CN112972274A

CN112972274A - Dental desensitizer and preparation method and application thereof

Info

Publication number: CN112972274A
Application number: CN202110134136.1A
Authority: CN
Inventors: 蓝咏; 刘玉
Original assignee: Guangzhou Bioscience Co ltd
Current assignee: Guangzhou Bioscience Co ltd
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2021-06-18

Abstract

The invention discloses a dental desensitizer, and relates to the technical field of biomedical engineering materials. The dental desensitizer comprises the following components: sodium fluoride, potassium nitrate, LL-37 antibacterial peptide, sodium carboxymethylcellulose-modified dopamine and methacrylic acid gelatin. The dental desensitizer prepared from the components disclosed by the invention has good antibacterial and dentin tubule sealing effects. The photo-curing technology is adopted to apply the anti-sensitivity paste on the surface of teeth, so that the anti-sensitivity effect of the teeth can be rapidly improved.

Description

Dental desensitizer and preparation method and application thereof

Technical Field

The invention relates to the technical field of biomedical engineering materials, in particular to a dental desensitizer and a preparation method and application thereof.

Background

Dentine hypersensitivity is also called as hypersensitive dentin, which is an abnormal aching pain symptom caused by external stimulation such as temperature (cold and heat), chemical substances (sour and sweet), mechanical friction (abrasion and hard biting) and the like, and is characterized by rapid onset, sharp pain and short time, the first dentin hypersensitivity epidemiological investigation in China shows that the incidence of dentine hypersensitivity of adults is 8-30%, and the adult dentine hypersensitivity is a high-incidence population about 40 years old and is a common disease and a frequently encountered disease in oral clinic. Oral diseases caused by dentine hypersensitivity are more widely involved. Such as: wedge-shaped defects, periodontal atrophy tooth root exposure, tooth body trauma and dentin exposure, severe abrasion, tooth preparation, cavity preparation, tooth washing, scaling, tooth discoloration, jaw adjustment and the like.

There are many types of tooth desensitizers used clinically, and there are no specific classification criteria to guide clinical application. Depending on the main mechanism of action of the drug desensitizer, it can be classified into: inductive desensitizers, corrosive desensitizers, occlusive desensitizers, covering desensitizers, and blocking inhibitory desensitizers. For example, sodium fluoride desensitization, with 75% sodium fluoride glycerol as the major ingredient, was an earlier clinical desensitizing agent. The main principle is that fluoride ions permeate into hard tissues of teeth to be combined with calcium salt to form calcium fluorapatite deposition, so as to seal dentinal tubules or reduce the diameter of the dentinal tubules and promote secondary dentin formation. Because the permeability of restorative dentin is lower than that of primary dentin, it can protect dental pulp against irritation. However, the effect is not satisfactory through years of clinical observation.

In addition, the types of the existing anti-sensitivity toothpaste are more, and the research on all aspects of the anti-sensitivity toothpaste is greatly advanced. Because the anti-sensitive toothpaste is convenient to use and low in price, the anti-sensitive toothpaste can prevent and treat dentin hypersensitivity in daily life, and is the first choice of many patients. Common anti-sensitivity toothpastes are: sodium fluoride, sodium monofluorophosphate, potassium nitrate, strontium fluoride, oxalate and the like. Clinical observation shows that the DH has definite curative effect, and in vivo and in vitro experiments show that the DH can seal most dentinal tubules when being used for brushing teeth. Anti-sensitivity toothpaste offers the distinct advantages of ease of use and economy over other desensitization methods, but also has significant disadvantages: has slow effect, debates on the curative effect at present, has long treatment course and is not as instant as other methods.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a dental desensitizer, a preparation method and application thereof.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a dental desensitizer comprising the following ingredients: sodium fluoride, potassium nitrate, LL-37 antibacterial peptide, sodium carboxymethylcellulose-modified dopamine and methacrylic acid gelatin.

Potassium nitrate and sodium fluoride are functional components of a dental desensitizer, soluble potassium salt can depolarize nerve fibers and reduce the sensitivity of nerves, and free inorganic salt ions are redeposited on the surface of enamel in the form of low-solubility fluorapatite or fluorhydroxyapatite by combining with a classical remineralization medicament fluoride to promote enamel remineralization. In addition, sodium fluoride can play a role in preventing caries in toothpaste. Research shows that the fluorine-containing toothpaste has a certain caries preventing effect and can reduce the caries rate by 28 percent at most.

Antimicrobial peptides (AMPs) are a class of active polypeptides that are induced by the biological immune system. Can be used for resisting infection of various pathogens. Compared with the traditional antibiotics, AMPs have the advantages of wide antibacterial spectrum, high antibacterial activity and the like. LL-37 peptides are members of the Cathelicidin family of peptides and are known as being composed of 37 amino acids. LL-37 antibacterial peptide is expressed and secreted in various epithelial cells, immune cells, body fluid, wound secretion and the like in a human body, can exert antimicrobial activity, participates in the immune regulation of the body and promotes the wound repair, and is an active small molecular peptide with multiple functions except killing free bacteria. LL-37 antibacterial peptide can also inhibit Staphylococcus epidermidis, Pseudomonas aeruginosa, Acinetobacter baumannii, etc. in the form of biomembrane. According to the report of LL-37 antibacterial peptide and the relation between LL-37 antibacterial peptide and periodontal disease, LL-37 antibacterial peptide can effectively identify periodontal pathogenic bacteria in time, prevent and kill pathogenic bacteria from invading epithelial cells, neutralize LPS, reduce damage to periodontal tissues, chemotaxis immune cells and participate in immune defense reaction of organisms; some systemic disease patients lacking LL-37 antimicrobial peptide may be associated with severe periodontal tissue destruction.

Gelatin is a high polymer derived from collagen, has good biocompatibility and biodegradability, and is low in cost and biosafety. Therefore, gelatin is widely used in pharmaceutical and medical applications. The methacrylated gelatin is a photosensitive biological hydrogel, is obtained by the reaction of gelatin and methacrylic anhydride, has excellent biocompatibility, is rapidly cured under visible light or ultraviolet light to form a three-dimensional structure which is suitable for cell growth and has strength, and is widely applied to the fields of tissue engineering and regenerative medicine. However, the mere photocuring of methacrylated gelatin has poor adhesion and limited its use.

The natural cellulose is polysaccharide which is most widely distributed and contained in nature, and has abundant sources. Current cellulose modification technologies focus primarily on both etherification and esterification. Carboxymethylation is one of the etherification techniques. Carboxymethyl cellulose sodium (CMC-Na) is obtained after carboxymethylation of cellulose. Sodium carboxymethylcellulose (CMC-Na) is an anionic polymer compound and is white flocculent powder in appearance. It is odorless, nontoxic, tasteless, and easily soluble in water. The sodium carboxymethyl cellulose water solution is a transparent liquid, is stable to light and heat, and has strong hygroscopicity and film-forming property.

Dopamine (DOPA) is an important component of adhesion proteins secreted by marine mussels, and it contains catechol (catechol) units that play an important role in the function of adhesion of mussels to wet surfaces. The catechol-containing materials may serve as an adhesive, finishing and anchoring means, which may strongly bond a variety of inorganic and organic surfaces.

The sodium carboxymethylcellulose modified dopamine (CMC-Na-DA) has a mussel-like functional group and can increase the adhesion of a system. The system can realize injectability at the early stage of adding the cross-linking agent.

The applicant of the invention finds out through experiments that the dental desensitizer prepared from the materials has excellent effect of sealing dentinal tubules and has good antibacterial property.

Preferably, the dental desensitizer comprises the following components in parts by weight: 0.01-0.04 part of sodium fluoride, 0.1-0.5 part of potassium nitrate, 0.01-0.05 part of LL-37 antibacterial peptide, 0.03-0.08 part of sodium carboxymethylcellulose-modified dopamine and 0.8-1.2 parts of methacrylic acid gelatin.

Further preferably, the dental desensitizer comprises the following components in parts by weight: 0.02-0.03 part of sodium fluoride, 0.2-0.4 part of potassium nitrate, 0.01-0.03 part of LL-37 antibacterial peptide, 0.04-0.06 part of sodium carboxymethylcellulose-modified dopamine and 0.9-1.1 parts of methacrylic acid gelatin.

Preferably, the dental desensitizer also comprises 0.01-0.05 part of photoinitiator. The applicant has found that when a dental desensitizer is applied to the surface of a tooth by photocuring, the resistance of the tooth is rapidly increased.

In addition, the invention also discloses a preparation method of the dental desensitizer, which comprises the following steps:

(1) preparing methacrylated gelatin;

(2) preparing sodium carboxymethylcellulose modified dopamine;

(3) dissolving methacrylated gelatin and sodium carboxymethylcellulose-modified dopamine in water, then adding sodium fluoride, potassium nitrate, LL-37 antibacterial peptide and a photoinitiator, and stirring to obtain the dental desensitizer.

Preferably, in the step (1), the preparation method of the methacrylated gelatin comprises the following steps: dissolving gelatin in water, adding methacrylic anhydride, reacting for 3-5 h at 45-55 ℃, dialyzing for 5-7 days with distilled water, carrying out cutoff molecular weight of a dialysis bag to 3000-4000, and freeze-drying at-85-75 ℃ to obtain the methacrylic acid gelatin.

Preferably, in the step (2), the preparation method of the sodium carboxymethyl cellulose modified dopamine comprises the following steps: adding sodium carboxymethylcellulose into water, introducing inert gas or nitrogen, adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) after the sodium carboxymethylcellulose is completely dissolved, uniformly stirring, adding dopamine hydrochloride, adjusting the pH of a reaction system to 5-6 by using a pH regulator, reacting at room temperature for 10-15 h, dialyzing for 2-3 days by using distilled water, intercepting the molecular weight of a dialysis bag to 9000-11000, and freeze-drying at-85 to-75 ℃ to obtain the sodium carboxymethylcellulose modified dopamine.

Meanwhile, the invention also discloses a use method of the dental desensitizer, which comprises the following steps: the dental desensitizer is coated on the surface of a tooth and is cured by ultraviolet light, the curing time of the ultraviolet light is 10-30 s, and the power of an ultraviolet lamp is 1.8-2.2W/cm²。

Compared with the prior art, the invention has the beneficial effects that:

(1) sodium fluoride, potassium nitrate and LL-37 antibacterial peptide are used as functional components, so that the desensitizer has desensitizing, caries preventing and antibacterial functions.

(2) The components are compounded with the methacrylic acid gelatin and the sodium carboxymethylcellulose modified dopamine, so that the anti-sensitivity effect of teeth is synergistically improved.

(3) The preparation method is simple, the required raw materials are easy to obtain and the components are low, the problem of tooth ache and other allergy of a tooth allergy patient is solved, and the preparation method has obvious clinical significance.

(4) The desensitizer can stay on the tooth surface for a long time by a light curing method.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

Examples 1 to 5

In the embodiment of the dental desensitizer, the formula of the embodiment 1-5 is shown in table 1, and the preparation method comprises the following steps:

(1) preparation of methacrylated gelatin: 10g of gelatin was dissolved in 100mL of distilled water at 50 ℃ and then 6mL of methacrylic anhydride was added, followed by reaction at 50 ℃ for 4 hours, dialyzed against distilled water for 6 days (molecular weight cut-off: 3500), and lyophilized at-80 ℃ to obtain methacrylated gelatin (GelMA).

(2) Preparing sodium carboxymethylcellulose modified dopamine: dissolving 1g of sodium carboxymethylcellulose in 100mL of deionized water, introducing nitrogen, slowly adding 575mg of EDC and 345mg of NHS into the solution after the sodium carboxymethylcellulose is completely dissolved, stirring for 20min, then adding 569mg of dopamine hydrochloride into the mixed solution, adjusting the pH of the solution to be 5-6, reacting for 12h at room temperature, dialyzing for 3 days with distilled water (molecular weight cut-off: 10000), and freeze-drying at-80 ℃ to obtain sodium carboxymethylcellulose modified dopamine (CMC-NA-DA).

(3) And dissolving GelMA, CMC-NA-DA, a photoinitiator LAP, sodium fluoride, potassium nitrate and LL-37 antibacterial peptide into 10mL of deionized water to obtain the dental desensitizer, and storing at 4 ℃ for later use.

Comparative examples 1 to 4

Comparative examples 1 to 4 are dental desensitizers, the formulations of which are shown in table 1, and the preparation methods are the same as in the examples.

Comparative example 5

A dental desensitizer which differs from example 3 only in that sodium carboxymethylcellulose-modified dopamine is replaced with dopamine.

TABLE 1 formula of dental desensitizer table (g)

Performance testing

(1) Photocuring time and peel strength testing

The examples 1 to 5 and the comparative examples 1 to 5 were respectively dropped into a 2cm × 5cm glass mold, followed by curing with ultraviolet light under the following conditions: ultraviolet light for 30s and ultraviolet lamp power of 2W/cm². The photocuring time was recorded and the test results are recorded in table 2.

The peel strength was tested according to the GB 2792-81 standard and the test results are reported in Table 2.

TABLE 2 Cure time and Peel Strength test results

As can be seen from Table 2, the photocuring time of examples 1 to 5, comparative examples 1 to 3 and comparative example 5 was within 30 seconds, and the requirements for clinical use were satisfied with almost no difference. As for the peel strength, the peel strength of examples 1 to 5 and comparative examples 2 to 3 was maintained at 2 to 4 N.mm^-1Whereas comparative example 1, comparative example 4 and comparative example 5 had no adhesion and a peel strength of 0. Comparative example 4, the CMC-NA-DA is present in excess of the system, resulting in no cure of the system.

(2) Dentinal tubule occlusion Rate test

The examples 1 to 5 and comparative examples 1 to 5 were applied to the surface of a test dentin block (3mm × 4mm × 4mm), i.e., dentin surface, with a disposable small brush, and the entire area was back and forth coated for about 15 seconds, a dental desensitizer was gently blown down, followed by curing with ultraviolet light under the photocuring conditions: ultraviolet light for 30s and ultraviolet lamp power of 2W/cm². Each set of samples was coated with 5 pieces of dentin. The statistical method of dentin tubule occlusion rate is as follows:

and counting the total number of dentinal tubules of the dentinal modules of the blank control group under the same magnification view field, taking the counted number as a base number, calculating the total number of the unclosed dentinal tubules of each group of dentinal modules under the same magnification view field, calculating the dentinal tubule blocking rate, and recording the rate in the table 3.

TABLE 3 dentinal tubule occlusion ratio (%)

Dentinal hypersensitivity is usually caused by erosion, abrasion or abrasion, gingival recession, periodontal treatment, and the like. The hydrodynamics first presented in 1960 suggested that it was the exposed dentinal tubules that were stimulated to initiate the flow of dentinal tubule fluid that ultimately caused pain. Based on the principle, most of the desensitizing materials used clinically at present use inorganic materials, such as fluoride, oxalate and the like, to seal dentinal tubules by deposition. The dentinal tubule blocking rate is an important in vitro index for evaluating the dental desensitizer, and the industry generally requires that the dentinal tubule blocking rate of the dental desensitizer is more than or equal to 70 percent, so that the dental desensitizer belongs to an effective dental desensitizer.

As can be seen from Table 3, the dentinal tubule blocking rate of the examples 1-5 is obviously higher than that of the comparative examples 1-5, and the dentinal tubule blocking rate of the examples 1-5 is more than 75%, which indicates that the dental desensitizer prepared by the formula provided by the invention has good desensitizing effect.

(3) Fluoride ion concentration test

The dental desensitizers prepared in examples 1 to 5 and comparative examples 3 to 5 were tested for fluoride ion concentration. The test method is carried out according to the specification of 2.4.4.1 method I in YY 0623 + 2008 < determination method for dissolving out fluorine from dental material >, 1.0g of sample is weighed in a 100ml volumetric flask, 20ml of total ion intensity adjusting buffer solution is added, deionized water is added to dilute the sample to a scale, the sample is placed in (37 +/-1) DEG C water for about 5min, and the sample is detected by a fluorine ion concentration meter. Table 4 shows the results of the fluoride ion concentration test.

Table 4 fluoride ion concentration (wt.%)

Item	Fluoride ion concentration/wt. -%)
		Example 1	0.048
Example 2	0.096
		Example 3	0.12
Example 4	0.144
		Example 5	0.144

As can be seen from table 4, the fluoride ion concentrations were all greater than 0.04 wt.% and less than 0.15%. Research shows that when a small amount of sodium fluoride is added into gargle or toothpaste, caries can be reduced by 40%, and fluorine has an inhibiting effect on acid-producing bacteria. It can inhibit the storage of polysaccharide in cariogenic streptococcus cell, and influence the growth and reproduction of bacteria; inhibit exopolysaccharide synthesis by streptococcus cariogenic, and reduce adhesion of bacteria and plaque on tooth surface. In addition, fluorine can promote remineralization of enamel that has been demineralized at the initial stage of caries. However, prolonged ingestion of high doses of fluoride may lead to neurological disorders and malfunction of the endocrine system. In toothpaste or dental desensitizers, the upper limit of use for the fluoride ion concentration is 0.15%. In conclusion, the addition amount of the sodium fluoride in the range disclosed by the invention can effectively prevent caries and avoid the stimulation of fluoride to nerves.

(4) Antibacterial property test

Zone of inhibition experiments adopted standards established by the american Clinical and Laboratory Standards Institute (CLSI), detailed procedures: sterilizing a laboratory clean bench, and starting ultraviolet irradiation for 30min before operation. Then, 100. mu.L of the E.coli or S.aureus bacterial suspension was dropped onto the solid LB medium and spread on a spreading barThe surface is coated evenly. Subsequently, examples 1 to 5 and comparative examples 1 to 5 were dropped on the culture medium to form droplets of 1cm × 1cm, respectively, and cured with an ultraviolet lamp under the following conditions: ultraviolet light for 30s and ultraviolet lamp power of 2W/cm². The dental desensitizer after photocuring is pasted on the culture medium, and after 15min, the culture dish is placed back to a biochemical incubator at 37 ℃ for inverted culture, wherein the culture time is 24 h. The medium was removed and the size of the zone of inhibition and the growth of the bacteria were observed, and three replicates of each group were taken and the average values recorded in table 5.

Table 4 antibacterial property test results

As can be seen from Table 4, comparative examples 1 to 3 had no antibacterial activity, while examples 1 to 5 had good antibacterial activity against both Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative). By integrating the test results of dentinal tubule occlusion rate, fluoride ion concentration, antibacterial property and the like, examples 2 to 4 are relatively better formulas.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A dental desensitizer comprising the following components: sodium fluoride, potassium nitrate, LL-37 antibacterial peptide, sodium carboxymethylcellulose-modified dopamine and methacrylic acid gelatin.

2. A dental desensitizer according to claim 1, comprising the following ingredients in parts by weight: 0.01-0.04 part of sodium fluoride, 0.1-0.5 part of potassium nitrate, 0.01-0.05 part of LL-37 antibacterial peptide, 0.03-0.08 part of sodium carboxymethylcellulose-modified dopamine and 0.8-1.2 parts of methacrylic acid gelatin.

3. A dental desensitizer according to claim 2, comprising the following ingredients in parts by weight: 0.02-0.03 part of sodium fluoride, 0.2-0.4 part of potassium nitrate, 0.01-0.03 part of LL-37 antibacterial peptide, 0.04-0.06 part of sodium carboxymethylcellulose-modified dopamine and 0.9-1.1 parts of methacrylic acid gelatin.

4. A dental desensitizer according to claim 2, further comprising 0.01 to 0.05 parts of a photoinitiator.

5. A method of preparing a dental desensitizer according to claim 4, including the steps of:

(1) preparing methacrylated gelatin;

(2) preparing sodium carboxymethylcellulose modified dopamine;

6. A method of preparing a dental desensitizer according to claim 5, wherein in step (1), methacrylated gelatin is prepared by: dissolving gelatin in water, adding methacrylic anhydride, reacting for 3-5 h at 45-55 ℃, dialyzing for 5-7 days with distilled water, carrying out cutoff molecular weight of a dialysis bag to 3000-4000, and freeze-drying at-85-75 ℃ to obtain the methacrylic acid gelatin.

7. The method of preparing a dental desensitizer according to claim 5, wherein in step (2), the sodium carboxymethylcellulose-modified dopamine is prepared by: adding sodium carboxymethylcellulose into water, introducing inert gas or nitrogen, adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide after the sodium carboxymethylcellulose is completely dissolved, uniformly stirring, adding dopamine hydrochloride, adjusting the pH of a reaction system to 5-6 by using a pH regulator, reacting for 10-15 h at room temperature, dialyzing for 2-3 days by using distilled water, and freeze-drying at-85 to-75 ℃ to obtain the sodium carboxymethylcellulose modified dopamine.

8. A method of use of a dental desensitizer according to claim 4, wherein the dental desensitizer is applied to the tooth surface and subsequently cured with UV light.

9. The use of claim 8, wherein the UV curing time is 10-30 s, and the power of the UV lamp is 1.8-2.2W/cm²。