This study was done to determine if there is any difference in microleakage between experimental composite resins, in which various proportions of three component photoinitiators (Camphoroquinone, OPPI, Amine) were included. Four kinds of experimental composite resin were made by mixing 3.2% silanated barium glass (78 wt.%, average size; 1 microm) with each monomer system including variously proportioned photoinitiator systems used for photoinitiating BisGMA/BisEMA/TEGDMA monomer blend (37.5:37.5:25 wt.%). The weight percentage of each component were as follows (in sequence Camphoroquinone, OPPI, Amine): Group A - 0.5%, 0%, 1% / Group B - 2%, 0.2%, 2% / Group C - 0.2%, 1%, 0.2% / Group D - 1%, 1%, 2%. Each composite resin was used as a filling material for round class V cavities (diameter: 2/3 of mesiodistal width; depth: 1.5 mm) made on extracted human premolars and they were polymerized using curing light unit (XL 2500, 3M ESPE) for 40 s with an intensity of 600 mW/cm2. Teeth were thermocycled five-hundred times between 50degrees C and 550degrees C for 30s at each temperature. Electrical conductivity (microA) was recorded two times (just after thermocycling and after three-month storage in saline solution) by electrochemical method. Microleakage scores of each group according to evaluation time were as follows [Group: at first record / at second record; unit (microA)]: A: 3.80 (0.69) / 13.22 (4.48), B: 3.42 (1.33) / 18.84 (5.53), C: 4.18 (2.55) / 28.08 (7.75), D: 4.12 (1.86) / 7.41 (3.41). Just after thermocycling, there was no difference in microleakage between groups, however, group C showed the largest score after three-month storage. Although there seems to be no difference in microleakage between groups just after thermocycling, composite resin with highly concentrated initiation system or classical design (Camphoroquinone and Amine system) would be more desirable for minimizing microleakage after three-month storage.
Barium ; Barium Compounds ; Bicuspid ; Composite Resins ; Electric Conductivity ; Glass ; Humans ; Light ; Polymers ; Silicon Dioxide ; Terpenes ; Tooth

OBJECTIVEAs a new kind of reinforcing filler, ultrafine diamond (UFD) is added into photocurable composite core materials. The properties of the materials are then measured to see if there is any improvement.

METHODSDifferent content of barium glass and UFD were added into resin matrix to fabricate six groups of photocurable composite core materials. For each group of the materials, the flexural strength, Vicker's micro-hardness and depth of cure were measured. Data of the flexural strength and Vicker's micro-hardness was then collected and analyzed by One-Way ANOVA.

RESULTSFor the two kinds of composites with barium glass of 60% and 70%, only a small quantity of modified UFD with 0.2% weight percentage could improve the flexural strength of the composites by 34% and 21% respectively, the microhardness was improved by 23% and 30% respectively. The depth of cure of the composite core materials were more than 2 mm, which had reached the demand of the corresponding ISO criteria. The addition of UFD could make the composite core materials darker and grayer.

CONCLUSIONMicro-quantity of UFD can improve the mechanical properties of composite resins notably, and it will not affect the curability of the materials, but the defect in the color need to be reformed.

Barium Compounds ; Composite Resins ; Diamond ; Hardness ; Materials Testing ; Methacrylates ; Pliability ; Silicon Dioxide

OBJECTIVETo study the monomolecular coverage of the silane coupling agent gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) on the barium glass filler surface.

METHODSKubelka-Munk (K-M) function values of the isolated OH-groups on the barium glass filler surface, which were based on the change of gamma-MPS concentrations, were measured using the quantitative analysis of the diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. When all of the isolated OH-groups on the filler surface disappeared (where the K-M function values was zero), the monomolecular coverage of the gamma-MPS molecules on the filler surface was indicated by the linear regression analysis.

RESULTSThe relationship tallied with negative linear correlation between the K-M function values of the isolated OH-groups on the barium glass surface and the concentrations of gamma-MPS. Each gamma-MPS molecule occupied 0.21 nm(2) when the monomolecular coverage was formed on the barium glass surface.

CONCLUSIONSThe result of this study indicated the optimal amount of silane coupling agent on silanated barium glass filler during the production of resin composite.

Barium Compounds ; chemistry ; Composite Resins ; chemistry ; Dental Materials ; chemistry ; Methacrylates ; chemistry ; Silanes ; chemistry ; Silicon Dioxide ; chemistry

The aim of this study was to evaluate the effect of fiber direction on the polymerization shrinkage of fiber-reinforced composite. The disc-shaped flowable composite specimens (d = 10 mm, h = 2 mm, Aeliteflo A2, Bisco, Inc., IL, USA) with or without glass fiber bundle (X-80821P Glass Fiber, Bisco, Inc., IL, USA) inside were prepared, and the longitudinal and transversal polymerization shrinkage of the specimens on radial plane were measured with strain gages (Linear S-series 350omega, CAS, Seoul, Korea). In order to measure the free polymerization shrinkage of the flowable composite itself, the disc-shaped specimens (d = 7 mm, h = 1 mm) without fiber were prepared, and the axial shrinkage was measured with an LVDT (linear variable differential transformer) displacement sensor. The cross-section of the polymerized specimens was observed with a scanning electron microscope to examine the arrangement of the fiber bundle in composite. The mean polymerization shrinkage value of each specimen group was analyzed with ANOVA and Scheffe post-hoc test (alpha=0.05). The radial polymerization shrinkage of fiber-reinforced composite was decreased in the longitudinal direction of fiber, but increased in the transversal direction of fiber (p<0.05). We can conclude that the polymerization shrinkage of fiber-reinforced composite splint or restoratives is dependent on the direction of fiber.
Barium Compounds ; Bisphenol A-Glycidyl Methacrylate ; Composite Resins ; Displacement (Psychology) ; Electrons ; Glass ; Polymerization ; Polymers ; Silicon Dioxide ; Splints ; Sprains and Strains

Eosinophilic Esophagitis (EoE) is a chronic inflammatory disease of the esophagus triggered by an immune response that leads to symptoms of dysphagia, chest pain, and food impaction. EoE is a clinicopathologic syndrome that requires clinical symptoms and pathologic findings for a diagnosis. The inflammatory process and eosinophilic infiltration of the esophagus in EoE lead to fibrosis and structural changes within the esophagus that cause esophageal dysfunction. The biomechanics of the esophageal function in EoE have been explored using manometry, impedance planimetry, barium esophagograms, and endoscopic ultrasound. These studies have identified several biomechanical changes to the esophagus in EoE including pan-esophageal pressurization on manometry, changes in esophageal compliance with decreased distentisbility by impedance planimetry, decreased esophageal luminal diameter by esophagograms, and dysfunction in the esophageal longitudinal muscles by endoscopic ultrasound. Treatments for the disease involve dietary changes, immunosuppressive drugs, and dilation techniques. However, the data regarding the effect of these therapies on altering mechanical properties of the esophagus is limited. As the pathogenesis of esophageal dysfunction in EoE appears multifactorial, further study of the biomechanics of EoE is critical to better diagnose, monitor and treat the disease.
Barium ; Biomechanics ; Chest Pain ; Compliance ; Deglutition Disorders ; Dilatation ; Electric Impedance ; Eosinophilic Esophagitis ; Eosinophils ; Esophagus ; Fibrosis ; Manometry ; Muscles ; Organothiophosphorus Compounds ; Phenobarbital

OBJECTIVETo investigate the biocompatibility of polyurethane-BaFe(12)O(19) magnetic composite microsphere as a new endovascular embolization material.

METHODSThe biocompatibility of BaFe(12)O(19) particle was evaluated in vitro using Ames test, cell toxicity test, acute and subacute systemic toxicity test, hemolysis test, bleeding time and clotting time test and blood clotting function assay.

RESULTSAmes test showed that the MR values of this particle leaching solution were all less than 2 without mutagenicity. Cell toxicity test showed that leaching solution at different concentrations had grade I toxicity on L929 cells. Acute and subacute systemic toxicity test showed that the experimental animals had good general condition without obvious pathological abnormality. The hemolysis rate of experimental group was 2.43%, which met the ISO standard (no more than 5%). The bleeding time and clotting time in mice were comparable between the experimental group and control group (P>0.05). There were no significant differences in blood clotting function between experimental group and control group (P>0.05).

CONCLUSIONThe material has no obvious toxicity or mutagenicity, and does not cause hemolysis or hemopexis or affect the bleeding time and clotting time. Polyurethane-BaFe(12)O( 19) particle possesses satisfactory biocompatibility.

Animals ; Barium Compounds ; chemistry ; toxicity ; Biocompatible Materials ; Cell Line, Tumor ; Embolization, Therapeutic ; instrumentation ; Ferric Compounds ; chemistry ; toxicity ; Microspheres ; Polyurethanes ; chemistry ; toxicity ; Toxicity Tests

OBJECTIVES: The purpose of this study was to determine the effect of barium on gene expression in differentiation of human mesenchymal stem cells into osteoblasts in vitro. METHODS: Human bone marrow stem cells were cultured for 0~14 days in osteogenic differentiation medium with strontium chloride (SrCl2) and barium chloride (BaCl2). Alkaline phosphatase (ALP) activity staining was the method selected for measuring osteoblast differentiation. Total ribonucleic acid (RNA) was extracted after 1, 3, 7, and 14 days, and analysis of runt-related transcription factor 2/core-binding factor alpha 1 (Runx2/Cbfa1), bone morphogenetic protein-2 (BMP-2), and bone sialoprotein (BSP) gene expression was performed by real-time reverse transcriptase (RT)-polymerase chain reaction (PCR). RESULTS: Barium and strontium had a superior enhancing effect on cell proliferation when compared to cells cultured in media without strontium or barium. BaCl2 produced a 2-fold increase in the expression of Runx2/Cbfa1 at 14 days. SrCl2 (0.1~0.3 mM) produced a 2-fold increase in the expression of Runx2/Cbfa1 at 14 days. Barium produced a 1.5-fold increase in the expression of BMP-2 on days 1 or 3. Expression of BSP was increased 1.5~1.7- and 2-fold on days 1 and 14 by barium and strontium, respectively. CONCLUSION: Barium-like strontium is considered one of the important factors in inducing mesenchymal stem cells to differentiate into osteoblasts with further enhancement on bone formation.
Alkaline Phosphatase ; Barium ; Barium Compounds ; Bone Marrow ; Cell Proliferation ; Chlorides ; Durapatite ; Gene Expression ; Humans ; Integrin-Binding Sialoprotein ; Mesenchymal Stromal Cells ; Osteoblasts ; Osteogenesis ; RNA ; RNA-Directed DNA Polymerase ; Stem Cells ; Strontium ; Transcription Factors

Ischemic colitis is the most prevalent form of ischemic vascular compromise of the gastrointestinal tract. Although frequent in the elderly with co-morbidity, numerous pharmacologic agents including diuretics, pseudoephedrine, nonsteroidal anti-inflammatory drugs, oral contraceptives, and cocaine may produce colonic ischemia by mesenteric vasoconstriction. Oral hyperosmotic laxatives are frequently used as cleansing agents in bowel preparation for both radiologic and endoscopic studies. They are regarded as safe and effective agents, but can produce a rapid osmotic-mediated fluid loss, resulting in transient meseneteric hypoperfusion and subsequent ischemic colitis. Here, we describe a case of acute ischemic colitis caused by the oral osmotic laxative magnesium citrate, which was given for bowel preparation before a barium enema in a young healthy patient without underlying disease.
Aged ; Barium ; Citric Acid ; Cocaine ; Colitis ; Colitis, Ischemic ; Colon ; Colonoscopy ; Contraceptives, Oral ; Detergents ; Diuretics ; Enema ; Gastrointestinal Tract ; Humans ; Ischemia ; Laxatives ; Magnesium ; Organometallic Compounds ; Pseudoephedrine ; Vasoconstriction

The aim of this study was to obtain the alginate gels which could have proper compressive strength and excellent permeability for cell proliferation and could have more promising potentials in the application of tissue engineering. Through the reaction of the carboxyl of the alginate and the amino of methacrylic acid, methylacrylic was generated into alginate long chain which could be enhanced by the polymerization of double bond under thermal reaction condition. And then alginate gel beads were prepared using the mixture of calcium chloride and barium chloride solution as cationic crosslinker, and the compressive modulus and permeability of the prepared alginate gel beads were investigated. When the ratio of barium ions to calcium ions was 5:5, the compression modulus was 189.7 kPa, and it showed the best permeability for trypsin with molecular weight of 24 kDa and entrapment effect for bovine serum albumin with molecular weight of 67 kDa. Compared to compositions of other ratios, the alginate gel beads made in 5:5 mixture indicated excellent compressive modulus and permeability. These results indicated that the alginate hydrogel beads with the ratio of barium ions to calcium ions being 5:5 have a potential application in tissue engineering as a support material and encapsulating materials in cell culture.
Alginates ; chemistry ; Barium Compounds ; chemistry ; Calcium Chloride ; chemistry ; Cations ; Cell Culture Techniques ; Cell Proliferation ; Chlorides ; chemistry ; Cross-Linking Reagents ; chemistry ; Gels ; chemistry ; Metals ; Polymethacrylic Acids ; chemistry ; Tissue Engineering

OBJECTIVETo investigate the effects of inward rectifier potassium channel blockers (BaCl2, CsCl) on the functions of endothelial progenitor cells (EPCs).

METHODSDensity gradient centrifugation-isolated rat hone marrow mononuclear cells were cultured in vitro. EPCs were harvested and seeded on six culture dish when cells grew to 3-5 passages. Before testing the EPCs were synchronized with M199, which contain 2% fetal calf serum. In the end, EPCs were treated with different intervention. The experiment mainly included two parts: (1) BaCl2 (100 micromol/L) and free BaC2 of Tyrodes solution; (2) CsCl (1 mmol/L) and control. Cell pretreated with blockers above mentioned for 12 h, then the gene expression of stromal cell-derived factor-1 (SDF-1), epoprotenol (PGI2) were assessed, beyond that the ability of adhesion, migration were assayed with different tests. In addition, the medium was collected when EPCs were treated for 3 days. The levels of SDF-1 were measured by sandwich enzyme-linked immunosorbent assay (ELISA). Going even further, EPCs were treated with the signal pathway blockers in advance, after repeat the above steps, in order to analyze the change of SDF-1 and then discuss its mechanism.

RESULTSCompared with control group, BaCl2, CsCl could increase EPC adhesion and migration to same extent. Moreover, the gene expression of SDF-1, PGI2 was significantly up-regulated and the production of SDF-1 increased evidently. Furthermore, the mechanism of SDF-1 secretion increasing mainly was associated with eNOS signaling pathways.

CONCLUSIONBa2+ and Cs+ play important roles in increasing EPCs functions, such as adhesion, migration and secretion.

Animals ; Barium Compounds ; pharmacology ; Cells, Cultured ; Cesium ; pharmacology ; Chemokine CXCL12 ; metabolism ; Chlorides ; pharmacology ; Endothelial Cells ; cytology ; Enzyme-Linked Immunosorbent Assay ; Potassium Channels, Inwardly Rectifying ; antagonists & inhibitors ; physiology ; Rats ; Stem Cells ; cytology