OBJECTIVEThis study aimed to synthesize a novel nano-antibacterial inorganic filler that contains a quaternary ammonium salt with long chain alkyl and to report the antibacterial property of dental resin composites.

METHODSA novel nano-antibacterial inorganic filler that contains a quaternary ammonium salt with long chain alkyl was synthesized based on previous research. The antibacterial property of the filler was measured. The surface of the novel nano-antibacterial inorganic filler was modified by a coupling agent to achieve a good interfacial bonding between the filler and the resin matrix. Infrared spectrum analysis was carried out. The modified novel nano-antibacterial inorganic fillers were then incorporated into the dental resin matrix. The dispersion of the fillers was observed and compared with those incorporated into Tetric N-Ceram, a commercial resin composite, under a scanning electron microscope. Streptococcus mutans was used in testing the antibacterial property of the dental resin composites.

RESULTSA quaternary ammonium salt with a long chain alkyl was successfully grafted onto the surface of nano-silica particles. The novel nano-antibacterial inorganic filler that contains quaternary ammonium salt with a long chain alkyl showed stronger antibacterial efficacy than the antibacterial inorganic filler that contains quaternary ammonium salt with a short chain alkyl. The modified novel antibacterial inorganic fillers displayed a homogeneous dispersion in the resin composite bulk and combined closely with the resin matrix, similar to the Tetric N-Ceram. The resin composites that contain novel antibacterial inorganic fillers showed stronger antibacterial effect on Streptococcus mutans compared with the control group.

CONCLUSIONThe novel nano-antibacterial inorganic filler that contains a quaternary ammonium salt with long chain alkyl showed a strong antibacterial property. It also exhibited good compatibility with the dental resin matrix after undergoing coupling treatment.

Acrylic Resins ; Anti-Bacterial Agents ; Composite Resins ; Polyurethanes ; Quaternary Ammonium Compounds ; Streptococcus mutans

OBJECTIVETo develop a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt, and to measure its effect on human dental plaque microcosm biofilm.

METHODSA novel nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt was synthesized according to methods introduced in previous research. Samples of the novel nano-antibacterial inorganic fillers were modified by a coupling agent and then added into resin composite at 0%, 5%, 10%, 15% or 20% mass fractions; 0% composite was used as control. A flexural test was used to measure resin composite mechanical properties. Results showed that a dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony-forming unit (CFU) counts, lactic acid production, and live/dead assay of biofilm on the resin composite were calculated to test the effect of the resin composite on human dental plaque microcosm biofilm.

RESULTSThe incorporation of nano-antibacterial inorganic fillers with as much as 15% concentration into the resin composite showed no adverse effect on the mechanical properties of the resin composite (P > 0.05). Resin composite containing 5% or more nano-antibacterial inorganic fillers significantly inhibited the metabolic activity of dental plaque microcosm biofilm, suggesting its strong antibacterial potency (P < 0.05).

CONCLUSIONThis novel resin composite exhibited a strong antibacterial property upon the addition of up to 5% nano-antibacterial inorganic fillers, thereby leading to effective caries inhibition in dental application.

Anti-Bacterial Agents ; pharmacology ; Biofilms ; drug effects ; Composite Resins ; chemistry ; Dental Caries ; prevention & control ; Dental Plaque ; Humans ; Lactic Acid ; Quaternary Ammonium Compounds ; pharmacology ; Saliva

To investigate the changes in T lymphocyte subsets in patients with different syndrome types infected by influenza A (H1N1) virus after treatment.

OBJECTIVETo synthesize a novel nano-antibacterial inorganic filler and provide a new way to give dental composite resin antibacterial property.

METHODSQuaternary 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.

RESULTSQuaternary 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).

CONCLUSIONThe nano-silica particle grafted with quaternary ammonium salt has a strong antibacterial property and could be used to improve dental composite resin antibacterial property.

Acrylic Resins ; Ammonium Compounds ; Anti-Bacterial Agents ; Composite Resins ; Polyurethanes ; Quaternary Ammonium Compounds ; Silicon Dioxide ; Streptococcus mutans

Objective To investigate the effect of Bortezomib on renal tubular epithelialmesenchymal transition (EMT),and to determine whether Smad ubiquitin regulatory factor 2 (Smurf2) expression induced by tumor necrosis factor-α (TNF-α) can be reversed by Bortezomib in human renal tubular epithelial cells (HK-2).Methods The HK-2 cells were divided into control group (cultured with fetal bovine serum),TNF-α group (cultured with TNF-α),Bortezomib group (cultured with Bortezomib) and experimental group (treated with Bortezomib and TNF-α together).Each group of cells was observed under an inverted microscope,and then the cells of each group were collected.RT-PCR and Western blotting were performed to detect the expression levels of fibronectin (FN),Smurf2,E-cadherin and α-smooth muscle actin (α-SMA).Results As compared with the TNF-α-treated group,the morphology of HK-2 cells was still cobblestone-like after intervention with bortezomib;however,the cellular morphology did not change significantly in the bortezomib-treated group as compared with the control group.As compared with the control group,the expression of FN mRNA and protein in the TNF-α group was significantly increased (P＜0.05).As compared with the TNF-α group,bortezomib inhibited the expression of FN induced by TNF-α (P＜0.05) There was no significant difference in the expression of FN between bortezomib-treated group and control group (P ＞0.05).As compared with the control group,E cadherin was significantly decreased in HK-2 cellsafter treatment with TNF-α,and α-SMA was significantly increased (P＜0.05).As compared with TNFα group,co-stimulation with bortezomib reversed the expression of E cadherin and α-SMA induced by TNF-α (P ＜ 0.05),but the expression of E-cadherin and α-SMA did not change significantly in the bortezomib-treated group as compared with the control group (P ＞ 0.05).As compared with the control group,TNF-α could increase the expression of Smurf2 mRNA and protein (P＜0.05),and bortezomib could inhibit the increase in Smurf2 induced by TNFα (P＜0.05).As compared with the control group,the expression of Smurf2 did not change significantly in the bortezomib-treated group (P＞0.05).Conclusion Bortezomib can antagonize the expression of Smurf2 and EMT induced by TNF-α in HK-2 cells.

OBJECTIVETo develop novel self- healing and antibacterial resin composite containing microcapsules filled with polymerizable healing monomer, and to measure its properties for further clinical application.

METHODSMicrocapsules 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.

RESULTSThe 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.

Anti-Bacterial Agents ; Bisphenol A-Glycidyl Methacrylate ; chemical synthesis ; Capsules ; Composite Resins ; chemistry ; Drug Compounding ; methods ; Elastic Modulus ; Humans ; Microscopy, Electrochemical, Scanning ; Polyethylene Glycols ; chemistry ; Polymerization ; Polymethacrylic Acids ; chemistry ; Silicon Dioxide

OBJECTIVE: This investigation aimed to develop a novel antibacterial dental adhesive containing nanoantibacterial inorganic fillers and measure the dentin bonding strength, mechanical properties, and antibacterial property of the novel adhesive in vitro. METHODS: Novel nanoantibacterial inorganic fillers containing quaternary ammonium salt with long chain alkyl were synthesized on the basis of previous research. These novel nanoantibacterial inorganic fillers were added into the dental adhesive to prepare novel nanoantibacterial dental resin composite at mass fractions of 0%, 2.5%, 5.0%, 7.5%, and 10%; 0% was used as control. Dentin shear bonding test was used to evaluate the bonding strength. Flexural test was utilized to measure the novel resin composite flexural strength and elastic modulus. A dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony forming unit, lactic acid production, and live/dead assay of the biofilm on novel dental adhesive were calculated to assess the effect of novel dental adhesive on human dental plaque microcosm biofilm. RESULTS: The dentin shear bond strength, flexural strength, and elastic modulus were 28.9 MPa, 86.6 MPa, and 4.2 GPa, respectively, when the nanoantibacterial inorganic filler mass fraction in the dental adhesive reached approximately 5.0%. Consequently, the dentin shear bond strength and mechanical properties significantly increased. Addition of 2.5% nanoantibacterial inorganic fillers into the dental adhesive exerted no adverse effect on the mechanical properties significantly (P>0.05). Dental adhesive containing 5% or more nanoantibacterial inorganic fillers inhibited the metabolic activity of the dental plaque microcosm biofilm significantly, thereby displaying a strong antibacterial potency (P<0.05). CONCLUSIONS This novel antibacterial dental adhesive, which contained 5.0% nanoantibacterial inorganic filler, exhibited promising bonding strength, mechanical property, and antibacterial ability. Hence, this adhesive can be potentially used in caries inhibition in dental application.
Anti-Bacterial Agents ; Biofilms ; Dental Bonding ; Dental Cements ; Dental Plaque ; prevention & control ; Humans ; Materials Testing ; Methacrylates ; Resin Cements ; Shear Strength

OBJECTIVES: The current study aimed to investigate the bonding properties of a novel low-shrinkage resin adhesive containing expanding monomer and epoxy resin monomer after thermal cycling aging treatment. METHODS: Expanding monomer of 3,9-diethyl-3,9-dimethylol-1,5,7,11-tetraoxaspiro-[5,5] undecane (DDTU) as an anti-shrinkage additive and unsaturated epoxy monomer of diallyl bisphenol A diglycidyl ether (DBDE) as a coupling agent were synthesized. A blend of DDTU and DBDE at a mass ratio of 1∶1, referred to as "UE", was added into the resin matrix at the mass fraction of 20% to prepare a novel low-shrinkage resin adhesive.Then, the methacrylate resin adhesive without UE was used as the blank control group, and a commercial resin adhesive system was selected as the commercial control group. Moreover, the resin-dentin bonding and micro-leakage testing specimens were prepared for the thermal cycling aging treatment. The bonding strength was tested, the fracture modes were calculated, the bonding fracture surface was observed by scanning electron microscope (SEM), and the dye penetration was used to evaluate the tooth-restoration marginal interface micro-leakage. All the data were analyzed statistically. RESULTS: After aging, the dentin bonding strength of the experimental group was (19.20±1.03) MPa without a significant decrease (P>0.05), that of the blank control group was (11.22±1.48) MPa with a significant decrease (P<0.05) and that of the commercial control group was (19.16±1.68) MPa without a significant decrease (P>0.05). The interface fracture was observed as the main fracture mode in each group after thermal cycling by SEM. The fractured bonding surfaces of the experimental group often occurred on the top of the hybrid layer, whereas those of the blank and commercial control groups mostly occurred on the bottom of the hybrid layer. Micro-leakage rating counts of specimens before and after thermal cycling were as follows: the experimental group was primarily 0 grade, thereby indicating that a relatively ideal marginal sealing effect could be achieved (P>0.05); meanwhile, the blank control group was primarily 1 grade, and the penetration depth of dye significantly increased after thermal cycling (P<0.05); the commercial control group was primarily 0 grade without statistical difference before and after thermal cycling (P>0.05), while a significant difference was observed between the commercial control group and experimental group after thermal cycling (P<0.05). CONCLUSIONS The novel low-shrinkage resin adhesive containing 20%UE exhibited excellent bonding properties even after thermal cycling aging treatment, thereby showing a promising prospect for dental application.
Composite Resins ; Dental Bonding ; Dental Cements ; Surface Properties ; Resin Cements ; Dentin-Bonding Agents ; Dentin ; Materials Testing ; Microscopy, Electron, Scanning