Search results for "Chemo mechanical"
showing 5 items of 5 documents
An analysis in vivo of intracanal bacterial load before and after chemo-mechanical preparation: A comparative analysis of two irrigants and two activ…
2016
Background: The goals of this randomized double-blind trial were to assess the antimicrobial activity in vivo of Sodium hypochlorite (NaOCl) vs. chlorhexidine gluconate (CHX) used in combination either with EndoActivator® or IRRI S® files in patients with apical periodontitis. Material and Methods: A total of 120 patients with apical periodontitis (in single or multiple root canals) were randomly assigned to the four irrigation protocols outlined below: Group A: 5.25% sodium hypochlorite (NaOCl) + EndoActivator®; Group B: 5.25% NaOCl + IRRI S® files; Group C: 2% chlorhexidine gluconate (CHX) + EndoActivator®; Group D: 2% CHX + IRRI S® files. Paper points were used to collect microbiological…
On the contractile mechanism of insect fibrillar flight muscle. IV. A quantitative chemo-mechanical model.
1975
Ausgehend von detaillierten Vorstellungen zur Kinetik der myofibrillaren ATPase und der Ankopplung der Enzymwirkung an die Mechanik der Myosinbruckenzyklen wird ein quantitatives chemo-mechanisches Modell fur den fibrillaren Insektenflugmuskel vorgeschlagen. Mit der Wahl eines einheitlichen Parametersatzes gelingt es praktisch alle bisher in der Literatur beschriebenen Resultate zu simulieren. Dazu gehoren der verzogerte Spannungsaufbau bei rechteckformigen und sinusoidalen Langenanderungen, charakteristische Nichtlinearitaten in den oszillatorischen Langen-Spannungsschleifen, die Aktivierung der ATPase Aktivitat durch statische und dynamische Dehnung, der proportionale Anstieg des Wirkungs…
Fabric evolution and the related swelling behaviour of a sand/bentonite mixture upon hydro-chemo-mechanical loadings
2015
This experimental study investigates the swelling behaviour of an 80/20 sand/bentonite mixture and the associated fabric evolution under different hydro-chemo-mechanical loadings. Free and confined swelling tests are performed on specimens compacted to different dry densities and wetted with different pore fluids. Controlled suction confined swelling tests are performed to determine the suction–swelling pressure relationship for two different densities. An extensive microstructural characterisation is performed to relate the observed swelling behaviour to the evolution of the different pore networks during wetting. Based on the microstructural analysis, an expression is proposed to determi…
An experimental and constitutive investigation on the chemo-mechanical behaviour of a clay
2013
Engineering issues for which the understanding of the chemo-mechanical behaviour of soils is relevant include wellbore stability problems, the salinification of groundwater, and nuclear waste storage. However, despite the vast number of situations in which couplings between chemistry and mechanics occur, the available constitutive models rely on limited experimental evidence. This paper presents the results of an experimental programme on the chemo-mechanical behaviour of a non-swelling illite. The osmotic suction is controlled through the ion concentration of sodium chloride in the pore water. Stress paths include mechanical loading at a constant osmotic suction, and an increasing osmotic …
Chemomechanical preparation by hand instrumentation and by Mtwo engine-driven rotary files, an ex vivo study
2011
Objective: To compare the disinfecting efficacy of the sodium hypochlorite irrigation by root canal preparation with stainless steel hand files, taper 0.02 and nickel-titanium Mtwo files with taper 0.04-0.06. Study Design: 40 extracted human teeth were sterilized, and then inoculated with Enterococcus faecalis (ATCC 29212). After 6 day incubation time the root canals were prepared by hand with K-files (n=20) and by engine-driven Mtwo files (VDW, Munich, Germany) (n=20). Irrigation was carried out with 2.5% NaOCl in both cases. Samples were taken and determined in colony forming units (CFU) from the root canals before and after the preparation with instruments #25 and #35. Results: Significa…