Elastic layer material for preventing micro-leakage after dental caries repair as well as preparation method and application of elastic layer material
The elastic layer material formed by polyurethane elastomer and hyperbranched polyester acrylate prepolymer solves the problem of microleakage in composite resin dental caries repair, and achieves stress buffering and leakage protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-03-31
AI Technical Summary
Existing composite resins cannot effectively prevent microleakage in dental caries restorations, leading to tiny cracks at the restoration margins and increasing the risk of secondary caries.
The main components are polyurethane elastomer prepolymer and hyperbranched polyester acrylate prepolymer, combined with silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles. The elastic layer material is formed by photocuring to buffer the shrinkage and thermal stress of the composite resin.
It significantly reduces penetration depth, withstands thermal cycles and mechanical loads, achieves a long-lasting stress buffering effect, and prevents microleakage at the restoration edges.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of oral medical materials technology, and in particular to an elastic layer material for preventing microleakage after dental caries restoration, its preparation method, and its application. Background Technology
[0002] Since composite resins were introduced into the field of dental restoration, they have played a crucial role in the clinical treatment of caries restoration due to their excellent aesthetic properties and mechanical strength. However, despite continuous optimization of the materials themselves, a long-standing clinical challenge—microleakage after restoration and the resulting secondary caries—has not yet been fundamentally resolved.
[0003] During the light curing process, composite resins inevitably undergo polymerization shrinkage. This shrinkage generates internal stress at the bonding interface between the restoration and the tooth structure. Simultaneously, the oral environment experiences frequent temperature fluctuations, and the mismatch in thermal expansion coefficients between the composite resin and the tooth structure leads to asynchronous shrinkage and expansion, further exacerbating the accumulation of interfacial stress. When this stress exceeds the adhesive strength, micro-leakage occurs between the restoration margin and the tooth structure. To ensure a strong bond between the composite resin and the tooth structure, modern dental adhesives typically contain a high proportion of hydrophilic components, such as hydroxyethyl methacrylate (HEMA). This causes the cured adhesive layer to gradually absorb water and swell in the moist oral environment. This swelling itself can create adverse stress at the interface, allowing water molecules to gradually penetrate the hydrophilic adhesive into the composite resin. Prolonged water absorption by the composite resin leads to decreased mechanical strength, monomer dissolution, and even degradation, ultimately resulting in marginal staining, postoperative sensitivity, loosening or detachment of the restoration, significantly increasing the risk of secondary caries.
[0004] Currently, clinical practice mainly relies on optimizing adhesive properties to combat microleakage. However, existing adhesive systems have significant limitations: excessive rigidity and lack of elasticity. While existing adhesives have a high modulus after curing, providing initial high bond strength, they cannot effectively buffer and release the polymerization shrinkage stress and thermal stress of the composite resin, making the interface prone to damage due to stress concentration. Therefore, researching an elastic layer material for preventing microleakage after dental caries restoration and its preparation method, and applying it to dental caries restoration, is of great significance. Summary of the Invention
[0005] The purpose of this invention is to provide an elastic layer material for preventing microleakage after dental caries repair, as well as its preparation method and application, in order to solve the problem that composite resins in the prior art cannot avoid microleakage.
[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an elastic layer material for preventing microleakage after dental caries restoration. The raw materials of the elastic layer material include a main component, auxiliary components, diluent, mixed filler, and photoinitiator. The main component is a polyurethane elastomer prepolymer; the auxiliary component is a hyperbranched polyester acrylate prepolymer.
[0007] Preferably, the mass ratio of the polyurethane elastomer prepolymer to the hyperbranched polyester acrylate prepolymer is 10~15:1~2.
[0008] Preferably, the polyurethane elastomer prepolymer is prepared by mixing isophorone diisocyanate and polyether diol, adding dibutyltin dilaurate for a first reaction, and then adding hydroxyethyl methacrylate for a second reaction to obtain the polyurethane elastomer prepolymer.
[0009] Preferably, the amount of the diluent added is 5-15% based on the mass of the main component.
[0010] Preferably, the mixed filler comprises silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles.
[0011] Preferably, the amount of the mixed filler added is 5-10% based on the mass of the main component.
[0012] Preferably, the mass ratio of the silane-modified silica to the zinc oxide-nano hydroxyapatite antibacterial particles is 1:3~5.
[0013] Preferably, the photoinitiator is a mixed initiator composed of camphorquinone, diphenyliodonium hexafluorophosphate and N,N-dimethylaminoethyl ester.
[0014] The present invention also provides a method for preparing the above-mentioned elastic layer material for preventing microleakage after dental caries repair. The preparation method is as follows: mixing the main component, auxiliary component and diluent, adding mixed filler and photoinitiator and photocuring to obtain the elastic layer material.
[0015] The present invention also provides the application of the above-described elastic layer material for preventing microleakage after dental caries repair in oral caries repair.
[0016] The beneficial effects of this invention are: The main component of this invention, polyurethane elastomer prepolymer, forms the skeleton of the elastic layer material, ensuring that it has a certain degree of elasticity. The terminal groups of the introduced auxiliary component, hyperbranched polyester acrylate prepolymer, are efficiently cross-linked with polyurethane, so that the elastic layer has a stable three-dimensional network structure, which can significantly reduce the penetration depth of dyes.
[0017] The elastic layer material of this invention can withstand the stress generated by thermal cycling and the mechanical load from daily chewing, thus achieving a long-lasting stress buffering effect. Detailed Implementation
[0018] This invention provides an elastic layer material for preventing microleakage after dental caries restoration. The raw materials of the elastic layer material include a main component, auxiliary components, diluent, mixed filler, and photoinitiator. The main component is a polyurethane elastomer prepolymer; the auxiliary component is a hyperbranched polyester acrylate prepolymer.
[0019] In this invention, the mass ratio of the polyurethane elastomer prepolymer to the hyperbranched polyester acrylate prepolymer is 10~15:1~2, specifically 10:1, 12:1, or 15:2.
[0020] In this invention, there are no special limitations on the type of hyperbranched polyester acrylate prepolymer. The hyperesterified polyester acrylate prepolymer used in the embodiments of this invention is Sartamomer CN2301.
[0021] In this invention, the polyurethane elastomer prepolymer is prepared by mixing isophorone diisocyanate and polyether diol, adding dibutyltin dilaurate for a first reaction, and then adding hydroxyethyl methacrylate for a second reaction to obtain the polyurethane elastomer prepolymer.
[0022] In this invention, the amount of diluent added is 5-15% based on the mass of the main component, preferably 8-12%, and more preferably 10%.
[0023] In this invention, the mixed filler comprises silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles.
[0024] In this invention, the amount of the mixed filler added is 5-10% based on the mass of the main component, preferably 6-8%, and more preferably 7-9%.
[0025] In this invention, the mass ratio of the silane-modified silica to the zinc oxide-nano hydroxyapatite antibacterial particles is 1:3 to 5, specifically 1:3, 1:4, or 1:5.
[0026] In this invention, the preparation method of the zinc oxide-nano hydroxyapatite antibacterial particles is as follows: after mixing zinc salt solution and nano hydroxyapatite dispersion, the pH value is adjusted to 4~5 for reaction, the reaction product is dried and then calcined to obtain zinc oxide-nano hydroxyapatite.
[0027] In this invention, the concentration of the zinc salt solution is 0.04~0.08 mol / L, preferably 0.05~0.07 mol / L, and more preferably 0.06 mol / L; the concentration of the nano-hydroxyapatite dispersion is 0.1~0.5 g / mL, preferably 0.2~0.4 g / mL, and more preferably 0.3 g / mL; the volume ratio of the zinc salt solution to the nano-hydroxyapatite dispersion is 1:1.
[0028] In this invention, the calcination temperature is 600~800℃, preferably 650~750℃, and more preferably 700℃.
[0029] In this invention, the photoinitiator is a mixed initiator composed of camphorquinone, diphenyliodonium hexafluorophosphate and N,N-dimethylaminoethyl ester.
[0030] In this invention, the amount of photoinitiator added is 0.5-2% based on the mass of the main component, preferably 0.8-1.5%, and more preferably 1%.
[0031] In this invention, the mass ratio of camphorquinone, diphenyliodonium hexafluorophosphate and N,N-dimethylaminoethyl ester is 0.4~0.6:0.4~0.6:1, preferably 0.5:0.5:1.
[0032] The present invention also provides a method for preparing the above-mentioned elastic layer material for preventing microleakage after dental caries repair. The preparation method is as follows: mixing the main component, auxiliary component and diluent, adding mixed filler and photoinitiator and photocuring to obtain the elastic layer material.
[0033] The present invention also provides the application of the above-described elastic layer material for preventing microleakage after dental caries repair in oral caries repair.
[0034] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0035] Raw materials used in the examples and comparative examples: Polyether diol (PPG-2000, Mn=2000 g / mol); Isophorone diisocyanate (IPDI); Hydroxyethyl methacrylate (HEMA); Dibutyltin dilaurate (DBTL); Hyperbranched polyester acrylate prepolymer (Sartomer CN2301, Sartomer Inc.); Triethylene glycol dimethacrylate (TEGDMA); Camphorquinone (CQ), diphenyliodonium hexafluorophosphate (DPIHP), N,N-dimethylaminoethyl ester (DMAEMA). Silane coupling agent KH570; Preparation of polyurethane elastomer prepolymer: 4.44g IPDI and 20g PPG-2000 were added to 0.1g DBTL and stirred at 68℃ for 3h. After 3h, 3g HEMA was added and the reaction was continued for another 3h to obtain polyurethane elastomer prepolymer.
[0036] Preparation of silane-modified silica: 10g of nano-silica (particle size 10~20nm) was dispersed in 100mL of toluene, 3mL of silane coupling agent KH570 was added, and the reaction was carried out at 80℃ for 12h. After the reaction was completed, the silica was separated by centrifugation, washed three times with ethanol, and dried in a vacuum drying oven at 60℃ for 24h to obtain silane-modified silica.
[0037] Example 1
[0038] A 0.06 mol / L zinc salt ethanol solution and a 3 g / mL nano hydroxyapatite ethanol dispersion were mixed at a volume ratio of 1:1. The pH was adjusted to 4.5 and the mixture was reacted at room temperature for 6 h. The solvent was evaporated at 80 °C and the product was calcined at 700 °C for 1 h to obtain zinc oxide-nano hydroxyapatite antibacterial particles.
[0039] Take 10g of polyurethane elastomer prepolymer, 1g of SartomerCN2301 and 1g of TEGDMA and mix them. After stirring evenly, add 0.2g of silane-modified silica and 0.8g of zinc oxide-nano hydroxyapatite antibacterial particles (the mass ratio of silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles is 1:4), and 0.1g of photoinitiator (the mass ratio of CQ / DMAEMA / DPIHP is 0.5:1:0.5). After stirring evenly, remove the bubbles completely under vacuum conditions (-0.095 MPa) to obtain paste-like elastic layer prepolymer material A.
[0040] Example 2
[0041] The difference from Example 1 is that the amount of SartomerCN2301 added is 0.83g, and all other conditions are the same, resulting in paste-like elastic layer prepolymer material B.
[0042] Example 3
[0043] The difference from Example 1 is that the amount of SartomerCN2301 added is 0.67g, and all other conditions are the same, resulting in a paste-like elastic layer prepolymer material C.
[0044] Comparative Example 1
[0045] Take 10g of polyurethane elastomer prepolymer and 1g of TEGDMA, mix them evenly, then add 0.2g of silane-modified silica and 0.8g of zinc oxide-nano hydroxyapatite antibacterial particles (the mass ratio of silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles is 1:4), and 0.1g of photoinitiator (the mass ratio of CQ / DMAEMA / DPIHP is 0.5:1:0.5). After stirring evenly, remove the bubbles completely under vacuum conditions (-0.095 MPa) to obtain paste-like elastic layer prepolymer material D.
[0046] Comparative Example 2
[0047] Take 10g of polyurethane elastomer prepolymer, 0.5g of SartomerCN2301 and 1g of TEGDMA, mix them, and stir evenly. Then add 0.2g of silane-modified silica and 0.8g of zinc oxide-nano hydroxyapatite antibacterial particles (the mass ratio of silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles is 1:4), and 0.1g of photoinitiator (the mass ratio of CQ / DMAEMA / DPIHP is 0.5:1:0.5). After stirring evenly, remove the bubbles completely under vacuum conditions (-0.095 MPa) to obtain paste-like elastic layer prepolymer material E.
[0048] Comparative Example 3
[0049] Take 10g of polyurethane elastomer prepolymer, 3g of SartomerCN2301 and 1g of TEGDMA, mix them, stir evenly, then add 0.2g of silane-modified silica and 0.8g of zinc oxide-nano hydroxyapatite antibacterial particles (the mass ratio of silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles is 1:4), and 0.1g of photoinitiator (the mass ratio of CQ / DMAEMA / DPIHP is 0.5:1:0.5). After stirring evenly, remove the bubbles completely under vacuum conditions (-0.095 MPa) to obtain paste-like elastic layer prepolymer material F.
[0050] Comparative Example 4
[0051] Take 10g of polyurethane elastomer prepolymer, 1g of SartomerCN2301 and 1g of TEGDMA and mix them. After stirring evenly, add 1g of silane-modified silica and 0.1g of photoinitiator (CQ / DMAEMA / DPIHP mass ratio of 0.5:1:0.5). After stirring evenly, remove the bubbles completely under vacuum conditions (-0.095 MPa) to obtain paste-like elastic layer prepolymer material G.
[0052] The performance of the paste-like elastic layer materials of Examples 1-3 and Comparative Examples 1-4 was verified as follows: Artificial caries cavities (3mm deep, 3mm in diameter) were first cleaned with phosphoric acid solution for 10 seconds, then quickly rinsed clean, dried, and coated with adhesive (3M product). After drying with a hairdryer for 20 seconds, another layer of adhesive was applied and cured with blue light for 20 seconds. Then, an elastic layer prepolymer material was applied, cured with blue light for 20 seconds, and finally, composite resin (3M product) was filled and cured with blue light for 40 seconds.
[0053] The cured material was subjected to 1000 cycles of hot and cold, and then soaked in a 1% (mass fraction) methylene blue aqueous solution for 24 hours to obtain the penetration depth. The results are shown in Table 1.
[0054] Table 1 Penetration Depth
[0055] As shown in Table 1, the present invention can further reduce the penetration depth of methylene blue by adding hyperbranched polyester acrylate prepolymer. However, the amount of hyperbranched polyester acrylate prepolymer added needs to be controlled; too much or too little will reduce the effect. Comparing Example 1 and Comparative Example 4, it can be seen that the present invention can also improve the anti-leakage performance to a certain extent by adding zinc oxide-nano hydroxyapatite antibacterial particles.
[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. An elastic layer material for preventing microleakage after dental caries restoration, characterized in that, The raw materials of the elastic layer material include main components, auxiliary components, diluents, mixed fillers, and photoinitiators; The main component is a polyurethane elastomer prepolymer; the auxiliary component is a hyperbranched polyester acrylate prepolymer.
2. The elastic layer material for preventing microleakage after dental caries restoration according to claim 1, characterized in that, The mass ratio of the polyurethane elastomer prepolymer to the hyperbranched polyester acrylate prepolymer is 10~15:1~2.
3. The elastic layer material for preventing microleakage after dental caries restoration according to claim 1 or 2, characterized in that, The polyurethane elastomer prepolymer is prepared by mixing isophorone diisocyanate and polyether diol, adding dibutyltin dilaurate for a first reaction, and then adding hydroxyethyl methacrylate for a second reaction to obtain the polyurethane elastomer prepolymer.
4. The elastic layer material for preventing microleakage after dental caries restoration according to claim 3, characterized in that, The amount of the diluent added is 5-15% based on the mass of the main component.
5. The elastic layer material for preventing microleakage after dental caries restoration according to claim 1, 2, or 4, characterized in that, The mixed filler comprises silane-modified silica and zinc oxide-nano hydroxyapatite antibacterial particles.
6. The elastic layer material for preventing microleakage after dental caries restoration according to claim 5, characterized in that, The amount of the mixed filler added is 5-10% based on the mass of the main component.
7. The elastic layer material for preventing microleakage after dental caries restoration according to claim 6, characterized in that, The mass ratio of the silane-modified silica to the zinc oxide-nano hydroxyapatite antibacterial particles is 1:3~5.
8. The elastic layer material for preventing microleakage after dental caries restoration according to claim 4 or 7, characterized in that, The photoinitiator is a mixed initiator composed of camphorquinone, diphenyliodonium hexafluorophosphate and N,N-dimethylaminoethyl ester.
9. The method for preparing the elastic layer material for preventing microleakage after dental caries restoration according to any one of claims 1 to 8, characterized in that, The preparation method is as follows: the main component, auxiliary component and diluent are mixed, a mixed filler and a photoinitiator are added and photocured to obtain an elastic layer material.
10. The application of the elastic layer material for preventing microleakage after dental caries restoration as described in any one of claims 1 to 8 in the restoration of dental caries.