43 results on '"Scotti R"'
Search Results
2. Tracing the Source of the Bio/Siliciclastic Beach Sands at Rosa Marina (Apulian Coast, SE Italy)
- Author
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Van Loon, A.J. (Tom), primary, Moretti, M., additional, Tropeano, M., additional, Acquafredda, P., additional, Baldacconi, R., additional, Festa, V., additional, Lisco, S., additional, Mastronuzzi, G., additional, Moretti, V., additional, and Scotti, R., additional
- Published
- 2017
- Full Text
- View/download PDF
3. Contributors
- Author
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Abbott, D., primary, Acquafredda, P., additional, Agangi, A., additional, Armstrong-Altrin, J.S., additional, Balakrishnan, S., additional, Baldacconi, R., additional, Basu, A., additional, Bennett, V.C., additional, Bose, P.K., additional, Breger, D., additional, Chakraborty, N., additional, Chakraborty, P.P., additional, Chan, M.A., additional, Chiarenzelli, J., additional, Chivas, A.R., additional, da Costa, G., additional, Das, K., additional, Dasgupta, P., additional, De, S., additional, deLorraine, W., additional, Dey, A., additional, Eriksson, P.G., additional, Fergusson, C.L., additional, Festa, V., additional, Friend, C.R.L., additional, Galinskaya, K., additional, Ghosh, S., additional, Gusiakov, V., additional, Han, Y., additional, Han, Z., additional, Henderson, R.A., additional, Hofmann, A., additional, Horie, K., additional, Ibanez-Mejia, M., additional, Jong, J., additional, Kessler, F.L., additional, Kratzmann, D., additional, Lisco, S., additional, Long, D.G.F., additional, Lupulescu, M., additional, Mandal, A., additional, Mastronuzzi, G., additional, Mazumder, R., additional, Mejiama, W., additional, Moretti, M., additional, Moretti, V., additional, Mukherjee, S., additional, Mukhopadhyay, J., additional, Nagarajan, R., additional, Nagendra, R., additional, Nutman, A.P., additional, Offler, R., additional, Pisarska-Jamroży, M., additional, Rambolamanana, G., additional, Rosiere, C.A., additional, Saha, S., additional, Sanyal, S., additional, Sarkar, S., additional, Sato, T., additional, Scotti, R., additional, Selleck, B., additional, Sengupta, P., additional, Shanmugam, G., additional, Tawfik, H.A., additional, Tropeano, M., additional, Tsutsumi, Y., additional, Van Loon, A.J. (Tom), additional, and Young, G.M., additional
- Published
- 2017
- Full Text
- View/download PDF
4. ZnO nanoparticles anchored to silica filler. A curing accelerator for isoprene rubber composites
- Author
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Susanna, A, Armelao, L, Callone, E, Dirè, S, D'Arienzo, M, DI CREDICO, B, Giannini, L, Hanel, T, Morazzoni, F, Scotti, R, SUSANNA, ANTONIO, D'ARIENZO, MASSIMILIANO, DI CREDICO, BARBARA, MORAZZONI, FRANCA, SCOTTI, ROBERTO, Susanna, A, Armelao, L, Callone, E, Dirè, S, D'Arienzo, M, DI CREDICO, B, Giannini, L, Hanel, T, Morazzoni, F, Scotti, R, SUSANNA, ANTONIO, D'ARIENZO, MASSIMILIANO, DI CREDICO, BARBARA, MORAZZONI, FRANCA, and SCOTTI, ROBERTO
- Abstract
ZnO nanoparticles (NPs) were anchored to SiO2 spherical nanoparticles by hydrolysis and condensation of Zn(CH3COO)2 in the presence of SiO2. The ZnO/SiO2 NPs were then blended with isoprene rubber. The immobilization of ZnO NPs on the silica surface, due to covalent SiOZn bonds provides a homogeneous dispersion of zinc in the rubber matrix and increases the accessibility of the curative reactants to Zn2+ ions. This improves the efficiency of the rubber curing and reduces the amount of used ZnO.
- Published
- 2015
5. Shape controlled spherical (0D) and rod-like (1D) silica nanoparticles in silica/styrene butadiene rubber nanocomposites: Role of the particle morphology on the filler reinforcing effect
- Author
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Scotti, R, Conzatti, L, D'Arienzo, M, DI CREDICO, B, Giannini, L, Hanel, T, Stagnaro, P, Susanna, A, Tadiello, L, Morazzoni, F, SCOTTI, ROBERTO, D'ARIENZO, MASSIMILIANO, DI CREDICO, BARBARA, SUSANNA, ANTONIO, TADIELLO, LUCIANO, MORAZZONI, FRANCA, Scotti, R, Conzatti, L, D'Arienzo, M, DI CREDICO, B, Giannini, L, Hanel, T, Stagnaro, P, Susanna, A, Tadiello, L, Morazzoni, F, SCOTTI, ROBERTO, D'ARIENZO, MASSIMILIANO, DI CREDICO, BARBARA, SUSANNA, ANTONIO, TADIELLO, LUCIANO, and MORAZZONI, FRANCA
- Abstract
Silica/styrene butadiene rubber (SBR) nanocomposites were prepared by blending method using shape-controlled spherical and rod-like nanoparticles with different aspect ratios as filler for the rubber reinforcement. The differently shaped silica particles were synthesized by sol-gel method using tetraethoxysilane (TEOS) and (3-mercaptopropyl) trimethoxysilane (MPTSM) as silica precursors, and cetyltrimethylammonium bromide (CTAB) as structure directing agent. This strategy allowed to study the influence of the particle morphology on the reinforcing effect independently of the silica surface chemistry and considering the aspect ratio as the only geometrical variance. Spherical and anisotropic rod-like particles, dispersed in the nanocomposites, formed a network of particles bridged by thin rubber layers throughout the SBR matrix. Moreover, differently oriented domains of aligned rods are observed when the aspect ratio of particles increases and is ≥2. Dynamic-mechanical properties demonstrated that the rod-like particles with the higher aspect ratio provided stronger reinforcement of the rubber. This was related to the self-alignment of the anisotropic particles and to the consequent larger filler/polymer interface, compared to that of spherical ones.
- Published
- 2014
6. Molybdenum-MCM-41 silica as heterogeneous catalyst for olefin epoxidation
- Author
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Bigi, F, Piscopo, C, Predieri, G, Sartori, G, Scotti, R, Zanoni, R, Maggi, R, Piscopo, CG, Maggi, R., SCOTTI, ROBERTO, Bigi, F, Piscopo, C, Predieri, G, Sartori, G, Scotti, R, Zanoni, R, Maggi, R, Piscopo, CG, Maggi, R., and SCOTTI, ROBERTO
- Abstract
MCM-41-supported molybdenum/bis-dithiocarbamate complex can be efficiently utilized, after treatment with tert-butylhydroperoxide (TBHP), for the epoxidation of alkenes under solventless conditions. The treatment with TBHP allows the formation of the real catalyst through oxidative decomposition of the complex affording well dispersed Mo(VI) species grafted onto the silica surface through the silanol groups. Experimental results, catalytic efficiency and spectroscopy data, allow to advance some hypotheses on the molybdenum-grafted catalyst formation. The grafted catalyst can be reused several times in the model epoxidation of cyclohexene affording the epoxide with very good yield; only during the first run a modest molybdenum leaching is observed. Both cyclic and linear alkenes can be epoxidized in good to excellent yields and selectivities.
- Published
- 2014
7. Pt and Au/TiO2 photocatalysts for methanol reforming: Role of metal nanoparticles in tuning charge trapping properties and photoefficiency
- Author
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Naldoni, A, D'Arienzo, M, Altomare, M, Marelli, M, Scotti, R, Morazzoni, F, Selli, E, Dal Santo, V, Dal Santo, V., D'ARIENZO, MASSIMILIANO, SCOTTI, ROBERTO, MORAZZONI, FRANCA, Naldoni, A, D'Arienzo, M, Altomare, M, Marelli, M, Scotti, R, Morazzoni, F, Selli, E, Dal Santo, V, Dal Santo, V., D'ARIENZO, MASSIMILIANO, SCOTTI, ROBERTO, and MORAZZONI, FRANCA
- Abstract
Metal-loaded TiO2 is, by far, one of the most important class of photocatalysts in hydrogen production through photoreforming of organics and water photosplitting. In this study anatase loaded with Au and Pt nanoparticles (Au/TiO2 and Pt/TiO2) by an impregnation-reduction method was investigated as for morphological, electronic (XPS) and photocatalytic properties in hydrogen production by methanol photoreforming. The electron and hole trapping centers, Ti3+ and O-, respectively, formed under UV-vis irradiation of the photocatalysts, were studied by in situ electron spin resonance (ESR) spectroscopy. The nature of the loaded metal affected both the H2 evolution rate and the distribution of the methanol oxidation products. The better performance of Pt/TiO2 is attributable to the greater ability of Pt with respect to Au to act as electron sink, slowering the recombination of photoproduced electron-hole couples. Direct evidence of this effect was obtained by ESR analysis, showing that the amount of Ti3+ active sites follows the order TiO2>Au/TiO2Pt/TiO2, thus confirming easier electron transfer from Ti3+ to Pt, where the H+ reduction to H2 occurs. © 2012 Elsevier B.V.
- Published
- 2013
8. TiO2 nanocrystal grafted on macroporous silica: a novel hybrid organic-inorganic sol-gel approach for the synthesis of highly photoactive composite material
- Author
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Crippa, M, Callone, M, D'Arienzo, M, Mueller, K, Polizzi, S, Wahba, L, Morazzoni, F, Scotti, R, CRIPPA, MAURIZIO, D'ARIENZO, MASSIMILIANO, WAHBA, LAURA, MORAZZONI, FRANCA, SCOTTI, ROBERTO, Crippa, M, Callone, M, D'Arienzo, M, Mueller, K, Polizzi, S, Wahba, L, Morazzoni, F, Scotti, R, CRIPPA, MAURIZIO, D'ARIENZO, MASSIMILIANO, WAHBA, LAURA, MORAZZONI, FRANCA, and SCOTTI, ROBERTO
- Abstract
TiO2-SiO2 composite materials with photocatalytic properties similar to those of slurry powdered TiO2 is obtained by a novel sol-gel synthetic strategy involving the hydrolysis/condensation of TMOS assisted by PEG as templating agent and the grafting of preformed titania nanocrystals onto the macropore walls of the silica matrix. In order to anchor TiO2 particles to the surface of SiO2, avoiding their embedding into silica matrix, functionalization with carboxylic acid or amine derivatives was carried out. The functionalization induces the confinement of titania nanocrystals in PEG, during the silica formation, and allows their dispersion on the silica surface. TiO2-SiO2 materials exhibit high thermal and chemical stability and a photocatalytic activity in the phenol mineralization comparable to that of powder TiO2 in slurry (half degradation time ∼120min). These results suggest that the immobilization procedure here reported provides high accessibility of the catalyst active sites preserving the functional properties of the photoactive catalyst. © 2011 Elsevier B.V.
- Published
- 2011
9. Immobilization of hydrothermally produced TiO2 with different phase composition for photocatalytic degradation of phenol
- Author
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Scotti, R, D'Arienzo, M, Morazzoni, F, Bellobono, I, SCOTTI, ROBERTO, MORAZZONI, FRANCA, D'ARIENZO, MASSIMILIANO, Bellobono, IR, Scotti, R, D'Arienzo, M, Morazzoni, F, Bellobono, I, SCOTTI, ROBERTO, MORAZZONI, FRANCA, D'ARIENZO, MASSIMILIANO, and Bellobono, IR
- Abstract
Hydrothermally produced TiO2 powders with different phase composition (anatase, rutile and mixed phase) were immobilized on glass fibers and tested in the phenol mineralization process. Both H2O2 and O2 were used as oxygen donors, and their performances were compared with those of the same TiO2 samples as slurries. The catalytic properties of the immobilized different crystalline phases, rutile and anatase, show the same trend as the slurry samples: pure rutile displays the highest catalytic efficiency in the presence of H2O2, while samples containing anatase improve the photodegradation efficacy with O2. It was suggested that the stability of the photogenerated electron-hole couple allows high activity of rutile in the presence of H2O2, while the relevant oxygen chemisorption on anatase causes high catalytic activity in the presence of O2. A four parameters kinetics model shows that both reaction steps, the phenol degradation and the mineralization of the intermediates, are photoactivated by TiO2. Photoactivity of the coated glass fibers is generally lower than that of slurries, even if their efficiencies are almost comparable when the oxidation is performed by H2O2, while much lower when the oxygen donor is O2. As a matter of fact, the morphology of immobilized catalysts shows the presence of chestnut burr aggregates of large rutile crystalline rods on the glass fiber, which are much less compact than the aggregates of small anatase particles. This preserves rutile surface area from the coarsening effects; thus, when rutile is the more active species, as in the presence of H2O2, the photocatalytic activity is less affected by immobilization. © 2008 Elsevier B.V. All rights reserved.
- Published
- 2009
10. Photocatalytic mineralization of phenol catalyzed by pure and mixed phase hydrothermal titanium dioxide
- Author
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Scotti, R, D'Arienzo, M, Testino, A, Morazzoni, F, SCOTTI, ROBERTO, MORAZZONI, FRANCA, D'ARIENZO, MASSIMILIANO, Scotti, R, D'Arienzo, M, Testino, A, Morazzoni, F, SCOTTI, ROBERTO, MORAZZONI, FRANCA, and D'ARIENZO, MASSIMILIANO
- Abstract
The spectral response of newly synthesized and doped TiO(2) nanostructures, which are designed for the operation under solar light, is key to their potential performance as photocatalyst materials. In the case of nitrogen-doped TiO(2) particles, the presence of the photoactive defect can be verified via characteristic spectroscopic fingerprints, such as (1) an optical absorption band above lambda > 400 nm, (2) paramagnetic defect states related to substitutional and interstitial nitrogen atoms, and (3) a photoluminescence emission feature that can be induced by band gap excitation. We report these spectroscopic fingerprints for hydrothermally derived and N-doped TiO(2) powder samples. On the basis of defined annealing procedures, we also found a way to eliminate the photoactive nitrogen defects and performed light-induced charge separation experiments on samples before and after dopant elimination in O(2) atmosphere. The concentrations of adsorbed O(2)(-) ions, which stand for scavenged photogenerated electrons, were determined by electron paramagnetic resonance (EPR) spectroscopy. On the basis of these data, we calculated the number of photons, which (a) were additionally utilized because of the beneficial effect of photoactive nitrogen and (b) were lost because of the dopant-induced recombination of UV light generated charge carriers. As a major result, we found for the doped materials that both effects actually compensate each other. With regard to the synthesis and characterization of doped TiO(2) systems, these findings underline the importance to include dopant-induced charge-carrier recombination effects in the evaluation of the photocatalyst's spectral response in order to reach a fair evaluation of its properties.
- Published
- 2009
11. Mechanism of NH3 interaction with transition metal-added nanosized WO3 for gas sensing: In situ electron paramagnetic resonance study
- Author
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Morazzoni, F, Scotti, R, Origoni, L, D'Arienzo, M, Jimenez, I, Cornet, A, Morante, A, MORAZZONI, FRANCA, SCOTTI, ROBERTO, D'ARIENZO, MASSIMILIANO, Morante, AR, Morazzoni, F, Scotti, R, Origoni, L, D'Arienzo, M, Jimenez, I, Cornet, A, Morante, A, MORAZZONI, FRANCA, SCOTTI, ROBERTO, D'ARIENZO, MASSIMILIANO, and Morante, AR
- Abstract
The interaction of ammonia with transition metal (Cr, V, Cu)-added WO3, base materials for NH3 gas sensing devices, was investigated by electron paramagnetic resonance. The EPR analysis was carried out on samples obtained as nanosized powders by wet method. It was demonstrated that the addition of transition metal ions promotes the ammonia oxidative dehydrogenation to N2 and N2O, due to trapping of NH3 electrons on Cu(II), V(V) and Cr(V) centres. The higher catalytic efficiency of Cr(V) is relatable to the acceptance of two electrons by each metal ion, instead of one electron as by Cu(II) and V(V) ions. Cr(V) centres are present as chromyl groups, [Cr{double bond, long}O]3+, which were found in higher amount when the annealing takes place without an effective oxidative dehydration (673 K instead of 973 K). This condition stabilizes the chemisorption of NO on the oxide surface annealed at 673 K. A relevant quantity of NO affects the resistance base line of the electrical response and has to be avoided. © 2006 Elsevier B.V. All rights reserved.
- Published
- 2007
12. Mechanism of sensing NO in argon by nanocrystalline SnO2: Electron paramagnetic resonance, Mössbauer and electrical study
- Author
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Canevali, C, Mari, C, Mattoni, M, Morazzoni, F, Ruffo, R, Scotti, R, Russo, U, Nodari, L, CANEVALI, CARMEN, MARI, CLAUDIO MARIA, MORAZZONI, FRANCA, RUFFO, RICCARDO, SCOTTI, ROBERTO, Nodari, L., Canevali, C, Mari, C, Mattoni, M, Morazzoni, F, Ruffo, R, Scotti, R, Russo, U, Nodari, L, CANEVALI, CARMEN, MARI, CLAUDIO MARIA, MORAZZONI, FRANCA, RUFFO, RICCARDO, SCOTTI, ROBERTO, and Nodari, L.
- Abstract
The mechanism of NO interaction with nanocrystalline (6-10nm particle size) SnO2 powdered samples, obtained by sol-gel synthesis, was studied by electron paramagnetic resonance and Mössbauer spectroscopy. Resistance measurements on nanostructured (3nm particle size) SnO2 thin films (80-160nm), still obtained by sol-gel route, were coupled to spectral results. Spectroscopic investigations demonstrated that the NO interaction involves electron injection to the oxide, formation of oxygen vacancies, and chemisorption of NO2- and NO3- anions. The amount of oxygen vacancies depends on the annealing atmosphere of SnO2. When it was previously annealed under inert (Ar) atmosphere, the NO interaction causes a great amount of oxygen defects as the lack of chemisorbed oxygen species forces NO to interact with lattice oxide anions; instead when annealed in air, NO also reacts with chemisorbed oxygen species giving NO2- and NO3- anions. Accordingly, the electrical response is higher in the case of predominant NO interaction with lattice oxide anions, because a great amount of NO electrons are transferred to SnO2. © 2003 Elsevier B.V. All rights reserved.
- Published
- 2004
13. Defect chemistry in ruthenium-supported tin dioxide: a spectromagnetic approach
- Author
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Chiodini, N, Canevali, C, Morazzoni, F, Scotti, R, Bianchi, C, CHIODINI, NORBERTO, CANEVALI, CARMEN, MORAZZONI, FRANCA, SCOTTI, ROBERTO, Bianchi, CL, Chiodini, N, Canevali, C, Morazzoni, F, Scotti, R, Bianchi, C, CHIODINI, NORBERTO, CANEVALI, CARMEN, MORAZZONI, FRANCA, SCOTTI, ROBERTO, and Bianchi, CL
- Abstract
The reactivity towards CO and air of SnO2 defects, singly and doubly ionized oxygen vacancies (V(o)/· V(o)/··), bivalent tin centers, was studied in ruthenium-supported tin oxide (Ru/SnO2), and compared with that in pure SnO2. Electron paramagnetic resonance and X-ray photoelectron spectroscopy studies demonstrated that CO treatment produces V(o)/· and V(o)/·· defects in SnO2, some V(o)/· transferring their electrons to Sn4+ centers; instead in Ru/SnO2, some V(o)/· defects transferred their electrons to Ru(n+) centers (n=0,1,2,3) and no one bivalent tin center was observed. When contacted with air, pure SnO2 transferred a part of the electrons of V(o)/· and of bivalent tin centers to O2, instead Ru/SnO2 emptied all V(o)/· defects transferring the electrons from V(o)/· to ruthenium and to O2. The via ruthenium transfer increases the number of electrons exchanged between SnO2 and the surrounding atmosphere and gave a rationale for the higher sensitivity towards CO displayed by transition metal-doped SnO2 with respect to pure SnO2. (C) 2000 Elsevier Science Ltd.
- Published
- 2000
14. Photocatalytic mineralization of phenol catalyzed by pure and mixed phase hydrothermal titanium dioxide
- Author
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Franca Morazzoni, Andrea Testino, Massimiliano D’Arienzo, Roberto Scotti, Scotti, R, D'Arienzo, M, Testino, A, and Morazzoni, F
- Subjects
Anatase ,Aqueous solution ,Process Chemistry and Technology ,Radical ,Inorganic chemistry ,Photochemistry ,Catalysis ,law.invention ,chemistry.chemical_compound ,chemistry ,Rutile ,law ,Titanium dioxide ,Photocatalysis ,Photocatalysis, titanium dioxide, EPR, spin-trap, water purification ,Electron paramagnetic resonance ,General Environmental Science - Abstract
The spectral response of newly synthesized and doped TiO(2) nanostructures, which are designed for the operation under solar light, is key to their potential performance as photocatalyst materials. In the case of nitrogen-doped TiO(2) particles, the presence of the photoactive defect can be verified via characteristic spectroscopic fingerprints, such as (1) an optical absorption band above lambda > 400 nm, (2) paramagnetic defect states related to substitutional and interstitial nitrogen atoms, and (3) a photoluminescence emission feature that can be induced by band gap excitation. We report these spectroscopic fingerprints for hydrothermally derived and N-doped TiO(2) powder samples. On the basis of defined annealing procedures, we also found a way to eliminate the photoactive nitrogen defects and performed light-induced charge separation experiments on samples before and after dopant elimination in O(2) atmosphere. The concentrations of adsorbed O(2)(-) ions, which stand for scavenged photogenerated electrons, were determined by electron paramagnetic resonance (EPR) spectroscopy. On the basis of these data, we calculated the number of photons, which (a) were additionally utilized because of the beneficial effect of photoactive nitrogen and (b) were lost because of the dopant-induced recombination of UV light generated charge carriers. As a major result, we found for the doped materials that both effects actually compensate each other. With regard to the synthesis and characterization of doped TiO(2) systems, these findings underline the importance to include dopant-induced charge-carrier recombination effects in the evaluation of the photocatalyst's spectral response in order to reach a fair evaluation of its properties.
- Published
- 2009
15. Mechanism of NH3 interaction with transition metal-added nanosized WO3 for gas sensing: In situ electron paramagnetic resonance study
- Author
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L. Origoni, Roberto Scotti, Joan Ramon Morante, Franca Morazzoni, A. Cornet, I. Jiménez, Massimiliano D’Arienzo, Morazzoni, F, Scotti, R, Origoni, L, D'Arienzo, M, Jimenez, I, Cornet, A, and Morante, A
- Subjects
Sensing, EPR, ammonia, tungsten oxide ,Chemistry ,Inorganic chemistry ,Oxide ,General Chemistry ,Catalysis ,law.invention ,Ion ,Metal ,chemistry.chemical_compound ,Transition metal ,Chemisorption ,law ,visual_art ,visual_art.visual_art_medium ,Dehydrogenation ,Electron paramagnetic resonance - Abstract
The interaction of ammonia with transition metal (Cr, V, Cu)-added WO3, base materials for NH3 gas sensing devices, was investigated by electron paramagnetic resonance. The EPR analysis was carried out on samples obtained as nanosized powders by wet method. It was demonstrated that the addition of transition metal ions promotes the ammonia oxidative dehydrogenation to N2 and N2O, due to trapping of NH3 electrons on Cu(II), V(V) and Cr(V) centres. The higher catalytic efficiency of Cr(V) is relatable to the acceptance of two electrons by each metal ion, instead of one electron as by Cu(II) and V(V) ions. Cr(V) centres are present as chromyl groups, [Cr{double bond, long}O]3+, which were found in higher amount when the annealing takes place without an effective oxidative dehydration (673 K instead of 973 K). This condition stabilizes the chemisorption of NO on the oxide surface annealed at 673 K. A relevant quantity of NO affects the resistance base line of the electrical response and has to be avoided. © 2006 Elsevier B.V. All rights reserved.
- Published
- 2007
16. Mechanism of Sensing NO in Argon by Nanocrystalline SnO2: Electron Paramagnetic Resonance, Mössbauer and Electrical Study
- Author
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Umberto Russo, M. Mattoni, Claudio Maria Mari, Roberto Scotti, Carmen Canevali, Franca Morazzoni, Luca Nodari, Riccardo Ruffo, Canevali, C, Mari, C, Mattoni, M, Morazzoni, F, Ruffo, R, Scotti, R, Russo, U, and Nodari, L
- Subjects
CHIM/03 - CHIMICA GENERALE E INORGANICA ,Argon ,Metals and Alloys ,Analytical chemistry ,Oxide ,chemistry.chemical_element ,Condensed Matter Physics ,Oxygen ,Nanocrystalline material ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,CHIM/02 - CHIMICA FISICA ,chemistry ,Chemisorption ,law ,Mössbauer spectroscopy ,Materials Chemistry ,Physical chemistry ,Electrical and Electronic Engineering ,Thin film ,ossido di stagno, no, sensore per gas, EPR, Mosssbauer, nanocristalli ,Electron paramagnetic resonance ,Instrumentation - Abstract
The mechanism of NO interaction with nanocrystalline (6-10nm particle size) SnO2 powdered samples, obtained by sol-gel synthesis, was studied by electron paramagnetic resonance and Mössbauer spectroscopy. Resistance measurements on nanostructured (3nm particle size) SnO2 thin films (80-160nm), still obtained by sol-gel route, were coupled to spectral results. Spectroscopic investigations demonstrated that the NO interaction involves electron injection to the oxide, formation of oxygen vacancies, and chemisorption of NO2- and NO3- anions. The amount of oxygen vacancies depends on the annealing atmosphere of SnO2. When it was previously annealed under inert (Ar) atmosphere, the NO interaction causes a great amount of oxygen defects as the lack of chemisorbed oxygen species forces NO to interact with lattice oxide anions; instead when annealed in air, NO also reacts with chemisorbed oxygen species giving NO2- and NO3- anions. Accordingly, the electrical response is higher in the case of predominant NO interaction with lattice oxide anions, because a great amount of NO electrons are transferred to SnO2. © 2003 Elsevier B.V. All rights reserved.
- Published
- 2004
17. A spectroscopic study of Cu(II)-complexes of chelating resins containing nitrogen and sulfur atoms in the chelating groups
- Author
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Roberto Scotti, S. Cobianco, A. Lezzi, Cobianco, S, Lezzi, S, and Scotti, R
- Subjects
Polymers and Plastics ,General Chemical Engineering ,Chemical structure ,chemistry.chemical_element ,Biochemistry ,law.invention ,Metal ,Chelating resin ,chemistry.chemical_compound ,law ,Polymer chemistry ,Materials Chemistry ,Environmental Chemistry ,Chelation ,Dithiocarbamate ,Electron paramagnetic resonance ,ESR ,chemistry.chemical_classification ,CHIM/03 - CHIMICA GENERALE E INORGANICA ,General Chemistry ,Copper ,chemistry ,visual_art ,copper ,Functional group ,visual_art.visual_art_medium ,Ethylene glycol - Abstract
The structures of different Cu(II)-thiol, dithiocarbamate, methylthiourea and amino complexes have been investigated on the basis of their spectroscopic properties. The influence of the chemical structure, both the nature of the functional groups and the spacers, on the resin chelating behaviour towards Cu(II) ions in diluted solution has been evaluated. The resins are macroporous polystyrene–divinylbenzene polymer functionalized with two spacer groups, poly(ethylene glycol) and poly(ethylene imine) chains, supporting thiol, dithiocarbamate, methylthiourea and amino groups. Electron paramagnetic resonance (EPR) was employed to show the coordination of Cu(II) ions into the complexes. Cu(II)-dithiocarbamate complexes have a square planar coordination with two dithiocarbamate groups bound to the metal. The resins with methylthiourea as functional group form Cu(II)-complexes in tetragonal symmetry with four nitrogen atoms as equatorial ligands. Further, a partial reduction of Cu(II) to diamagnetic Cu(I) with formation of Cu(I)-methylthiourea complexes, where copper is S-bonded to the methylthiourea group, could be suggested. In Cu(II)-thiol complexes, Cu(II) ions are bound through sulfur bridges.
- Published
- 2000
18. The surface of small glaciers as radioactive hotspots: Concentration of radioisotopes during predicted intensive melting in the Alps.
- Author
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Buda J, Błażej S, Ambrosini R, Scotti R, Pittino F, Sala D, Zawierucha K, and Łokas E
- Abstract
Glaciers are considered secondary sources of pollutants, including radioisotopes such as Cesium or Plutonium, with heightened concentrations compared to other ecosystems. The predicted melting of glaciers poses a substantial risk of releasing stored radioisotopes, yet understanding the glacier-specific factors influencing their concentration remains limited. This study investigates the relationship between glacier altitude, surface area, organic matter content in dark supraglacial sediment (cryoconite), precipitation, and activity concentrations of natural (
210 Pb) and anthropogenic radionuclides (137 Cs and241 Am) across 19 Alpine glaciers. Results indicate that radioisotope concentrations depend on organic matter content in the cryoconite, highlighting the role of biotic-abiotic interactions in pollutant accumulation on glaciers. Moreover,210 Pb activity concentration decreases with glacier altitude, likely due to atmospheric variations in222 Rn. Water precipitation events, such as during peaks in137 Cs deposition and after the Chernobyl Nuclear Power Plant disaster, do not impact current activity concentrations. Importantly, radioisotope concentrations in cryoconite are higher on smaller glaciers. This directly supports the hypothesis that the cryoconite retains a significant share of radioisotopes stored in the ice during intensive melting. Since many small glaciers in the Alps are predicted to disappear within the next 50 years, we anticipate release of radioisotopes to mountain ecosystems might be higher than previously forecasted., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
19. Evaluation of the accuracy and stress distribution of 3-unit implant supported prostheses obtained by different manufacturing methods.
- Author
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Mello CC, Santiago Junior JF, Lemos CAA, Galhano GA, Evangelisti E, Scotti R, Verri FR, and Pellizzer EP
- Subjects
- Computer Simulation, Finite Element Analysis, Dental Implants, Dental Prosthesis Design methods, Stress, Mechanical
- Abstract
The purpose of this in vitro study was to measure the vertical, positive-horizontal, and negative-horizontal misfit (VM, PHM, and NHM, respectively) of the zirconia three-element prosthetic framework, fabricated using different methods, and compare them with conventional fabrication methods (lost-wax casting). Furthermore, this study aimed to evaluate the influence of the misfit values on the biomechanical behavior of the 3-unit fixed prosthetic frameworks using three-dimensional finite element analysis (3D-FEA). Forty frameworks (n = 10) were fabricated as follow: G1, Cerec Bluecam; G2, iTero; G3, 3Series; and G4, conventional method. The samples were randomized to measure marginal misfit using a high-precision three-dimensional (3D)-optical microscope. The results were submitted to analysis of variance (ANOVA), with the significance level set at 5%. The mean VM values of each group were used in creating the models by 3D-FEA with the misfit found in optical microscopy. The programs used were the InVesalius, Rhinoceros, SolidWorks, FEMAP and NEiNastran. The von Mises map was plotted for each model. The G4 showed the lowest mean VM value (16.73 μm), followed by G3 (20.71 μm), G2 (21.01 μm), and G1 (41.77 μm) (p < 0.001). G2 was more accurate than G1 (p < 0.05) and similar to G3 (p = 0.319). For PHM, G4 was the most accurate and did not present overextended values. With regard to NHM, the computer-aided design and computer-aided manufacturing (CAD-CAM) systems were more accurate (-61.91 μm) than G4 (-95.36 μm) (p = 0.014). In biomechanical analysis, stress concentration caused by oblique loading is greater than caused by axial loading. In axial loading, G4 was the most favorable while G1 was the least favorable, biomechanically, in oblique loading, similar stress patterns were observed in all the models. The prosthetic screw was the most overloaded structure, but the material did not influence the stress distribution. The misfit prostheses showed a greater degree of stress than the controls (without misfit). The manufacturing method influenced the marginal misfit of the frameworks, with the conventional method being the most accurate and the Cerec Bluecam System (closed system) the least accurate. Biomechanically, fitting prostheses were more favorable than misfit prostheses., (Copyright © 2019. Published by Elsevier B.V.)
- Published
- 2019
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20. Zirconia-based versus metal-based single crowns veneered with overpressing ceramic for restoration of posterior endodontically treated teeth: 5-year results of a randomized controlled clinical study.
- Author
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Monaco C, Llukacej A, Baldissara P, Arena A, and Scotti R
- Subjects
- Adolescent, Adult, Aged, Bicuspid, Ceramics adverse effects, Computer-Aided Design, Dental Alloys adverse effects, Dental Alloys therapeutic use, Dental Materials adverse effects, Dental Materials therapeutic use, Dental Porcelain adverse effects, Dental Prosthesis Design standards, Female, Humans, Male, Metal Ceramic Alloys adverse effects, Metal Ceramic Alloys therapeutic use, Middle Aged, Molar, Time Factors, Tooth Fractures, Treatment Outcome, Young Adult, Yttrium, Zirconium adverse effects, Ceramics therapeutic use, Crowns adverse effects, Crowns statistics & numerical data, Dental Porcelain therapeutic use, Dental Restoration Failure statistics & numerical data, Dental Veneers adverse effects, Dental Veneers statistics & numerical data, Denture, Partial, Fixed adverse effects, Denture, Partial, Fixed statistics & numerical data, Tooth, Nonvital, Zirconium therapeutic use
- Abstract
Objectives: The aim of this 5-year randomized controlled trial was to compare the longevity and clinical behavior of single posterior crowns made with pressable ceramic on zirconia and on metal frameworks, and if failures occur, to delineate the contributing factors., Methods: 72 patients, who needed the covering of at least a molar and/or premolar, were included in the study. All teeth were endodontically treated, with absence of periapical lesion or active periodontitis. Ninety single crowns were made with zirconia or metal framework and covered with pressable veneering ceramics. Two independent examiners assessed the survival of restorations at 6 months, 1-4 and 5 years after restoration placement including periapical radiographs, intraoral photographs, and USPHS modified criteria. The statistical analyses were performed with the Kaplan-Meier method., Results: One core fracture occurred in Zircad/Zirpress crowns and one metal ceramic crown was lost for root fracture. Chipping fracture of the veneering ceramic was detected in 2 metal-ceramic crowns and in 3 zirconia-based crowns. The Estimate Cumulative Survival (ECS) and the Estimate Cumulative Success (ECSs) with standard deviation (SE) were respectively 97,73±2,19 and 92,64±4,14 for zirconia-based crowns whereas 97,44±2,39 and 91,11±4,27 for porcelain fused to metal crowns., Conclusions: The present randomized controlled trial shows that the survival of zirconia-based and metal-based single crowns is similar over a follow-up period of 5 years. No significant differences in esthetic, functional and biological outcomes were demonstrated between the two groups. The main failure mode was the chipping fracture of the veneering ceramic in both materials. Study number on ClinicalTrial.gov NCT02758457., Clinical Significance: According to the results of this clinical study, zirconia-based rehabilitations with overpressing veneering technique represent a valid alternative to metal-based for posterior single crown restorations., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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21. Photon correlation spectroscopy applied to tear analysis.
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Picarazzi S, Lecchi M, Pastori V, D'Arienzo M, Scotti R, and Tavazzi S
- Subjects
- Adult, Contact Lenses, Female, Humans, Hydrodynamics, Male, Electron Spin Resonance Spectroscopy methods, Tears chemistry
- Abstract
This study aims to deepen the knowledge on tear film properties by the development of a protocol for analyses of Photon Correlation Spectroscopy (PCS) on human tears and by the comparison between PCS results obtained on tears of contact lens wearers and non-wearers. Tears (5μL) were collected by a glass capillary. The analyses provide the hydrodynamic diameter of tear components by analyzing intensity fluctuations in time of scattered light. PCS appears a promising technique for studying tear features and for shedding light on specific eye conditions, such as on the clinical effects of CL wear. In fact, statistical difference (p<0.001) was found between the measured mean hydrodynamic diameter of tear components of wearers and non-wearers, the resulting value significantly higher for CL wearers. The scenario does not substantially change after (25±5)min from the CL removal. The difference is attributed to changes in the interactions between tear constituents due to CL wear. In order to get deeper insights on the influence of CL wear on aggregation and structure of tear components, a preliminary Electron Spin Resonance (ESR) investigation was performed, monitoring Fe
3+ species. ESR spectra on tears of both CL wearers and non-wearers showed the presence of intense signals, probably associated to iron (III) centers in proteins such as lactoferrin, and a weaker resonance attributable to Fe3+ species interacting with S-S bridges of lysozyme. Differences in ESR spectra between CL wearers and non-wearers were detected and tentatively ascribed to changes in coordination or in local environment of Fe3+ centers connected to aggregation phenomena induced by CL wear, which promote their interaction with other neighboring iron species., (Copyright © 2017. Published by Elsevier B.V.)- Published
- 2017
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22. Short-term outcomes of mandibular reconstruction in oncological patients using a CAD/CAM prosthesis including a condyle supporting a fibular free flap.
- Author
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Tarsitano A, Battaglia S, Ramieri V, Cascone P, Ciocca L, Scotti R, and Marchetti C
- Subjects
- Adolescent, Adult, Aged, Female, Humans, Male, Middle Aged, Treatment Outcome, Young Adult, Bone Plates, Computer-Aided Design, Fibula transplantation, Free Tissue Flaps surgery, Mandibular Neoplasms surgery, Mandibular Reconstruction methods, Prosthesis Design methods
- Abstract
Purpose: Condylar reconstruction and replacement using alloplastic materials currently attracts much surgical interest. The major challenge is to functionally reconstruct the anatomical region; this is crucial in terms of correct mandibular function. The goal of the present study was to evaluate the clinical outcomes of and complications experienced by a series of oncological patients who underwent computer-aided design/computer-aided manufacturing (CAD/CAM) condylar reconstruction following resection-disarticulation of the mandible., Materials and Methods: We included nine patients who underwent disarticulation resection surgery to treat benign and malignant mandibular tumors involving the condylar region. All resections preserved the articular meniscus and featured placement of a CAD/CAM reconstructive plate supporting a fibular, microvascular free flap. The head of the prosthetic condyle reproduced the anatomical morphology of the native condyle. Patients were clinically evaluated in terms of occlusion stability, mandibular functional recovery, static and dynamic pain, and preservation of the normal mandibular contour. Planning and postoperative computed tomography (CT) scans were superimposed to assess the accuracy of reconstruction., Results: No patient experienced plate exposure and, on direct clinical examination, no patient complained of joint pain. No patient developed plate loosening. No resorption of the glenoid fossa was evident when pre- and postoperative bone thicknesses were compared by CT. Preoperative occlusion was preserved in all dentate patients. One patient exhibited condylar displacement. In terms of reconstructive accuracy, the average postoperative deviation of the condyle from the preoperative position was 3.8 mm (range: 1.3-6.7 mm)., Conclusions: The clinical outcomes of our series of oncological patients who underwent reconstruction using CAD/CAM plates including condyles were encouraging. The utility of our protocol needs to be confirmed in larger patient series., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2017
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23. Surgical reconstruction of maxillary defects using a computer-assisted design/computer-assisted manufacturing-produced titanium mesh supporting a free flap.
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Tarsitano A, Battaglia S, Ciocca L, Scotti R, Cipriani R, and Marchetti C
- Subjects
- Contrast Media, Esthetics, Female, Humans, Leg blood supply, Leg diagnostic imaging, Male, Maxillary Neoplasms diagnostic imaging, Osteotomy, Prospective Studies, Prosthesis Design, Radiography, Panoramic, Titanium, Tomography, X-Ray Computed, Treatment Outcome, Computer-Aided Design, Free Tissue Flaps, Maxillary Neoplasms surgery, Plastic Surgery Procedures methods, Surgery, Computer-Assisted, Surgical Mesh
- Abstract
The maxilla provides support to the overlying structures and contributes significantly to the overall facial appearance and to critical functions such as mastication, speech, and deglutition. Many different techniques have been used over the years to achieve this reconstructive goal. Modern computer-assisted surgery affords new methods for planning resections, as well as optimising reconstructive outcomes and functional rehabilitation. The aim of this study was to describe our experience with, and technique for, the functional, structural, and aesthetic reconstruction of maxillary bone defects using a computer-assisted design (CAD)/computer-assisted manufacturing (CAM)-printed titanium mesh to provide structural support for free flap reconstruction. Four patients who underwent reconstruction with a CAD/CAM-printed titanium mesh were included in this study. The preoperative computed tomography (CT) data set used for virtual planning was superimposed onto the postoperative CT scan to calculate the difference between the virtually planned position and the postoperative position of the titanium mesh. The orbital floor and alveolus were the most frequent sites of deviation, and good reproducibility could be obtained with less than 1 mm of deviation between planning and results in most regions. Printed titanium meshes obtained with CAD/CAM technology and used to structurally support free flaps provide a valuable method for the achievement of good aesthetic, structural, and functional outcomes in maxillary reconstruction. Reconstructive accuracy using this technique is reasonably high. Further studies with a larger number of patients would be useful to confirm these results., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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24. Is a computer-assisted design and computer-assisted manufacturing method for mandibular reconstruction economically viable?
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Tarsitano A, Battaglia S, Crimi S, Ciocca L, Scotti R, and Marchetti C
- Subjects
- Adolescent, Adult, Aged, Child, Female, Fibula transplantation, Free Tissue Flaps adverse effects, Free Tissue Flaps economics, Free Tissue Flaps transplantation, Hospital Costs, Humans, Length of Stay economics, Male, Mandibular Reconstruction adverse effects, Middle Aged, Operative Time, Postoperative Complications, Prospective Studies, Young Adult, Computer-Aided Design, Mandibular Neoplasms surgery, Mandibular Reconstruction economics, Mandibular Reconstruction methods
- Abstract
The design and manufacture of patient-specific mandibular reconstruction plates, particularly in combination with cutting guides, has created many new opportunities for the planning and implementation of mandibular reconstruction. Although this surgical method is being used more widely and the outcomes appear to be improved, the question of the additional cost has to be discussed. To evaluate the cost generated by the management of this technology, we studied a cohort of patients treated for mandibular neoplasms. The population was divided into two groups of 20 patients each who were undergoing a 'traditional' freehand mandibular reconstruction or a computer-aided design/computer-aided manufacturing (CAD-CAM) mandibular reconstruction. Data concerning operation time, complications, and days of hospitalisation were used to evaluate costs related to the management of these patients. The mean operating time for the CAD-CAM group was 435 min, whereas that for the freehand group was 550.5 min. The total difference in terms of average time gain was 115.5 min. No microvascular complication occurred in the CAD-CAM group; two complications (10%) were observed in patients undergoing freehand reconstructions. The mean overall lengths of hospital stay were 13.8 days for the CAD-CAM group and 17 days for the freehand group. Finally, considering that the institutional cost per minute of theatre time is €30, the money saved as a result of the time gained was €3,450. This cost corresponds approximately to the total price of the CAD-CAM surgery. In conclusion, we believe that CAD-CAM technology for mandibular reconstruction will become a widely used reconstructive method and that its cost will be covered by gains in terms of surgical time, quality of reconstruction, and reduced complications., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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25. A CAD-CAM-prototyped temporomandibular condyle connected to a bony plate to support a free fibula flap in patients undergoing mandiblectomy: A pilot study with 5 years of follow up.
- Author
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Ciocca L, Tarsitano A, Marchetti C, and Scotti R
- Subjects
- Follow-Up Studies, Humans, Mandibular Reconstruction instrumentation, Pilot Projects, Bone Plates, Computer-Aided Design, Fibula transplantation, Free Tissue Flaps transplantation, Mandibular Condyle surgery, Mandibular Neoplasms surgery, Mandibular Prosthesis, Mandibular Reconstruction methods
- Abstract
Reconstruction of the condyle after an ablative procedure with the aim of cancer elimination remains surgically challenging. This pilot study focused on mandibular condylar replacement using CAD-CAM temporomandibular prostheses connected to customized reconstructive plates to support free fibula flaps in oncological patients. Five patients underwent mandibular disarticulation resection, and two of them completed their 5-year follow ups. The condylar anatomy, the position of the condyle within the glenoid fossa, and glenoid anatomy were measured by superimposing pre- and postoperative CT images (obtained after 6 months and 5 years of follow up). When comparing condyle anatomy, the shift was no more than 0.19 mm; when calculating condyle downward displacement the values were inferior to 2.92 mm; when analyzing glenoid fossa thickness, in case #1, glenoid fossa thickness increased by 0.62 and 0.48 mm at the 6-month and 5-year follow ups, respectively, and in case #2 were 0.50 and -0.11 mm, respectively. The hypothesis that the absence of anatomical change would prevent biodynamic alteration of tissues of the articulation chamber (the glenoid fossa, the synovial liquid, and the disc) was confirmed by the preliminary findings of this study., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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26. Morphological results of customized microvascular mandibular reconstruction: A comparative study.
- Author
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Tarsitano A, Ciocca L, Scotti R, and Marchetti C
- Subjects
- Fibula transplantation, Free Tissue Flaps, Humans, Mandible diagnostic imaging, Mandible surgery, Mandibular Neoplasms diagnostic imaging, Mandibular Neoplasms surgery, Prosthesis Design methods, Tomography, X-Ray Computed, Treatment Outcome, Computer-Aided Design, Mandibular Reconstruction methods
- Abstract
Introduction: Virtual planning and guided surgery with customized reconstructive plates are becoming more and more common for mandibular reconstruction with fibular free flaps. Although the literature describes many potential applications, no systematic analyses have been made about morphological results regarding computer-aided reconstruction compared to traditional freehand bent plate., Materials and Methods: In the present study, we propose a comparative study in this innovative field, analysing a case series of 30 CAD/CAM reconstructed mandibles, compared to traditional reconstructed mandibles, in terms of morphological results. All patients were evaluated by pre-operative and a post-operative CT scan. To evaluate the morphological results, several anatomical landmarks were measured on CT scan: 1) the midline deviation; 2) the amplitude variation, in grades, of the mandibular angle; 3) the bi-gonial diameter of the mandibular and 4) the chin protrusion., Results: The mean differences registered between pre-operative and post-operative CT scan were significantly better for test group regarding mandibular angle (p = 0.034), bi-gonial diameter (p = 0.041), chin protrusion (p = 0.05). No significant differences were registered for midline deviation (p = 0.092)., Conclusion: CAD/CAM reconstructive technique appears to be a valid method to accurately restore the pre-operative morphological situation., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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27. Mandibular reconstructions using computer-aided design/computer-aided manufacturing: A systematic review of a defect-based reconstructive algorithm.
- Author
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Tarsitano A, Del Corso G, Ciocca L, Scotti R, and Marchetti C
- Subjects
- Esthetics, Head and Neck Neoplasms surgery, Humans, Algorithms, Computer-Aided Design, Mandibular Reconstruction classification, Mandibular Reconstruction methods
- Abstract
Modern planning techniques, including computer-aided design/computer-aided manufacturing (CAD-CAM) can be used to plan reconstructive surgery, optimising aesthetic outcomes and functional rehabilitation. However, although many such applications are available, no systematic protocol yet describes the entire reconstructive procedure, which must include virtual planning, custom manufacture, and a reconstructive algorithm. We reviewed current practices in this novel field, analysed case series described in the literature, and developed a new, defect-based reconstructive algorithm. We also evaluated methods of mandibular reconstruction featuring virtual planning, the use of surgical guides, and laser printing of custom titanium bony plates to support composite free flaps, and evaluated their utility., (Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2015
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28. Accuracy of fibular sectioning and insertion into a rapid-prototyped bone plate, for mandibular reconstruction using CAD-CAM technology.
- Author
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Ciocca L, Marchetti C, Mazzoni S, Baldissara P, Gatto MR, Cipriani R, Scotti R, and Tarsitano A
- Subjects
- Ameloblastoma surgery, Carcinoma, Squamous Cell surgery, Chemotherapy, Adjuvant, Cost Savings, Fibula transplantation, Humans, Mandibular Neoplasms surgery, Mandibular Reconstruction economics, Mandibular Reconstruction instrumentation, Neoadjuvant Therapy, Operative Time, Osteosarcoma surgery, Patient Care Planning, Piezosurgery methods, Radiotherapy, Adjuvant, Retrospective Studies, Treatment Outcome, User-Computer Interface, Bone Plates, Bone Transplantation methods, Computer-Aided Design, Fibula surgery, Free Tissue Flaps transplantation, Mandibular Reconstruction methods, Transplant Donor Site surgery
- Abstract
Modern techniques of mandibular reconstruction, such as CAD-CAM technology and rapid prototyping, offer new means by which reconstructive surgery can be planned to optimise aesthetic outcomes and prosthetic rehabilitation. The high degree of accuracy afforded by these approaches is principally attributable to high-precision fibular sectioning and insertion of the bone into a customised bone plate. CAD-CAM mandibular reconstruction procedures using vascularised bone free-flap transfers were performed on 10 patients with benign or malignant neoplasms. Five were not treated with the aid of CAD-CAM technology, and served as the control group. Five were scheduled for maxillofacial surgery using surgical cutting guides and customised bone plates. A generalised linear model for linear measures was used to compare the accuracy of reconstruction between the two groups. A difference, even though not significant, in the lateral shift of the mesial and distal positions of the fibular units was evident between groups. CAD-CAM-generated fibular surgical guides afford improved accuracy when used to restore native anatomy, especially in the context of mandibular arch restoration, and both operating room time and related costs are reduced during fibular sectioning., (Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2015
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29. Adhesion mechanisms at the interface between Y-TZP and veneering ceramic with and without modifier.
- Author
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Monaco C, Tucci A, Esposito L, and Scotti R
- Subjects
- Adhesiveness, Coated Materials, Biocompatible chemistry, Dental Etching methods, Dental Polishing methods, Dental Porcelain chemistry, Hot Temperature, Humans, Materials Testing, Microscopy, Electron, Scanning, Porosity, Random Allocation, Silicon Dioxide chemistry, Spectrometry, X-Ray Emission, Surface Properties, Wettability, X-Ray Diffraction, Ceramics chemistry, Dental Bonding, Dental Materials chemistry, Dental Veneers, Yttrium chemistry, Zirconium chemistry
- Abstract
Objective: This study investigated the mechanism of action at the interface between a commercially available Y-TZP and its veneering ceramic after final firing. Particular attention was paid, from a microstructural point of view, to evaluating the effects of different surface treatments carried out on the zirconia., Methods: In total, 32 specimens of presintered zirconia Y-TZP (LavaFrame, 3M ESPE, Germany) were cut with a low-speed diamond blade. The specimens were divided in two major groups, for testing after fracture or after mirror finishing, and were sintered following the manufacturer's instructions. Each major group was then randomly divided into four subgroups, according to using or not using the dedicated framework modifier, with or without a preliminary silica coating (CoJet, 3M ESPE). A suitable veneering ceramic was used for each group (Lava Ceram Overlay Porcelain, 3M ESPE). A detailed microstructural study of the interfaces of the zirconia-veneering ceramic was performed using a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer to evaluate chemical variation at the interfaces., Results: When the framework modifier was not applied on the Y-TZP surface, microdetachments, porosities, and openings in the ceramic layer were observed at the interlayers. A degree of diffusion of different elements through the interfaces from both the zirconia and veneering layers was detected., Conclusions: Application of the framework modifier can increase the wettability of the zirconia surfaces, allowing a continuous contact with the veneering layer. The micro-analysis performed showed the presence of a reaction area at the interface between the different materials., Clinical Significance: the increase of the wettability of the zirconia surface could improve the adhesion at interface with the veneering ceramic and reduce the clinical failure as chipping or delamination., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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30. The CAD-CAM technique for mandibular reconstruction: an 18 patients oncological case-series.
- Author
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Tarsitano A, Mazzoni S, Cipriani R, Scotti R, Marchetti C, and Ciocca L
- Subjects
- Ameloblastoma surgery, Biocompatible Materials chemistry, Bone Transplantation methods, Carcinoma, Squamous Cell surgery, Disease-Free Survival, Fibula surgery, Follow-Up Studies, Free Tissue Flaps transplantation, Graft Survival, Humans, Mandibular Reconstruction instrumentation, Patient Care Planning, Plastic Surgery Procedures instrumentation, Surgery, Computer-Assisted, Titanium chemistry, Transplant Donor Site surgery, User-Computer Interface, Computer-Aided Design, Mandibular Neoplasms surgery, Mandibular Reconstruction methods, Plastic Surgery Procedures methods
- Abstract
Background: Modern techniques for mandibular reconstruction, such as CAD-CAM, offer new solutions for planning of reconstructive surgery in relation to the aesthetic outcome and the prosthetic rehabilitation., Methods: CAD-CAM reconstruction procedures using vascularised bone free-flap transfers and surgical guides to cut the mandible and fibula were performed in 18 cases of neoplasms. The planned surgery was used to design and manufacture customised surgical devices., Results: The mean follow-up was 12 months. All patients, except one, are alive without disease at the time of writing. Reconstructive microvascular flap survival was 100%. No major or minor microvascular complication occurred. No donor site complication was observed., Conclusions: CAD-CAM technology is a very useful way to obtain the native morphology of the mandible, especially when both bi-dimensional and tri-dimensional defects occur. The reconstruction protocol presented offers several benefits and few disadvantages, which are discussed in the article., (Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2014
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31. Effect of ferrule and post placement on fracture resistance of endodontically treated teeth after fatigue loading.
- Author
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Zicari F, Van Meerbeek B, Scotti R, and Naert I
- Subjects
- Analysis of Variance, Dental Stress Analysis, Glass, Humans, Statistics, Nonparametric, Post and Core Technique, Tooth Fractures etiology, Tooth, Nonvital complications
- Abstract
Objectives: To evaluate the influence of the ferrule effect (1) and the fibre-post placement (2) on the fracture resistance of endodontically treated teeth subjected to cyclic fatigue loading., Methods: 40 extracted single-rooted upper pre-molars were sectioned at the CEJ (groups a and b) or 2mm above the CEJ (groups c and d), and subsequently endodontically treated. After 24-h water storage at 37°C, specimens were restored according to four build-up approaches (n=10 per group): (a) NF-NP (no ferrule, no post), (b) NF-P (no ferrule, fibre-post), (c) F-NP (ferrule, no post) and (d) F-P (ferrule, fibre post). RelyX Posts (3M-ESPE) were used in groups NF-P and F-P, and were cemented with Panavia F 2.0 (Kuraray). A standardized composite core was built, after which specimens were restored with an all-ceramic crown (IPS Empress CAD, Ivoclar-Vivadent) Specimens were fatigued by exposure to 1,200,000 cycles using a chewing simulator (Willytech). All specimens that survived fatigue loading were fractured using a universal loading device (Micro-Tester, Instron). A two-way analysis of variance was used to determine the statistical significance of the factors ferrule and post on fracture resistance., Results: Only one NF-NP specimen failed under fatigue. The ferrule effect significantly enhanced the fracture resistance of the restored teeth, regardless the use of a post (p=0.003). F-NP obtained the highest fracture resistance (758.52±121.89N), which was not significantly different from F-P (647.58±132.95N); NF-NP presented the lowest fracture resistance (361.52±151.69N). For all groups, only 'repairable' failures were recorded., Conclusions: Avoiding extra-removal of sound tooth structure, rather than placing a fibre post, can protect endodontically treated teeth against catastrophic failure. However, when any ferrule can be preserved, a fibre-post may improve the retention and fatigue resistance of the restoration., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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32. Microstructural changes produced by abrading Y-TZP in presintered and sintered conditions.
- Author
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Monaco C, Tucci A, Esposito L, and Scotti R
- Subjects
- Algorithms, Aluminum Oxide chemistry, Carbon Compounds, Inorganic chemistry, Chemical Phenomena, Crystallography, Hardness, Hot Temperature, Humans, Materials Testing, Microscopy, Electron, Scanning, Particle Size, Porosity, Silicon Compounds chemistry, Silicon Dioxide chemistry, Stress, Mechanical, Surface Properties, X-Ray Diffraction, Ceramics chemistry, Dental Etching methods, Dental Materials chemistry, Yttrium chemistry, Zirconium chemistry
- Abstract
Objective: To evaluate the effect of abrading before and after sintering using alumina-based abrasives on the surface of yttria-tetragonal zirconia polycrystals. Particular attention was paid to the amount of surface stress-assisted phase transformation (tetragonal→monoclinic) and the presence of microcracks., Methods: Pre-sintered zirconia ceramic specimens (ZirCAD; Ivoclar Vivadent) were first surface-ground flat with #600-800-1000-grit SiC paper. They were then surface-treated with different grain size abrasives before and after the sintering step. Samples that underwent no surface treatment were used as controls. For each condition, eight specimens were prepared. The physical/mechanical characteristics of zirconia material were determined by measuring density, porosity, grain size, hardness, and fracture toughness. The effects of surface treatments were assessed by surface roughness measurements, quantitative X-ray diffraction analysis, and scanning electron microscopy., Results: With increased dimensions of the abrasive particles, the abraded surfaces of zirconia specimens exhibited a widespread system of microcracks and an increased monoclinic zirconia quantity. These structural changes likely affect the aging of the material during its clinical service., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
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33. CAD/CAM guided secondary mandibular reconstruction of a discontinuity defect after ablative cancer surgery.
- Author
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Ciocca L, Mazzoni S, Fantini M, Persiani F, Marchetti C, and Scotti R
- Subjects
- Bone Plates, Computer Simulation, Equipment Design, Follow-Up Studies, Humans, Image Processing, Computer-Assisted methods, Imaging, Three-Dimensional methods, Intraoperative Care, Male, Mandible surgery, Middle Aged, Models, Anatomic, Multidetector Computed Tomography methods, Operative Time, Patient Care Planning, Software, User-Computer Interface, Computer-Aided Design, Mandibular Neoplasms surgery, Mandibular Reconstruction instrumentation, Plastic Surgery Procedures instrumentation, Surgical Flaps transplantation
- Abstract
A surgical guide is projected to aid the repositioning of the mandibular segments in their original locations, and a reconstruction bone plate is provided to support the fibula free flap. Computer-aided mandibular reconstruction involves three steps: virtual surgical planning, CAD/CAM and rapid-prototyping procedures for the design and manufacture of the customised surgical device and surgery. The duration of the reconstructive phase (<1.5 h intraoperative time) was reduced in comparison with traditional secondary mandibular reconstruction. The bone plate permitted the maximal restoration of the original facial and mandibular contours and the more precise positioning of the residual mandibular ramus in comparison with conventional procedures. No complication was noted during the mean follow-up period of 12 months. The protocol presented in this paper offers some benefits: 1) The virtual environment permitted ideal preoperative planning of mandibular segment repositioning in secondary reconstruction; 2) Intraoperative time was not consumed by approximate and repeated bone plate modelling; 3) Using CT data obtained before primary surgery, the reconstruction bone plate was designed using the original external cortical bone as a template to reproduce the ideal mandibular contour; 4) Prototyped resin models of the bone defect allowed the surgeon to train preoperatively by simulating the surgery., (Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2012
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34. Effect of fibre post length and adhesive strategy on fracture resistance of endodontically treated teeth after fatigue loading.
- Author
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Zicari F, Van Meerbeek B, Scotti R, and Naert I
- Subjects
- Bicuspid physiopathology, Bite Force, Composite Resins chemistry, Dental Cements chemistry, Dental Stress Analysis instrumentation, Dentin-Bonding Agents chemistry, Humans, Materials Testing, Methacrylates chemistry, Resin Cements chemistry, Root Canal Preparation instrumentation, Root Canal Preparation methods, Stress, Mechanical, Surface Properties, Temperature, Time Factors, Tooth, Nonvital physiopathology, Water chemistry, Cementation methods, Dental Materials chemistry, Dental Prosthesis Design, Glass chemistry, Post and Core Technique instrumentation, Tooth Fractures physiopathology, Tooth, Nonvital therapy
- Abstract
Objectives: To evaluate the effect of the length of fibre-posts(1) and type of adhesive cement(2) on the fracture resistance of endodontically treated teeth, after fatigue loading., Methods: Eighty extracted upper pre-molars were sectioned at the CEJ and endodontically treated. After 24 h of water storage at 37°C, RelyX Posts (3M-ESPE) were cemented with Panavia F 2.0 (Kuraray) or RelyX Unicem (3M-ESPE). A standardized composite core was built. Specimens were divided into four groups depending on the post-core ratio: (A) 2/1 (control); (B) 3/2; (C) 1/1 (small diameter); (D) 1/1(large diameter) and submitted to 1,200,000 cycles using a chewing simulator (Willytech). Immediately afterwards, all specimens that survived fatigue loading were fractured using a universal loading device (Micro-tester, Instron). Data were analysed with ANOVA., Results: Four percent of the specimens failed during fatigue loading. The length of the post into the root affected the fracture resistance. The statistical outcome varied according to the inclusion of specimens failed during fatigue loading. However, the control group always had the lowest fracture resistance. The type of adhesive cement did not affect the fracture resistance. A prevalence of not-repairable failures was observed in specimens restored with the longest posts, whilst shorter posts led to more repairable failures., Conclusions: Shortening the post length and the ensuing preservation of more tooth structure, offer the potential for reparability through an in-built fail safe mechanism and may thus reduce the occurrence of catastrophic failures., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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35. WITHDRAWN: Clinical fitting of CAD/CAM zirconia single crowns generated from digital intraoral impressions based on active wavefront sampling.
- Author
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Scotti R, Cardelli P, Baldissara P, and Monaco C
- Abstract
OBJECTIVES: The aim of this clinical trial was to test the accuracy of single all-ceramic zirconia crowns resulting from digital intraoral impressions with active wavefront sampling technology by measuring the marginal and internal fits of the crowns. MATERIALS AND METHODS: Thirty-seven teeth (24 anterior and 13 posterior) in fifteen patients were restored with single zirconia-ceramic crowns (Lava/Lava Ceram; 3M ESPE) generated from a digital intraoral scanner (Lava Chairside Oral Scanner; 3M ESPE). Before definitive insertion, silicone replicas were produced for all 37 crowns. The sample was cut in four sections; each section was evaluated in four points: marginal gap, mid-axial wall, axio-occlusal edge and centro-occlusal. A total of 592 measurements (148 for each evaluation point) was examined using stereomicroscopy with a magnification of 50×. The Mann-Whitney U test was used to evaluate whether there were differences between anterior and posterior values (alpha=0.05). RESULTS: The mean values for each point were: 48.65μm (SD 29.45μm) for the marginal gap, 112.25μm (SD 55.54μm) at the mid-axial wall, 137.81μm (SD 71.31μm) at the axio-occlusal edge of the abutments, and 157.25μm (SD 75.51μm) at the centro-occlusal location. No statistical differences were found between the anterior and posterior group for each point (p-values: P1=0.39; P2=0.38; P3=0.07; P4=0.30). CONCLUSIONS: The marginal and internal fitting values obtained were within literature agreed as clinically acceptable for both anterior and posterior teeth. CLINICAL RELEVANCE: Single crown restorations obtained using digital intraoral impressions based on active wavefront sampling technology presented enough accuracy to be used as an alternative to the conventional impression techniques., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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36. Magnetic resonance imaging of a hypereosinophilic endocarditis with apical thrombotic obliteration in Churg-Strauss syndrome complicated with acute abdominal aortic embolic occlusion.
- Author
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Esposito A, De Cobelli F, Belloni E, Ravelli S, Scotti R, Sabbadini MG, and Del Maschio A
- Subjects
- Acute Disease, Adult, Aorta, Abdominal, Cardiac Imaging Techniques, Churg-Strauss Syndrome complications, Embolism complications, Endocarditis complications, Female, Humans, Hypereosinophilic Syndrome complications, Thrombosis complications, Churg-Strauss Syndrome pathology, Embolism pathology, Endocarditis pathology, Hypereosinophilic Syndrome pathology, Magnetic Resonance Imaging, Thrombosis pathology
- Abstract
Churg-Strauss syndrome can be associated with Loeffler-like eosinophilic endocarditis. We report a case of a young woman in which the diagnosis of Churg-Strauss syndrome was made subsequently to the magnetic resonance demonstration of eosinophilic endocarditis associated to left ventricle apical thrombosis. In our report, this rare condition evolved in an unusual complication: the embolic migration of the left ventricle apical thrombus in the abdominal aorta as showed by multi-detector-computed-tomography angiography., (Copyright © 2008 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2010
- Full Text
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37. A new method for quantitative analysis of dentinal tubules.
- Author
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Ciocca L, Gallina I, Navacchia E, Baldissara P, and Scotti R
- Subjects
- Computer Graphics, Humans, Mathematical Computing, Reference Values, Dentin anatomy & histology, Image Processing, Computer-Assisted, Microscopy, Electron, Scanning, Software
- Abstract
Conventional methods to estimate the number of dentinal tubules cannot be considered reliable and repeatable, because results depends on the operator outlining of the tubules contours. In this study, we propose a totally automated computerized analysis technique to evaluate dentinal tubules and their surface area. The comparison test of these conventional with a semi-automatic methods shows that the automated analysis allowed a reliable identification and numbering of dentinal tubules, by means of high-quality images. No statistically significant difference exists in the number of tubules and the total tubule surface area between the control and test groups.
- Published
- 2007
- Full Text
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38. Effect of root canal treatments on quartz fiber posts bonding to root dentin.
- Author
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Baldissara P, Zicari F, Valandro LF, and Scotti R
- Subjects
- Chelating Agents chemistry, Composite Resins chemistry, Dental Cements chemistry, Dental Restoration Failure, Edetic Acid chemistry, Epoxy Resins chemistry, Gutta-Percha chemistry, Humans, Materials Testing, Root Canal Filling Materials chemistry, Root Canal Irrigants chemistry, Sodium Hypochlorite chemistry, Stress, Mechanical, Surface Properties, Zinc Oxide-Eugenol Cement chemistry, Dental Bonding, Dental Materials chemistry, Dentin ultrastructure, Post and Core Technique instrumentation, Quartz chemistry, Root Canal Therapy methods
- Abstract
The aim of this study was to evaluate the effect of irrigants and endodontic sealers on fiber post push-out strength in both fatigue cycling and no-cycling conditions. Fifty single-rooted human teeth received five endodontic treatments. The posts were cemented using a flowable composite and a three-steps adhesive. Five specimens from each group were subjected to 2 x 10(6) cycles of 37.5 N. There were 200 sections obtained for the push-out test. Fatigue cycled groups treated with an eugenol-containing sealer showed the lowest push-out strength (p < 0.001). No significant differences were found among no-cycled groups (p = 0.665). The post-cement interface was found to be weaker than the cement-dentin one. However, fatigue cycles increased the occurrence of cement-dentin failures (p = 0.001). The eugenol-containing sealer reduced the bonding of fiber posts when mechanically cycled, thus the use of a resin-based sealer is advisable.
- Published
- 2006
- Full Text
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39. Evaluation of the flexural strength of carbon fiber-, quartz fiber-, and glass fiber-based posts.
- Author
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Galhano GA, Valandro LF, de Melo RM, Scotti R, and Bottino MA
- Subjects
- Analysis of Variance, Carbon, Carbon Fiber, Composite Resins, Dental Materials, Elasticity, Glass, Humans, Materials Testing, Microscopy, Electron, Scanning, Pliability, Quartz, Statistics, Nonparametric, Dental Stress Analysis, Post and Core Technique
- Abstract
This study investigated the flexural strength of eight fiber posts (one carbon fiber, one carbon/quartz fiber, one opaque quartz fiber, two translucent quartz fiber, and three glass fiber posts). Eighty fiber posts were used and divided into eight groups (n = 10): G1: C-POST (Bisco); G2: AESTHETI-POST (Bisco); G3: AESTHETI-PLUS (Bisco); G4: LIGHT-POST (Bisco); G5: D.T. LIGHT-POST (Bisco); G6: PARAPOST WHITE (Coltene); G7: FIBERKOR (Pentron); G8: REFORPOST (Angelus). All of the samples were tested using the three-point bending test. The averages obtained were submitted to the ANOVA and to Tukey's test (p < 0.05). The mean values (MPa) of the groups AESTHETI-POST-carbon/quartz fiber post (Bisco) and AESTHETI-PLUS-quartz fiber post (Bisco) were statistically similar and higher than the mean values of the other groups. The mean values of the groups C-POST-carbon fiber post (Bisco), LIGHT-POST-translucent quartz fiber post (Bisco), D.T. LIGHT-POST-double tapered translucent quartz fiber post (Bisco), PARAPOST WHITE-glass fiber post (Coltene) and FIBREKOR--glass fiber post (Pentron) were similar and higher than the group REFORPOST-glass fiber post (Angelus).
- Published
- 2005
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40. Paravaginal repair of lateral vaginal wall defects by fixation to the ischial periosteum and obturator membrane.
- Author
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Scotti RJ, Garely AD, Greston WM, Flora RF, and Olson TR
- Subjects
- Abdomen anatomy & histology, Aged, Female, Follow-Up Studies, Humans, Middle Aged, Recurrence, Suture Techniques, Urinary Incontinence, Stress surgery, Gynecologic Surgical Procedures methods, Uterine Prolapse surgery, Vagina anatomy & histology, Vagina surgery
- Abstract
Objective: The aim of the study was to evaluate the anatomic basis, efficacy, and safety of a technique for correcting lateral wall vaginal defects., Study Design: Phase I was cadaveric dissection carried out to ascertain the strength and position of structures likely to support lateral vaginal wall defects. The ischial periosteum just anterior to the ischial spine was found to be strong tissue, relatively free of nerves and vessels. In phase II, paravaginal defects were repaired by placing sutures through the arcus tendineus and underlying obturator fascia, obturator membrane, and ischial periosteum. Other defects and urinary incontinence were corrected within the same surgical setting. Forty patients were followed up for an average of 39 months (range 7-52 months). Preoperative evaluation consisted of an extensive history, cough stress test, spontaneous uroflowmetry, postvoid residual urine determination, urethral axis determination, site-specific pelvic floor defect evaluation, and multichannel urodynamic studies. After the operation patients underwent evaluations at 3 months, at 6 months, and then annually., Results: Objective site-specific re-examination of the 40 patients revealed the following recurrences: lateral wall in 1 of 40 procedures, anterior wall in 3 of 35 procedures, posterior wall in 1 of 36 procedures, and apical wall in 1 of 27 procedures. Thirty-four of 36 women (94.4%) with urodynamically confirmed genuine stress incontinence or potential incontinence achieved cure (P <.001)., Conclusions: (1) The ischial periosteum and obturator membrane are consistently strong reattachment sites. (2) Repair of paravaginal defects with these tissues is effective and safe. (3) Urodynamic parameters were unchanged after the operation except for measures of incontinence, which were improved (P <.001). (4) Performing other pelvic procedures did not negatively alter the success rates of paravaginal repair. (5) The urethral axis was favorably altered after the operation (P <.01).
- Published
- 1998
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41. Prophylactic sacrospinous fixation discouraged.
- Author
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Scotti RJ
- Subjects
- Female, Humans, Sacrococcygeal Region, Hysterectomy methods, Ligaments, Articular surgery, Spine, Uterine Prolapse prevention & control
- Published
- 1992
- Full Text
- View/download PDF
42. Menstrual regulation and early pregnancy termination performed by paraprofessionals under medical supervision.
- Author
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Scotti RJ and Karman HL
- Subjects
- Adolescent, Adult, Evaluation Studies as Topic, Female, Humans, Parity, Pregnancy, Pregnancy Trimester, First, Vacuum Curettage adverse effects, Abortion, Induced, Allied Health Personnel
- Published
- 1976
- Full Text
- View/download PDF
43. Direct detection of paramagnetic species in adriamycin perfused rat hearts.
- Author
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Costa L, Malatesta V, Morazzoni F, Scotti R, Monti E, and Paracchini L
- Subjects
- Animals, Electron Spin Resonance Spectroscopy, Female, Perfusion, Rats, Rats, Inbred Strains, Doxorubicin pharmacology, Heart drug effects
- Abstract
Direct detection of paramagnetic species in control and adriamycin-perfused rat hearts has been carried out. Depending on the flow rate of the perfusion solution (8,4,2 and 1 ml/min) different paramagnetic species were observed: Fe(III)(g = 2.12) at 4 ml/min; three types of oxygen centered radicals of which two in control hearts (g = 2.05 g = 2.038 g = g = 2.008) and the third one (g = 2.03 g = 2.005) in adriamycin perfused hearts, at 2 ml/min. The latter radical was the only one observed at perfusion rate of 1 ml/min both in control and adriamycin treated systems. A relationship between the intracellular enzymatic reductive activation of the anthracycline and the occurrence of ischemic conditions (4,2 and 1 ml/min) in myocardial tissues is proposed basing on the relative amounts of the paramagnetic species above mentioned.
- Published
- 1988
- Full Text
- View/download PDF
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