CN114795973B

CN114795973B - Dental filler and preparation method thereof

Info

Publication number: CN114795973B
Application number: CN202210518386.XA
Authority: CN
Inventors: 李建树; 邱佩瑜; 徐心源
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2023-02-28
Anticipated expiration: 2042-05-12
Also published as: CN114795973A

Abstract

The invention belongs to the field of inorganic filler, and discloses a dental filler and a preparation method thereof. The preparation method comprises the following steps: firstly, quartz fiber and bismuth trioxide are blended by a ball mill, and then are sintered at high temperature by a muffle furnace, and finally, the novel filler with the roughened surface structure is obtained. The invention adopts the technology of sintering small particles attached to large particles, solves the problem that the traditional method for improving the surface roughness of the filler can damage the structure of the filler, and finally can endow the novel filler with functionality due to the introduction of the small particles. Therefore, the method improves the interface compatibility between the filler and the resin, and simultaneously, the novel filler not only keeps the excellent X-ray radiation resistance of the bismuth trioxide, but also maintains the white appearance of the quartz fiber, and has aesthetic property when being doped in the resin.

Description

Dental filler and preparation method thereof

Technical Field

The invention belongs to the field of inorganic fillers, discloses a dental filler and a preparation method thereof, and particularly discloses a novel multifunctional filler with interface compatibility, X-ray radiation resistance and aesthetic property and a preparation method thereof.

Background

Fillers generally refer to materials filled into other objects with different structures and functions depending on the differences in the properties of the filled matrix and the application requirements of the final material. The composite material taking the epoxy resin as the matrix can be used in the fields of aerospace, electronic devices, biomedicine and the like. However, the difference in properties between the inorganic filler and the organic resin is such that the inorganic filler and the organic resin are often incompatible complex systems, and thus it is important to enhance the interfacial compatibility of the inorganic filler in the organic resin. According to different requirements of application scenes, the composite material can better meet the use requirement by improving the interface compatibility and endowing the filler with the functionality. In the field of dentistry, materials such as dental fiber posts, dental filling resin, orthodontic adhesives and the like need to have X-ray radiation resistance so that doctors can observe the position of the material through equipment, and the materials after the fillers are added need to maintain a white appearance close to the tooth surface so as to meet the requirement of patients on aesthetic measure.

Quartz fibers are widely used for addition to resins because of their advantages such as low cost, excellent modulus, and ease of modification. The existing methods can improve the interfacial compatibility between the inorganic filler and the organic resin, but the modification process is complex and time-consuming and heavy. Bismuth trioxide is a commonly used X-ray-blocking particle, but the appearance is yellow, and the whole color of the composite material is yellow due to a small amount of bismuth trioxide, so that the white aesthetic appearance is difficult to realize to meet the requirements of specific biomedical materials, particularly in the dental field.

If the two can be skillfully combined, the requirements of good interface compatibility, X-ray radiation resistance and aesthetic property of the filler can be maintained while the traditional complex process flow is solved, and the method has important significance in the industry.

Disclosure of Invention

Based on the above analysis, it is urgently needed in the industry to provide a novel multifunctional filler having interfacial compatibility, X-ray radiation resistance and aesthetic property at the same time. The invention is realized by the following technical means:

a dental filler comprising:

quartz fibers and bismuth trioxide;

wherein the mass ratio of the quartz fiber to the bismuth trioxide is (2-32): 1.

further, the length of the quartz fiber is 20-150 μm.

Furthermore, the bismuth trioxide is spherical-like, and the particle size is 200-500nm.

The invention also discloses a method for preparing any dental filler, which comprises the following steps:

(1) Weighing quartz fibers and bismuth trioxide, and mixing in a ball mill to obtain a first material;

(2) And putting the first material into a ceramic crucible, and sintering in a muffle furnace to obtain the dental filler.

Further, the mass ratio of the quartz fiber to the bismuth trioxide in the step (1) is (2-32): 1.

further, the length of the quartz fiber in the step (1) is 20-150 μm.

Further, the bismuth trioxide in the step (1) is spherical-like, and the particle size is 200-500nm.

Further, the mixing and mixing condition of the step (1) is mixing for 3 hours at the rotating speed of 500 r/min.

Further, the sintering temperature in the step (2) is 500-800 ℃.

Further, the sintering time in the step (2) is 0.5-3h.

The invention also discloses a dental filler prepared by any one of the preparation methods.

The invention has the beneficial effects that:

1. compared with the traditional method of improving the interface compatibility of silicon dioxide and resin by improving the roughness through surface acid etching, the method not only can cause the filler to generate an uneven effect and damage the structure of the filler, but also can influence the modulus and the performance of the filler. And the method only can improve the roughness of the filler and does not endow the filler with new functionality. According to the larger particle size difference between the quartz fiber and the bismuth trioxide, the bismuth trioxide can be uniformly distributed on the surface of the quartz fiber through a ball mill. Then selecting proper sintering temperature and time according to the larger melting point difference between the quartz fiber (1723 ℃) and the bismuth trioxide (825 ℃) to ensure that the bismuth trioxide and the surface of the quartz fiber are subjected to chemical reaction, and the bismuth trioxide is bonded to the surface of the quartz fiber while new crystals are generated, so that the originally smooth surface of the quartz fiber becomes rough, and the roughness can be provided for the mechanical locking sites of the resin matrix, so that the filler and the resin matrix are bonded more tightly, and the interface compatibility is improved. The X-ray resistance of the bismuth trioxide can not disappear due to sintering, so that the novel filler has the X-ray resistance. Therefore, the combination of the raw material combination and the process improves the interface compatibility between the filler and the resin, and simultaneously can endow the filler with the technical effect of new functionality.

2. Bismuth trioxide is a commonly used X-ray-blocking particle, but the appearance is yellow, and the whole color of the composite material is yellow due to a small amount of bismuth trioxide, so that the white aesthetic appearance is difficult to realize to meet the requirements of specific biomedical materials, particularly in the dental field. Even if a white silica filler is used to neutralize the yellow color of bismuth trioxide, the desired effect is not achieved. In the subsequent experimental results, it was found that even when the silica and the bismuth trioxide were compounded in a ratio of 99. The mass ratio of the quartz fiber to the bismuth trioxide selected by the invention is (2-32): under the condition of the mixture ratio, the special sintering temperature and sintering time are given to generate new crystals, so that the filler has white characteristic, and the application range of the filler in oral cavity filler is widened.

Drawings

FIG. 1 is an SEM of Nos. 1 to 4 of the filler in example 1 of the present invention;

FIG. 2 is an SEM of a cross section of a test specimen in test example 3 of the present invention;

FIG. 3 is a comparison of X-ray radiation-blocking abilities in test example 3 of the present invention;

FIG. 4 is a comparison of the aesthetics of inventive test example 3, wherein the sample made with filler No. 1 plus epoxy is white; the sample prepared by quartz fiber and epoxy resin is white and slightly transparent; the sample prepared from bismuth trioxide plus epoxy resin is bright yellow.

Detailed Description

The present invention will be described in further detail with reference to specific examples. It is to be understood that these embodiments are provided to illustrate the general principles, major features and advantages of the present invention, and the present invention is not limited in scope by the following embodiments. The implementation conditions used in the examples can be further adjusted according to specific requirements, and the implementation conditions not noted are generally those in routine experiments.

Example 1

A preparation method of a dental filler comprises the following steps:

(1) Quartz fibers and bismuth trioxide with different mass ratios (see table 1) are selected to be put into a ball milling pot and mixed for 3 hours by a ball mill under the condition of 500r/min to obtain a first material.

(2) And sintering the first material in a muffle furnace at 700 ℃ for 2h to obtain the dental filler. The microscopic appearance of each set of samples is shown in fig. 1. As can be seen, in samples No. 1-4, the surfaces of samples No. 3 and No. 4 cannot be completely covered by the bismuth trioxide, and smooth quartz fiber surfaces are exposed; while the surfaces of sample nos. 1 and 2 were covered with bismuth trioxide, it was observed that the surface of sample No. 1 had more distinct small protrusions.

TABLE 1 different sample preparation parameters

Sample number	1	2	3	4
					m _{Quartz fiber} ：m _{Bismuth oxide}	2:1	4:1	8:1	16:1

Application example 2

The filler No. 1 in the example 1 is added into epoxy resin to prepare a composite resin material, and the specific operation process is as follows:

(1) Mixing and stirring 12% by mass of No. 1 filler and 88% by mass of epoxy resin (consisting of E51+ curing agent and 3 by mass ratio;

(2) Placing the first slurry in a vacuum oven at 60 ℃, evacuating and removing bubbles for 15min to obtain second slurry;

(3) And casting the second slurry into two different types of molds, curing at normal temperature for 24 hours, and taking out. The invention uses two moulds in common, namely rectangular sample bars with the size of 40X 10X 1.5mm and

the circular spline of (2);

(4) Preparing a sample of a comparison group according to the method of the step 1-3, wherein in the preparation process of the sample of the comparison group 1-3, 8 mass percent of quartz fiber, 92 mass percent of epoxy resin, 4 mass percent of bismuth trioxide, 96 mass percent of epoxy resin and pure epoxy resin are respectively selected as raw materials.

Test example 3

The composite material prepared in example 2 was subjected to functional characterization.

(1) Interface compatibility: the rectangular sample strip is broken by pressing according to a three-point bending test method, and then SEM shooting is carried out on the cross section to observe the change of the interface compatibility, and the specific result is shown in FIG. 2. It can be seen that in the epoxy resin + quartz fiber group, there are significant gaps between the quartz fibers and the resin; in the epoxy resin + filler No. 1 group, no gap was observed between the filler and the resin. This indicates that the novel filler is more tightly bound to the resin and has better interfacial compatibility.

(2) X-ray opacity: the circular sample strip in application example 2 was placed on a substrate dedicated to a dental X-ray machine, and photographed with the dental X-ray machine according to clinical parameters, and the test results were analyzed for the gradation value with Image J software, thereby judging the radiation blocking capability. The test results are shown in fig. 3. Gray Value represents a Gray Value, and the smaller the Value is, the darker the color is; the larger the value, the whiter the color. When an X-ray film is clinically taken, the substance with the X-ray blocking property can show a whiter color so as to be distinguished from the human tissue without the X-ray blocking property at the periphery. It can be seen that the gray value of the group of filler No. 1 and epoxy resin is obviously improved compared with other groups, which indicates that the novel filler has the X-ray radiation-blocking capability.

(3) The aesthetic property is as follows: an optical picture was taken of the prepared filler No. 1, the raw materials quartz fiber, bismuth trioxide and their obtained composite material of a round sample bar, and the result is shown in fig. 4. The quartz fiber, the quartz fiber and the epoxy resin group are all white, and the bismuth trioxide, the bismuth trioxide and the epoxy resin group are all yellow. The No. 1 filler prepared from quartz fiber and bismuth trioxide, the No. 1 filler and the epoxy resin group all show white color, and the yellow color of the bismuth trioxide is not generated. This indicates that the novel filler can achieve the same aesthetic effect as silica-based fillers.

The above examples are merely preferred embodiments of the present invention, and the scope of the present invention is not limited to the above examples. All technical schemes belonging to the idea of the invention belong to the protection scope of the invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention, and such modifications and embellishments should also be considered as within the scope of the invention.

Claims

1. A dental filler comprising:

quartz fibers and bismuth trioxide;

wherein the mass ratio of the quartz fiber to the bismuth trioxide is 2;

the dental filler is prepared by the following method:

(2) And putting the first material into a ceramic crucible, and sintering the ceramic crucible in a muffle furnace at 700 ℃ for 2 hours to obtain the dental filler.

2. The dental filler of claim 1, wherein:

the length of the quartz fiber is 20-150 μm.

3. The dental filler of claim 1, wherein:

the bismuth trioxide is spherical-like, and the particle size is 200-500nm.