 45min, and then photographed and subjected to color comparison by a vita color comparator, and the whitening effect graph is shown in fig. 3.

The values of L, a and b measured by the Vita colorimeter are determined according to the formula { (Δ L)²+(Δa)²+(Δb)²}^1/2The color difference before and after bleaching was calculated, Δ L represents the difference between L before and after bleaching, Δ a represents the difference between a before and after bleaching, and Δ b represents the difference between b before and after bleaching. The greater the color difference Δ E, the higher the bleaching performance, and the two results are shown in fig. 4, where gel G has similar whitening effect to HP gel.

Example 11.

As shown in fig. 5, the enamel proof mass 3 was placed on the enamel proof frame 1 and then placed on the walls 4 of the 24-well plate hole. The tooth whitening gel 2 described herein is applied to the surface of the enamel mass 3 such that the enamel mass 3 is entirely immersed in the culture solution 5. The penetrating fluid is used for detecting the apoptosis level of the dental pulp cells (Annexin V/PI double staining method), the result is shown in figure 6, the HP bleached gel penetrating fluid has obvious toxicity to the dental pulp cells, the apoptosis level of the cells is obviously improved after 30min and 2h of co-culture, and the biocompatibility of the gel G is good.

Example 12.

Gel G or commercially available HP gel is coated on enamel surface and removed after 45min, the surface of a tooth block is plated with gold after dehydration, and SEM detection is carried out, wherein the voltage is 5kV, and the magnification is 20000 times. The results are shown in fig. 7, where the gel G group enamel showed no significant demineralization and the surface was smooth and flat and close to normal enamel. The HP gel group has rough enamel surface and obvious demineralization.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A tooth whitening gel, characterized in that it comprises, in mass fraction:

5% -25% of an oxidant;

10 to 35 percent of activating agent;

5% -10% of a thickening agent; and

the balance being water.

2. The tooth whitening gel of claim 1, wherein the oxidizing agent is peroxymonosulfate or peroxydisulfate.

3. The tooth whitening gel of claim 2, wherein the peroxymonosulfate salt is potassium peroxymonosulfate, sodium peroxymonosulfate, or a combination thereof; the peroxydisulfate salt is potassium peroxydisulfate, sodium peroxydisulfate or a combination thereof.

4. The tooth whitening gel of claim 1, wherein the activator is a phosphate buffer, and the phosphate is one or more selected from the group consisting of tripolyphosphate, pyrophosphate, hexametaphosphate, dihydrogen phosphate, and dihydrogen phosphate.

5. The tooth whitening gel according to claim 4, wherein the phosphate buffer solution comprises phosphate and a solvent in a mass ratio of (0.03-0.3): 1.

6. the tooth whitening gel according to claim 4, wherein the tripolyphosphate is one or a mixture of sodium tripolyphosphate and potassium tripolyphosphate; the pyrophosphate is one or a mixture of sodium pyrophosphate and potassium pyrophosphate; the hexametaphosphate is one or a mixture of sodium hexametaphosphate and potassium hexametaphosphate; the dihydric phosphate is one or a mixture of potassium dihydrogen phosphate and sodium dihydrogen phosphate; the dibasic phosphate is one or a mixture of dipotassium phosphate and disodium phosphate.

7. The tooth whitening gel of claim 1, wherein the thickening agent is a mixture of one or more of silicon dioxide, sodium alginate, or sodium carboxymethylcellulose.

8. The tooth whitening gel according to claim 1, wherein the mass ratio of the activator to the oxidizing agent is (4-25): 1.

9. a method of preparing the tooth whitening gel of claim 1, comprising the steps of:

dissolving phosphate in a solvent to obtain a phosphate buffer as an activator;

and (3) after the activator and the oxidant fully react, adding the thickening agent, mixing, uniformly stirring, and standing to obtain the tooth whitening gel.

10. Use of the tooth whitening gel of claim 1 for tooth whitening.