OBJECTIVES: The mechanism of the odontogenic differentiation of apical papillary cells (APCs) stimulated by bioactive glass 45S5 is still unclear. This study aims to investigate the effect of autophagy on the odontogenic differentiation of APCs stimulated by bioactive glass 45S5. METHODS: APCs were isolated and cultured in vitro, and the cell origin was identified by flow cytometry. The culture medium was prepared with 1 mg/mL 45S5, and its pH and ion concentration were determined. The experiments were divided into control, 45S5, and 3-methyladenine (3-MA) 45S5 groups. In the 45S5 group, APCs were induced to culture with 1 mg/mL 45S5. In the 3-MA 45S5 group, the autophagy inhibitor 3-MA was added to 1 mg/mL 45S5. Protein immunoblotting assay (Western blot) was used to detect the expression of autophagy-associated proteins of microtubule-associated protein 1 light-chain 3β (LC3B) and P62 after 24 h of induction culture in each group. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of bone sialoprotein (BSP), Runt-related transcription factor 2 (Runx2), dentin sialophosphoprotein (DSPP), and dentin matrix protein-1 (DMP-1) after 7 d of induction culture. Cellular alkaline phosphatase (ALP) staining analyzed cellular ALP activity at 7 d of induction, and alizarin red staining evaluated the formation of mineralized nodules at 21 d of induction. RESULTS: The pH of the 45S5 extract culture medium was 8.65±0.01, which was not significantly different from that of the control group (P>0.05). The silicon ion concentration of the 45S5 induction culture medium was (1.56±0.07) mmol/L, which was higher than that of the control group (0.08±0.01) mmol/L (P<0.05). The calcium ion concentration of the 45S5 induction culture was (1.57±0.15) mmol/L, which was not significantly different from that of the control group (P>0.05). Western blot results showed that LC3B-Ⅱ/Ⅰ ratio increased and P62 expression decreased in the 45S5 group compared with those in the control group (P<0.05). By contrast, the ratio decreased and the expression increased in the 3-MA 45S5 group compared with those in the 45S5 group (P<0.05). RT-qPCR results showed that the expression of BSP, Runx2, DMP-1, and DSPP enhanced in the 45S5 group compared with that in the control group (P<0.05), but the expression decreased in the 3-MA 45S5 group compared with that in the 45S5 group (P<0.05). Semi-quantitative analysis of ALP staining and alizarin red staining showed that the ALP activity was enhanced, and the formation mineralized nodule increased in the 45S5 group compared with those in the control group. The ALP activity weakened, and the formation mineralized nodules were reduced in the 3-MA 45S5 group compared with that those in the 45S5 group. CONCLUSIONS Cell autophagy participates in the odontogenic differentiation of APCs induced by 1 mg/mL 45S5 in vitro.
Autophagy/drug effects* ; Cell Differentiation/drug effects* ; Odontogenesis/drug effects* ; Dental Papilla/cytology* ; Humans ; Microtubule-Associated Proteins/metabolism* ; Glass/chemistry* ; Cells, Cultured ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Extracellular Matrix Proteins/metabolism* ; Ceramics/pharmacology* ; Adenine/pharmacology* ; Sialoglycoproteins/metabolism* ; Phosphoproteins/metabolism* ; Integrin-Binding Sialoprotein/metabolism* ; Alkaline Phosphatase/metabolism* ; RNA-Binding Proteins

To explore the remineralization effect of bioactive glass NovaMin on demineralized dentin specimens, and to study the physical and chemical properties of formed structure at dentin surface.
 Methods: One mm-thickness coronal dentin slices were soaked in ethylene diamine tetraacetic acid (EDTA) for 48 h to prepare the completely demineralized dentin specimens and they were divided into 2 groups: an artificial saliva group (control group) and a NovaMin powder group. The specimens were treated with artificial saliva or NovaMin powder for 2 min (2 times every day), and the interval was 8 hours. Then, the specimens were soaked in the remineralization solution. After 7 days, the scanning electron microscope (SEM), energy dispersive X-ray (EDX), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD) were used to detect dentin morphology, the physical and chemical properties of the formed structure at dentin surface.
 Results: The results of SEM showed that a defined surface layer in the NovaMin powder group could be observed in the SEM imaging at the 7th day, which completely occluded dentinal tubules; the EDX, ATR-FTIR and XRD analysis found that the mineralized layer formed at dentin surface was mainly composed of calcium and phosphate elements, which was similar to the hydroxyapatite-like crystal. However, there were no materials formed at the dentin surface in the control group, and the dentinal tubules were still open.
 Conclusion: NovaMin can remineralize the demineralized dentin specimens and occlude the dentinal tubules in hydroxyapatite-like crystal structure.
Dental Pulp Cavity ; Dentin ; chemistry ; Glass ; Microscopy, Electron, Scanning ; Saliva, Artificial ; Spectroscopy, Fourier Transform Infrared ; Tooth Remineralization ; methods

Objective: To evaluate the application of mechanically reinforced 45S5 Bioglass^®-derived glass ceramic porous scaffolds for repair of bone defect in rabbits. Methods: The BG-ZnB powders were added into the 45S5 Bioglass^® powder/paraffin microsphere mixtures and were sintered at 900℃ to obtain porous scaffolds with highly bioactive BG-ZnB of 0%, 2% or 4% of mass fraction (denoted as 45S5/ZnB0, 45S5/ZnB2, 45S5/ZnB4). Phase composition, porosity and compression properties of three kinds of as-sintered scaffolds were characterized by X-ray analysis, mercury porosimetry, and mechanical test. Thirty-six male New Zealand rabbits with critical-sized femoral bone defects were randomly divided into three groups (45S5/ZnB0 group, 45S5/ZnB2 group and 45S5/ZnB4 group, 12 for each), and were implanted with three kinds of porous scaffolds respectively. X-ray, micro-CT three-dimensional reconstruction and tissue slice staining were used to detected the efficiency of bone regeneration at 6 and 16 weeks after operation. The growth of newly formed bone was observed using HE, Masson staining and EnVision method. Results: Phase compositions of 45S5/ZnB2 and 45S5/ZnB4 were the same with 45S5/ZnB0, but the average pore size and porosity of the scaffolds were decreased with the increase of BG-ZnB content. 45S5/ZnB2 and 45S5/ZnB4 scaffolds exhibited higher compressive strength, osteogenesis and trabecular density than those of the 45S5/ZnB0 scaffold (all P<0.05). With the mechanical reinforcement of BG-ZnB increased, the content of new bone, collagen type I and osteocalcin increased. Conclusion: Low-melt BG-ZnB-assisted sintering is a promising approach to improve the mechanical strength of 45S5 Bioglass^®.
Animals ; Bone and Bones ; drug effects ; physiology ; Ceramics ; chemistry ; Glass ; Male ; Porosity ; Rabbits ; Tissue Scaffolds ; chemistry

In this study, we evaluate the influence of post surface pre-treatments on the bond strength of four different cements to glass fiber posts. Eighty extracted human maxillary central incisors and canines were endodontically treated and standardized post spaces were prepared. Four post pre-treatments were tested: (i) no pre-treatment (NS, control), (ii) sandblasting (SA), (iii) silanization (SI) and (iv) sandblasting followed by silanization (SS). Per pre-treatment, four dual-cure resin cements were used for luting posts: DMG LUXACORE Smartmix Dual, Multilink Automix, RelyX Unicem and Panavia F2.0. All the specimens were subjected to micro push-out test. Two-way analysis of variance and Tukey post hoc tests were performed (α=0.05) to analyze the data. Bond strength was significantly affected by the type of resin cement, and bond strengths of RelyX Unicem and Panavia F2.0 to the fiber posts were significantly higher than the other cement groups. Sandblasting significantly increased the bond strength of DMG group to the fiber posts.
Aluminum Oxide ; chemistry ; Composite Resins ; chemistry ; Curing Lights, Dental ; classification ; Cuspid ; pathology ; Dental Bonding ; Dental Etching ; methods ; Dental Materials ; chemistry ; Dental Stress Analysis ; instrumentation ; Glass ; chemistry ; Humans ; Incisor ; pathology ; Materials Testing ; Microscopy, Electron, Scanning ; Polymerization ; Post and Core Technique ; instrumentation ; Resin Cements ; chemistry ; Root Canal Preparation ; methods ; Self-Curing of Dental Resins ; methods ; Silanes ; chemistry ; Stress, Mechanical ; Surface Properties ; Tooth, Nonvital ; therapy

A stable, uniform, easily implemented, LC-based chemical and biological sensor substrate for orientations of liquid crystals (LCs) for a long-term is urgently needed for medical applications of the sensors. We proposed a use of spin-coating of copper perchlorate (Cu(ClO4)2), with five different concentrations(0-100mmol/L), directly on glass slides for fabricating a layer of chemically-sensitive copper ions. Observing the transmitted light with a polarized microscope, we found the luminosity of the light propagated through sensors deposited with copper ions started to weaken gradually after a certain time. The higher was the concentration of copper ions covered on the glass substrates of the sensors, the faster the weakening occurred, and the less time was needed for transmitted light to turn completely dark. But there was no change in luminosity of the transmitted light for the sensors without Cu(ClO4)2 spin-coating even after stored at room temperature (25 degrees C) for a whole day. When the Cu(ClO4)2 deposited sensors were stored within a drying oven at room temperature (25 degrees C) for 2 months, it was found that there vas almost no change in luminosity of the transmitted lights. The results showed that all the thin films of LC on glass slides functionalized with Cu(ClO4)2 could keep homeotropic and stable orientation for a long time; the concentration of Cu (ClO4)2I has an influence on the orientation response speed of LC from planar to perpendicular orientation.
Biosensing Techniques ; instrumentation ; Copper ; chemistry ; Glass ; chemistry ; Liquid Crystals ; chemistry

In this study, the relationship between mycelium morphology and laccase production was studied. The results indicated that the morphology of P. ferulae pellets was changed when glass beads were added. Laccase production showed higher with spherical mycelium than with filamentous or flocculent mycelium. In addition, the spherical mycelium with a diameter of 0.2-0.4 mm highly affected laccase production. Effect of the composition of culture medium on pellets was investigated and results indicated that various concentrations of glucose, corn meal and wheat bran were important to the formation of pellets in diameter of 0.2-0.4 mm. Besides nutrients, the addition of non-nutritional substrates influenced the distribution of P. ferulae pellets. However, the production of laccase was not promoted by non-nutritional substrates.
Culture Media ; Fermentation ; Glass ; chemistry ; Industrial Microbiology ; Laccase ; biosynthesis ; Mycelium ; cytology ; growth & development ; Pleurotus ; cytology ; enzymology

Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass (BG) before, after, and during 35% hydrogen peroxide (HP) bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups: distilled deionized water (DDW), BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order: group HP>BG before HP, BG after HP>BG during HP>DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.
Animals ; Biomimetic Materials ; analysis ; therapeutic use ; Cattle ; Ceramics ; analysis ; chemistry ; Chemical Phenomena ; Color ; Colorimetry ; Dental Enamel ; drug effects ; ultrastructure ; Electron Probe Microanalysis ; Glass ; analysis ; chemistry ; Hardness ; Hydrogen Peroxide ; pharmacology ; Hydrogen-Ion Concentration ; Microscopy, Electron, Scanning ; Protective Agents ; analysis ; therapeutic use ; Random Allocation ; Solubility ; Spectroscopy, Fourier Transform Infrared ; Time Factors ; Tooth Bleaching ; methods ; Tooth Bleaching Agents ; pharmacology ; Water ; chemistry ; X-Ray Diffraction

Animals ; Dental Cements ; chemistry ; Glass ; chemistry ; Humans ; Materials Testing ; Post and Core Technique ; instrumentation ; Quartz ; chemistry ; Root Canal Therapy ; Tooth Fractures ; prevention & control

OBJECTIVES: In 1995, an outbreak survey in Gozan-dong concluded that an association between fiberglass exposure in drinking water and cancer outbreak cannot be established. This study follows the subjects from a study in 1995 using a data linkage method to examine whether an association existed. The authors will address the potential benefits and methodological issues following outbreak surveys using data linkage, particularly when informed consent is absent. METHODS: This is a follow-up study of 697 (30 exposed) individuals out of the original 888 (31 exposed) participants (78.5%) from 1995 to 2007 assessing the cancer outcomes and deaths of these individuals. The National Cancer Registry (KNCR) and death certificate data were linked using the ID numbers of the participants. The standardized incidence ratio (SIR) and standardized mortality ratio (SMR) from cancers were calculated by the KNCR. RESULTS: The SIR values for all cancer or gastrointestinal cancer (GI) occurrences were the lowest in the exposed group (SIR, 0.73; 95% CI, 0.10 to 5.21; 0.00 for GI), while the two control groups (control 1: external, control 2: internal) showed slight increases in their SIR values (SIR, 1.18 and 1.27 for all cancers; 1.62 and 1.46 for GI). All lacked statistical significance. All-cause mortality levels for the three groups showed the same pattern (SMR 0.37, 1.29, and 1.11). CONCLUSIONS: This study did not refute a finding of non-association with a 13-year follow-up. Considering that many outbreak surveys are associated with a small sample size and a cross-sectional design, follow-up studies that utilize data linkage should become standard procedure.
Drinking Water/chemistry ; Environmental Exposure/*adverse effects ; Female ; Follow-Up Studies ; *Glass ; Humans ; Incidence ; Male ; Neoplasms/epidemiology/etiology/*mortality ; Registries ; Republic of Korea ; Risk Factors ; Time Factors

OBJECTIVETo analyze the effect of different silane coupling agents on the resin bond durability of glass-infiltrated alumina ceramic. Methods A glass-infiltrated alumina ceramic was silanized or not by three silane coupling agents. The treated ceramic surfaces were bonded with two resin cements. Their micro-bond strength were measured after 0, 30,000 thermal cycles.

RESULTSBefore thermal cycling, resin cement A had lowest bond strength to ceramic, and ceramic treated by silane coupling agent A with two cements had lower bond strength than those treated by silane coupling agent B and C. After thermal cycling, cement A had no bond strength with no treated ceramic, only ceramic treated by silane coupling agent A with two cements had more than 5 MPa bond strength.

CONCLUSIONThe glass-infiltrated alumina cermaic treated by the silane coupling agent activated by 10-methacryloyloxydecyl-dihydrogen phosphate could obtain better bond durability with different type of resin cements.