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Oral Surgery, Oral Medicine, and Oral... Jan 1986Endodontic therapy often results in discoloration of the tooth crown. The main causes are blood, necrotic pulp tissue, and endodontic materials. The staining potentials...
Endodontic therapy often results in discoloration of the tooth crown. The main causes are blood, necrotic pulp tissue, and endodontic materials. The staining potentials of various materials were examined in vitro by means of a visual method for tooth color determination. Extracted premolars were prepared, and the following sealers were introduced into the pulp cavities: Zinc oxide eugenol cement, Grossman's cement, AH26, Diaket, N2, Riebler's paste, Tubliseal, and Endomethasone. Before the sealers were applied, the original tooth colors were assessed on the external buccal tooth surfaces. Further color determinations were carried out at regular intervals up to 6 months after introduction of the sealers. Each material induced measurable tooth discoloration within 3 weeks. Riebler's paste caused the most severe discoloration while Diaket caused a mild stain. The other materials produced intermediate discolorations between those of Riebler and Diaket.
Topics: Administration, Topical; Anti-Inflammatory Agents; Bicuspid; Bismuth; Color; Dexamethasone; Drug Combinations; Epoxy Resins; Eugenol; Formaldehyde; Humans; Hydrocortisone; Methenamine; Polyvinyls; Resorcinols; Root Canal Filling Materials; Silver; Thymol; Time Factors; Titanium; Tooth Discoloration; Zinc Oxide; Zinc Oxide-Eugenol Cement
PubMed: 3456145
DOI: 10.1016/0030-4220(86)90208-2 -
The Analyst Apr 1990A fluorescence fibre optic sensor has been developed for measurement of the potassium concentration in aqueous solution based on the change in optical absorbance of the...
A fluorescence fibre optic sensor has been developed for measurement of the potassium concentration in aqueous solution based on the change in optical absorbance of the hydrophobic indicator 7-decyl-2-methyl-4-(3',5'-dichlorophen-4'-one)indonaphth-1-o l (MEDPIN). The sensor was constructed by dipping the distal end of a single optical fibre in a poly(vinyl chloride) (PVC) coating solution containing MEDPIN, a plasticiser, the ionophore valinomycin and the fluorescent dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine perchlorate [DilC18(5)]. The change in the absorbance of MEDPIN induced by potassium was detected from the quenching of the fluorescence of DilC18(5) due to energy transfer. Glass slides dipped in the PVC coating solution were used to establish the optical properties of the sensor. The potassium concentration was detected by the absorbance of MEDPIN at 650 nm and by the quenching of the DilC18(5) fluorescence by MEDPIN. The fluorescence intensity and lifetime of DilC18(5) decreased by ca. 40% with the addition of 33 mM KCl, indicating a resonance energy transfer mechanism. Experiments with the fibre optic sensor showed a decrease in the fluorescence of 57% with increasing potassium concentration (0-5 mM) at pH 7.45. The potassium concentration giving a 50% decrease in the fluorescence (Kd) for the most sensitive probe was 0.05 mM KCl. The value of Kd was increased to 1.3 mM when the plasticiser was changed from 2-nitrophenyl octyl ether to tris(2-ethylhexyl)phosphate; however, the 90% response time increased from 10 s to 4.2 min.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Chemical Phenomena; Chemistry, Physical; Fiber Optic Technology; Fluorescence; Humans; Potassium
PubMed: 2363517
DOI: 10.1039/an9901500353 -
Chemosphere Apr 2023Microbes play a dominant role for the transformation of organic contaminants in the environment, while a significant gap exists in understanding the degradation...
Microbes play a dominant role for the transformation of organic contaminants in the environment, while a significant gap exists in understanding the degradation mechanism and the function of different species. Herein, the possible bio-degradation of triclosan in microbial fuel cell was explored, with the investigation of degradation kinetics, microbial community, and possible degradation products. 5 mg/L of triclosan could be degraded within 3 days, and an intermediate degradation product (2,4-dichlorophen) could be further degraded in system. 32 kinds of dominant bacteria (relative intensity >0.5%) were identified in the biofilm, and 10 possible degradation products were identified. By analyzing the possible involved bioreactions (including decarboxylation, dehalogenation, dioxygenation, hydrolysis, hydroxylation, and ring-cleavage) of the dominant bacteria and possible degradation pathway of triclosan based on the identified products, biodegradation mechanism and function of the bacteria involved in the degradation of triclosan was clarified simultaneously. This study provides useful information for further interpreting the degradation mechanism of organic pollutants in mixed flora by combining analysis microbiome community and degradation pathway.
Topics: Triclosan; Bioelectric Energy Sources; Biodegradation, Environmental; Bacteria; Microbiota
PubMed: 36739987
DOI: 10.1016/j.chemosphere.2023.137983 -
European Journal of Pharmacology Jan 2009The possible inhibition of kinin B(1) receptor up-regulation by arachidonoylethanolamide (anandamide) was evaluated in isolated human umbilical vein. Anandamide and its...
The possible inhibition of kinin B(1) receptor up-regulation by arachidonoylethanolamide (anandamide) was evaluated in isolated human umbilical vein. Anandamide and its metabolically stable analogue, R-N-(2-Hydroxy-1-methylethyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (R-(+)-methanandamide), produced a selective and dose-dependent inhibition of kinin B(1) receptor-sensitized contractile responses. The inhibitory effect of anandamide on B(1) receptor-sensitized responses failed to be modified either by 5-biphenyl-4-ylmethyl-tetrazole-1-carboxylic acid dimethylamide (LY2183240), a selective anandamide uptake inhibitor, or 6-Iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-y l](4-methoxyphenyl) methanone (AM630), selective cannabinoid CB(2) receptor antagonist. However, the cannabinoid CB(1) receptor antagonist, N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophen yl)-4-methyl-1H-pyrazole-3-carboxamide (AM251), abolished anandamide effects on kinin B(1) receptor sensitization. The present results provide strong pharmacological evidence indicating that endocannabinoid anandamide inhibits kinin B(1) receptor up-regulation through cannabinoid CB(1) receptor stimulation in human umbilical vein.
Topics: Arachidonic Acids; Bradykinin B1 Receptor Antagonists; Cannabinoid Receptor Modulators; Dose-Response Relationship, Drug; Endocannabinoids; Humans; Polyunsaturated Alkamides; Receptor, Bradykinin B1; Receptor, Cannabinoid, CB1; Umbilical Veins; Up-Regulation
PubMed: 19022239
DOI: 10.1016/j.ejphar.2008.10.058 -
Journal of Toxicology and Environmental... 1986The disposition and metabolism of o-benzyl-p-chlorophenol (BCP) were studied in male Fischer-344 rats. Three days after oral administration of [14C]BCP at 10, 100, or...
The disposition and metabolism of o-benzyl-p-chlorophenol (BCP) were studied in male Fischer-344 rats. Three days after oral administration of [14C]BCP at 10, 100, or 1000 mg/kg, more than 90% of each dose was excreted in urine and feces. Comparison of disposition after intravenous, dermal, or oral administration indicated that BCP was not completely absorbed from the gastrointestinal tract or skin. Biliary excretion of BCP was dose-dependent, with proportionally less BCP-derived radioactivity being excreted in the bile as the dose was raised. The results also indicated that enterohepatic circulation was involved in BCP disposition. The major in vivo metabolites were glucuronyl conjugates of BCP and hydroxy-BCP. Glutathione conjugates were also present in urine. In vitro metabolism studies support the observation that microsomal oxidation and glutathione and glucuronyl conjugation play major roles in BCP metabolism. Spleen, kidney, and liver contained the highest tissue concentrations of BCP-derived radioactivity. The presence of more nonextractable BCP-derived radioactivity in kidney than in liver is compatible with the hypothesis that covalent binding of BCP to renal tissue may be associated with BCP-induced nephrotoxicity.
Topics: Administration, Oral; Administration, Topical; Animals; Bile; Chromatography, High Pressure Liquid; Dichlorophen; Feces; In Vitro Techniques; Injections, Intravenous; Kidney; Liver; Male; Rats; Rats, Inbred F344; Tissue Distribution
PubMed: 3712501
DOI: 10.1080/15287398609530884 -
International Endodontic Journal Sep 1999The aim of this study was to examine the apical sealing ability of five root canal sealers using a fluid transport model. (Comparative Study)
Comparative Study
AIM
The aim of this study was to examine the apical sealing ability of five root canal sealers using a fluid transport model.
METHODOLOGY
A comparison of root canal scalers AH26, AH Plus, Diaket, Apexit, and Ketac-Endo were tested on 60 single-rooted teeth. The coronal part of each tooth was removed at the amelo-cemento junction, and also 3 mm of the root tip. Root canals were instrumented using the 'step-back' technique with Gates Glidden drills and irrigated with 2.5% NaOCl. The specimens were divided into five groups of 10 samples each and filled with test materials and gutta-percha points by the cold lateral condensation technique. Ten teeth were used as a control group, out of which five served as negative and five as positive controls. The leakage was measured by the movement of an air bubble in a capillary glass tube connected to the experimental root section.
RESULTS
The differences in leakage amongst Ketac-Endo (0.318 microL: SD 0.084), AH26 (0.319 microL; SD 0.075), AH Plus (0.330L; SD 0.085) Apexit (0.360 microL; SD 0.127) and Diaket (0.387 microL; SD 0.140) were not statistically significant (P > 0.05).
CONCLUSIONS
Under the conditions of this study, all five sealers produced a satisfactory seal.
Topics: Bismuth; Calcium Hydroxide; Cuspid; Dental Leakage; Drug Combinations; Epoxy Resins; Evaluation Studies as Topic; Glass Ionomer Cements; Humans; Incisor; Methenamine; Polyvinyls; Root Canal Filling Materials; Silver; Titanium; Zinc Oxide
PubMed: 10551116
DOI: 10.1046/j.1365-2591.1999.00254.x -
Oral Surgery, Oral Medicine, Oral... Sep 2009The aims of this study were to compare the radiopacity of 8 root canal sealers relative to gutta-percha and dentin in standard discs and to evaluate the effect of these... (Comparative Study)
Comparative Study
OBJECTIVE
The aims of this study were to compare the radiopacity of 8 root canal sealers relative to gutta-percha and dentin in standard discs and to evaluate the effect of these sealers on the radiopacity of root canal fillings in simulated canals.
STUDY DESIGN
Radiographs were taken of 1-mm-thick specimens of 8 root canal sealers (Diaket, Endion, MTA, Endofil, Roeko Seal, Sealite, AH26, AH Plus) and gutta-percha, a 1-mm-thick human tooth slice, and aluminum stepwedge.Simulated canals were used to evaluate the effect of the sealer on radiopacity of the root fillings. After enlargement of the simulated canals with ProTaper instrument, root canals were filled with these 8 sealers alone and with single ProTaper gutta-percha cone. Radiographs of all filled simulated canals were taken with an aluminum stepwedge.
RESULTS
All the sealers demonstrated greater radiopacity than dentin (0.7940 mm Al) (P < .001). AH Plus showed the highest radiopacity in the standard disc group (Group 1) (8.9881 mm Al) (P < .001), and in the sealer group in simulated canals (Group 2) (9.2100 mm Al) (P < .001). In the sealer plus gutta-percha group in simulated canals (Group 3), Sealite plus gutta-percha showed greater radiopacity (8.4460 mm Al) (P < .001).
CONCLUSION
Whether the opacity of the sealers alone is more or less than 3 mm Al, their radiopacity is increased when they are used in combination with gutta-percha, because of its higher radiopacity. However, when sealers are used in conjunction with gutta-percha, they can affect the radiopacity of the root canal filling according to their type and thickness.
Topics: Aluminum; Aluminum Compounds; Bismuth; Calcium Compounds; Contrast Media; Dental Cements; Dental Pulp Cavity; Dentin; Drug Combinations; Epoxy Resins; Glass Ionomer Cements; Gutta-Percha; Humans; Materials Testing; Models, Anatomic; Oxides; Polyvinyls; Radiography, Dental; Root Canal Filling Materials; Root Canal Preparation; Silicates; Silver; Surface Properties; Titanium; Zinc Oxide; Zinc Oxide-Eugenol Cement
PubMed: 19577493
DOI: 10.1016/j.tripleo.2009.04.016 -
Oral Surgery, Oral Medicine, and Oral... Jun 1983
Comparative Study
Topics: Administration, Topical; Anti-Infective Agents, Local; Anti-Inflammatory Agents; Bacteria; Balsams; Barium Sulfate; Bismuth; Borates; Condiments; Dental Pulp Cavity; Dexamethasone; Drug Combinations; Epoxy Resins; Eugenol; Formaldehyde; Hydrocortisone; Methenamine; Polyvinyls; Resins, Plant; Resins, Synthetic; Root Canal Filling Materials; Silver; Thymol; Time Factors; Titanium; Zinc Oxide
PubMed: 6576294
DOI: 10.1016/0030-4220(83)90383-3 -
Analytical and Bioanalytical Chemistry Feb 2007Although there is increasing concern about residues from personal care products entering the aquatic environment and their potential to accumulate to levels that pose a...
Although there is increasing concern about residues from personal care products entering the aquatic environment and their potential to accumulate to levels that pose a health threat to humans and wildlife, we still know little about the extent and magnitude of their presence in the aquatic environment. In this study we describe a procedure for isolation, and subsequent determination, of compounds commonly added to personal care products. The compounds of interest include UV filters with the commercial name Eusolex (homosalate, 4-methylbenzylidenecamphor, benzophenone-3, octocrylene, butylmethoxydibenzoylmethane, ethylhexyl methoxycinnamate) and two common anti-microbial agents, clorophene and triclosan. Water samples were filtered, acidified, and extracted by use of solid-phase extraction. Extracted compounds were then derivatised before analysis by gas chromatography-mass spectroscopy. By use of our method we obtained limits of detection of 13-266 ng L(-1) for UV filters, and 10-186 ng L(-1) for triclosan and clorophene. Recoveries were 82-98% for deionised water and 50-98% for natural water (seawater, pool water, lake water, and river water). Samples collected in Slovenia included seventeen recreational waters (seawater, pool water, lake water, and river water; August 2004) and four wastewaters (January 2005). The most abundant UV filter was benzophenone-3 (11-400 ng L(-1)). Of the two anti-microbial agents studied, trace amounts, only, of triclosan were present in the river Kolpa (68 ng L(-1)) and in an hospital effluent (122 ng L(-1)).
Topics: Anti-Infective Agents; Dichlorophen; Molecular Structure; Triclosan; Ultraviolet Rays; Water; Water Pollutants, Chemical
PubMed: 17136341
DOI: 10.1007/s00216-006-0927-y -
Environmental Science & Technology Nov 2018Potassium ferrate [Fe(VI)] is a promising oxidant widely used in water treatment for the elimination of organic pollutants. In this work, the reaction kinetics,...
Potassium ferrate [Fe(VI)] is a promising oxidant widely used in water treatment for the elimination of organic pollutants. In this work, the reaction kinetics, products, and mechanisms of the antimicrobial agent chlorophene (CP) undergoing Fe(VI) oxidation in aqueous solutions were investigated. CP is very readily degraded by Fe(VI), with the apparent second-order rate constant, k, being 423.2 M s at pH 8.0. A total of 22 oxidation products were identified using liquid chromatography-quadrupole time-of-flight-mass spectrometry , and their structures were further elucidated using tandem mass spectrometry. According to the extracted peak areas in mass spectra, the main reaction products were the coupling products (dimers, trimers, and tetramers) that formed via single-electron coupling. Theoretical calculations demonstrated that hydrogen abstraction should easily occur at the hydroxyl group to produce reactive CP· radicals for subsequent polymerization. Cleavage of the C-C bridge bond, electrophilic substitution, hydroxylation, ring opening, and decarboxylation were also observed during the Fe(VI) oxidation process. In addition, the degradation of CP by Fe(VI) was also effective in real waters, which provides a basis for potential applications.
Topics: Dichlorophen; Electrons; Iron; Kinetics; Oxidation-Reduction; Water Pollutants, Chemical; Water Purification
PubMed: 30299936
DOI: 10.1021/acs.est.8b01830