Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a root canal filling material of premixed nano niobium silicate and a preparation method thereof.
The technical scheme of the invention is as follows:
The invention provides a root canal filling material of premixed nano niobium silicate, which consists of a) nano niobium silicate powder, b) calcium silicate compound powder, c) X-ray radiation-resistant filler and d) excipient, wherein the dosage of the component a) is 1-10% and the sum of the components a) and b) c) is 40-90% according to mass percentage.
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) c) is 70%.
Further preferably, the content of component a) is 2.5 to 7%.
Further preferably, the root canal filling material of the present invention consists of 2.5-7% of a), 40% -50% of b), 10-20% of c) and the balance d).
Preferably, the calcium silicate compound is at least one of tricalcium silicate, dicalcium silicate and calcium silicate.
Preferably, the X-ray radiation-resistant filler is at least one of zirconium oxide, barium sulfate, tantalum oxide and bismuth oxide.
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 thereof, the excipient consists of hydroxypropyl methylcellulose and polyethylene glycol.
The invention also provides a preparation method of the root canal filling material, which comprises the following steps:
Step 1, mixing and dispersing the component d) to obtain a phase A;
step 2, adding the component c) into the phase A, and uniformly dispersing to obtain a suspension;
and 3) adding the components a) and b) into the suspension, and uniformly dispersing until the components are pasty.
Compared with the prior art, the invention has the following beneficial effects:
1) The curing time is greatly shortened, the curing time of the traditional root filling material is too long, some of the traditional root filling material can be solidified within 72 hours, and the compression strength of the material in the initial stage of curing is poor. The calcium silicate base root canal filling material of the premixed nano niobium silicate provided by the invention has the curing time of only 2.5-6 hours, and the compressive strength after curing is obviously enhanced.
2) After premixing the nano niobium silicate, the fluidity of the material is enhanced, so that the material can enter the lateral branch root canal and root tip more easily, and the edge closure of the root canal is improved.
3) The radiation-resistant effect is enhanced, namely, the radiation-resistant effect of the original material is obviously enhanced after the nano niobium silicate is premixed.
In conclusion, the filling material of the invention improves fluidity and shortens curing time by optimizing a formula, and can form tight bonding with tissues around a root canal when being filled, and the repairing and regenerating of dentin can be obviously improved after the defect of the alveolar bone of the root tip compared with the existing material because the nano niobium silicate actively promotes the repairing and regenerating of dentin.
Detailed Description
The present invention is further illustrated below with reference to specific examples, which are not intended to limit the invention in any way. Unless specifically stated otherwise, the reagents, methods and apparatus employed in the present invention are those conventional in the art. Reagents and materials used in the following examples are commercially available unless otherwise specified.
Example 1
The root canal filling material of the premixed nano niobium silicate comprises the following components in percentage by mass of 7% of nano niobium silicate, 45% of calcium silicate, 18% of zirconia, 22% of polyethylene glycol and 8% of hydroxypropyl methyl cellulose.
The preparation method comprises the following steps:
Step 1, adding hydroxypropyl methylcellulose into polyethylene glycol, stirring and dissolving to obtain a phase A;
step 2, adding zirconia into the phase A, and uniformly stirring until the zirconia is dispersed to obtain a suspension;
And 3, adding nano niobium silicate and calcium silicate into the suspension, and uniformly stirring to form paste, thus obtaining the calcium silicate root tube filling material of the premixed nano niobium silicate.
Example 2
A root canal filling material of premixed nano niobium silicate comprises the following components in percentage by mass of 2.5% of nano niobium silicate, 49.5% of calcium silicate, 18% of zirconium oxide, 25% of polyethylene glycol and 5% of hydroxypropyl methyl cellulose.
The preparation method comprises the following steps:
Step 1, adding hydroxypropyl methylcellulose into polyethylene glycol, stirring and dissolving to obtain a phase A;
step 2, adding zirconia into the phase A, and uniformly stirring until the zirconia is dispersed to obtain a suspension;
And 3, adding nano niobium silicate and calcium silicate into the suspension, and uniformly stirring to form paste, thus obtaining the calcium silicate root tube filling material of the premixed nano niobium silicate.
Example 3
A root canal filling material of premixed nano niobium silicate comprises the following components in percentage by mass of 5% of nano niobium silicate, 50% of calcium silicate, 15% of zirconia, 25% of polyethylene glycol and 5% of hydroxypropyl methyl cellulose.
The preparation method comprises the following steps:
Step 1, adding hydroxypropyl methylcellulose into polyethylene glycol, stirring and dissolving to obtain a phase A;
step 2, adding zirconia into the phase A, and uniformly stirring until the zirconia is dispersed to obtain a suspension;
And 3, adding nano niobium silicate and calcium silicate into the suspension, and uniformly stirring to form paste, thus obtaining the calcium silicate root tube filling material of the premixed nano niobium silicate.
Comparative example 1
A dental root canal filling material comprises, by mass, 50% of calcium silicate, 18% of zirconia, 27% of polyethylene glycol and 5% of hydroxypropyl methylcellulose.
The preparation method comprises the following steps:
Step 1, adding hydroxypropyl methylcellulose into polyethylene glycol, stirring and dissolving to obtain a phase A;
step 2, adding zirconia into the phase A, and uniformly stirring until the zirconia is dispersed to obtain a suspension;
And 3, adding calcium silicate into the suspension, and uniformly stirring to form paste to obtain the premixed calcium silicate root canal filling material.
Comparative example 2
A root canal filling material of premixed nano niobium silicate comprises the following components in percentage by mass of 15% of nano niobium silicate, 37% of calcium silicate, 18% of zirconia, 25% of polyethylene glycol and 5% of hydroxypropyl methyl cellulose.
The preparation method comprises the following steps:
Step 1, adding hydroxypropyl methylcellulose into polyethylene glycol, stirring and dissolving to obtain a phase A;
step 2, adding zirconia into the phase A, and uniformly stirring until the zirconia is dispersed to obtain a suspension;
And 3, adding nano niobium silicate and calcium silicate into the suspension, and uniformly stirring to form paste, thus obtaining the calcium silicate root tube filling material of the premixed nano niobium silicate.
Table 1 examples and comparative examples formulation tables
| Example 1 | Example 2 | Example 3 | Comparative example 1 | Comparative example 2 |
| Nanometer niobium silicate | 7 | 2.5 | 5 | 0 | 15 |
| Calcium silicate | 45 | 49.5 | 50 | 50 | 37 |
| Zirconia (zirconia) | 18 | 18 | 15 | 18 | 18 |
| Polyethylene glycol | 22 | 25 | 25 | 27 | 25 |
| Hydroxypropyl methylcellulose | 8 | 5 | 5 | 5 | 5 |
Performance testing
1. Curing time
The appliance was prepared as required by 7.5.1 in the YY0717-2023 standard. The mold was placed in an environment of 37 ℃ and 95% relative humidity for 24 hours, and then the materials of examples 1-3 and comparative examples 1-2 were filled into the pretreated mold cavities, respectively, and 3 products were taken for parallel testing, and tested according to 7.5.3 in YY0717-2023, to obtain curing times.
The results are shown in Table 2. As can be seen from Table 2, the setting time of the paste filled with a premixed amount of nano niobium silicate was significantly shorter than that of the product of comparative example 1 without nano niobium silicate. However, when the niobium silicate content is too high, the curing time is not significantly shortened. From this, it can be seen that the pre-mixed nano niobium silicate filling paste provided by the invention significantly shortens the curing time, and is beneficial to realizing high-quality clinical filling effect. Wherein the sample curing time of example 2 is the shortest, fig. 1 is a picture of the filling material sample obtained in example 2, and fig. 2 is an SEM picture of the filling material of example 2 after curing, it can be seen that the structure is compact after hydraulic curing, and can form tight bonding with the tissue around the root canal.
2. Flowability test
The filling pastes prepared in examples 1 to 3 and comparative examples 1 to 2 were respectively taken and subjected to fluidity test with reference to the standard requirements of YY/T0717-2009 dental root canal sealer.
The results are shown in Table 2 below. Examples 1-3 significantly improved the flowability of the filling material relative to comparative example 1, and more facilitated the product to enter the root canal and root tip of the side branch more easily. Whereas comparative example 2 was too fluid, the risk of overcharge was clinically liable to occur.
TABLE 2 curing time and flowability of the different examples and comparative examples
| Numbering device | Sample name | Curing time (h) | Fluidity (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 |
3. Resistance to radiation test
Taking 0.05mL of the samples of the example 2, the comparative example 1 and the comparative example 2 respectively, preparing wafers with the diameter of about 10mm, curing, placing the wafers in the center of an X-ray film, and carrying out X-ray shooting by referring to YY0717-2023 to obtain an X-ray gray scale contrast diagram.
The results are shown in FIG. 3. From the results of fig. 3, it is understood that the X-ray blocking effect is improved in example 2 compared with comparative example 1 in which a certain amount of nano niobium silicate is premixed in the paste. Among them, comparative example 2 had better X-ray resistance, which simultaneously increased hardness, but resulted in the cracking of the cured product.
In conclusion, the calcium silicate tube filling material of the premixed nano niobium silicate obviously reduces the curing time by introducing the nano niobium silicate and matching with other components, and meanwhile, the compressive strength after curing is obviously enhanced. And the fluidity of the material is increased, so that the material can enter the lateral branch root canal and root tip more easily, and a better filling effect is formed. Meanwhile, the nano niobium silicate also enhances the radiation resistance effect of the original material.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.