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1.
Integr Pharm Res Pract ; 12: 87-99, 2023.
Article in English | MEDLINE | ID: mdl-37124706

ABSTRACT

Purpose: Contributing to public health by supporting people's health is the social mission of community pharmacists. This multicenter, prospective case series study aimed to evaluate changes in people's behavior and health states through community pharmacists' self-care support for healthy lifestyles. Methods: The participants were recruited from voluntary adults aged ≥20 years who agreed to participate in the study, at community pharmacies in Gifu, Japan, between June and September 2021. Participants self-managed their lifestyles for six months while recording their health data, including blood pressure (BP), daily using devices (home BP monitor, body composition monitor, and activity meter) and a diet-recording app. They received lifestyle modification support at pharmacies at least once per month. Participants' subjective health status, attitudes, and behavioral changes were evaluated using self-report questionnaires. Due to the exploratory nature of this study, data were primarily analyzed descriptively. Results: Fifty-four participants aged 20 to 77 (mean age: 49.6 years; female participant proportion: 55.6%) participated in this study. Their mean weekly BP shifted almost horizontally from baseline to week 24 (systolic BP: 118.8 to 121.5 mmHg; diastolic BP: 76.1 to 77.5 mmHg). At six months, 38.9% and 35.2% of the participants reported better overall health and mental health, respectively, than at baseline. Over 85% of the participants became more proactive in improving their lifestyles regarding salt intake, diet, weight loss, and exercise, although drinking and smoking habits were more challenging to change. All the participants reported that they intended to continue to improve their lifestyle. Conclusion: The participants' responses suggested that community pharmacists' support helped increase participants' health awareness and promote their health-enhancing behaviors. However, its impact on health parameters should be further examined in future studies. More vigorous, tailored self-care support may be worth considering in developing a more effective, community-fitted health/well-being support system in Japan.

2.
Odontology ; 110(1): 70-80, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34272634

ABSTRACT

The aim of this study was to investigate the effect of two different priming agents and/or sandblasting on the shear bond strength of self-adhesive resin cement to the resin composite for core build-up to CAD/CAM blocks. A CAD/CAM ceramic block (GN I CERAMIC BLOCK, GC) and a CAD/CAM resin composite block (CERASMART 270, GC), a self-adhesive resin cement (G-CEM ONE, GC) and two different primers, i.e., a multipurpose primer (MP; G-Multi Primer, GC) and a ceramic primer (CP; Ceramic Primer II, GC), were examined. Five different surface treatments with priming and/or sandblasting and no surface treatment (control) were performed on the block. Disk specimens (6 mm in diameter and 4 mm in thickness) made from core composites were cemented to the blocks after the surface treatments. Then, the 24-h shear bond strength of the resin cement between the block and the resin composite core was determined (n = 15). Sandblasted specimens had greater bond strength than controls for both blocks (p < 0.05). Priming to both blocks significantly increased the bond strength of resin cement compared to that of controls (p < 0.05). Although Weibull moduli were not significantly changed among all surface treatments for both blocks, the strengths with 5% and 95% failure probability of sandblasted and/or primed blocks were estimated to be greater than those of controls. The combination of priming and sandblasting to the CAD/CAM composite and ceramic surface was effective in increasing the bond strength of the resin cement.


Subject(s)
Dental Bonding , Resin Cements , Ceramics , Dental Cements , Materials Testing , Shear Strength , Surface Properties
3.
Dent Mater J ; 40(2): 364-378, 2021 Mar 31.
Article in English | MEDLINE | ID: mdl-33100298

ABSTRACT

This study examined the effects of sandblasting, hydrofluoric acid etching and priming on the shear bond strength of self-adhesive resin cement between seven different CAD/CAM resin composites and a resin composite core material at 24-h after cement mixing. Five surface treatments [control (C), sandblasting (S), priming (P), sandblasting with priming (SP), and 9% HF etching with priming (HFP)] were performed respectively for disc specimens of CAD/CAM blocks. There were no significant differences in bond strength among the C, S, and P, except for one block (p>0.05). SP showed a greater bond strength than S. Weibull moduli were not changed significantly among all treatments for all blocks, whereas the strengths with 5% and 95% failure probability of SP and HFP showed greater values than the others. The bond strengths of HFP were comparable to those of SP. Priming after sandblasting or HF etching could be effective to increase the bond strength of CAD/CAM blocks.


Subject(s)
Dental Bonding , Resin Cements , Ceramics , Composite Resins , Dental Cements , Materials Testing , Shear Strength , Surface Properties
4.
Mater Sci Eng C Mater Biol Appl ; 116: 111146, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32806323

ABSTRACT

Tooth root surfaces restored with dental resin composites exhibit inferior biocompatibility. The objective of this study was to develop a simple technique for coating apatite onto a resin composite to improve its surface biocompatibility. First, we fabricated a polymer film coated with a micro-rough apatite layer and pressed it (coating-side down) onto a viscous resin composite precursor. As a result of light-induced curing of the precursor through the overlaid film, the micro-rough apatite layer was integrated with the resin composite and, thus, transferred from the polymer film surface to the cured resin composite surface as a result of the difference in interfacial adhesion strength. The transferred apatite layer attached directly to the cured resin composite without any gaps at the microscopic level. The adhesion between the apatite layer and the cured resin composite was so strong that the layer was not peeled off even by a tape-detaching test. The flexural strength of the resulting apatite-coated resin composite was comparable to that of the clinically used resin composite while satisfying the ISO requirement for dental polymer-based restorative materials. Furthermore, the apatite-coated resin composite showed better cell compatibility than the uncoated resin composite. The present apatite coating technique is well suited for dental treatment because the coating is applied during a conventional light curing procedure through simple utilization of the apatite-coated polymer film in place of an uncoated film. The proposed technique represents a practical evolution in dental treatment using light-curing resin composites, although further in vitro and in vivo studies are needed.


Subject(s)
Dental Bonding , Light-Curing of Dental Adhesives , Apatites , Composite Resins , Curing Lights, Dental , Materials Testing , Resin Cements , Surface Properties
5.
In Vivo ; 34(4): 1729-1738, 2020.
Article in English | MEDLINE | ID: mdl-32606141

ABSTRACT

BACKGROUND/AIM: Chitosan-coated iron oxide nanoparticles (Chi-NP) have gained attention because of their biocompatibility, biodegradability, low toxicity and targetability under magnetic field. In this study, we investigated various biological properties of Chi-NP. MATERIALS AND METHODS: Chi-NP was prepared by mixing magnetic NP with chitosan FL-80. Particle size was determined by scanning and transmission electron microscopes, cell viability by MTT assay, cell cycle distribution by cell sorter, synergism with anticancer drugs by combination index, PGE2 production in human gingival fibroblast was assayed by ELISA. RESULTS: The synthetic process of Chi-NP from FL-80 and magnetic NP increased the affinity to cells, up to the level attained by nanofibers. Upon contact with the culture medium, Chi-NP instantly formed aggregates and interfered with intracellular uptake. Aggregated Chi-NP did not show cytotoxicity, synergism with anticancer drugs, induce apoptosis (accumulation of subG1 cell population), protect the cells from X-ray-induced damage, nor affected both basal and IL-1ß-induced PGE2 production. CONCLUSION: Chi-NP is biologically inert and shows high affinity to cells, further confirming its superiority as a scaffold for drug delivery.


Subject(s)
Chitosan , Magnetite Nanoparticles , Nanoparticles , Drug Carriers , Drug Delivery Systems , Humans , Particle Size
6.
Dent Mater J ; 39(5): 742-751, 2020 Sep 29.
Article in English | MEDLINE | ID: mdl-32418950

ABSTRACT

The objective of this study was to examine the effects of storage conditions on the flexural strengths of resin composite materials for CAD/CAM restorations. Seven commercially available resin composite CAD/CAM blanks were examined. Rectangular specimens (4.0×1.2×4.0 mm) of each material were trimmed from the blanks and subjected to thermal cycling between 5°C and 55°C in deionized water at 10,000 cycles or stored in 37°C deionized water for one week or air for one day (n=10 for each condition). The difference in storage condition between water immersion and thermal cycling did not affect the flexural strengths of resin composite materials for CAD/CAM examined in this study. The resin composite block CS300 made from Bis-MEPP and UDMA showed the greatest flexural strength under all storage conditions and less deterioration of strength by thermal cycling and water immersion among the resin composite blocks tested.


Subject(s)
Composite Resins , Crowns , Computer-Aided Design , Flexural Strength , Materials Testing , Surface Properties
7.
Dent Mater J ; 39(3): 355-366, 2020 Jun 05.
Article in English | MEDLINE | ID: mdl-31852877

ABSTRACT

This study evaluated the physical and mechanical properties of a dental stone mixed by shaking. A shake-mix dental stone (Shake! Mix STONE; SM) was characterized in comparison with three conventional dental stones. The fluidity at pouring time, setting time, density, powder particle distributions, linear setting expansion, compressive strength and surface reproduction of detail for dental stones were investigated. The marginal adaptations of cast crowns to dies made with each stone were also determined. SM had higher fluidity and faster setting time than the other stones (p<0.05). The setting expansion of SM at 2 h was lower than those of other two stones (p<0.05). The 15-min compressive strength of SM was higher than the others (p<0.05). There were no significant differences in the marginal adaptations of the cast crowns fabricated using all the stones (p>0.05). In spite of the different mixing method, the shake-mix type dental stone had comparable physical and mechanical properties to the conventional dental stones.


Subject(s)
Calcium Sulfate , Dental Materials , Compressive Strength , Crowns , Materials Testing , Models, Dental , Surface Properties
8.
Dent Mater J ; 37(2): 272-277, 2018 Mar 30.
Article in English | MEDLINE | ID: mdl-29109339

ABSTRACT

The surface topography of implant fixture is an important factor affecting the osseointegration. We herein demonstrated the effects of surface microtopography of titanium disks on proliferation and differentiation of osteoblast-like cells isolated from rat calvariae. Titanium disks with machine surface (MS), rough surface (R1) and rough surface combined with small cavities (R2) were used in an in vitro culture system. Rough surfaces (R1 and R2 disks) induced stronger osteoblast proliferation and differentiation (BGP and sclerostin mRNA expressions and calcium content) than the smooth surface (MS disk). Furthermore, surface microtopography of R2 disk, which was rough with small cavities, more strongly induced cell proliferation and mineralized bone matrix production than R1 disk. Our results suggest that surface microtopography influences osteoblast proliferation and differentiation. R2 disk, which is rough with small cavities, may be used in implant fixtures to increase osseointegration.


Subject(s)
Osteoblasts/cytology , Skull/cytology , Titanium/pharmacology , Acid Etching, Dental , Animals , Biocompatible Materials/pharmacology , Calcification, Physiologic/physiology , Calcium/chemistry , Cell Differentiation/physiology , Cell Proliferation/physiology , Cells, Cultured , In Vitro Techniques , Microscopy, Electron, Scanning , Rats , Surface Properties
9.
Dent Mater J ; 34(1): 70-7, 2015.
Article in English | MEDLINE | ID: mdl-25748461

ABSTRACT

The influence of monomer content on the viscoelasticity, water sorption and solubility of experimental fluorinated soft lining materials was investigated. Changes in the viscoelastic properties of the materials were also examined after thermal cycling. Four fluorinated soft lining materials containing different amounts of methoxy diethylene glycol methacrylate (MDGMA) and tridecafluorooctyl methacrylate (13FMA) were prepared. The viscoelastic displacement for specimens containing 13FMA was found to be less than that without 13FMA (p<0.05), and the values tended to decrease with increasing 13FMA content. Reduction of the MDGMA content and addition of 13FMA caused a decrease of water sorption and solubility (p<0.05). Thermal cycling was found to affect the viscoelastic deformation of the specimens without 13FMA and those specimens with relatively large amounts of 13FMA.


Subject(s)
Dental Materials/chemistry , Denture Liners , Fluorine/chemistry , Methacrylates/chemistry , Elasticity , Materials Testing , Molecular Structure , Solubility , Viscosity , Water
10.
Dent Mater J ; 33(6): 835-44, 2014.
Article in English | MEDLINE | ID: mdl-25483383

ABSTRACT

This study was to examine the retentive force of crowns to implant abutments with commercial temporary cements. Six different temporary cements were investigated. Cast crowns were cemented to the abutments using each cement and their retentive forces to abutments were determined 7 or 28 days after cementing (n=10). The retentive force of the cements to abutments varied widely among the products [27-109 N (7-day), 18-80 N (28-days)]. The retentive force of all the cements was not reduced as the time elapsed, except for two products tested. The polycarboxylate cements and paste-mixing type eugenol-free cements revealed comparable retentive force after 28 days of storage. The powder-liquid type cements showed a positive correlation (p<0.05) between the retentive force and the shear strength, while a negative correlation (p<0.05) was obtained for paste-mixing type cement between the retentive force and compressive strength. Mechanical strength of temporary cements could not be a prominent predicting factor for retention of the crowns on the abutments.


Subject(s)
Crowns , Dental Abutments , Dental Cements/chemistry , Dental Prosthesis Retention , Dental Stress Analysis , Eugenol/chemistry , Materials Testing , Surface Properties , Zinc Oxide/chemistry , Zinc Phosphate Cement/chemistry
11.
Dent Mater J ; 33(5): 621-30, 2014.
Article in English | MEDLINE | ID: mdl-25273041

ABSTRACT

The purpose of the present study was to investigate the effect of the composition of experimental fluorinated soft lining materials on bond strength to denture base resin. Vinylidene fluoride/hexafluoro propylene copolymer (2-6F), tridecafluorooctyl methacrylate (13FMA), methoxy diethylene glycol methacrylate (MDGMA), and silica (as filler) were used for fabrication of the experimental soft lining materials. Nine experimental soft lining materials having various compositions of 2-6F, 13FMA, and MDGMA were prepared. Shear and tensile bond strength tests were performed before and after immersion in water. The water sorption for the materials was also measured. An increase in the content of acrylic monomer, MDGMA, in the experimental materials increased the bond strength before immersion in water but reduced the bond strength after immersion in water as compared to that before immersion in water. The inclusion of fluorinated monomer (13FMA) in the materials appeared to affect water sorption.


Subject(s)
Dental Bonding , Denture Bases , Denture Liners , Fluorine/chemistry , Materials Testing
12.
In Vivo ; 28(2): 209-15, 2014.
Article in English | MEDLINE | ID: mdl-24632975

ABSTRACT

BACKGROUND: Despite the rapid development of nanotechnology, the biological significance of TiO2 nanoparticles (NPs), possibly released from dental materials, is not well-understood. We investigated the effect of TiO2 NPs on the sensitivity of human oral squamous cell carcinoma (OSCC) cell line (HSC-2) to five popular chemotherapeutic agents. MATERIALS AND METHODS: Viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The aggregation and cellular uptake of TiO2 NPs were assessed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Adsorption of TiO2 NPs to anticancer drugs was assessed by the antitumor activity recovered from the TiO2 NP-free supernatant. RESULTS: When mixed with culture medium, TiO2 NPs instantly aggregated, and some particles were incorporated into the cells, exclusively in the vacuoles. TiO2 NPs showed no cytotoxicity nor hormetic growth stimulation at lower concentrations. Doxorubicin, melphalan, 5-fluorouracil and gefitinib were cytotoxic, whereas docetaxel was cytostatic with or without TiO2 NPs. TiO2 NPs, at wide concentration ranges (0.2-3.2 mM), did not significantly affect the adsorption of NPs to any of these anticancer drugs, nor affected their cytotoxic or cytostatic activity. CONCLUSION: This experimental study demonstrated for the first time that TiO2 NP do not affect the antitumor potential of chemotherapeutic agents against the HSC-2 OSCC cell line.


Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Agents/toxicity , Nanoparticles , Titanium , Carcinoma, Squamous Cell , Cell Line, Tumor , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Delivery Systems , Humans , Mouth Neoplasms , Nanoparticles/chemistry , Nanoparticles/ultrastructure , Titanium/chemistry
13.
In Vivo ; 26(4): 651-6, 2012.
Article in English | MEDLINE | ID: mdl-22773579

ABSTRACT

BACKGROUND: We previously reported that contact with copper (Cu) induced immediate cell death via an oxidation-involved mechanism, and the Cu-induced oxidation and cell death were effectively alleviated under hypoxic conditions. In order to explore alternative strategies for the protection from the Cu-induced cytotoxicity, we investigated whether the inclusion of gold (Au) in the Cu plate, as alloy,has a protective effect. MATERIALS AND METHODS: Human gingival fibroblast (HGF) cells, established from periodontal tissues, were inoculated on Au/Cu alloy of different Au ratios. After incubation at 37°C for different times under normoxic conditions, cellular viability and amino acid consumption were determined. Changes in the elemental composition of the alloy and in the culture medium were chemically analyzed by X-ray photoelectron spectroscopy and by inductively coupled plasma-optical emission spectrometry. RESULTS: Contact with the Cu plate induced cytotoxicity and cystine oxidation in time-dependent manners. Inclusion of Au at more than 10% in the alloy, completely abrogated the cytotoxicity and reduced the oxidation of Cu and the elution of Cu from the alloy. CONCLUSION: Inclusion of Au as a component of alloy reduces the cytotoxicity of the Cu plate, possibly by reducing its oxidation.


Subject(s)
Copper/toxicity , Gold/chemistry , Cells, Cultured , Drug Antagonism , Humans , Oxidation-Reduction , Surface Properties
14.
In Vivo ; 24(4): 507-12, 2010.
Article in English | MEDLINE | ID: mdl-20668317

ABSTRACT

The use of dental metal alloys in the daily clinic makes it necessary to evaluate the cytotoxicity of eluted metal components against oral cells. However, the cytotoxic mechanism and the type of cell death induced by dental metals in osteoblasts have not been well characterized. This study investigated the cytotoxicity of seven metals against the mouse osteoblastic cell line MC3T3-E1. alpha-MEM was used as a culture medium, since this medium provided much superior proliferation of MC3T3-E1 cells over DMEM. Ag (NH(3))(2)F was the most cytotoxic, followed by CuCl>CuCl(2) >CoCl(2), NiCl(2)>FeCl(3) and FeCl(2) (least toxic). None of the metals showed any apparent growth stimulating effect (so-called 'hormesis') at lower concentrations. A time course study demonstrated that two hours of contact between oral cells and Ag (NH(3))(2)F, CuCl, CoCl(2) or NiCl(2) induced irreversible cell death. Contact with these metals induced a smear pattern of DNA fragmentation without activation of caspase-3. Preincubation of MC3T3-E1 cells with either a caspase inhibitor (Z-VAD-FMK) or autophagy inhibitors (3-methyladenine, bafilomycin) failed to rescue them from metal cytotoxicity. These data suggest the induction of necrotic cell death rather than apoptosis and autophagy by metals in this osteoblastic cell line.


Subject(s)
Cell Death/drug effects , Metals/toxicity , Osteoblasts/cytology , 3T3 Cells/cytology , 3T3 Cells/drug effects , Animals , Autophagy/drug effects , Cells, Cultured , Chlorides/therapeutic use , Cobalt/toxicity , Copper/toxicity , Culture Media , DNA Fragmentation/drug effects , Ferric Compounds/therapeutic use , Kinetics , Mice , Nickel/pharmacology , Osteoblasts/drug effects
15.
In Vivo ; 24(4): 519-23, 2010.
Article in English | MEDLINE | ID: mdl-20668319

ABSTRACT

Although the advantage of ultraviolet (UV) irradiation of titanium plates for the attachment of osteoblast is known, the details of the experimental conditions have not been described in previous literature. We established optimal conditions of UV irradiation of titanium plate for the adhesion of mouse osteoblast MC3T3-E1 cells. The viable cell number was determined by MTT method. UV irradiation at two different wavelengths (253.7 and 365 nm) enhanced the cell attachment on titanium plate to comparable extents. The optimal UV exposure duration was 20 minutes and prolonged irradiation slightly reduced cell attachment. The attached cells proliferated during 24 hours, accompanied by the enhanced consumption of extracellular glutamine and arginine. The present study supports the previous reports of the efficacy of UV irradiation, and this simple and rapid assay system may be applicable for the study of the interaction of osteoblast and UV-activated titanium plates.


Subject(s)
3T3 Cells/radiation effects , Cell Adhesion/radiation effects , Osteoblasts/radiation effects , Titanium/radiation effects , 3T3 Cells/cytology , Animals , Arginine/metabolism , Cell Division/radiation effects , Glutamine/metabolism , Mice , Osteoblasts/cytology , Surface Properties , Ultraviolet Rays
16.
In Vivo ; 24(1): 29-37, 2010.
Article in English | MEDLINE | ID: mdl-20133972

ABSTRACT

This study was aimed at studying the effect of contact with titanium alloy plates of different surface textures on the proliferative capability of mouse osteoblastic MC3T3-E1 cells. First, the proliferation characteristics of MC3T3-E1 cells were investigated. MC3T3-E1 cells showed a high capacity for proliferation and survived for a long period even under nutritionally starved conditions. During logarithmic cell growth, the consumption of Ser, Gln, Val, Ile and Leu increased time-dependently. Contact with an hydoxyapatite (HA)-coated titanium alloy plate resulted in the increase in the recovery of cells from the plate by trypsin, and an increase in the consumption of these amino acids, suggesting enhanced cell proliferation. On the contrary, contact with the sandblasted and anodized titanium alloy plates resulted in the reduction of the recovery of the cells from the plate, but a slight increase in the amino acid consumption, suggesting the tight adhesion of the cells to the plates. This study demonstrates that the present method, based on the amino acid consumption of the cells, is useful for monitoring the cell proliferative capability, without detachment of the cells from the plate. This method may be applicable to the study of the interaction between cells and metal plates.


Subject(s)
Alloys/pharmacology , Osteoblasts/drug effects , Titanium/pharmacology , Amino Acids/metabolism , Animals , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Coated Materials, Biocompatible , Durapatite , Mice , Mice, Inbred C57BL , Microscopy, Electron, Scanning , Osteoblasts/metabolism , Osteoblasts/ultrastructure , Surface Properties
17.
In Vivo ; 21(5): 835-40, 2007.
Article in English | MEDLINE | ID: mdl-18019420

ABSTRACT

There are very few studies on the interaction between dental alloys and oral tissues. The effect of direct contact with copper (Cu) on the cellular function of human gingival fibroblast (HGF) derived from the periodontal tissues was investigated. When HGF cells were inoculated onto a Cu plate, the viability of HGF cells immediately declined. This was accompanied by vacuolization and chromatin condensation near the nuclear membrane. The intracellular concentration of spermidine and spermine declined, whereas that of putrescine slightly increased. Amino acid analysis of the medium revealed that glutamine was consumed at the greatest rate, amounting to more than half of the total amino acid consumption. Contact with the Cu plate resulted in the complete elimination of glutamine utilization and a simultaneous increase in the production of most amino acids, possibly due to enhanced proteolysis. This was accompanied by a time-dependent increase in the consumption of cystine, possibly due to oxidative reactions, and the enhanced production of glycine and glutamic acid. These data suggest that the contact with the Cu plate induced non-apoptotic cell death in HGF cells, which was tightly coupled with a rapid dysfunction of amino acid and polyamine metabolism.


Subject(s)
Amino Acids/metabolism , Apoptosis/drug effects , Copper/pharmacology , Gingiva/cytology , Gingiva/metabolism , Polyamines/metabolism , Cells, Cultured , Gingiva/drug effects , Humans , Microscopy, Electron, Transmission , Time Factors
18.
In Vivo ; 21(4): 603-7, 2007.
Article in English | MEDLINE | ID: mdl-17708353

ABSTRACT

We have previously reported that contact with copper (Cu) induced immediate cell death via an oxidation-involved mechanism in human promyelocytic leukemic HL-60 cells, whereas contact with other metals (Au, Ag, Pd) produced no discernible effect. In the present study, we investigated the conditions under which Cu-induced oxidative stress can be reduced. Contact with a Cu plate in the absence of cells enhanced the rate of consumption of cystine to the greatest extent, followed by that of methionine and histidine. Under hypoxic conditions, the consumption of all these amino acids was significantly reduced. On the other hand, the addition of saliva slightly, but not significantly, reduced the amino acid oxidation. The addition of epigallocatechin gallate (EGCG) slightly, but significantly reduced the consumption of cystine and histidine. The inhibitory effect of EGCG on the methionine consumption was more prominent, especially at higher concentrations. The Cu-induced cell death was significantly inhibited when freshly-prepared human gingival fibroblasts were incubated under hypoxic conditions. The present study demonstrates for the first time that the Cu-induced oxidation and cell death were effectively alleviated under hypoxic conditions.


Subject(s)
Antioxidants/pharmacology , Catechin/analogs & derivatives , Copper/toxicity , Fibroblasts/drug effects , Gingiva/cytology , Saliva/metabolism , Catechin/pharmacology , Cell Hypoxia/physiology , Cells, Cultured , Cystine/pharmacokinetics , Fibroblasts/cytology , Fibroblasts/metabolism , Histidine/pharmacokinetics , Humans , Methionine/pharmacokinetics , Oxidative Stress/drug effects , Oxidative Stress/physiology , Oxygen/pharmacology
19.
Dent Mater J ; 26(5): 708-12, 2007 Sep.
Article in English | MEDLINE | ID: mdl-18203472

ABSTRACT

This study examined the effect of ambient water on the shear strength of glass ionomer cements for luting. Disk specimens were fabricated from four commercially available glass ionomer cements with different setting modes. At one hour after the start of mixing, the specimens were stored at 37 degrees C for 24 and 168 hours in dry condition or in deionized water. Shear strength was then determined using a punch tool. The shear strengths of both conventional cements were significantly greater for the specimens stored dry as compared to those kept in deionized water (p < 0.05). Conversely, resin-modified cement specimens stored dry had significantly lower strength compared to the specimens kept in deionized water (p < 0.05). This was because the ambient water surrounding the resin-modified glass ionomer cements helped increase the shear strength of the cements under the experimental conditions tested.


Subject(s)
Dental Bonding , Glass Ionomer Cements , Analysis of Variance , Dental Stress Analysis , Drug Storage , Materials Testing , Shear Strength , Water
20.
In Vivo ; 20(5): 605-11, 2006.
Article in English | MEDLINE | ID: mdl-17091767

ABSTRACT

In order to investigate the in vivo effect of metals used in dentistry, we investigated the effect of direct contact with metal plates (20 x 20 x 0.5 mm3) made of gold (Au), silver (Ag), copper (Cu) or palladium (Pd) on human promyelocytic leukemic HL-60 cells grown in RPMI1640 medium supplemented with 10% fetal bovine serum. When 0.5 mL of cell suspension was applied to the metal plates, cells were precipitated on the surface of the metal plate within 10 min. Contact with Cu induced a rapid decline of cell viability, the smear pattern of DNA fragmentation, and only minor activation of caspase-3. These effects were accompanied by a progressive decrease in the extracellular concentration of methionine, cysteine and histidine, with a corresponding increase in the concentration of methionine sulfoxide. Electron microscopy showed that contact with Cu induced vacuolization and cytoplasmic damage, prior to nuclear damage, without affecting the cell surface microvilli or mitochondrial integrity. Contact with the other metals did not induce such changes during the 3 h incubation, nor was any hormetic response (beneficial action at lower concentration) observed in the cells with any metals. Addition of N-acetyl-L-cysteine (4-5 mM) almost completely abrogated the Cu-induced cytotoxicity, whereas sodium ascorbate (0.1-0.5 mM) and catalase (6,000(1)-30,000 units/mL) were ineffective. Numerous serum proteins were adsorbed to the Ag plate, while bovine serum albumin was the major protein adsorbed to other metal plates. The present study suggests that direct contact with Cu induced non-apoptotic cell death by an oxidation-involved mechanism. The present model system may be applicable to the study of the interaction between cells and dental restorative materials.


Subject(s)
Caspase 3/metabolism , DNA Fragmentation , Dental Materials/toxicity , Metals/toxicity , Acetylcysteine/pharmacology , Cell Death , Cell Survival , Copper/toxicity , Drug Antagonism , Gold/toxicity , HL-60 Cells , Humans , Microscopy, Electron , Oxidation-Reduction , Palladium/toxicity , Silver/toxicity
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