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1.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(1): 75-79, 2020 Feb 01.
Artigo em Chinês | MEDLINE | ID: mdl-32037770

RESUMO

Self-healing materials have rapidly developed in recent years to overcome the micro-cracks occurring in the polymer matrix. Self-healing ability offers autonomous crack repairs to prolong the service lives of polymers or polymer composites. As a main approach, extrinsic self-healing materials based on microcapsules have been applied in dentistry recently. This paper comprehensively presented and reviewed the definition and classification of self-healing materials, the synthesis of microcapsules, the calculation of self-healing efficiency, and the application of self-healing materials in dentistry. The future directions of self-healing polymers are also discussed.


Assuntos
Odontologia , Polímeros , Cápsulas
2.
Polymers (Basel) ; 11(12)2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31810258

RESUMO

The excellent performance and wide applications of phenyl polysiloxanes are largely due to their phenyl units and monomer sequences. However, the relationship between molecular structure and material properties has not been explicitly elucidated. In this work, the sequence distribution and microstructure of random copolymers were quantitatively investigated by means of a molecular dynamics (MD) simulation combined with experimental verification. The results of 29Si NMR showed that the large number of phenyl units not only shortened the length of the dimethyl units, but also significantly increased the proportion of consecutive phenyl units. The simulation results indicated the attraction between adjacent phenyl groups that were effectively strengthened intra- and inter- molecular interactions, which determined the equilibrium population of conformations and the dynamics of conformational transitions. Furthermore, the evolution of bond angle distribution, torsion distribution, and mean-squared displacements (MSD) shed light on the conformational characteristics that induce the unique thermodynamics properties and photophysical behavior of high-phenyl polysiloxanes. Differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA), spectrofluorimetry, and laser scanning confocal microscopy (LSCM) were performed to verify the conclusions drawn from the simulation. Overall, the complementary use of MD simulations and experiments provided a deep molecular insight into structure-property relationships, which will provide theoretical guidance for the rational design and preparation of high-performance siloxanes.

3.
Dent Mater ; 35(8): 1104-1116, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31104922

RESUMO

OBJECTIVE: Secondary caries and micro-cracks are the main limiting factors for dentin bond durability. The objectives of this study were to develop a self-healing adhesive containing dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP), and investigate the effects of water-aging for 12 months on self-healing, dentin bonding, and antibacterial properties for the first time. METHODS: Microcapsules were synthesized with poly (urea-formaldehyde) (PUF) shells containing triethylene glycol dimethacrylate (TEGDMA) and N,N-dihydroxyethyl-p-toluidine (DHEPT). The adhesive contained 7.5% microcapsules, 10% DMAHDM, and 20% NACP (all mass). Specimens were water-aged at 37 °C for 1 day to 12 months. Dentin bond strength was measured using extracted human teeth. A single-edge-V-notched-beam (SEVNB) method was used to measure fracture toughness KIC and self-healing efficiency. A dental plaque microcosm biofilm model was used with human saliva as inoculum. RESULTS: The microcapsules + DMAHDM + NACP group showed no decline in dentin bond strength after water-aging for 12 months, which was significantly higher than that of other groups without DMAHDM (p < 0.05). A self-healing efficiency of 67% recovery in KIC was obtained even after 12 months of water immersion, indicating that the self-healing ability was not lost in water-aging (p > 0.1). The bacteria-killing ability of this adhesive did not decline from 1 day to 12 months (p > 0.1), with biofilm CFU reduction by 3-4 orders of magnitude after the resin was water-aged for 12 months, compared to control resin. SIGNIFICANCE: This novel adhesive with triple merits of self-healing, antibacterial and remineralization functions showed an excellent long-term durability in water-aging for 12 months. This multifunctional adhesive has the potential for dental applications to heal cracks, inhibit bacteria, provide ions for remineralization, and increase the restoration longevity.


Assuntos
Cimentos Dentários , Água , Antibacterianos , Biofilmes , Pré-Escolar , Humanos , Lactente , Metacrilatos
4.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 36(5): 521-527, 2018 Oct 01.
Artigo em Chinês | MEDLINE | ID: mdl-30465346

RESUMO

OBJECTIVE: This investigation aimed to develop a novel self-healing and antibacterial dental resin composite. The effects of water immersion on its properties were also evaluated. METHODS: Microcapsules filled with healing agent of triethylene glycol dimethacrylate were synthesized on the basis of previous studies. Antibacterial resin composite contained nano-antibacterial inorganic fillers that were modified by quaternary ammonium salt with long-chain alkyl. Microcapsules were incorporated into antibacterial resin composite at mass fraction of 7.5%. A commercial resin composite named Tetric N-Ceram was used as control. The resin samples were immersed in 37 °C distilled water for different periods. A flexural test was used to measure the mechanical properties of the novel resin composite. A single-edge V-notched beam method was used to measure fracture toughness and self-healing efficiency. A dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony-forming units (CFU) and lactic acid production of biofilm on the novel resin composite were calculated to test the antibacterial property. RESULTS: Mechanical properties and fracture toughness decreased significantly after the composite was immersed in water for 30 days (P<0.05), and no significant reduction was found from then on (P>0.05). Water immersion did not weaken the self-healing capability of the composite (P>0.05), and self-healing efficiency of 64% could still be obtained even after 270 days. The antibacterial resin composite showed a strong inhibition effect on the biofilm metabolic activity versus water immersion time from 1 day to 270 days. Therefore, the composite could still have a promising antibacterial property even after being immersed in water (P<0.05). CONCLUSIONS: Water immersion could weaken the mechanical properties of the novel self-healing and antibacterial resin composite, but it insignificantly affected the self-healing and antibacterial properties of the composite.


Assuntos
Antibacterianos , Resinas Compostas , Placa Dentária , Biofilmes , Cápsulas , Humanos , Teste de Materiais , Metacrilatos , Água
5.
J Dent ; 66: 76-82, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28826985

RESUMO

OBJECTIVES: Dental luting cements are widely used to bond indirect restorations to teeth. Microcracks often lead to cement failures. The objectives of this study were to develop the first self-healing luting cement, and investigate dentin bond strength, mechanical properties, crack-healing, and self-healing durability in water-aging for 6 months. METHODS: Microcapsules of poly(urea-formaldehyde) (PUF) shells with triethylene glycol dimethacrylate (TEGDMA) as healing liquid were synthesized. Cement contained bisphenol A glycidyl dimethacrylate, TEGDMA, 4-methacryloyloxyethyl trimellitic and glass fillers. Microcapsules were added at 0%, 2.5%, 5%, 7.5%, 8.5%, 9.5% and 10%. Dentin shear bond strength was measured using extracted human teeth. Flexural strength and elastic modulus were measured. Single edge V-notched beams were used to measure fracture toughness (KIC) and self-healing. Specimens were water-aged at 37°C for 6 months and then tested for self-healing durability. RESULTS: Adding 7.5% microcapsules into cement achieved effective self-healing, without adverse effects on dentin bond strength and virgin mechanical properties (p>0.1). Excellent self-healing of 68%-77% recovery was obtained. Six months of water-aging did not decrease the self-healing efficiency, compared to 1 d (p>0.1), indicating that the self-healing property did not degrade in water-aging. CONCLUSIONS: A self-healing dental luting cement was developed for the first time. It contained fine microcapsules and exhibited an excellent self-healing efficiency, even after being immersed in water for 6 months. CLINICAL SIGNIFICANCE: The self-healing cement is promising for cementing crowns and bridges and other adhesive cement applications, to heal cracks and increase restoration longevity.


Assuntos
Cápsulas/química , Cimentos Dentários/química , Restauração Dentária Permanente , Teste de Materiais , Compostos Benzidrílicos , Bis-Fenol A-Glicidil Metacrilato/química , Resinas Compostas/química , Colagem Dentária , Materiais Dentários/química , Falha de Restauração Dentária , Módulo de Elasticidade , Vidro , Cimentos de Ionômeros de Vidro/química , Humanos , Metacrilatos/química , Polietilenoglicóis/química , Polimerização , Ácidos Polimetacrílicos/química , Resistência à Tração , Água/química
6.
ACS Appl Mater Interfaces ; 8(15): 9961-8, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-27035213

RESUMO

In this work, aminopropylmethylpolysiloxane (AMS) functionalized luminescent carbon dots (AMS-CDs) were prepared via a one-step solvothermal method. AMS-CDs could be self- or co-cross-linking with AMS to form 3D flexible transparent silicone rubbers (SRs) where CDs acted as cross-linking points, so the loading fraction of AMS-CDs could be adjusted from 10 to 100 wt %, thus modulating fluorescence properties and flexibility of silicone rubbers. Because of the self-curing property and high thermal stability, AMS-CDs were also studied in white LEDs (WLEDs), serving as a color conversion and encapsulation layer of GaN based blue LEDs simultaneously that would avoid the traditional problem of poor compatibility between emitting and packaging materials. And the color coordinate of AMS-CDs based WLEDs (0.33, 0.28) was very close to the pure white light. In addition, the obtained CDs cross-linked SRs had good transparency (T > 80%) at 510-1400 nm and high refractive indexes (1.33-1.54) that could meet the need of commercial packaging materials and optical application. AMS-CDs were also promising to be used in the UV LEDs based WLEDs according to their wide wavelength emission and flexible optoelectronic device.

7.
Dent Mater ; 32(2): 294-304, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26743969

RESUMO

OBJECTIVE: Bulk fracture is one of the primary reasons for resin-based dental restoration failures. To date, there has been no report on the use of polymerizable dental monomers with acceptable biocompatibility to develop a resin with substantial self-healing capability. The objectives of this study were to: (1) develop a self-healing resin containing microcapsules with triethylene glycol dimethacrylate (TEGDMA)-N,N-dihydroxyethyl-p-toluidine (DHEPT) healing liquid in poly(urea-formaldehyde) (PUF) shells for the first time, and (2) determine the physical and mechanical properties, self-healing efficiency, and fibroblast cytotoxicity. METHODS: Microcapsules of polymerizable TEGDMA-DHEPT in PUF were prepared via an in situ polymerization method. Microcapsules were added into a BisGMA-TEGDMA resin at microcapsule mass fractions of 0%, 5%, 10%, 15% and 20%. A flexural test was used to measure composite strength and elastic modulus. A single edge V-notched beam method was used to measure fracture toughness KIC and self-healing efficiency. RESULTS: Flexural strength and elastic modulus (mean±sd; n=6) of resin containing 5-15% microcapsules were similar to control without microcapsules (p>0.1). Adding microcapsules into the resin increased the virgin KIC, which was about 40% higher at 15% microcapsules than that with 0% microcapsules (p<0.05). Specimens were fractured and healed, then fractured again to measure the healed KIC. A self-healing efficiency of about 65% in KIC recovery was obtained with 10-20% microcapsules. All specimens with 0-20% microcapsules had fibroblast viability similar to control without resin eluents (p>0.1). SIGNIFICANCE: Self-healing dental resin containing microcapsules with polymerizable TEGDMA-DHEPT healing liquid in PUF shells were prepared for the first time with excellent self-healing capability. These microcapsules and self-healing resins containing them may be promising for dental restorations to heal cracks/damage and increase durability.


Assuntos
Materiais Biocompatíveis/química , Resinas Compostas/química , Materiais Dentários/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Toluidinas/química , Materiais Biocompatíveis/síntese química , Cápsulas , Resinas Compostas/síntese química , Materiais Dentários/síntese química , Falha de Restauração Dentária , Módulo de Elasticidade , Formaldeído/química , Polímeros/química
8.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 50(8): 469-73, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26702663

RESUMO

OBJECTIVE: To develop novel self- healing and antibacterial resin composite containing microcapsules filled with polymerizable healing monomer, and to measure its properties for further clinical application. METHODS: Microcapsules filled with healing monomer of triethylene glycol dimethacrylate were synthesized according to methods introduced in the previous research. Microcapsules were added into novel resin composite containing nano-antibacterial silica fillers grafted with long chain alkyl quaternary ammonium at mass fractions of 0, 2.5%, 5.0%, 7.5% or 10.0%. A commercial resin composite (Tetric N-Ceram) was used as control. Flexural test was used to measure resin composite flexural strength and elastic modulus. The single edge V-notched beam method was used to measure fracture toughness and self-healing efficiency. Scanning electron microscope (SEM) was used to examine the fractured surface of selected specimen for investigation of fracture mechanisms. RESULTS: The flexural strength and elastic modulus of the resin composite were (96.4 ± 14.3) MPa and (6.2 ± 1.1) GPa respectively after incorporation of microcapsules up to 7.5%, and no significant difference was found between the experimental group and the control group [(99.1 ± 11.9) MPa and (6.1 ± 1.1) GPa] (P>0.05). The self-healing efficiency of (66.8 ± 7.0)% and (79.3 ± 9.7)% were achieved for resin composite with microcapsule mass fractions at 7.5% and 10.0%. SEM image showed that irregular films covered the fractured surface. Conclusions This novel self-healing and antibacterial resin composite containing microcapsules filled with polymerizable healing monomer exhibited a promising self- healing ability, which enabled itself well up for combating bulk fracture and secondary caries in clinical application.


Assuntos
Antibacterianos , Bis-Fenol A-Glicidil Metacrilato/síntese química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Dióxido de Silício , Cápsulas , Resinas Compostas/química , Composição de Medicamentos/métodos , Módulo de Elasticidade , Humanos , Microscopia Eletroquímica de Varredura , Polimerização
9.
Artigo em Inglês | MEDLINE | ID: mdl-23973584

RESUMO

Three new 4-hydroxy aurone compounds 1-3 with dimethylamino (1), bromine (2) and cyano (3) as terminal group have been synthesized. Their photophysical properties as well as recognition properties for cyanide anions in acetonitrile and aqueous solution have also been examined. These compounds exhibit remarkable response to cyanide anions with obvious color and fluorescence change owing to hydrogen bonding reaction between cyanide anions and the O-H moiety of the sensors, which allows naked eye detection of cyanide anions.


Assuntos
Benzofuranos/química , Cianetos/análise , Ânions/análise , Colorimetria , Ligações de Hidrogênio , Espectrometria de Fluorescência
10.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 30(5): 526-9, 534, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23173321

RESUMO

OBJECTIVE: To synthesize a novel nano-antibacterial inorganic filler and provide a new way to give dental composite resin antibacterial property. METHODS: Quaternary ammonium iodide N,N,N-trimethyl-3-(trimethoxysilyl) propan-1-aminium iodide were organically synthesized firstly and then the N,N,N-trimethyl-3-(trimethoxysilyl) propan-1-aminium iodide was grafted to the nano-silica particle to synthesize the antihacterial inorganic fillers nano-silica particle grafted with quaternary ammonium salt. All the products were analyzed and identified by infrared spectrum analysis. Then Streptococcus mutans were chosen as experimental object to analysis the antibacterial property of nanoantibacterial inorganic filler. RESULTS: Quaternary ammonium salt was grafted to the surface of nano-silica particles successfully by infrared spectrum analysis. Compared with the control group, the nano-silica particle grafted with quaternary ammonium salt had a strong bactericidal effect on Streptococcus mutons (P < 0.01). CONCLUSION: The nano-silica particle grafted with quaternary ammonium salt has a strong antibacterial property and could be used to improve dental composite resin antibacterial property.


Assuntos
Antibacterianos , Streptococcus mutans , Resinas Acrílicas , Compostos de Amônio , Resinas Compostas , Poliuretanos , Compostos de Amônio Quaternário , Dióxido de Silício
11.
J Chromatogr A ; 1256: 213-21, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-22883157

RESUMO

Phenyl-ended hyperbranched carbosilane (HBC) is synthesized and immobilized onto the inner wall of a fused silica capillary column using a sol-gel process. The hybrid coating layer formed is used as a stationary phase for gas chromatography (GC) and as an adsorption medium for solid phase microextraction (SPME). Trifluoroacetic acid, as a catalyst in this process, helps produce a homogeneous hybrid coating layer. This result is beneficial for better column chromatographic performances, such as high efficiency and high resolution. Extraction tests using the novel hybrid layer show an extraordinarily large adsorption capacity and specific adsorption behavior for aromatic compounds. A 1 ppm trace level detectability is obtained with the SPME/GC work model when both of the stationary phase and adsorption layer bear a hyperbranched structure. A large amount of phenyl groups and a low viscosity of hyperbranched polymers contribute to these valuable properties, which are important to environment and safety control, wherein detection sensitivity and special adsorption behavior are usually required.


Assuntos
Cromatografia Gasosa , Silanos/química , Dióxido de Silício/química , Microextração em Fase Sólida , Adsorção , Catálise , Termogravimetria , Ácido Trifluoracético/química
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