Search results for "Chlorite"
showing 10 items of 76 documents
In vitro antimicrobial activity of sodium hypochlorite, chlorhexidine gluconate and octenidine dihydrochloride in elimination of microor- ganisms wit…
2011
The aim of this study was to evaluate the effectiveness of different irrigation solutions at different time intervals for the elimination of E.faecalis and C.albicans penetrated into the dentine tubules of primary and permanent teeth in vitro. The 4 mm primary and permanent teeth sections were sterilized and contaminated with a mixture of E.faecalis and C.albicans strains. After the application of different irrigation solutions (Sodium hypochlorite, Chlorhexidine gluconate, Octenidine Dihydrochloride, saline) to the contaminated tooth sections according to study groups, neutralizers were applied for inactivation of the solutions after 30 sec, 1 min and 5 min. Dentine shavings were placed in…
A new hydrous Al-bearing pyroxene as a water carrier in subduction zones
2011
Abstract A new Hydrous Al-bearing PYroxene (HAPY) phase has been synthesized at 5.4 GPa, 720 °C in the MgO–Al2O3–SiO2–H2O model system. It has the composition Mg2.1Al0.9(OH)2Al0.9Si1.1O6, a C-centered monoclinic cell with a = 9.8827(2), b = 11.6254(2) c = 5.0828(1) A and β = 111.07(1)°. The calculated density is 3.175 g/cm3 and the water content is 6.9% H2O by weight. Its structure has been solved in space group C2/c by the recently developed automated electron diffraction tomography method and refined by synchrotron X-ray powder diffraction. HAPY is a single chain inosilicate very similar to pyroxenes but with three instead of two cations in the octahedral layer, bonded to four oxygens and…
Structure-related geochemical (REE) and isotopic (K-Ar, Rb-Sr, δ18O) characteristics of clay minerals from Rotliegend sandstone reservoirs (Permian, …
1999
Abstract Euhedral illite cementing the gas-bearing sandstone reservoirs of the Rotliegend in the Niedersachsische rift system (northern Germany) was studied along a horst-to-graben cross-section to examine its chemical and isotopic characteristics. The data show that differentiated illite particles grew during a tectono-thermal event marked by distinct episodic hydrothermal activities along fault drains and in the poral space of sandstones at 210 Ma and at 195 to 190 Ma in horst positions, at 185 to 175 Ma in the nearby graben, and at 170 to 165 Ma in both the horst and graben. Varied REE distribution patterns and initial 87Sr/86Sr ratios (from 0.7124 to 0.7142) relative to illite-particle …
The Efficacy of an Experimental Single Solution versus Alternate Use of Multiple Irrigants on Root Dentin Microhardness
2013
The objective of this work was to use fnite element analysis to compare the effect of forces coming to bear on abutments 4.1 or 5.0 mm in diameter connThis study was carried-out to evaluate and compare the efficacy of various irrigants when used singly or in combination on the microhardness of root canal dentin. Study Design: A total of 50 root-halves were randomly divided into 5 groups immediately after the initial baseline microhardness measurements and treated with: Group-1; 7.5%Ethylenediaminetetraaceticacid (EDTA)+ 2.5%sodium hypochlorite (NaOCl), Group-2; 7.5%ethyleneglycol-bis[b-aminoethylether]-N, N,N0,N0-tetraaceticacid (EGTA)+ 2.5%NaOCl, Group-3; 7.5%trans1,2diaminocyclohexane NNN…
Effectiveness of different disinfection techniques of the root canal in the elimination of a multi-species biofilm.
2019
Background The purpose of the study was to evaluate the effectiveness of different root canal disinfection techniques in the elimination of a multi-species biofilm from inside the root canal. Material and methods Fifty mandibular first premolars were used in the present study, standardized to 11mm of root length, and instrumented with a reciprocation system Reciproc, (VDW GmbH, Munich, Germany) to a #50. Longitudinally sectioned halves of the roots were obtained and washed with NaOCl 4%, EDTA 17% and 5% sodium thiosulfate, and sterilized by autoclaving for 15 minutes at 121°C. A multi-species biofilm broth was developed with three strains of bacteria under laboratory conditions: Enterococcu…
Evaluation of antibacterial efficacy of Chitosan, Chlorhexidine, Propolis and Sodium hypochlorite on Enterococcus faecalis biofilm : an in vitro study
2017
Background Long term successful root canal treatment requires effective debridement and disinfection of root canal system. Persistent periradicular lesions are usually associated with Enterococccus faecalis. Prompt research for natural alternatives for irrigation is mainly due to the constant increase in antibiotic resistant strains and side effects caused by synthetic drugs. Sodium hypochlorite; the gold standard for irrigation has many disadvantages. Therefore, the present study was aimed to explore newer irrigants probably be as more effective and at the same time would be less irritating to the tissues than NaOCl. Material and methods Ninety extracted human mandibular premolars were bio…
In Vitro Evaluation of the Accuracy of the Root Zx in the Presence of Naocl 2.5% and Chlorhexidine 0.2%
2018
Background Establishing the working length at the apical constriction is considered ideal for root canal therapy. Because of the limitations of radiography and complicacy of the apex of the root, electronic measurement of canal length has become valuable for endodontic treatment. This study was designed to evaluation of the accuracy of the Root zx electronic apex locator in the presence of NaOCl 2.5% and chlorhexidine 0.2%. Material and Methods Thirty extracted human premolars with complete root formation were enrolled. The actual length (AL) was assessed visually (under stereo microscope) and teeth mounted in the saline model. The electronic length (EL) measurements were recorded in the pr…
Assessment of the microbiological quality and wash treatments of lettuce served in University restaurants
2000
Abstract One hundred and forty-four samples of lettuce from 16 University restaurants were analyzed. The mesophilic aerobic counts of all samples ranged from 3.01 to 7.81 log 10 CFU g −1 . Results of total coliforms ranged from 3.38 log 10 most probable number (MPN) g −1 . Of the lettuce samples, 25.7% harbored Escherichia coli , 22.9% Staphylococcus aureus and 84% group D streptococci. Similarly, 10.4% of the samples harbored Aeromonas hydrophila , 2.8% Pseudomonas aeruginosa , and coliforms such as 14.6% Citrobacter freundii , 8.3% Klebsiella pneumoniae , 4.2% Enterobacter cloacae and 1.4% Providencia spp. Salmonella , Shigella and E. coli O157:H7 were not detected. When sodium hypochlori…
The adaptation of mechanically softened gutta-percha to the canal walls in the presence or absence of smear layer: a scanning electron microscopic st…
1995
Summary The objective of this study was to compare the adaptation of mechanically softened gutta-percha to the root canal wall in the presence and absence of smear layer. The root canals of 20 freshly extracted human maxillary incisors were cleaned and shaped. Prior to obturation, 10 root canals were irrigated with 20 ml of 50% citric acid followed by 20 ml of 5.25% sodium hypochlorite. All canals were obturated with mechanical compaction of gutta-percha and AH-26 sealer. After 72h, each tooth was fractured in half. Scanning electron microscopy demonstrated that the sealer had formed a continuous layer in contact with the canal walls, becoming progressively thinner towards the apex. The sea…
Bonding efficacy of an acetone/based etch-and-rinse adhesive after dentin deproteinization
2012
Objectives: to evaluate the effect of sodium hypochlorite (NaOCl) treatment on dentin bonding by means of shear bond strength (SBS) measurements when using Prime&Bond NT (PB NT) adhesive. Ultrastructure of the interfaces was examined by scanning electron microscopy (SEM). Study design: Extracted human third molars were sectioned and ground to expose flat surfaces of superficial or deep dentin. Specimens were randomly assigned to two equal groups, and bonded as follows: (1) according to the manufacturers’ directions, after 35% H3PO4 etching, (2) 5% NaOCl treated for 2 minutes, after 35% H3PO4 etching. Each sample was embedded in a Watanabe shear test assembly for a single plane lap shear. Af…