159 research outputs found
A SEM evaluation of debris removal from endodontic files after cleaning and steam sterilization procedures
The document attached has been archived with permission from the Australian Dental Association (8th Jan 2008). An external link to the publisher’s copy is included.Background: In recent times, it has been proposed to classify endodontic files as single-use items due to a perceived inability to adequately clean the instruments. The purpose of the present study was to quantify the surface debris on files removed from the manufacturer’s packaging, and after cleaning using an ultrasonic bath or a thermal disinfector. Methods: Stainless steel and rotary nickel-titanium files were examined after removal from the manufacturer’s packaging, after instrumentation in broth-contaminated human teeth, and after various cleaning procedures. The cleaning procedures consisted of either a thermal disinfector cycle, ultrasonication with the files placed in a perforated container or ultrasonication with the files loosely placed in a beaker. The presence of manufacturing debris and biological debris was evaluated using scanning electron microscopy and quantified using image analysis software. Results: The effectiveness of cleaning was not affected by variation in the size or taper of the files when an effective cleaning procedure was used. Cleaning the files in a thermal disinfector or by ultrasonication within a container did not consistently achieve complete removal of biological debris. Placing the files loosely in the ultrasonic bath achieved the most effective cleaning, an average of 98.33 per cent of the file surface area was freed of any biological debris. Conclusions: A conventional cleaning method is capable of effectively removing biological debris from endodontic files. The efficacy of ultrasonic cleaning was impaired when the files were placed within a perforated container
The Synthesis Telescope at the Dominion Radio Astrophysical Observatory
We describe an aperture synthesis radio telescope optimized for studies of
the Galactic interstellar medium (ISM), providing the ability to image extended
structures with high angular resolution over wide fields. The telescope
produces images of atomic hydrogen emission using the 21-cm HI spectral line,
and, simultaneously, continuum emission in two bands centred at 1420 MHz and
408 MHz, including linearly polarized emission at 1420 MHz, with synthesized
beams of 1 degree and 3.4 degrees at the respective frequencies.Comment: Accepted for publication by Astronomy and Astrophysics, Supplement
Serie
Anionopentaaminecobalt(III) Complexes With Polyamine Ligands. XXVI. Spontaneous and Hg2+-Assisted Chloride Release Kinetics From Some CoCl(tacn)(diamine)2+ Complexes
Dynamic Effect of \u201cProtein Friction\u201d as Revealed by High Pressure and Mixed-SAM Bioelectrochemical Strategies
Quinquedentate Coordination of 10-Methyl-1,4,8,12-tetraazacyclopentadecan-10-amine (L) to Rhodium(III). Crystal Structure of cis-[Rh(L)Cl][ClO4]2.H2O And Comparative Activation Volumes for Base Hydrolysis of [M(L)Cl]2+ (M = Rh, Co, Cr)
S100 Beta and Serotonin - a Possible Astrocytic-Neuronal Link to Neuropathology of Alzheimers-Disease
Studies in nickel(IV) chemistry. Kinetics of electron transfer from dimethyl sulfoxide to oxohydroxonickel(IV) in aqueous acid medium
- …