A Dental Self-Healing Resin Composite Based on Biomineralization, Its Preparation and Application

Abstract

The present invention relates to a dental self-healing resin composite based on biomineralization, its preparation and application. The dental self-healing resin composite includes: a base resin, a filler, a nutrient powder, and a bacterial powder; wherein the bacteria in the bacterial powder are selected from at least one of Bacillus, Bifidobacterium longum, or Lactobacillus reuteri; the Bacillus is selected from at least one of Bacillus sphaericus, Lysinibacillus sphaericus, Bacillus licheniformis, Bacillus pasteurii, or Bacillus subtilis; the preparation method includes: mixing the base resin, barium glass powder, nutrient powder, and bacterial powder, and subjecting it to photocuring to obtain. Compared with the prior art, the present invention introduces bacteria that can induce calcium carbonate precipitation into the dental resin composite, and achieves the purpose of self-healing through biomineralization, and realizes multiple self-healings.

Description

Technical Field

[0001] The present invention belongs to the technical field of dental biomedical materials, and relates to a dental self-healing resin composite based on biomineralization, its preparation and application. Background Art

[0002] In dental clinics, dental resin composites have been widely used due to their excellent aesthetics and good mechanical properties. However, due to factors such as chewing force and thermal stress, microcracks tend to accumulate, especially in high-stress bearing areas, and the filling body is prone to fracture, thus shortening its service life. To solve this problem, developing a composite material that can resist cracks is crucial for improving the durability of dental resin fillings. Simulating the principle of biological self-healing in nature and developing new biomedical materials that can sense damage and self-repair has become a hot research direction. Introducing a self-healing system into the dental resin composite system to develop a dental self-healing resin composite, which has the ability to sense and autonomously repair cracks. When microcracks appear, the self-healing system in the composite material is activated, effectively sealing the cracks and restoring the pressure-bearing capacity of the material, further restricting the expansion of the cracks to heal the cracks, thereby significantly improving the fracture resistance of the resin filling and extending the service life of the filling, showing exciting potential in actual load-bearing applications.

[0003] Currently, the research on self-healing dental resin composites mainly focuses on microcapsule self-healing technology. Microcapsules can be easily dispersed in the resin matrix. When the material cracks, the microcapsules will rupture and release the self-healing agent, effectively sealing the cracks and preventing their further expansion, significantly enhancing the fracture resistance of the material, thereby effectively extending the life of the dental resin composite filling.

[0004] Chinese Patent Application CN117815084A discloses a self-repairing dental resin, its preparation method and uses. The self-repairing dental resin consists of microcapsules and a polymerizable repair material; the microcapsules are core-shell structured particles, the core of which consists of a good solvent of acrylic resin, including a mixture of one or more of acetone, ethyl acetate, chloroform; the shell layer of the microcapsules consists of a mixture of one or more of silicon dioxide, titanium dioxide, zirconium oxide, calcium phosphate, calcium silicate, calcium sulfate; the polymerizable repair material is similar to common commercial dental resins, mainly including acrylate monomers, initiators and inorganic fillers, and may also include a small amount of stabilizers, solvents, etc. The microcapsules in the resin rupture when the resin cracks, releasing the solvent contained therein, making the polymer material near the crack soften and become sticky, and re-bonding together to prevent the crack from expanding and causing material failure, playing a role in extending the service life of dental resin.

[0005] Chinese Patent Application CN113768795A discloses a self-healing photocurable restorative material and its preparation method. By preparing microcapsules that can be co-melted with the composite resin matrix and adding them to the composite resin restorative material. Due to the addition of inorganic nanoparticles and microcapsules, the volume shrinkage rate is small, and the volume shrinkage rate after curing is ≤0.03%. At the same time, the tensile strength, fracture toughness, and wear resistance of the restorative resin material are improved. The surface microcrack self-healing test shows that the resin material with self-healing function can achieve a 68% microcrack repair success rate, effectively extending the clinical service life.

[0006] Although certain progress has been made in the research of microcapsule self-healing technology, there are still some problems with the self-healing microcapsule system. The limitations of microcapsules are reflected in each stage from production to mixing into the resin matrix and then to exercising functions: First, regarding the size of microcapsules, there is still no clear standard. If the microcapsule size is very small (such as submicron level), they will not contain enough core material to become effective functional particles, but if the microcapsule size is too large, they will damage the mechanical properties of the host resin material; Second, there are many factors affecting the self-healing efficiency, and the most important one is the perception of microcapsules to the propagation of microcracks. The real-time rupture and release of monomers by microcapsules are the key points. During the preparation process of dental resin composites, the shell of microcapsules must have sufficient strength to withstand mixing with the composite resin, and it should rupture in a timely manner when the composite resin breaks; Third, after the microcapsules rupture, voids will be formed on the surface of the composite material, affecting the polishing property of the material, and may further weaken the overall structural strength; In addition, it also includes the biological toxicity of monomers and catalysts, the premature polymerization reaction of monomers inside the microcapsules, and the heat generated during the photocuring process will cause the decomposition of high-cost catalysts; Finally, after the microcapsules rupture under the action of cracks and the self-healing agent overflows, secondary repair cannot be carried out.

[0007] Therefore, whether multiple repairs of self-healing materials can be achieved will become the future research focus of dental self-healing resin composites. Summary of the Invention

[0008] The purpose of the present invention is to provide a dental self-healing resin composite based on biomineralization and its preparation and application. The present invention introduces bacteria that can induce calcium carbonate precipitation into dental resin composites, and achieves self-healing and multiple self-healings through biomineralization.

[0009] The purpose of the present invention can be achieved through the following technical solutions:

[0010] The first aspect of the present invention provides a dental self-healing resin composite based on biomineralization, including: a base resin, barium glass powder, nutrient powder, and bacterial powder;

[0011] The bacteria in the bacterial powder are selected from at least one of Bacillus, Bifidobacterium longum or Lactobacillus reuteri; the Bacillus is selected from at least one of Bacillus sphaericus, Lysinibacillus sphaericus, Bacillus licheniformis, Bacillus pasteurii or Bacillus subtilis.

[0012] Further, when the bacteria are Bacillus, the bacteria exist in the bacterial powder in the form of spores.

[0013] Further, the bacterial powder is selected from one of freeze-dried bacterial liquid powder or freeze-dried bacterial powder.

[0014] Further, the Bacillus sphaericus is selected from at least one of Bacillus sphaericus ATCC4525 or Bacillus sphaericus DSM22257;

[0015] The Lysinibacillus sphaericus is Lysinibacillus sphaericus BMZ008183;

[0016] The Bacillus licheniformis is selected from one or a combination of two of Bacillus licheniformis ATCC9789 or Bacillus licheniformis ATCC9859;

[0017] The Bacillus subtilis is Bacillus subtilis DSM402;

[0018] The Bacillus pasteurii is Bacillus pasteurii B80469;

[0019] The Bifidobacterium longum is Bifidobacterium longum B81617;

[0020] The Lactobacillus reuteri is Lactobacillus reuteri BMZ140479. <�

[0021] Further, the filling material is barium glass powder.

[0022] Further, the mass ratio of the base resin, the filling material, the nutrient powder and the bacterial powder is (8 - 10):(8 - 10):(0.5 - 1.5):1.

[0023] As a preferred technical solution, the mass ratio of the base resin, the filling material, the nutrient powder and the bacterial powder is 9:9:1:1.

[0024] Further, the nutrient powder includes calcium chloride, urea, yeast extract with a mass ratio of (35 - 45):(60 - 70):2, or the nutrient powder includes calcium lactate, glucose, yeast extract with a mass ratio of (4 - 6):(7 - 9):20.

[0025] As a preferred technical solution, the mass ratio of the calcium chloride, the urea and the yeast extract is 40:65:2.

[0026] As a preferred technical solution, the mass ratio of calcium lactate, glucose, and yeast extract is 5:8:20.

[0027] Furthermore, the base resin includes bisphenol A glycerol dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), camphorquinone (CQ), and ethyl 4-(dimethylamino)benzoate (EDMAB) in a mass ratio of (48 - 50):(48 - 50):(0.3 - 0.5):(1.4 - 1.8).

[0028] As a preferred technical solution, the mass ratio of bisphenol A glycerol dimethacrylate, triethylene glycol dimethacrylate, camphorquinone, and ethyl 4-(dimethylamino)benzoate is 49:49:0.4:1.6.

[0029] The second aspect of the present invention provides a preparation method of a dental self-healing resin composite based on biomineralization, including: mixing the base resin, barium glass powder, nutrient powder, and bacterial powder, and subjecting it to photocuring.

[0030] As a preferred technical solution, the preparation method of the bacterial powder includes: subjecting the Bacillus sp. bacterial solution to pasteurization, centrifuging to collect spores, washing with water and formulating into a water suspension, centrifuging to remove the supernatant, and freeze-drying to obtain the bacterial powder; or,

[0031] The preparation method of the bacterial powder includes: washing the bacterial solution of Bifidobacterium longum or Lactobacillus reuteri with water and formulating into a water suspension, centrifuging to remove the supernatant, and freeze-drying to obtain the bacterial powder.

[0032] As a preferred technical solution, during the preparation process of the bacterial powder, a protective carrier is further included, and the protective carrier includes at least one of silica gel, expanded clay, diatomaceous earth, hydrogel, microcapsule, or magnetic iron oxide.

[0033] As a preferred technical solution, during the preparation process of the bacterial powder, MnSO4·H2O is further included in the culture medium, and the addition amount is 4 - 6 mg / L of the culture medium. A further preferred addition amount is 5 mg / L.

[0034] As a preferred technical solution, the photocuring includes irradiating the mixed powder of the base resin, barium glass powder, nutrient powder, and bacterial powder filled in a silica gel mold, and the irradiation conditions include: blue light, irradiation time 30 - 180 s.

[0035] As a preferred technical solution, the irradiation conditions include: irradiation wavelength 450 - 500 nm; more preferably, the wavelength is 470 nm, and the irradiation time is 120 s.

[0036] A third aspect of the present invention provides an application of a dental self-healing resin composite material based on biomineralization, comprising using the dental self-healing resin composite material to prepare a tooth restorative agent.

[0037] Furthermore, the tooth restorative agent includes dental resin cement or dental resin adhesive.

[0038] This invention incorporates generally recognized as safe (GRAS) bacteria into dental resin composites and uses highly biocompatible calcium salts (preferably calcium lactate and calcium chloride) as nutrients, thereby incorporating the principles of biomineralization into the composite, enabling self-healing and multiple self-healing. When cracks develop in the composite, the bacteria are activated by exposure to water and oxygen, allowing them to continuously biomineralize and induce the precipitation of calcium carbonate (CaCO3) to seal the cracks. This process, known as microbially induced calcium carbonate deposition (MICP), limits crack expansion, thereby enabling self-healing of dental resin fillings. This invention thus provides a promising solution to the problem of fracture and structural failure of dental resin fillings.

[0039] Once the cracks are sealed, the bacteria, deprived of water and oxygen, enter a dormant state (for Bacillus, they transform into spores). They remain dormant in the resin matrix until cracks reappear, reactivating the bacteria (for Bacillus, they release spores, which germinate in suitable environments and transform into bacteria). This initiates the self-healing process, leading to a second repair. Therefore, the dental resin composite material of the present invention can achieve multiple repairs.

[0040] Compared with the prior art, the present invention has the following characteristics:

[0041] The dental self-healing resin composite material of the present invention has good long-term self-healing performance in a simulated oral environment, effectively prevents the expansion of microcracks, solves the problem of failure of dental resin fillings after fracture, extends the service life of the fillings, reduces the number of times patients need to repeatedly fill their teeth, reduces the risk of further root canal treatment or tooth extraction of affected teeth, and significantly reduces medical costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of the self-healing principle of a dental self-healing resin composite material based on biomineralization in the present invention;

[0043] Figure 2 A schematic diagram of the conversion between spores and bacteria during the self-healing process of a dental self-healing resin composite material based on biomineralization in the present invention;

[0044] Figure 3 The crack development of the seven groups of dental self-healing resin discs and the control group of resin discs in Example 1;

[0045] Figure 4 It is the initial and final state diagrams of the self-healing experiment of the resin disc prepared with the dental self-healing resin based on Bacillus sphaericus ATCC4525 in Example 1;

[0046] Figure 5 It is the initial and final state diagrams of the self-healing experiment of the resin disc prepared with the dental self-healing resin based on Bifidobacterium longum B81617 in Example 6;

[0047] Figure 6 It is the comparison diagram of the healing rate changes between the dental self-healing resin discs of two Bacillus licheniformis, Lactobacillus reuteri, and Bifidobacterium longum in Example 1 and the control group resin discs;

[0048] Figure 7 It is the comparison diagram of the healing rate changes between the dental self-healing resin discs of Bacillus sphaericus, Lysinibacillus sphaericus, and Bacillus pasteurii in Example 1 and the control group resin discs;

[0049] Figure 8 It is the comparison diagram of the final healing rates between the seven groups of dental self-healing resin discs in Example 1 and the control group resin discs;

[0050] Figure 9 It is the crack development of the nine groups of dental self-healing resin discs and the control group resin discs in the first self-healing performance experiment in Example 2;

[0051] Figure 10 It is the comparison diagram of the healing rate changes between the nine groups of dental self-healing resin discs and the control group resin discs in the first self-healing performance experiment in Example 2;

[0052] Figure 11 It is the time-accumulative bar chart of the healing rates of the nine groups of dental self-healing resin discs and the control group resin discs in the first self-healing performance experiment in Example 2;

[0053] Figure 12 It is the comparison diagram of the final healing rates between the nine groups of dental self-healing resin discs and the control group resin discs in the first self-healing performance experiment in Example 2; where, P<0.01, P<0.001;

[0054] Figure 13 It is the crack development of the eight groups of dental self-healing resin discs and the control group resin discs in the second self-healing performance experiment in Example 2;

[0055] Figure 14 It is the comparison diagram of the healing rate changes between the eight groups of dental self-healing resin discs and the control group resin discs in the second self-healing performance experiment in Example 2;

[0056] Figure 15 It is a time - cumulative bar graph of the healing rates of eight groups of dental self - healing resin discs and control - group resin discs in the re - self - healing performance experiment in Application Example 2;

[0057] Figure 16 It is a comparison graph of the final healing rates of eight groups of dental self - healing resin discs and control - group resin discs in the re - self - healing performance experiment in Application Example 2; among which, P < 0.05, P < 0.01, P < 0.001, P < 0.0001;

[0058] Figure 17 It is a comparison of the final healing rates of eight groups of dental self - healing resin discs and control - group resin discs in the first self - healing performance experiment and the re - self - healing performance experiment in Application Example 2; among which, P < 0.05, P < 0.001;

[0059] Figure 18 It is a scanning electron microscope image of the final healing state of eight groups of dental self - healing resin discs and control - group resin discs in the first self - healing performance experiment in Application Example 2. Detailed implementation manners

[0060] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and gives detailed implementation manners and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0061] In the following embodiments, unless otherwise specified for raw material reagents or treatment techniques, it means that they are all conventional commercially available products or conventional treatment techniques in the art.

[0062] 1. Strain cultivation

[0063] Screen generally recognized as safe (GRAS) strains, and select 7 strains as follows:

[0064] Bacillus sphaericus ATCC4525 (denoted as Ball A), Bacillus licheniformis ATCC9789 (denoted as Lichen B), and the above 2 strains are purchased from Shanghai Rongmin Biotechnology Center;

[0065] Bacillus sphaericus lysine BMZ008183 (denoted as Lai), Bacillus licheniformis ATCC9859 (denoted as Di A), Bacillus pasteurii B80469 (derived from NCIM2477) (denoted as Ba), Bifidobacterium longum B81617 (derived from ATCC15702) (denoted as Chang), Lactobacillus reuteri BMZ140479 (derived from ATCC55739) (denoted as Luo), Bacillus sphaericus DSM22257 (denoted as Qiu B), and Bacillus subtilis DSM402. These 7 strains were purchased from Ningbo Mingzhou Biotechnology Co., Ltd.

[0066] The strains were added to different sterilized culture mediums at an inoculation amount of 1‰ (volume fraction) (specifically as shown in Table 1), and grown in a shaker incubator at 150 rpm for 48 hours. Thereafter, the culture medium was transferred to a nutrient agar plate with 15 g / L agar, evenly distributed on the entire surface, and left standing for 48 hours. The bacteria grown on the nutrient plate were scraped off and used as the initial strains. Then, they were added to the corresponding sterilized culture medium at 1‰ (volume fraction) and continued to grow in a shaker incubator at 150 rpm for 48 hours to obtain the bacterial liquid corresponding to bacillus or non-bacillus.

[0067] Table 1

[0068] Strain Name Number Aerobic Mode Cultivation Temperature (°C) pH Value Culture Medium Bacillus licheniforms ATCC9859 / ATCC9789 Facultative Anaerobic 37 8 NA Medium Lactobacillus reuteri BMZ140479 Anaerobic 37 7.0 MRS Agar Medium Bifidobacterium longum B81617 Anaerobic 37 7.0 BBL Agar Medium Lysinibacillus sphaericus ATCC4525 / DSM22257 Aerobic 37 7.0 NA Medium Lysinibacillus sphaericus BMZ008183 Aerobic 37 7.2 NA Medium Sporosarcina pasteurii B80469 Aerobic 30 7.0 CASO Medium + 20g Urea / L Bacillus subtilis DSM402 Aerobic 37 7.0 NA Medium

[0069] Calcium chloride, urea, yeast extract, CASO medium (soybean powder casein digest), MRS agar medium, BBL agar medium, and NA medium were all purchased from Beijing Pufei Biotechnology Co., Ltd.

[0070] 2. Spore preparation

[0071] The bacterial liquid of bacillus was pasteurized (80 °C, 20 minutes, then 5 minutes in ice water) to minimize vegetative cells, and then centrifuged for 7 minutes (7000 rpm, 4 °C, BIORIDGRE TGL-18M) to harvest spores.

[0072] 3. Preparation of encapsulated bacterial powder and nutrients

[0073] The collected spores (bacillus) and bacterial liquid (non-bacillus) were washed 5 - 6 times with deionized water respectively to make spore (bacterial) suspensions. The spore (bacterial) suspensions were centrifuged to remove the supernatant to obtain a paste. The paste was freeze-dried (BiLon, Shanghai Bilang Instrument Manufacturing Co., Ltd.) for 3 days and ground to obtain the encapsulated bacterial powder.

[0074] There are two kinds of nutrients. The first is calcium chloride: urea: yeast extract with a weight ratio of 40:65:2, and the second is calcium lactate: glucose: yeast extract with a ratio of 5:8:20.

[0075] 4. Preparation of Dental Resin Composites Containing Bacteria and Nutrients

[0076] The base resin consists of 49 wt% BisGMA, 49 wt% TEGDMA, 0.4 wt% CQ, and 1.6 wt% EDMAB, and is magnetically mixed at room temperature for 24 hours. The base resin, barium glass powder (SCHOTT AG, Landshut, NanoFine, Germany, NF180nm), nutrient powder, and bacterial powder (base resin: barium glass powder: nutrient powder: bacterial powder = 45:45:5:5, mass ratio) are mixed together using a dual-center mixing and dispersing machine SpeedMixer (DAC150.1 FVZ-K, FlackTek, Inc., Germany), and then further mixed using a three-roll mill (EXAKT 80E, Exakt Apparatebau GmbH & Co, Germany).

[0077] The dental resin composites in the following examples are all prepared based on the above method.

[0078] Example 1: Bacillus sphaericus ATCC4525

[0079] A bio-mineralization-based dental self-healing resin composite, and its preparation method includes:

[0080] 40 parts by weight of calcium chloride, 65 parts by weight of urea, and 2 parts by weight of yeast extract are fully mixed in a high-speed stirrer, and then mixed with 107 parts by weight of Bacillus sphaericus ATCC4525 (Ball A) bacterial powder, as well as the base resin and barium glass powder, to obtain.

[0081] Example 2: Lysinibacillus sphaericus BMZ008183

[0082] A bio-mineralization-based dental self-healing resin composite, and its preparation method is only different from that of Example 1 in that: the Lysinibacillus sphaericus BMZ008183 (Lys) bacterial powder is used instead of the Bacillus sphaericus ATCC4525 (Ball A) bacterial powder.

[0083] The remaining components and process conditions are the same as those in Example 1.

[0084] Example 3: Bacillus licheniformis ATCC9859

[0085] A bio-mineralization-based dental self-healing resin composite, and its preparation method is only different from that of Example 1 in that: the Bacillus licheniformis ATCC9859 (Lichen A) bacterial powder is used instead of the Bacillus sphaericus ATCC4525 (Ball A) bacterial powder.

[0086] The remaining components and process conditions are the same as those in Example 1.

[0087] Example 4: Bacillus licheniformis ATCC9789

[0088] A bio-mineralization-based dental self-healing resin composite, the difference in its preparation method compared with Example 1 is only that: the bacterial powder of Bacillus licheniformis ATCC9789 (Bacteria B) is used instead of the bacterial powder of Bacillus sphaericus ATCC4525 (Bacteria A).

[0089] The remaining components and process conditions are the same as those in Example 1.

[0090] Example 5: Bacillus pasteurii B80469

[0091] A bio-mineralization-based dental self-healing resin composite, the difference in its preparation method compared with Example 1 is only that: the bacterial powder of Bacillus pasteurii B80469 (Bacteria Ba) is used instead of the bacterial powder of Bacillus sphaericus ATCC4525 (Bacteria A).

[0092] The remaining components and process conditions are the same as those in Example 1.

[0093] Example 6: Bifidobacterium longum B81617

[0094] A bio-mineralization-based dental self-healing resin composite, the difference in its preparation method compared with Example 1 is only that: the bacterial powder of Bifidobacterium longum B81617 (Bacteria Lo) is used instead of the bacterial powder of Bacillus sphaericus ATCC4525 (Bacteria A).

[0095] The remaining components and process conditions are the same as those in Example 1.

[0096] Example 7: Lactobacillus reuteri BMZ140479

[0097] A bio-mineralization-based dental self-healing resin composite, the difference in its preparation method compared with Example 1 is only that: the bacterial powder of Lactobacillus reuteri BMZ140479 (Bacteria Ro) is used instead of the bacterial powder of Bacillus sphaericus ATCC4525 (Bacteria A).

[0098] The remaining components and process conditions are the same as those in Example 1.

[0099] Example 8:

[0100] A preparation method of a bio-mineralization-based dental self-healing resin composite includes: fully mixing 5 parts by weight of calcium lactate, 8 parts by weight of glucose, and 20 parts by weight of yeast extract in a high-speed stirrer, and then mixing with 33 parts by weight of the bacterial powder of Bacillus sphaericus ATCC4525 (Bacteria A), a base resin, and barium glass powder to obtain.

[0101] Example 9:

[0102] A dental self-healing resin composite based on biomineralization, the difference in its preparation method compared with Example 8 is only that: the bacterial powder of BMZ008183 Lysinibacillus sphaericus (Lai) is used instead of the bacterial powder of ATCC4525 Bacillus sphaericus (Qiu A).

[0103] The remaining components and process conditions are the same as those in Example 8.

[0104] Example 10:

[0105] A dental self-healing resin composite based on biomineralization, the difference in its preparation method compared with Example 8 is only that: the bacterial powder of ATCC9859 Bacillus licheniformis (Di A) is used instead of the bacterial powder of ATCC4525 Bacillus sphaericus (Qiu A).

[0106] The remaining components and process conditions are the same as those in Example 8.

[0107] Example 11:

[0108] A dental self-healing resin composite based on biomineralization, the difference in its preparation method compared with Example 8 is only that: the bacterial powder of ATCC9789 Bacillus licheniformis (Di B) is used instead of the bacterial powder of ATCC4525 Bacillus sphaericus (Qiu A).

[0109] The remaining components and process conditions are the same as those in Example 8.

[0110] Example 12:

[0111] A dental self-healing resin composite based on biomineralization, the difference in its preparation method compared with Example 8 is only that: the bacterial powder of B80469 Bacillus pasteurii (Ba) is used instead of the bacterial powder of ATCC4525 Bacillus sphaericus (Qiu A).

[0112] The remaining components and process conditions are the same as those in Example 8.

[0113] Example 13:

[0114] A dental self-healing resin composite based on biomineralization, the difference in its preparation method compared with Example 8 is only that: the bacterial powder of B81617 Bifidobacterium longum (Chang) is used instead of the bacterial powder of ATCC4525 Bacillus sphaericus (Qiu A).

[0115] The remaining components and process conditions are the same as those in Example 8.

[0116] Example 14:

[0117] A bio-mineralization-based dental self-healing resin composite, the difference in its preparation method compared with Example 8 is only that: the bacterial powder of Lactobacillus reuteri BMZ140479 (Luo) is used instead of the bacterial powder of Bacillus sphaericus ATCC4525 (Qiu A).

[0118] The remaining components and process conditions are the same as those in Example 8.

[0119] Example 15:

[0120] A bio-mineralization-based dental self-healing resin composite, the difference in its preparation method compared with Example 8 is only that: the bacterial powder of Bacillus sphaericus DSM22257 (Qiu B) is used instead of the bacterial powder of Bacillus sphaericus ATCC4525 (Qiu A).

[0121] The remaining components and process conditions are the same as those in Example 8.

[0122] Example 16:

[0123] A bio-mineralization-based dental self-healing resin composite, the difference in its preparation method compared with Example 8 is only that: 5 mg / L MnSO4·H2O (which is beneficial for spore production) is added to the culture medium used twice when culturing Qiu A, denoted as Qiu Mn.

[0124] The remaining components and process conditions are the same as those in Example 8.

[0125] Comparative Example 1:

[0126] A resin composite, the difference in its preparation method compared with Example 1 is only that: no bacterial powder is added, that is, an equal mass of nutrient powder is used to replace the bacterial powder.

[0127] The remaining components and process conditions are the same as those in Example 1.

[0128] Comparative Example 2:

[0129] A resin composite, the difference in its preparation method compared with Example 8 is only that: no bacterial powder is added, that is, an equal mass of nutrient powder is used to replace the bacterial powder.

[0130] The remaining components and process conditions are the same as those in Example 8.

[0131] Application Example 1:

[0132] This example is used to investigate the self-healing performance of the resin composites in Examples 1-7 and Comparative Example 1 (Control Group 1), and the specific experimental process is as follows:

[0133] The resin composite was filled into the silicone rubber mold of the disc and cured by irradiating both sides with a light-curing lamp (blue light, 470 nm, SLC-VIIIB, Hangzhou Sifang Medical Instrument Co., Ltd., Zhejiang, China) for 60 seconds, and then polished with silicon carbide paper (P1500 grit) to finally form disc samples with a thickness of 1 mm (Φ = 10 mm, 2 in a group), which were divided into dental self-healing resin discs and control group 1 resin discs; then a surgical blade was used to single-cut a crack on the resin disc, and the initial crack area was about 0.1 - 0.2 mm 2 ; then it was immersed in artificial saliva at 37°C and the self-healing of the resin disc was observed within 60 days, including taking pictures of the apparent morphology of the resin disc at the corresponding time points, performing basic processing on the taken pictures with Photoshop software (cropping the resin disc in the picture and making the image clear), using Image J image processing software for processing and data analysis software to calculate the area of the crack, and recording the crack area. As Figure 3 shown in the crack development of the above seven groups of dental self-healing resin discs and control group 1 resin discs, and as Figure 4 shown in the initial and final states of the self-healing experiment of the resin disc prepared with the dental self-healing resin based on Bacillus sphaericus ATCC4525 in Example 1, and as Figure 5 shown in the initial and final states of the self-healing experiment of the resin disc prepared with the dental self-healing resin based on Bifidobacterium longum B81617 in Example 6.

[0134] After collecting the data on the change in crack area of each experimental group and control group 1, data sorting and plotting were carried out using GraphPad Prism plotting design software. By subtracting the crack area of the resin disc at each experimental point from the crack area at Day0 and dividing by the crack area at Day0, the relative healing rate at this experimental point can be calculated. Calculate the data of each experimental point for each specimen, and use the software to plot and compare with control group 1, and the results are as Figure 6 shown.

[0135] It can be seen from Figure 6 and Figure 7 that the groups of Bacillus sphaericus (Bacillus sphaericus ATCC4525, Lysinibacillus sphaericus BMZ008183) had the highest relative healing rate in the first few days, followed by Bacillus licheniformis ATCC9859, and the lowest was the group of Bifidobacterium longum.

[0136] The comparison of the final healing rates is as Figure 8 shown. The final healing rate of Bacillus sphaericus ATCC4525 (sphere) was the highest, followed by Bacillus licheniformis ATCC9859 (licheniformis A), and the lowest was Bifidobacterium longum. The final healing rate was in a proportional relationship with the relative healing rate.

[0137] Application Example 2:

[0138] In this embodiment, the same method as in Application Example 1 was used to investigate the self-healing properties of the resin composites in Examples 8-16 and Comparative Example 2 (Control Group 2).

[0139] First self-healing property: At the 60th day, a resin disc sample was dried overnight in an oven at 60 °C, then weighed, and then placed on a microscope slide for microscopic observation. Finally, SEM was used to further observe the morphology and microstructure of the healed surface, and a sputtering coater was used for characterization research. To determine the elemental composition of the precipitate, EDS analysis was performed.

[0140] Second self-healing property: The resin disc after the first self-healing experiment was scratched again at the original scratch line, and the self-healing of the resin disc in artificial saliva was observed within 60 days, including taking pictures of the apparent morphology of the resin disc at the corresponding time points.

[0141] As Figure 9 shown is the crack development of the above nine groups of dental self-healing resin discs and the resin disc of Control Group 2 in the first self-healing experiment. As Figure 10 shown is the comparison of the healing of the nine groups of dental self-healing resin discs and the resin disc of Control Group 2 in the first self-healing property experiment. As Figure 11 shown is the bar chart of the time-cumulative healing rate of the nine groups of dental self-healing resin discs and the resin disc of Control Group 2 in the first self-healing property experiment. As Figure 12 shown is the comparison of the healing rate of the nine groups of dental self-healing resin discs and the resin disc of Control Group 2 on the 60th day of the first self-healing property experiment. It can be seen from Figure 12 that on the 60th day of the first self-healing property experiment, the crack healing rate on the resin discs prepared with Bacillus pasteurii (Ba) B80469, Lysinibacillus sphaericus (Lai) BMZ008183, and Bacillus licheniformis (Di A) ATCC9859 was low, and the efficiency of inducing calcium carbonate precipitation was low, but they were all better than Control Group 2; the crack healing rate on the resin discs prepared with Bacillus sphaericus + MnSO4 (Qiu Mn), Bifidobacterium longum (Chang) B81617, and Bacillus licheniformis (Di B) ATCC9789 was high, reaching 70%, and it could effectively induce calcium carbonate precipitation.

[0142] As Figure 13 shown is the comparison of the healing of the eight groups of dental self-healing resin discs and the resin disc of Control Group 2 in the second self-healing property experiment. As Figure 14 shown is the comparison of the healing of the eight groups of dental self-healing resin discs and the resin disc of Control Group 2 in the second self-healing property experiment. As Figure 15The figure shows a bar chart of the time - cumulative healing rate of eight groups of dental self - healing resin discs in the re - self - healing performance experiment and the resin discs of control group 2, as Figure 16 The figure shows the comparison of the healing rates of eight groups of dental self - healing resin discs and the resin discs of the control group on the 60th day of the re - self - healing performance experiment. From Figure 16 It can be seen that on the 60th day of the re - self - healing performance experiment, the crack healing rate on the resin discs prepared with Bacillus pasteurii B80469 (Ba), Lysinibacillus sphaericus BMZ008183 (Lai), and Bacillus licheniformis ATCC9789 (Di B) is relatively low, and the efficiency of inducing calcium carbonate precipitation is relatively low, but they are all better than control group 2; the crack healing rate on the resin discs prepared with Bacillus sphaericus DSM22257 (Qiu B), Bacillus sphaericus ATCC4525 (Qiu A), Lactobacillus reuteri BMZ140479 (Luo), and Bacillus licheniformis ATCC9859 (Di A) is relatively high, reaching 50%, which can effectively induce calcium carbonate precipitation, and the healing rate of long cracks is the highest, reaching nearly 70%, which can significantly induce calcium carbonate precipitation.

[0143] As Figure 17 The figure shows the comparison of the healing rates of eight groups of dental self - healing resin discs and the resin discs of control group 2 on the 60th day for the experimental group in the first self - healing performance experiment and the experimental group in the re - self - healing performance experiment. It can be seen that in the two experimental cycles (60 days) before and after, the healing rate of control group 2 is the lowest and there is no significant difference; there is no significant difference in the healing rates of the resin discs prepared with Bacillus pasteurii B80469 (Ba), Lactobacillus reuteri BMZ140479 (Luo), Bacillus sphaericus ATCC4525 (Qiu A), and Bifidobacterium longum B81617 (Chang); the healing rate of Bacillus licheniformis ATCC9859 (Di A) and Lysinibacillus sphaericus BMZ008183 (Lai) increases significantly in the re - self - healing performance experiment, while the healing rates of Bacillus sphaericus DSM22257 (Qiu B) and Bacillus licheniformis ATCC9789 (Di B) decrease significantly, but they are still higher than those of Bacillus pasteurii B80469 (Ba) and Lysinibacillus sphaericus BMZ008183 (Lai).

[0144] As Figure 18The SEM images of nine groups of dental self-healing resin discs and the resin discs of control group 2 on the 60th day of the first self-healing performance experiment are shown. It can be microscopically seen that the crack healing rate of Bacillus sphaericus ATCC4525 + MnSO4 (sphere Mn) is the most obvious. Bacillus licheniformis ATCC9859 (lichen A), Bacillus licheniformis ATCC9789 (lichen B), Lactobacillus reuteri BMZ140479 (reu), Bacillus sphaericus ATCC4525 (sphere A), Bacillus sphaericus DSM22257 (sphere B), Bifidobacterium longum B81617 (long), Lactobacillus reuteri BMZ140479 (reu) also have healing to a certain extent. The healing of control group 2 and Bacillus pasteurii (pas) is not obvious.

[0145] In summary, the best strain that induces calcium carbonate precipitation most obviously and can be repeatedly and effectively self-healed is Bifidobacterium longum B81617, followed by Bacillus sphaericus ATCC4525 and Lactobacillus reuteri BMZ140479. The second self-healing efficiency of Bacillus licheniformis ATCC9789 and Bacillus sphaericus DSM22257 decreases significantly, and the second self-healing efficiency of Bacillus licheniformis ATCC9859 increases significantly. In addition, Mn can effectively induce spore formation, thereby promoting calcium carbonate precipitation.

[0146] The novel dental self-healing resin composite material developed based on the biomineralization self-healing system in the present invention, as Figure 1 and Figure 2 shown, has the ability to sense and autonomously repair cracks, has better long-term self-healing performance under simulated oral environment, and is expected to solve the problem of resin filling fracture globally. When microcracks occur, the self-healing system in the composite material is activated to seal the cracks, effectively preventing the expansion of microcracks, thereby significantly improving the anti-fracture performance of the resin filling and prolonging the service life of the resin filling.

[0147] The present invention uses safe bacteria (some of which are probiotics), which can be repeatedly self-healed at the same site, innovatively solves the shortcoming that the previous self-healing materials cannot be repaired twice, and will not cause residual voids in the material, so it will not significantly affect the mechanical properties. This material can be further transformed for clinical application, thereby reducing the burden of repeated visits of patients, reducing the risk of further root canal treatment or tooth extraction of diseased teeth, significantly reducing the medical cost, having important social and economic significance, and bringing great well-being to human society.

[0148] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A dental self-healing resin composite material based on biomineralization, characterized in that: The base resin, barium glass powder, nutrient powder and bacterial powder are mixed and light cured. The mass ratio of the base resin, barium glass powder, nutrient powder and bacterial powder is 45:45:5:5; In the base resin, the mass ratio of bisphenol A propylene glycol dimethacrylate, triethylene glycol dimethacrylate, camphorquinone, and ethyl 4-(dimethylamino)benzoate is 49:49:0.4:1.6; The nutritional powder is a mixture of 5 parts by weight of calcium lactate, 8 parts by weight of glucose, and 20 parts by weight of yeast extract; The bacterial powder ATCC4525 Bacillus sphaericus bacterial powder; In the preparation of ATCC4525 sphaericus bacillus powder, 5 mg / L MnSO4·H2O was added to the culture medium.

2. An application of the biomineralized dental self-healing resin composite material according to claim 1, characterized in that: The dental self-healing resin composite material is used for preparing a tooth restorative agent.

3. The use of the biomineralized dental self-healing resin composite material according to claim 2, characterized in that: The tooth restorative agent includes dental resin cement or dental resin adhesive.

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