A root canal filling material premixed with nano-niobium silicate and its preparation method

Abstract

The present invention relates to a root canal filling material premixed with nano-niobium silicate and a preparation method thereof. The filling material comprises a) nano-niobium silicate powder; b) calcium silicate compound powder; c) an X-ray-blocking filler; and d) an excipient. Component a) is used in an amount of 1-10% by mass, and the sum of components a), b), and c) is 40-90% by mass. By incorporating an appropriate amount of nano-niobium silicate into the filling material, the present invention significantly shortens curing time and improves fluidity, enabling the filling material to form a bond with surrounding tissues of the root canal. The nano-niobium silicate actively promotes the repair and regeneration of dentin, significantly enhancing the repair and regeneration of apical alveolar bone defects compared to existing materials.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical materials, and in particular relates to a root canal filling material premixed with nano-niobium silicate and a preparation method thereof. Background Art

[0002] Root canal therapy is an effective method for treating pulp disease and periapical periodontitis, and root canal filling materials are the key to successful treatment. Ideal dental filling materials must have good biocompatibility, antibacterial properties and clinical operability. In addition, bioactivity is also used as a basis for measuring the bonding performance between the material and the tooth itself. However, the materials currently used in clinical practice have certain shortcomings. Calcium hydroxide-based materials are widely used in dental pulp as pulp capping agents, root canal disinfectants, and root canal filling materials, but they have strong cytotoxicity, weak solubility and diffusivity, lack solidification and molding properties, are prone to particle release, lack bioactivity, and increase the risk of dentin fracture; the performance of new calcium silicate materials such as MTA has been improved to a certain extent, and are now widely used in clinical practice as pulp capping agents and root canal sealers, but they cure slowly and have low early strength.

[0003] Chinese patent (publication number CN101668550A) "Premixed biological hydraulic cement paste composition and its application" discloses a premixed cement paste that can be used for medical or dental purposes. The patent premixes tricalcium silicate, dicalcium silicate and an organic solvent, which is convenient for doctors to use. However, the setting time is too long, and some require 72 hours to set. The long setting time not only causes the patient to wait longer, but also makes the surgical procedure more complicated. Chinese patent (publication number CN102049062 A) "Injectable, efficient, suspended and stable calcium phosphate bone cement and its preparation method and application" discloses an injectable calcium phosphate bone cement material system. The patent improves the suspension stability of the calcium phosphate bone cement premix system by adding fumed silica and its modified products. The disadvantage is that the calcium phosphate bone cement is not strong enough and is easily broken.

[0004] Based on this, it is necessary to further develop a premixed root filling material with short setting time, high strength, higher biological activity and better clinical operation performance.

[0005] Nano-niobium silicate is an emerging material with excellent osteogenesis and biocompatibility. Research has found that nano-niobium silicate can significantly enhance early osteogenic differentiation and later mature mineralization during bone repair. Niobium silicate's excellent chemical stability and high mechanical strength make it a promising material for bone repair. Summary of the Invention

[0006] In view of the above-mentioned current technical deficiencies, the present invention provides a root canal filling material premixed with nano-niobium silicate and a preparation method thereof.

[0007] The technical solutions of the present invention are as follows:

[0008] In a first aspect, the present invention provides a premixed nano-niobium silicate root canal filling material, comprising a) nano-niobium silicate powder; b) calcium silicate compound powder; c) X-ray blocking filler; and d) excipient. In terms of mass percentage, the amount of component a) is 1-10%, and the sum of components a), b) and c) is 40-90%.

[0009] Preferably, the sum of the three components a), b) and c) is 60-80%. In a preferred embodiment, the sum of the three components a), b) and c) is 70%.

[0010] More preferably, the content of component a) is 2.5-7%.

[0011] Further preferably, the root canal filling material of the present invention consists of 2.5-7% a), 40%-50% b), 10-20% c) and the balance d).

[0012] Preferably, the calcium silicate compound is at least one of tricalcium silicate, dicalcium silicate and calcium silicate.

[0013] Preferably, the X-ray blocking filler is at least one of zirconium oxide, barium sulfate, tantalum oxide, and bismuth oxide.

[0014] Preferably, the excipient is at least one of ethylene glycol, polyethylene glycol, propylene glycol, glycerol, ethanol, vegetable oil, animal oil, silicone oil, and hydroxypropyl methylcellulose. In some preferred embodiments, the excipient consists of hydroxypropyl methylcellulose and polyethylene glycol.

[0015] A second aspect of the present invention further provides a method for preparing the root canal filling material, comprising the following steps:

[0016] Step 1: Mix and disperse component d) to obtain phase A;

[0017] Step 2: Add component c) to phase A and disperse evenly to obtain a suspension;

[0018] Step 3: Add components a) and b) to the above suspension and disperse evenly to form a paste.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) Significantly shortened curing time: Conventional root canal filling materials take too long to cure, sometimes requiring up to 72 hours. Furthermore, the material's compressive strength is poor in the initial stages of curing. However, the calcium silicate-based root canal filling material premixed with nano-niobium silicate provided by the present invention cures in just 2.5-6 hours, while significantly enhancing its compressive strength after curing.

[0021] 2) Enhanced fluidity: After pre-mixing with nano-niobium silicate, the fluidity of the material is enhanced, making it easier to enter the lateral root canal and the root apex, thereby improving the marginal sealing of the root canal.

[0022] 3) Enhanced radiation blocking effect: After pre-mixing with nano-niobium silicate, the radiation blocking effect of the original material is significantly enhanced.

[0023] In summary, the filling material of the present invention improves fluidity and shortens curing time by optimizing the formula. During filling, the filling material can form a tight bond with the tissue surrounding the root canal. Since nano-niobium silicate actively promotes the repair and regeneration of dentin, it can significantly improve the repair and regeneration of apical alveolar bone defects compared to existing materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a photograph of the sample obtained from Example 2;

[0025] Figure 2 SEM image of the sample obtained in Example 2 after curing;

[0026] Figure 3 Schematic diagram of X-ray blocking effect. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific examples, but the examples do not limit the present invention in any form. Unless otherwise stated, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. Unless otherwise stated, the reagents and materials used in the following examples are commercially available.

[0028] Example 1

[0029] A root canal filling material of premixed nano-niobium silicate is composed of the following components in percentage by mass: 7% nano-niobium silicate, 45% calcium silicate, 18% zirconium oxide, 22% polyethylene glycol, and 8% hydroxypropyl methylcellulose.

[0030] The preparation method thereof comprises the following steps:

[0031] Step 1: Add hydroxypropyl methylcellulose to polyethylene glycol, stir and dissolve to obtain phase A;

[0032] Step 2: Add zirconium oxide to phase A and stir until dispersed to obtain a suspension;

[0033] Step 3: Add nano-niobium silicate and calcium silicate to the above suspension, and stir evenly until a paste is formed, thereby obtaining a calcium silicate root canal filling material pre-mixed with nano-niobium silicate.

[0034] Example 2

[0035] A root canal filling material of premixed nano-niobium silicate is composed of the following components in percentage by mass: 2.5% nano-niobium silicate, 49.5% calcium silicate, 18% zirconium oxide, 25% polyethylene glycol, and 5% hydroxypropyl methylcellulose.

[0036] The preparation method thereof comprises the following steps:

[0037] Step 1: Add hydroxypropyl methylcellulose to polyethylene glycol, stir and dissolve to obtain phase A;

[0038] Step 2: Add zirconium oxide to phase A and stir until dispersed to obtain a suspension;

[0039] Step 3: Add nano-niobium silicate and calcium silicate to the above suspension, and stir evenly until a paste is formed, thereby obtaining a calcium silicate root canal filling material pre-mixed with nano-niobium silicate.

[0040] Example 3

[0041] A root canal filling material of premixed nano-niobium silicate consists of the following components in percentage by mass: 5% nano-niobium silicate, 50% calcium silicate, 15% zirconium oxide, 25% polyethylene glycol, and 5% hydroxypropyl methylcellulose.

[0042] The preparation method thereof comprises the following steps:

[0043] Step 1: Add hydroxypropyl methylcellulose to polyethylene glycol, stir and dissolve to obtain phase A;

[0044] Step 2: Add zirconium oxide to phase A and stir until dispersed to obtain a suspension;

[0045] Step 3: Add nano-niobium silicate and calcium silicate to the above suspension, and stir evenly until a paste is formed, thereby obtaining a calcium silicate root canal filling material pre-mixed with nano-niobium silicate.

[0046] Comparative Example 1

[0047] A dental root canal filling material consists of the following components in percentage by mass: 50% calcium silicate, 18% zirconium oxide, 27% polyethylene glycol, and 5% hydroxypropyl methylcellulose.

[0048] The preparation method thereof comprises the following steps:

[0049] Step 1: Add hydroxypropyl methylcellulose to polyethylene glycol, stir and dissolve to obtain phase A;

[0050] Step 2: Add zirconium oxide to phase A and stir until dispersed to obtain a suspension;

[0051] Step 3: Add calcium silicate to the above suspension and stir evenly until a paste is formed to obtain a premixed calcium silicate root canal filling material.

[0052] Comparative Example 2

[0053] A root canal filling material premixed with nano-niobium silicate consists of the following components in percentage by mass: 15% nano-niobium silicate, 37% calcium silicate, 18% zirconium oxide, 25% polyethylene glycol, and 5% hydroxypropyl methylcellulose.

[0054] The preparation method thereof comprises the following steps:

[0055] Step 1: Add hydroxypropyl methylcellulose to polyethylene glycol, stir and dissolve to obtain phase A;

[0056] Step 2: Add zirconium oxide to phase A and stir until dispersed to obtain a suspension;

[0057] Step 3: Add nano-niobium silicate and calcium silicate to the above suspension, and stir evenly until a paste is formed, thereby obtaining a calcium silicate root canal filling material pre-mixed with nano-niobium silicate.

[0058] Table 1: Formulas of Examples and Comparative Examples

[0059] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Nano-niobium silicate 7 2.5 5 0 15 calcium silicate 45 49.5 50 50 37 Zirconia 18 18 15 18 18 polyethylene glycol 22 25 25 27 25 Hydroxypropyl methylcellulose 8 5 5 5 5

[0060] Performance Testing

[0061] 1. Curing time

[0062] Prepare the apparatus according to the requirements of 7.5.1 of the YY0717-2023 standard. Place the mold in an environment at 37°C and 95% relative humidity for 24 hours. Then fill the pretreated mold cavity with the materials of Examples 1-3 and Comparative Examples 1-2. Take three products for parallel testing and conduct the test according to 7.5.3 of YY0717-2023 to obtain the curing time.

[0063] The results are shown in Table 2. As can be seen from Table 2, the curing time of the filling paste pre-mixed with a certain amount of nano-niobium silicate is significantly shorter than that of the product of Comparative Example 1 that is not mixed with nano-niobium silicate. However, when the niobium silicate content is too high, the curing time is not significantly shortened. It can be seen that the filling paste pre-mixed with nano-niobium silicate provided by the present invention significantly shortens the curing time, which is conducive to achieving high-quality clinical filling effects. Among them, the sample in Example 2 has the shortest curing time. Figure 1 The filling material sample picture obtained for Example 2, Figure 2This is an SEM picture of the filling material of Example 2 after curing. It can be seen that after hydraulic curing, the structure is dense and can form a tight bond with the tissue around the root canal.

[0064] 2. Liquidity test

[0065] The filling pastes prepared in Examples 1-3 and Comparative Examples 1-2 were respectively subjected to flowability tests with reference to the standard requirements of YY / T0717-2009 “Dental Root Canal Sealing Materials”.

[0066] The results are shown in Table 2. Examples 1-3 significantly improved the fluidity of the filling material compared to Comparative Example 1, making it easier for the product to enter the lateral root canal and the root apex. However, the fluidity of Comparative Example 2 was too high, which could easily lead to the risk of overfilling in clinical practice.

[0067] Table 2 Curing time and fluidity of different embodiments and comparative examples

[0068] serial number Sample name Curing time (h) Flowability (mm) 1 Example 1 5h 24.42 2 Example 2 3h 22.61 3 Example 3 3.5h 25.28 4 Comparative Example 1 18h 17.25 5 Comparative Example 2 12h 28.89

[0069] 3. Radiation resistance test

[0070] Take 0.05 mL of the samples of Example 2, Comparative Example 1, and Comparative Example 2 respectively, make discs with a diameter of about 10 mm, and after curing, put them into the center of the X-ray film, and perform X-ray photography with reference to YY0717-2023 to obtain an X-ray grayscale contrast image.

[0071] The results are as follows Figure 3 As shown. Figure 3 The results show that Example 2, in which a certain amount of nano-niobium silicate is pre-mixed with the filling paste, has improved X-ray blocking effect compared to Comparative Example 1. Comparative Example 2 has better X-ray blocking performance and also improves hardness, but it also causes cracking in the product after curing.

[0072] In summary, the calcium silicate root canal filling material premixed with nano-niobium silicate of the present invention significantly reduces curing time by incorporating nano-niobium silicate into the material, along with other components, while significantly enhancing compressive strength after curing. Furthermore, the material's increased fluidity allows for easier entry into lateral root canals and the root apex, resulting in a more effective filling effect. Furthermore, the nano-niobium silicate also enhances the radiation-blocking properties of the original material.

[0073] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A root canal filling material premixed with nano-niobium silicate, characterized in that: Composed of a) nano-niobium silicate powder; b) calcium silicate compound powder; c) X-ray blocking filler; d) excipient, wherein the sum of a), b) and c) is 70% by mass, and the remainder is d); The content of component b) is 45%, 49.5% or 50%; The content of component a) is 2.5-7%; The excipients are polyethylene glycol and hydroxypropyl methylcellulose.

2. The root canal filling material according to claim 1, characterized in that The calcium silicate compound is at least one of tricalcium silicate, dicalcium silicate and calcium silicate.

3. The root canal filling material according to claim 1, characterized in that The X-ray blocking filler is at least one of zirconium oxide, barium sulfate, tantalum oxide, and bismuth oxide.

4. The method for preparing a root canal filling material according to any one of claims 1 to 3, wherein: The steps include: Step 1: Mix and disperse component d) to obtain phase A; Step 2: Add component c) to phase A and disperse evenly to obtain a suspension; Step 3: Add components a) and b) to the above suspension and disperse evenly to form a paste.

Images