Search results for "Crown"
showing 10 items of 324 documents
Leaf reflectance variation along a vertical crown gradient of two deciduous tree species in a Belgian industrial habitat
2015
Abstract: The reflectometry of leaf asymmetry is a novel approach in the bio-monitoring of tree health in urban or industrial habitats. Leaf asymmetry responds to the degree of environmental pollution and reflects structural changes in a leaf due to environmental pollution. This paper describes the boundary conditions to scale up from leaf to canopy level reflectance, by describing the variability of adaxial and abaxial leaf reflectance, hence leaf asymmetry, along the crown height gradients of two tree species. Our findings open a research pathway towards bio-monitoring based on the airborne remote sensing of tree canopies and their leaf asymmetric properties. (C) 2015 Elsevier Ltd. All ri…
Resorcinarene bis-crown silver complexes and their application as antibacterial Langmuir-Blodgett films
2012
Silver complexes of a cation binding supramolecular host, resorcinarene bis-crown (CNBC5) with propyl, nonyl, decyl and undecyl alkyl chains were investigated by NMR titration, picrate extraction and single crystal X-ray diffraction. Binding studies showed that both 1 : 1 and 1 : 2 (host-Ag(+)) complexes are present in solution with only a slight effect of the lower rim alkyl chain length on the binding constants (log K 4.0-4.2 for 1 : 2 complexes). Solid state complexes of the resorcinarene bis-crowns bearing either C(3) or C(11) chains were obtained. Single crystal X-ray analyses showed that both derivatives bind silver ions by metal-arene and Ag···O coordination from the crown ether brid…
Influence of resin cement shade on the color and translucency of zirconia crowns
2020
Background Zirconia crowns are highly attractive for clinicians, although have poor translucency when used as single restorations, in addition to unknown effect of resin cement shade on final cemented crown shade. This study aimed to assess effect of resin cement opacity on color replication potential of different zirconia frameworks with target tooth color, in addition to different zirconia crowns translucency evaluation. Material and methods Twenty-four zirconia crown restorations were fabricated to restore single central maxillary incisor for 8 patients, divided into 3 groups according to color and type of zirconia used (white Zr core, colored Zr core and monolithic HT Zrcowns). Each gro…
A prospective, multi-center, practice-based cohort study on all-ceramic crowns
2021
The aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of all-ceramic crowns.All-ceramic crowns placed in a practice-based research network ([Ceramic Success Analysis, AG Keramik) were analyzed. Data from 1254 patients with (mostly in-office CAD/CAM) all-ceramic crowns placed by 101 dentists being followed up for more than 5 years were evaluated. At the last follow-up visit crowns were considered as successful (not failed) if they were sufficient, whereas crowns were considered as survived (not lost) if they were still in function. Multi-level Cox proportional hazards models were used to evaluate the association between a ra…
Full maxillary rehabilitation with an all-ceramic system
2009
With the appearance of all-ceramic systems, providing a choice of framework porcelains and allowing the same material to be used for the veneer, it is now possible to select the ideal structure in terms of both function and esthetics. Silicate ceramics allow porcelain laminate veneers and crowns to be used in the anterior region, providing excellent esthetics; while for the posterior area, where function takes precedence, oxide ceramics, specifically zirconium oxide, are preferred. The IPS e.max ceramic system, heir apparent to the IPS Empress 2 system, combines the advantages of zirconium oxide ceramics (IPS e.max Zircad) with the excellent esthetic qualities of silicate ceramics (IPS e.ma…
Fracture resistance and the mode of failure produced in metal-free crowns cemented onto zirconia abutments in dental implants.
2019
The purpose of the investigation was to analyze fracture resistance and mode of failure of zirconium oxide (zirconia) abutments placed on dental implants bearing crowns of different esthetic materials: zirconia, lithium disilicate (LDS), and nano-ceramic resin, for replacing single teeth in the anterior sector. Eighty implant-abutment-crown units were divided into four groups: Group T-MC (control): 20 metal-ceramic crowns cemented onto titanium abutments; Group Z-Z: 20 zirconia crowns on zirconia abutments; Group Z-LD: 20 lithium disilicate crowns on zirconia abutments; and Group Z-NCR: 20 nano-ceramic resin crowns on zirconia abutments. Specimens underwent a fatiguing process (dynamic load…
Implant-supported metal-ceramic and resin-modified ceramic crowns: A 5-year prospective clinical study.
2018
Abstract Statement of problem Because of market demand for innovation, new restoration materials have been introduced without adequate testing; clinical failure may be the consequence, and clinical studies are needed. Purpose The purpose of this clinical study was to evaluate the biological and mechanical clinical behavior of implant-supported resin-modified ceramic crowns compared with that of metal-ceramic crowns. Material and methods Forty-two participants aged between 35 and 65 years received single implants in posterior edentulous sites. After the osseointegration period, half of the implants (selected randomly) (n=25) were restored with metal-ceramic crowns (MC group) and the other ha…
Synthesis and mössbauer studies of some aquo complexes of tin(IV) with crown ethers
1984
Abstract The preparation, characterization, and 119Sn Mossbauer spectra of a number of tin(IV) complexes with cyclic polyethers are presented. With tin(IV) chloride and methyltin(IV) trichloride, 1:1 and 2:1 metal-to-crown-ether complexes are formed, while dimethyltin(IV) dichloride forms only 2:1 complexes; in every case, two water molecules are present in the solid state structure. An octahedral coordination geometry around the tin(IV) center is proposed on the basis of Mossbauer and IR spectra.
Specific interaction of citrate with bis(fluorophoric) bibrachial lariat aza-crown in comparison with the other components of the Krebs cycle
2006
Clares Garcia, M. Paz, M.Paz.Clares@uv.es ; Garcia-España Monsonis, Enrique, Enrique.Garcia-Es@uv.es ; Soriano Soto, Concepcion, Concepcion.Soriano@uv.es ; Tejero Toquero, Roberto, Roberto.Tejero@uv.es
Endodontic re-treatment and restorative treatment of a dens invaginatus type II through new technologies
2019
Background The complex anatomy of dens invaginatus makes access cavity to root canal system difficult, which has an impact on the prognosis of these teeth. A novel technique, based on new technologies, is proposed to make access cavity conservative and guided with minimal dental structure lost. Material and Methods This case report shows the root canal retreatment and the endodontic surgery of a dens invaginatus type II in a left lateral upper incisor previously treated which was affected by a chronic apical abscess and an apical fracture. A Cone Beam Computed Tomography was performed to better diagnosis the dental anatomy. An intraoral scan was performed to get a digital 3D model. A comput…