Dental resin-based ceramic composite material and preparation method thereof

Abstract

The invention relates to a dental resin-based ceramic composite material and a preparation method thereof. The composite material comprises polymerizable resin and inorganic filler, the polymerizable resin matrix comprises dimethyl acrylic acid carbamate; the inorganic filler comprises a nano zirconium oxide filler and a nano silicon oxide filler; the polymerizable resin and / or the inorganic filler also comprises an antibacterial component. The preparation method has the following advantages: (1) a synergistic antibacterial system is constructed, and long-acting antibacterial activity is realized; (2) multiple chemical bonding interfaces are established to synergistically enhance the bonding strength; and (3) a material adaptive clinical digital chair-side repair system.

Description

Technical Field

[0001] The present invention belongs to the technical field of oral restoration, and in particular relates to a dental resin-based ceramic composite material and a preparation method thereof. Background Art

[0002] Secondary caries is the most common cause of restoration failure. The oral cavity is the natural habitat of hundreds of bacterial species. On the one hand, bacteria adhere, proliferate, and aggregate on the surface of restorations, gradually forming a dense biofilm that provides a protective barrier and continuously metabolizes to produce acid, directly eroding the hard tissue of the tooth, inducing and accelerating secondary caries. On the other hand, if the restoration-abutment bonding interface is not completely sealed, bacteria can easily enter the gap between the two, leading to secondary caries and even pulp lesions. Debonding of restorations is another key factor affecting the lifespan of restorations, and insufficient bonding strength is the core reason for the high clinical debonding rate. Therefore, ideal bonding should be able to form a strong and durable chemical and / or micromechanical bond between the restoration and the abutment, not only significantly reducing the clinical debonding rate, but also minimizing or even eliminating marginal microgaps, effectively preventing bacterial invasion and microleakage, and extending the service life of the restoration. Furthermore, high bonding strength is an important guarantee for the restoration to obtain sufficient retention and resistance, and is the basis for the oral chewing function. High adhesion "fuse" the restoration and abutment into a single unit. When the tooth is subjected to occlusal forces, the bonding between the restoration and the abutment evenly distributes the external force, preventing the abutment from being subjected to excessive localized pressure and fracture. At the same time, good adhesion helps effectively transmit external forces to the alveolar bone, maintaining its health and stability and avoiding problems such as gum recession and inflammation caused by concentrated external forces. Therefore, dental materials with both highly effective antimicrobial properties and strong bonding strength are essential for the long-term retention and functional performance of restorations.

[0003] While existing dental resin-based ceramic materials offer excellent aesthetics and machinability, they still suffer from the following deficiencies: 1. Lack of antimicrobial properties can lead to secondary problems: The lack of antimicrobial properties in the material itself can lead to microbial accumulation at the margins of restorations, which can easily lead to secondary caries and periodontal inflammation. Some researchers have attempted to impart antimicrobial properties by adding nano-zinc oxide powder to the composites. The zinc ions released by the nano-zinc oxide powder inhibit active bacterial transport and disrupt biofilm function by displacing magnesium ions, which are crucial for plaque biofilm enzyme activity. However, this release-based antimicrobial mechanism has inherent drawbacks: its antimicrobial efficacy is difficult to maintain over time as the active ingredient is consumed, and it can also weaken the mechanical strength of the material itself. 2. Inadequate bonding properties can impact the longevity of restorations: Inadequate bonding strength between restorations and tooth tissue is a pressing clinical issue, manifested by high rates of clinical disbonding (1%-3% debonding within one year and 5%-15% within five years). Furthermore, poor bonding can lead to incomplete sealing of the restoration-abutment interface, causing microleakage and facilitating bacterial entry, leading to secondary caries and even endodontic lesions. Ideal bonding should form a strong and lasting chemical and / or micromechanical bond between the restoration and the abutment, thereby reducing the clinical debonding rate and minimizing or even eliminating marginal microgaps, effectively preventing bacterial invasion and microleakage, and extending the service life of the restoration.

[0004] Currently, research on dental resin-based ceramic materials focuses primarily on improving mechanical properties such as hardness, flexural strength, wear resistance, and toughness, or streamlining the manufacturing process to increase efficiency. However, improvements in the materials' antibacterial and adhesive properties remain insufficient. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a dental resin-based ceramic composite material and a preparation method thereof. The composite material has long-lasting antibacterial properties, high bonding strength and mechanical properties of occlusal fit, and can be used for inlays, onlays, veneers, anterior and posterior crown restorations, etc.

[0006] The present invention provides a dental resin-based ceramic composite material, which includes a polymerizable resin and an inorganic filler; the polymerizable resin matrix includes urethane dimethacrylate (UDMA); the inorganic filler includes a nano-zirconia filler and a nano-silicon oxide filler; the polymerizable resin and / or the inorganic filler also include an antibacterial component.

[0007] Preferably, the antibacterial component in the polymerizable resin matrix is ​​an antibacterial resin monomer.

[0008] Furthermore, the antibacterial resin monomer includes a quaternary ammonium salt antibacterial monomer, such as bis(2-methacryloyloxyethyl)dimethylammonium bromide, methacryloyloxydodecylpyridinium bromide, methacryloyloxyethyl hexadecyldimethylammonium bromide, and the like.

[0009] Preferably, the antibacterial component in the inorganic filler is a nano-scale inorganic antibacterial agent.

[0010] Furthermore, the nano-scale inorganic antibacterial agent includes one or more of silver-loaded nanoparticles, nano-calcium phosphate, and porous zinc oxide.

[0011] Furthermore, the mass ratio of the silver-loaded nanoparticles, nano-calcium phosphate, and porous zinc oxide is 1:1:2.

[0012] Preferably, the antibacterial resin monomer accounts for 5wt% to 15wt% of the polymerizable resin matrix.

[0013] Preferably, the mass ratio of the nano-zirconia filler to the nano-silicon oxide filler is 1:2 to 2:1, and the nano-scale inorganic antibacterial agent accounts for 0.5wt% to 4wt% of the inorganic filler.

[0014] Preferably, the polymerizable resin accounts for 15 wt% to 25 wt% of the composite material, and the rest is inorganic filler.

[0015] The present invention also provides a method for preparing a dental resin-based ceramic composite material, comprising the following steps:

[0016] (1) pre-treating the inorganic filler with a silane coupling agent and then drying it; mixing the pre-treated inorganic filler with a polymerizable resin using anhydrous ethanol as a solvent, placing the mixture in an oven at 40-60° C. for 10-16 hours, and then taking it out;

[0017] (2) Grinding the product of step (1) into powder and pressing and molding to obtain an intermediate;

[0018] (3) curing the intermediate at high temperature to obtain a dental resin-based ceramic composite material.

[0019] Preferably, the drying temperature in step (1) is 100-120° C. and the drying time is 1-4 h.

[0020] Preferably, the pressurizing molding pressure in step (2) is 10-15 MPa.

[0021] Preferably, the high temperature curing temperature in step (3) is 120-140°C and the curing time is 10-14 hours.

[0022] like Figure 1 As shown, the principles of the present invention are as follows:

[0023] (1) The present invention introduces antibacterial functional groups into the resin through chemical bonds to prepare a polymer material with antibacterial activity, which can directly inhibit or kill bacteria adhering to the surface. The quaternary ammonium salt functional groups in the antibacterial resin monomer can penetrate into the bacterial cell membrane, destroy the cell membrane and cause cell death; in addition, it can also destroy the electrostatic balance of the cell membrane through ion exchange to exert antibacterial effects. The quaternary ammonium salt functional groups are introduced to synthesize quaternary ammonium salt monomers (QASMs), which are incorporated into UDMA resin monomers and polymerized under high temperature and high pressure to form a high cross-linking density network as the basic structure of the composite material and further encapsulate inorganic fillers. The quaternary ammonium salt monomer can give the resin matrix bulk antibacterial properties while maintaining the original mechanical properties of the resin. Furthermore, nano-scale inorganic antibacterial agents, such as silver-loaded nanoparticles, nano-calcium phosphate, porous zinc oxide, etc., are added to the resin-based ceramic as inorganic fillers. These inorganic antibacterial agents will synergistically enhance the overall antibacterial properties of the material by releasing antibacterial factors.

[0024] (2) Commonly used adhesives in clinical practice use methacryloyloxydecyl dihydrogen phosphate (10-MDP) and other functional monomers to treat the crown tissue surface and the abutment surface during bonding. The antibacterial resin monomer of the present invention has the same methacrylate active group as 10-MDP and can be covalently linked by free radical polymerization to ensure high bonding strength at the restoration interface. On the other hand, the inorganic filler components in resin-based ceramics contain various ions with high charge density and strong Lewis acidity (such as Zn 2+ , Ca 2+ 、Zr 4+ Plasma) can coordinately bind to the active groups in the antimicrobial resin monomer to form a corresponding complex. Therefore, the components of the resin-based ceramic can form a synergistic system of multiple chemical bonds, including covalent and coordination bonds, with the polymerizable resin, significantly enhancing the material's interfacial bonding properties.

[0025] Beneficial effects

[0026] (1) Constructing a synergistic antibacterial system to achieve long-lasting antibacterial activity: The present invention breaks through the timeliness limitation of a single antibacterial mode by using antibacterial resin monomers, or introducing nano-scale inorganic antibacterial agents into inorganic fillers, or synergizing antibacterial resin monomers and nano-scale inorganic antibacterial agents.

[0027] (2) Establishing multiple chemical bonding interfaces to synergistically enhance bonding strength: The present invention achieves synergistic enhancement of high bonding strength through multiple bonding of covalent bonds and coordination bonds formed between dimethacrylate urethane and antibacterial resin monomers.

[0028] (3) Material adaptation to clinical digital chairside restoration system: The present invention regulates the ratio of inorganic fillers (nano-zirconia and silica) and resin matrix to make the composite material have both high hardness and machinability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural principle diagram of the dental resin-based ceramic composite material of the present invention. DETAILED DESCRIPTION

[0030] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0031] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention. The quaternary ammonium salt antibacterial monomer used in the following examples is bis(2-methacryloyloxyethyl)dimethylammonium bromide (IDMA) (PubChem CID: 87148499).

[0032] Example 1 (1) Nano-zirconia filler (CAS No.: 1314-23-4), nano-silica filler (CAS No.: 7631-86-9), silver-loaded nanoparticles (CAS No.: 7440-22-4), nano-calcium phosphate (CAS No.: 7758-87-4) and porous zinc oxide (CAS No.: 1314-13-2) in a mass ratio of 48:48:1:1:2 were pretreated with a silane coupling agent as inorganic fillers and dried at 110°C for 2 hours to improve their bonding strength with the resin; the pretreated inorganic fillers were mixed with UDMA and IDMA in a mass ratio of 40:9:1 using anhydrous ethanol as solvent, and placed in a 50°C oven for 12 hours before being taken out; (2) Grinding the product of step (1) into powder and molding it under a pressure of 10 MPa to obtain an intermediate; (3) The intermediate is placed in an oven at 120° C. and cured under high temperature and high pressure for 12 hours to obtain a dental resin-based ceramic composite material.

[0033] Comparative Example 1

[0034] (1) Nano-zirconia filler and nano-silica filler with a mass ratio of 1:1 as inorganic fillers were pretreated with silane coupling agent and dried at 110°C for 2 hours to improve their bonding strength with the resin; the pretreated inorganic filler was mixed with UDMA at a mass ratio of 40:10 using anhydrous ethanol as solvent, and placed in a 50°C oven for 12 hours before being taken out;

[0035] (2) Grinding the product of step (1) into powder and molding it under a pressure of 10 MPa to obtain an intermediate;

[0036] (3) The intermediate is placed in an oven at 120° C. and cured under high temperature and high pressure for 12 hours to obtain a dental resin-based ceramic composite material.

[0037] Example 2

[0038] (1) Nano-zirconia filler and nano-silica filler with a mass ratio of 1:1 as inorganic fillers were pretreated with silane coupling agent and dried at 110°C for 2 hours to improve their bonding strength with the resin; the pretreated inorganic filler was mixed with UDMA and IDMA in a mass ratio of 40:9:1 using anhydrous ethanol as solvent, and placed in a 50°C oven for 12 hours before being taken out;

[0039] (2) Grinding the product of step (1) into powder and molding it under a pressure of 10 MPa to obtain an intermediate;

[0040] (3) The intermediate is placed in an oven at 120° C. and cured under high temperature and high pressure for 12 hours to obtain a dental resin-based ceramic composite material.

[0041] Example 3

[0042] (1) Nano-zirconia filler, nano-silicon oxide filler, silver-loaded nanoparticles, nano-calcium phosphate and porous zinc oxide as inorganic fillers in a mass ratio of 48:48:1:1:2 were pretreated with a silane coupling agent and dried at 110°C for 2 hours to improve their bonding strength with the resin; the pretreated inorganic filler was mixed with UDMA in a mass ratio of 40:10 using anhydrous ethanol as a solvent, and placed in a 50°C oven for 12 hours before being taken out;

[0043] (2) Grinding the product of step (1) into powder and molding it under a pressure of 10 MPa to obtain an intermediate;

[0044] (3) The intermediate is placed in an oven at 120° C. and cured under high temperature and high pressure for 12 hours to obtain a dental resin-based ceramic composite material.

[0045] The mechanical properties (Vickers hardness, flexural strength, fracture toughness), antibacterial properties, and bonding strength of the resin-based ceramic composite materials prepared in the above examples and comparative examples were tested.

[0046] After the hardness test surface of the sample was polished to Ra < 0.15 μm, the Vickers microhardness was characterized using a Vickers hardness tester. The load was 2 N, the holding time was 25 s, and the hardness was measured 5 times and the average value was taken.

[0047] The specimens were processed into 25 mm × 4 mm × 1.2 mm specimens, polished, cleaned, and dried. The specimens were placed in the fixture of a universal testing machine with an indenter diameter of 4 mm. The maximum breaking force of the specimens was measured at a loading speed of 0.5 mm / min and a test span of 20 mm. The three-point bending strength was then calculated using the formula.

[0048] The specimen was made into a 17mm×4mm×3mm specimen, and a V-shaped groove was ground in the center of the lower surface of the specimen using a V-notch machine. The specimen was loaded until fracture using the three-point bending test principle, and the maximum load value σ at fracture was recorded. The fracture toughness KIc (MPa·m 1 / 2 ).

[0049] The antibacterial performance test was carried out using the plate spreading counting method. Staphylococcus aureus was diluted to 10 6 CFU / mL. Add 50 μL of the diluted bacterial solution to the sample surface, cover with a film and gently press, then incubate in a constant temperature incubator at 37°C for 18 hours. After incubation, rinse with 2 mL of sterile PBS and make serial 10-fold dilutions with PBS. Spread 100 μL of the dilution evenly on LB solid medium. Incubate at 37°C for 18 hours. Remove, photograph, and record the number of colonies. Then, perform colony counts and calculate the antibacterial rate according to GB4789.2-2016.

[0050] The bonded specimens were mounted in a micro-force testing machine / universal mechanical testing machine. A pressure of 10 N was applied vertically to the specimens. After pre-curing with a light-curing lamp for 2–3 seconds, excess adhesive was removed from the surrounding area. The adhesive was then cured for an additional 20 seconds on each side. The bonded specimens were then placed in a 37°C water bath for 24 hours. Shear bond strength testing was performed at a speed of 1.0 mm / min, ensuring that the loading head remained parallel to the bonding interface and at a constant speed until the specimen detached from the tooth surface. The load to failure (N) was recorded, and the micro-shear bond strength (MPa) was calculated based on the bonded area.

[0051] Table 1 Test results

[0052]

[0053] From the results in Table 1, it can be seen that by introducing antibacterial resin monomers and / or inorganic antibacterial agents into the components, the bonding strength can be effectively improved and long-term antibacterial activity can be imparted while ensuring the mechanical properties of the resin-based ceramic material.

Claims

1. A dental resin-based ceramic composite material, characterized in that: The composite material comprises a polymerizable resin and an inorganic filler; the polymerizable resin matrix comprises dimethacrylate urethane; the inorganic filler comprises a nano-zirconia filler and a nano-silicon oxide filler; and the polymerizable resin and / or the inorganic filler further comprise an antibacterial component.

2. The dental resin-based ceramic composite material according to claim 1, characterized in that: The antibacterial component in the polymerizable resin matrix is ​​an antibacterial resin monomer.

3. The dental resin-based ceramic composite material according to claim 2, wherein: The antibacterial resin monomer includes a quaternary ammonium salt antibacterial monomer.

4. The dental resin-based ceramic composite material according to claim 1, wherein: The antibacterial component in the inorganic filler is a nano-scale inorganic antibacterial agent.

5. The dental resin-based ceramic composite material according to claim 4, characterized in that: The nano-scale inorganic antibacterial agent includes one or more of silver-loaded nanoparticles, nano calcium phosphate, and porous zinc oxide.

6. The dental resin-based ceramic composite material according to claim 1, wherein: The polymerizable resin accounts for 15wt% to 25wt% of the composite material, and the rest is inorganic filler.

7. A method for preparing the dental resin-based ceramic composite material according to any one of claims 1 to 6, comprising the following steps: (1) pre-treating the inorganic filler with a silane coupling agent and then drying it; mixing the pre-treated inorganic filler with a polymerizable resin using anhydrous ethanol as a solvent, placing the mixture in an oven at 40-60° C. for 10-16 hours, and then taking it out; (2) Grinding the product of step (1) into powder and pressing and molding to obtain an intermediate; (3) curing the intermediate at high temperature to obtain a dental resin-based ceramic composite material.

8. The preparation method according to claim 7, characterized in that: The drying temperature in step (1) is 100-120° C. and the drying time is 1-4 hours.

9. The preparation method according to claim 7, characterized in that: The pressure in the step (2) is 10-15 MPa.

10. The preparation method according to claim 7, characterized in that: The high temperature curing temperature in step (3) is 120-140°C and the curing time is 10-14 hours.

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