High-antibacterial oral sealant for treating dentin hypersensitivity and preparation method and application thereof

Abstract

This invention discloses a highly antibacterial oral sealant for treating dentin hypersensitivity, its preparation method, and its application. The sealant's raw materials include calcium oxalate, diammonium hydrogen phosphate, tetraethyl orthosilicate, and cerium nitrate hexahydrate. It is a bioactive material that can generate hydroxyapatite in a short time and exhibits good biocompatibility. This sealant regulates and stabilizes Ce... 3+ Ce 4+ The ratio of these components results in high antibacterial properties, making it suitable for use as an oral sealant. It primarily works by sealing the gaps between the pits and fissures of teeth to block bacterial invasion, thereby improving the acid resistance of tooth enamel and preventing cavities. At the same time, this material has good bactericidal properties, allowing for deeper bacterial removal and ensuring a clean oral environment.

Description

Technical Field

[0001] This invention relates to the field of biomaterials technology, specifically to a highly antibacterial oral sealant for treating dentin hypersensitivity, its preparation method, and its application. Background Technology

[0002] Currently, with the improvement of national strength, people's living standards have been greatly improved, the variety of food has become more and more abundant, and there are endless condiments on the market, as well as a full range of cold drinks and desserts. As a result, modern people often experience a variety of oral problems.

[0003] Dentin hypersensitivity (DH) is a common symptom and disease in the oral cavity. When exposed to temperature, air, mechanical, osmotic, or chemical stimuli, the exposed dentin experiences short, sharp pain, significantly impacting the patient's quality of life. As the risk factors for its development show, patients with DH can be encountered in all clinical departments of dentistry, but the incidence is relatively higher in prosthodontics, where the clinical need for effective treatment of DH is most urgent. Currently, sealing exposed dentinal tubules and reducing the excitability of the dental pulp nerve are the two main methods for treating dentin hypersensitivity. Bioactive glass is a type of biocompatible artificial biomaterial capable of repairing, replacing, and regenerating body tissues, initially used for bone repair and regeneration. In recent years, more and more scholars have applied bioactive glass to the prevention and treatment of oral diseases, and related clinical studies have shown that its desensitizing effect is superior to traditional desensitizing materials to some extent.

[0004] However, all materials used in tissue engineering for implants or scaffolds are susceptible to microbial contamination and colonization. In the case of intraosseous or intraoral implants, bacterial biofilms can gradually form on the implant surface. Delivering active antimicrobial substances at the interface with host tissue (the site of initial microbial infection) may be one of the most important actions to combat biomaterial-associated infections. Most infections develop from early contamination, disrupting the healing process. To reduce initial bacterial adhesion and thus prevent subsequent biofilm formation, bioactive materials with high antimicrobial properties, mimicking bioactive glass, are being manufactured to clinically protect patients from bacterial infections that could cause bodily damage.

[0005] Therefore, it is necessary to design a highly antibacterial and bioactive oral sealant to solve the above-mentioned technical problems. Summary of the Invention

[0006] In order to overcome the problems existing in the prior art, one of the objectives of the present invention is to provide a method for preparing a highly antibacterial oral sealant for treating dentin hypersensitivity.

[0007] The second objective of this invention is to provide a highly antibacterial oral sealant for treating dentin hypersensitivity.

[0008] A third objective of this invention is to provide the application of the aforementioned highly antibacterial oral sealant for treating dentin hypersensitivity.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A method for preparing a highly antibacterial oral sealant for treating dentin hypersensitivity includes the following steps:

[0011] (1) Preparation of premixed solution:

[0012] Solution A: Add tetraethyl orthosilicate, anhydrous ethanol, and deionized water to a container in sequence, then add cerium nitrate hexahydrate, stir well, adjust the pH to 1-2 with nitric acid, and after the pH is stable, add calcium oxalate and stir well to obtain solution A.

[0013] Solution B: Add deionized water, diammonium hydrogen phosphate, and calcium oxalate to a container in sequence, stir well, and you will get solution B.

[0014] (2) Preparation of cerium-doped apatite / calcium silicate composite bioactive glass:

[0015] Add solution B to solution A, stir to form a white slurry, place in an oven to dry slightly, crush and continue to place in the oven, then keep warm in a muffle furnace, and finally take it out and cool it rapidly to obtain cerium-doped apatite / calcium silicate composite bioactive glass.

[0016] Further, in step (1), the molar ratio of cerium nitrate hexahydrate to calcium oxalate is 1:8 to 100; preferably 1:9 to 99.

[0017] Further, in step (1), based on the amount of deionized water being 40 mL, the amounts of tetraethyl orthosilicate and anhydrous ethanol are 20-25 g and 20-25 g, respectively, preferably 20.833 g and 23.035 g; the amount of cerium nitrate hexahydrate is 0.1-25 g, preferably 1-20 g, most preferably 1.9540 g, 9.76995 g or 19.5399 g; and the amount of calcium oxalate is 30-50 g, preferably 35-45 g, most preferably 43.836 g, 43.1785 g, 40.5483 g or 37.2606 g.

[0018] Further, in step (2), the molar ratio of diammonium hydrogen phosphate and calcium oxalate is 1:1 to 2; preferably 1:1.5.

[0019] Further, in step (2), based on the amount of deionized water used being 40 mL, the amounts of diammonium hydrogen phosphate and calcium oxalate used are 10-15 g and 20-25 g, respectively; preferably 13.2069 g and 21.918 g.

[0020] Further, in step (2), liquid B is added to liquid A and stirred in a water bath at 60±5℃ for 30±5 min.

[0021] Furthermore, in step (2), after the white slurry is formed, it is placed in an oven at 80±5℃ and dried for 6±1h until slightly dry.

[0022] Furthermore, in step (2), after crushing, the product is placed in an oven at 120±5℃ for 24±5 hours.

[0023] Furthermore, in step (2), the temperature is maintained at 1400±100℃ for 4±1h at 5℃ / min in a muffle furnace.

[0024] A highly antibacterial oral sealant for treating dentin hypersensitivity is obtained by the above preparation method.

[0025] The application of the above-mentioned highly antibacterial oral sealant for treating dentin hypersensitivity in the preparation of drugs for treating dentin hypersensitivity.

[0026] Furthermore, the medication is a topical medication.

[0027] The principle of this invention is as follows: First, phosphate ions are introduced into the silicate group, which can induce the in-situ formation of hydroxyapatite during hydration, resulting in good biocompatibility. Second, rare earth element cerium ions are introduced, and by utilizing the valence state transformation of cerium ions, a high ratio of Ce(Ⅲ) / Ce(Ⅳ) is controlled, thereby improving the antibacterial ability of the material and reducing infection problems during treatment.

[0028] The present invention has the following advantages and effects compared with the prior art:

[0029] The highly antibacterial oral sealant of this invention is named Ce-W-1. Its raw materials include calcium oxalate, diammonium hydrogen phosphate, tetraethyl silicate, and cerium nitrate hexahydrate. It is a bioactive material that can produce hydroxyapatite in a short time, exhibiting good biocompatibility. Furthermore, due to the valence state transition characteristics and antibacterial properties of cerium ions, the bioactive material also possesses high antibacterial activity after the introduction of cerium ions. In addition, different proportions of cerium ions will slightly affect the stability of the material system, but the system tends to be more stable as the proportion of cerium ions increases, and there is no doubt that Ce-W-1 is effective. 3+ The proportion of antibacterial agents is increasing, and their antibacterial properties are becoming stronger.

[0030] The highly antibacterial oral sealant of this invention can induce hydroxyapatite in situ, producing it within 1 day and exhibiting excellent biocompatibility. Dentin is mainly composed of inorganic and organic substances, with inorganic substances accounting for over 96% of the total dentin volume. Its main component is calcium phosphate crystals, including hydroxyapatite and calcium carbonate, whose crystal structure is dense and ordered, effectively resisting external pressure and extrusion. Therefore, this bioactive oral sealant material can effectively strengthen the dentin structure, thereby enhancing its resistance. Attached Figure Description

[0031] Figure 1 The image shows the XRD pattern of Ce-W-1 prepared in Example 1.

[0032] Figure 2 The XRD and IR spectra of Ce-W-1 mineralized for 1 day as prepared in Example 1.

[0033] Figure 3 The image shows the antibacterial properties of Ce-W-1 prepared in Example 1.

[0034] Figure 4 The antibacterial diagram is shown for Ce-HAP prepared in Comparative Example 1.

[0035] Figure 5 XPS plot of 5% Ce-W-1 prepared in Example 1.

[0036] Figure 6 XPS image of 10% Ce-W-1 prepared in Example 1.

[0037] Figure 7 Potentiometric diagram and particle size diagram of Ce-W-1 prepared in Example 1. Detailed Implementation

[0038] The technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without innovative effort are within the scope of protection of this invention.

[0039] Example 1

[0040] (1) Preparation of premixed solution:

[0041] Solution A: Prepare four containers. Add 20.833g tetraethyl orthosilicate, 23.035g anhydrous ethanol, and 40mL deionized water to each container sequentially. Then add 0g, 1.9540g, 9.76995g, and 19.5399g cerium nitrate hexahydrate to each container, respectively. Stir well and adjust the pH to 1-2 using nitric acid. Once the pH is stable, add 43.836g, 43.1785g, 40.5483g, and 37.2606g calcium oxalate to each container, respectively, and stir well to obtain Solution A. The molar concentrations of cerium ions in Solution A are 0%, 1%, 5%, and 10%, respectively. Cover with plastic wrap to prevent evaporation of anhydrous ethanol, etc.

[0042] Solution B: Add 40 mL of deionized water, 13.206 g of diammonium hydrogen phosphate, and 21.918 g of calcium oxalate to a container in sequence, stir well, and you will get solution B.

[0043] (2) Preparation of cerium-doped apatite / calcium silicate composite bioactive glass:

[0044] Solution B was added to solution A and stirred in a water bath at 60°C for 30 minutes to form a white slurry. The slurry was then placed in an oven at 80°C for 6 hours until slightly dry. After crushing, the slurry was placed in an oven at 120°C for 24 hours. Subsequently, it was heated in a muffle furnace at 5°C / min and kept at 1400°C for 4 hours. Finally, it was taken out and rapidly cooled to obtain apatite / calcium silicate composite bioactive glass (Ce-W-1) with different Ce contents, which were named W-1, 1%Ce-W-1, 5%Ce-W-1, and 10%Ce-W-1, respectively.

[0045] Comparative Example 1

[0046] Preparation of cerium-doped apatite bioactive glass:

[0047] (1) Preparation of premixed solution:

[0048] Solution A: Prepare four containers, add 300ml of deionized water to each of the four containers, add 39.4369g, 39.0425g, 37.4652g, and 35.4932g of Ca(NO3)2·4H2O to each container respectively, and then add 13.2056g of (NH4)2HPO4. Stir well.

[0049] Solution B: Add 10ml of deionized water to a container, then add 0g, 0.7251g, 3.6257g, and 7.2514g of cerium nitrate hexahydrate respectively, and stir well;

[0050] (2) Preparation of cerium-doped apatite bioactive glass:

[0051] Solution B was mixed into solution A, the pH was adjusted to 10 with sodium hydroxide, and the mixture was stirred at 90°C for 8 hours. It was then ultrasonically washed three times with anhydrous ethanol and deionized water, followed by drying at 110°C for 22 hours. After thorough grinding, it was calcined at 750°C for 2 hours and cooled in the furnace to obtain cerium-doped apatite bioactive glass, which was named HAP, 1%Ce-HAP, 5%Ce-HAP, and 10%Ce-HAP, respectively.

[0052] Effect Example

[0053] (1) The prepared materials were characterized by X-ray diffraction analysis (XRD). Figure 1 The image shows the XRD pattern of Ce-W-1 prepared in Example 1. As can be seen from the figure, its spectral peaks are mainly calcium oxide, tricalcium silicate, and dicalcium silicate, which are not much different from W-1. However, Ce-W-1 shows a cerium dioxide peak, and the cerium dioxide peak red-shifts with the increase of cerium ion content. This indicates that cerium ions were successfully incorporated into W-1 and produced certain lattice defects or changes in crystal structure.

[0054] (2) For every 0.3g of W-1, 1% Ce-W-1, 5% Ce-W-1, and 10% Ce-W-1 powder, measure 200ml of SBF solution and mix. Then place the container in a water bath shaker at 37℃ and shake the reaction container at a shaking speed of 175r / min. Soak the sample for 1 day, separate the soaked sample, and rinse it with deionized water and acetone solution respectively. Dry it for testing. The preparation method of SBF refers to T / CSBN 0027-2022 α-tricalcium phosphate for surgical implants. The mineralized material was characterized by X-ray diffraction analysis and infrared spectroscopy (IR). Figure 2 The XRD and IR spectra of Ce-W-1 mineralized for 1 day as prepared in Example 1 are shown. The XRD pattern shows that W-1 and 1% Ce-W-1 both exhibit hydroxyapatite peaks around 31.9°, 32.2°, and 32.9°. The IR spectra show W-1 and 1% Ce-W-1 peaks at 602±20 and 564±20 cm⁻¹, respectively. -1 The presence of a peak in carbonated hydroxyapatite (CHA) indicates that Ce-W-1 is a bioactive material.

[0055] (3) Take Ce-W-1 prepared in Example 1 and conduct an antibacterial experiment. The steps are as follows:

[0056] 1. Sterilize agar and broth: Calculate the amount of agar based on 20-40ml of agar per petri dish, and 10-15ml of broth per petri dish, preferably 10ml.

[0057] A measured amount of LB agar and LB broth were placed in an autoclave and sterilized at 121°C for 15 minutes.

[0058] LB agar was purchased from Guangdong Huankai Microbial Technology Co., Ltd., and the ratio was 36g LB agar powder: 1000ml deionized water.

[0059] LB broth was purchased from Guangdong Huankai Microbial Technology Co., Ltd., and the ratio was 21g LB broth powder to 1000ml deionized water.

[0060] 2. Resuscitation: 9.9 μL of sterilized broth was mixed with 100 μL of E. coli purchased from South China Agricultural University and placed in a shaker at 37°C for 24 hours for resuscitation.

[0061] 3. Plate pouring: Pour 20-40 ml of sterile LB agar into each petri dish and allow it to solidify in the petri dish for later use.

[0062] 4. Dilution: The OD value of the resuscitated E. coli was measured using a microplate reader, and then diluted to 1*10. 8 spare.

[0063] 5. Co-cultivation: 1*10 8 Escherichia coli was co-cultured with 2 mg of Ce-W-1 at different concentrations for 2 hours.

[0064] 6. Spreading: Add 100 μL of the co-cultured bacterial solution and the material mixture to a culture dish (agar plate) containing agar, and spread it evenly with a spreader until there is slight resistance.

[0065] 7. Packaging: After applying the coating, cover it, seal it with sealing film, invert it and place it in a 37°C bacterial incubator with a carbon dioxide concentration of 0.5% for 10 hours, then take it out and take a picture. Figure 3 The image shows the antibacterial properties of Ce-W-1 prepared in Example 1. Figure 4 The image shows the antibacterial properties of Ce-HAP prepared in Comparative Example 1. As can be seen from the image, Ce-W-1 exhibits high antibacterial activity. Specifically, 10% Ce-W-1 achieved an antibacterial rate of 100%, and 5% Ce-W-1 achieved an antibacterial rate of over 95%. In Comparative Example 1, the antibacterial effect of 10% Ce-HAP was approximately 50%, significantly lower than that of 10% Ce-W-1. The oral cavity is a complex environment with temperatures and humidity suitable for the growth and reproduction of many microorganisms. It is home to over 700 types of microorganisms, including bacteria, fungi, viruses, and mycoplasma, with bacteria being the dominant species. During the treatment of dentin hypersensitivity, medical devices can reintroduce bacteria into the oral cavity, potentially causing infection. Using a highly antibacterial oral sealant can prevent this problem, ensuring a clean treatment and healing environment in the clinical setting.

[0066] (4) The Ce-W-1 and 10% Ce-W-1 prepared in Example 1 were characterized by X-ray photoelectron spectroscopy (XPS). Figure 5XPS plot of 5% Ce-W-1 prepared in Example 1. Figure 6 The XPS image shows the 10% Ce-W-1 prepared in Example 1. As can be seen from the image, by calculating the high-resolution XPS spectral area of ​​Ce 3d, the percentage of Ce(III) in 5% Ce-W-1 is 35.59%, the percentage of Ce(IV) is 64.41%, and the Ce(III) / Ce(IV) ratio is 55.26%. In contrast, the percentage of Ce(III) in 10% Ce-W-1 is 68.45%, the percentage of Ce(IV) is 31.55%, and the Ce(III) / Ce(IV) ratio is 216.9%. Therefore, a higher Ce(III) / Ce(IV) ratio indicates better antibacterial activity. The antibacterial mechanism of CeO2 is the electrostatic attraction between the CeO2 nanoparticles and bacteria. The bacteria are negatively charged, and the nanoparticles are positively charged, leading to oxidative stress and interfering with nutrient transport, thereby killing the bacteria.

[0067] (5) Take Ce-W-1 prepared in Example 1 and measure its potential and pore size. Figure 7 The potential and pore size diagrams of Ce-W-1 prepared in Example 1 are shown. As can be seen from the figures, Ce-W-1 with a cerium ion content of less than 10% exhibits an absolute potential value within the range of 0-5 mV, indicating an unstable state prone to aggregation. However, as the proportion of cerium ions increases, the absolute electronegativity increases, and the system moves towards a stable state, thereby further maintaining the stability of the oral cavity environment.

[0068] This highly antibacterial bioactive material regulates and stabilizes Ce 3+ Ce 4+ The high antibacterial properties are achieved through a specific ratio, making it a promising candidate for use in oral sealants. It primarily works by sealing the gaps between tooth pits and fissures to block bacterial invasion, thereby improving the acid resistance of tooth enamel and preventing caries. At the same time, the material has good bactericidal properties, enabling deeper bacterial removal and ensuring a clean oral environment.

[0069] Application Examples

[0070] Before using this antibacterial, bioactive oral sealant, thoroughly clean your teeth, then apply it to the non-chewing surfaces. The sealant bonds to the existing enamel, and then a curing lamp is used to accelerate its hardening. The core function of this material is to tightly seal the pits and fissures of the tooth surface, creating a barrier against microbial invasion and effectively enhancing the enamel's resistance to acid erosion, thereby preventing cavities. In addition, it possesses excellent antibacterial properties, capable of deeply removing bacteria hidden deep within the tooth surface, maintaining a clean and healthy oral environment.

[0071] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0072] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-antibacterial occlusive agent for treating dentin hypersensitivity, characterized by: Includes the following steps: (1) Preparation of premixed solution: Solution A: Add tetraethyl orthosilicate, anhydrous ethanol, and deionized water to a container in sequence, then add cerium nitrate hexahydrate, stir well, adjust the pH to 1-2 with nitric acid, and after the pH is stable, add calcium oxalate and stir well to obtain solution A. Solution B: Add deionized water, diammonium hydrogen phosphate, and calcium oxalate to a container in sequence, stir well, and you will get solution B. (2) Preparation of cerium-doped apatite / calcium silicate composite bioactive glass: Add solution B to solution A, stir, and after forming a white slurry, place it in an oven to dry slightly, crush it, and continue to place it in the oven. Then keep it warm in a muffle furnace, and finally take it out and cool it rapidly to obtain cerium-doped apatite / calcium silicate composite bioactive glass. In step (1), based on the amount of deionized water being 40 mL, the amounts of tetraethyl orthosilicate and anhydrous ethanol are 20–25 g and 20–25 g, respectively; the amount of cerium nitrate hexahydrate is 0.1–25 g; the amount of calcium oxalate is 30–50 g; and the amounts of diammonium hydrogen phosphate and calcium oxalate are 10–15 g and 20–25 g, respectively.

2. The method for preparing the highly antibacterial oral sealant for treating dentin hypersensitivity according to claim 1, characterized in that: In step (1), based on the amount of deionized water being 40 mL, the amounts of tetraethyl orthosilicate and anhydrous ethanol are 20.833 g and 23.035 g, respectively; the amounts of cerium nitrate hexahydrate are 1.9540 g, 9.76995 g, or 19.5399 g; the amounts of calcium oxalate are 43.836 g, 43.1785 g, 40.5483 g, or 37.2606 g; and the amounts of diammonium hydrogen phosphate and calcium oxalate are 13.2069 g and 21.918 g, respectively.

3. The method for preparing the highly antibacterial oral sealant for treating dentin hypersensitivity according to claim 1, characterized in that: In step (1), based on the amount of deionized water being 40 mL, the amounts of tetraethyl orthosilicate and anhydrous ethanol are 20.833 g and 23.035 g, respectively; the amount of cerium nitrate hexahydrate is 19.5399 g; the amount of calcium oxalate is 37.2606 g; and the amounts of diammonium hydrogen phosphate and calcium oxalate are 13.2069 g and 21.918 g, respectively.

4. The method for preparing the highly antibacterial oral sealant for treating dentin hypersensitivity according to any one of claims 1 to 3, characterized in that: In step (2), solution B is added to solution A and stirred in a water bath at 60±5℃ for 30±5 min; In step (2), after the white slurry is formed, it is placed in an oven at 80±5℃ and dried for 6±1h until slightly dry; In step (2), after crushing, continue to dry in an oven at 120±5℃ for 24±5h; In step (2), the temperature is maintained at 1400±100℃ for 4±1h in a muffle furnace at 5℃ / min.

5. A high-antimicrobial occluding agent for treating dentin hypersensitivity, characterized by: It is obtained by the preparation method described in any one of claims 1-4.

6. The use of the highly antibacterial oral sealant for treating dentin hypersensitivity as described in claim 5 in the preparation of a medicament for treating dentin hypersensitivity.

7. Use according to claim 6, characterized in that: The medication mentioned is a topical medication.

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