OBJECTIVE: To design and construct a graphene oxide (GO)/silver nitrate (Ag₃PO₄)/chitosan (CS) composite coating for rapidly killing bacteria and preventing postoperative infection in implant surgery. METHODS: GO/Ag₃PO₄ composites were prepared by ion exchange method, and CS and GO/Ag₃PO₄ composites were deposited on medical titanium (Ti) sheets successively. The morphology, physical image, photothermal and photocatalytic ability, antibacterial ability, and adhesion to the matrix of the materials were characterized. RESULTS: The GO/Ag₃PO₄ composites were successfully prepared by ion exchange method and the heterogeneous structure of GO/Ag₃PO₄ was proved by morphology phase test. The heterogeneous structure formed by Ag₃PO₄ and GO reduced the band gap from 1.79 eV to 1.39 eV which could be excited by 808 nm near-infrared light. The photothermal and photocatalytic experiments proved that the GO/Ag₃PO₄/CS coating had excellent photothermal and photodynamic properties. In vitro antibacterial experiments showed that the antibacterial rate of the GO/Ag₃PO₄/CS composite coating against Staphylococcus aureus reached 99.81% after 20 minutes irradiation with 808 nm near-infrared light. At the same time, the composite coating had excellent light stability, which could provide stable and sustained antibacterial effect. CONCLUSION GO/Ag₃PO₄/CS coating can be excited by 808 nm near infrared light to produce reactive oxygen species, which has excellent antibacterial activity under light.
Chitosan ; Silver Nitrate ; Titanium ; Anti-Bacterial Agents/pharmacology* ; Coloring Agents

This study was aimed to assess the new trial for minimal cavity preparation in composite restoration combined with resin infiltration, focusing at application sequence.32 human primary molars with early carious lesions around small cavity were selected and randomly divided into two groups, according to the sequence of cavity preparation (P), composite filling (F) and resin infiltration (I) as IPF and PFI group. Each group was assessed about amount of tooth reduction, features of resin infiltration, and marginal leakage around restoration.Amount of tooth reduction evaluated using micro-CT was decreased compared with the original lesion size in both groups. Features of resin infiltration were verified under confocal laser scanning microscopy. In both groups, infiltrant resin was found on all around the composite and maintained in spite of extent of decalcification even after artificial caries induction. Marginal micro leakage assessed with silver nitrate immersion and micro-CT was found more frequently in PFI group.The technique combining resin infiltration and composite restoration might ensure better adhesion prognosis as applied by the sequence of resin infiltration, cavity preparation, and composite filling. This new trial was thought meaningful in minimizing the cavity size and contributing to minimal invasive dentistry.
Dentistry ; Humans ; Immersion ; Microscopy, Confocal ; Molar ; Prognosis ; Silver Nitrate ; Tooth

New silver-containing dressings developed in recent years have brought new and powerful means for the prevention and treatment of wound infection, which promote development and progress of wound therapy. There are many kinds of silver-containing dressings, however, misunderstanding and even misapplication exist in how to choose and use these dressings. Based on literature evidence, we propose this national expert consensus on clinical application of silver-containing dressings, particularly in terms of kinds and mechanisms, indications, contraindications, rational selections in different wounds, and cautions in the clinical application of silver-containing dressings. This consensus would be helpful for medical and nursing personnels to use silver-containing dressings in wound repair field in clinic correctly and professionally.
Administration, Topical ; Bandages ; Burns ; therapy ; Consensus ; Humans ; Silver Compounds ; administration & dosage ; therapeutic use ; Surgical Wound Infection ; prevention & control ; Wound Infection ; therapy

New silver-containing dressings developed in recent years have brought new and powerful means for the prevention and treatment of wound infection, which promote development and progress of wound therapy. There are many kinds of silver-containing dressings, however, misunderstanding and even misapplication exist in how to choose and use these dressings. Based on literature evidence, we propose this national expert consensus on clinical application of silver-containing dressings, particularly in terms of kinds and mechanisms, indications, contraindications, rational selections in different wounds, and cautions in the clinical application of silver-containing dressings. This consensus would be helpful for medical and nursing personnel to use silver-containing dressings in wound repair field in clinic correctly and professionally.
Administration, Topical ; Bandages ; Burns ; therapy ; Consensus ; Humans ; Silver Compounds ; therapeutic use ; Surgical Wound Infection ; prevention & control ; Wound Healing ; drug effects ; Wound Infection ; prevention & control ; therapy

Silver nanoparticles were synthesized from the extract of Fagopyri Dibotryis Rhizoma and the optimization of synthesis was studied. The absorbance of UV-visible spectroscopy was determined under the different influencing factors such as extracting time of Fagopyri Dibotryis Rhizoma powder, reation temperature of synthesis, volume of Fagopyri Dibotryis Rhizoma extract and concentration of AgNO3 to seek the optimization conditions. By means of FT-IR, TEM, DLS and XRD, the silver nanoparticles were characterized. The results showed that when the boiling time of Fagopyri Dibotryis Rhizoma powder was 5 min, resultant temperature was 25 degrees C, the volume ratio of 0.1 g x mL(-1) Fagopyri Dibotryis Rhizoma extract and 1 mmol x L(-1) AgNO3 was 1 to 10, and the reaction time was 3.5 h, the obtained silver nanoparticles had mean size about 27 nm and Zeta potential about -34.3 mV with good uniformity and dispersivity. Therefore, the green synthesis method of silver nanoparticles using extract of traditional Chinese medicine is stable and feasible.
Fagopyrum ; chemistry ; Light ; Metal Nanoparticles ; chemistry ; ultrastructure ; Microscopy, Electron, Transmission ; Particle Size ; Plant Extracts ; chemistry ; Rhizome ; chemistry ; Scattering, Radiation ; Silver ; chemistry ; Silver Nitrate ; chemistry ; Spectroscopy, Fourier Transform Infrared ; Temperature ; X-Ray Diffraction

We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.
Anti-Bacterial Agents ; chemistry ; Graphite ; chemistry ; Light ; Nanoparticles ; chemistry ; Oxides ; chemistry ; Particle Size ; Polyethyleneimine ; chemistry ; Silver Compounds ; chemistry

OBJECTIVES: The purpose of present study was to evaluate the internal adaptation of composite restorations using different adhesive systems. MATERIALS AND METHODS: Typical class I cavities were prepared in 32 human third molars. The teeth were divided into the following four groups: 3-step etch-and-rinse, 2-step etch-and-rinse, 2-step self-etch and 1-step self-etch system were used. After the dentin adhesives were applied, composite resins were filled and light-cured in two layers. Then, silver nitrate solution was infiltrated, and all of the samples were scanned by micro-CT before and after thermo-mechanical load cycling. For each image, the length to which silver nitrate infiltrated, as a percentage of the whole pulpal floor length, was calculated (%SP). To evaluate the internal adaptation using conventional method, the samples were cut into 3 pieces by two sectioning at an interval of 1 mm in the middle of the cavity and they were dyed with Rhodamine-B. The cross sections of the specimens were examined by stereomicroscope. The lengths of the parts where actual leakage was shown were measured and calculated as a percentage of real leakage (%RP). The values for %SP and %RP were compared. RESULTS: After thermo-mechanical loading, all specimens showed significantly increased %SP compared to before thermo-mechanical loading and 1-step self-etch system had the highest %SP (p < 0.05). There was a tendency for %SP and %RP to show similar microleakage percentage depending on its sectioning. CONCLUSIONS: After thermo-mechanical load cycling, there were differences in internal adaptation among the groups using different adhesive systems.
Adhesives* ; Composite Resins ; Dentin* ; Humans ; Methods ; Molar, Third ; Silver Nitrate ; Tooth

OBJECTIVETo evaluate the antimicrobial activities of silver inorganic materials, including silver zeolite (AgZ), silver zirconium phosphate silicate (AgZrPSi) and silver zirconium phosphate (AgZrP), against oral microorganisms. In line with this objective, the morphology and structure of each type of silver based powders were also investigated.

METHODSThe antimicrobial activities of AgZ, AgZrPSi and AgZrP were tested against Streptococcus mutans, Lactobacillus casei, Candida albicans and Staphylococcus aureus using disk diffusion assay as a screening test. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the modified membrane method. Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials.

RESULTSAll forms of silver inorganic materials could inhibit the growth of all test microorganisms. The MIC of AgZ, AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0-60.0 g/L. In terms of morphology and structure, AgZrPSi and AgZrP had smaller sized particles (1.5-3.0 µm) and more uniformly shaped than AgZ.

CONCLUSIONSSilver inorganic materials in the form of AgZ, AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers. These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection.

Anti-Infective Agents ; pharmacology ; Bacteria ; drug effects ; Candida albicans ; drug effects ; Microbial Sensitivity Tests ; Powders ; pharmacology ; Silver Compounds ; pharmacology

This study reported the obtainment of the full-length cDNA of Salvia miltiorrhiza hairy roots (Abbr: SmHDR, GenBank number: JX233817), via extracting Salvia miltiorrhiza hairy roots total RNA, designing specific primers according to the transcriptome data and using the RACE strategy, and then analyzed it with bioinformatics approaches. On this basis, using the real-time PCR to detect SmHDR gene expression after Ag+ induction, and testing tanshinones contents of corresponding samples by UPLC. SmHDR has 1 647 nucleotides, and an open reading frame (ORF) encoding a protein of 463 amino acid residues. The deduced protein has isoelectric point (pI) of 5.72 and a calculated molecular weight about 51.88 kD. In the secondary structure, the percentage of alpha helix, beta turn and random coil were 35.64%, 20.30% and 44.06%, respectively. Sequence alignment and phylogenetic analysis demonstrated that SmHDR had relative close relationship to the HDR of Picrorhiza kurrooa, similar to HDR from other species of plants. Real time PCR results indicated that elicitor of Ag+ stimulated the increase of mRNA expression of SmHDR. At the same time, results of ultra performance liquid chromatography (UPLC), used to examine the accumulation of diterpenoid tanshinones in hairy roots, showed that the contents of diterpenoid tanshinones in hairy roots of Salvia miltiorrhiza were increased dramatically at 12 h after treated with Ag+, and then decreased significantly. This result showed a positive correlation between the levels of mRNA expression and tanshinones accumulation in Salvia miltiorrhiza stimulated by Ag+. The content of tanshinones was gradually raised, and it had an obvious increase at 120 h. The bioinformatics analysis and gene expression indicated that SmHDR might be involved in tanshinones biosynthesis, which laid the foundation for further study of secondary metabolic regulation mechanism of tanshinones.
Amino Acid Sequence ; Cloning, Molecular ; DNA, Complementary ; genetics ; Diterpenes, Abietane ; biosynthesis ; metabolism ; Gene Expression Regulation, Plant ; Open Reading Frames ; Oxidoreductases ; chemistry ; genetics ; metabolism ; Phylogeny ; Plant Roots ; genetics ; metabolism ; Plants, Medicinal ; genetics ; metabolism ; Protein Structure, Secondary ; RNA, Messenger ; metabolism ; Salvia miltiorrhiza ; genetics ; metabolism ; Sequence Alignment ; Silver Nitrate ; pharmacology ; Synthetic Biology

OBJECTIVES: The internal adaptation of composite restorations with or without resin modified glass ionomer cement (RMGIC) was analyzed non-destructively using Microcomputed tomography (micro-CT). MATERIALS AND METHODS: Thirty intact human teeth were used. The specimens were divided into 3 groups. In the control group, the cavities were etched with 10% phosphoric acid for 15 sec. Composite resin was filled into the cavity without adhesive. In group 1, light cured glass ionomer cement (GIC, Fuji II LC, GC) was applied as a base. The cavities were then etched, bonded, light cured and filled with composites. In group 2, the cavities were then etched, bonded, light cured and filled with composites without base application. They were immersed in a 25% silver nitrate solution. Micro-CT was performed before and after mechanical loading. One-way ANOVA with Duncan analysis was used to compare the internal adaptation between the groups before or after loading. A paired t-test was used to compare internal adaptation before and after mechanical loading. All statistical inferences were made within the 95% confidence interval. RESULTS: The silver nitrate solution successfully penetrated into the dentinal tubules from the pulp spaces, and infiltrated into the gap between restoration and pulpal floor. Group 2 showed a lower adaptation than the control group and group 1 (p < 0.05). There was no significant difference between the control group and group 1. For all groups, there was a significant difference between before and after mechanical loading (p < 0.05). CONCLUSIONS: The internal adaptation before and after loading was better when composites were bonded to tooth using adhesive than composites based with RMGIC.
Acrylic Resins ; Adhesives ; Dental Cements ; Dentin ; Floors and Floorcoverings ; Glass Ionomer Cements ; Humans ; Light ; Phosphoric Acids ; Resins, Synthetic ; Silicon Dioxide ; Silver Nitrate ; Tooth ; X-Ray Microtomography