Search results for "Color"
showing 10 items of 2721 documents
Effect of two whitening agents on the color of composite dental restorations
2018
Background To evaluate color changes to composite resins used to restore extracted teeth compared with composite discs after whitening with two agents: hydrogen peroxide (HP) and carbamide peroxide (CP). Material and methods Ten human molars with class V vestibular and palatine cavity preparation obturated with Vita hybrid nanocomposite were hemisected to obtain 20 specimens assigned randomly to two groups: O1 and O2. Twenty composite discs were divided into two groups: D1 and D2. The groups O1 and D1 were treated with 16% CP, while groups =2 and D2 were treated with 37.5 % HP. Chromaticity coordinates L*, a* and b* were registered using a spectrophotometer. Results Statistically significan…
Effect of diode laser irradiation on the attachment rate of periodontal ligament cells: an in vitro study.
2001
The present study is part of a basic research program investigating the cellular effects of an 810 nm GaAlAs-diode laser on human periodontal tissues. The aim of the investigation was to evaluate the effects of laser treatment of root surface specimens on the attachment of periodontal ligament (PDL) cells in vitro.Root specimens were prepared from periodontally diseased teeth. PDL cells were obtained from human third molar ligaments. Cells were cultured under simple, standardized, and reproducible experimental conditions. One hundred fifty root specimens were scaled and root planed with curets followed by air-powder abrasive treatment; 75 were then lased and 75 served as controls. The irrad…
Effects of elevated hydrogen peroxide 'strip' bleaching on surface and subsurface enamel including subsurface histomorphology, micro-chemical composi…
2007
Abstract Objectives This study examined the effects of elevated concentration hydrogen peroxide tooth whitening treatments on tooth surface and subsurface integrity. Methods Sound human molars were ground and polished to prepare an uniform substrate for bleaching treatments. A cycling treatment included alternating ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching was carried out with prototype bleaching strips containing hydrogen peroxide gel at 13% and 16% concentrations. A non-bleached group was used as a control. Treatments included 28 h of total bleaching exposure in vitro . Surface color was meas…
Calix[4]arene-functionalized naphthalene and perylene imide dyes.
2002
[reaction: see text] Calix[4]arenes bearing one, two, or four 1,8-naphthyl imide groups at the wide rim and bis-calix[4]arenes connected via perylene-bisimide dye spacers have been synthesized. The low-temperature NMR spectrum of the tetranaphthylimide suggests, in agreement with a crystal structure, a C2-symmetrical pinched cone conformation stabilized via face-to-face pi-pi interactions between opposite naphthylimide groups. UV-vis and fluorescence studies have been carried out for the perylene bis-calix[4]arene dyes.
Vesti la Giubba! Indumentaria, apariencia y comhunicación en la entrada triunfal de Alfonso el Magnánimo en Nápoles (1443)
2021
espanolLa entrada triunfal de Alfonso el Magnanimo en Napoles el 26 de febrero de 1443 es uno de esos momentos de la Historia que quedaron marcados para la posteridad, no solo por la importancia del hecho en si, sino por todo el despliegue de mensajes en clave simbolica que en ese acto se llegaron a emitir. Analizado por diversos autores desde diferentes puntos de vista, se ha abordado bastante menos hasta la fecha una interpretacion de los codigos implicitos en la indumentaria de quienes participaron en la ceremonia, que aqui se ha tratado de realizar en base a las variadas fuentes que la describieron y de los nuevos conocimientos que la historia del vestido pone hoy a nuestra disposicion …
Real-Time Monocular Pose Estimation of 3D Objects Using Temporally Consistent Local Color Histograms
2017
We present a novel approach to 6DOF pose estimation and segmentation of rigid 3D objects using a single monocular RGB camera based on temporally consistent, local color histograms. We show that this approach outperforms previous methods in cases of cluttered backgrounds, heterogenous objects, and occlusions. The proposed histograms can be used as statistical object descriptors within a template matching strategy for pose recovery after temporary tracking loss e.g. caused by massive occlusion or if the object leaves the camera’s field of view. The descriptors can be trained online within a couple of seconds moving a handheld object in front of a camera. During the training stage, our approac…
Real-Time Monocular Segmentation and Pose Tracking of Multiple Objects
2016
We present a real-time system capable of segmenting multiple 3D objects and tracking their pose using a single RGB camera, based on prior shape knowledge. The proposed method uses twist-coordinates for pose parametrization and a pixel-wise second-order optimization approach which lead to major improvements in terms of tracking robustness, especially in cases of fast motion and scale changes, compared to previous region-based approaches. Our implementation runs at about 50–100 Hz on a commodity laptop when tracking a single object without relying on GPGPU computations. We compare our method to the current state of the art in various experiments involving challenging motion sequences and diff…
Effect of Hydrogen and Carbamide Peroxide in Bleaching, Enamel Morphology, and Mineral Composition: In vitro Study
2017
ABSTRACT Aim The aim of the study was to evaluate the bleaching effect, morphological changes, and variations in calcium (Ca) and phosphate (P) in the enamel with hydrogen peroxide (HP) and carbamide peroxide (CP) after the use of different application regimens. Materials and methods Four groups of five teeth were randomly assigned, according to the treatment protocol: HP 37.5% applied for 30 or 60 minutes (HP30, HP60), CP 16% applied for 14 or 28 hours (CP14, CP28). Changes in dental color were evaluated, according to the following formula: ΔE = [(La−Lb)2+(aa−ab)2 + (ba−bb)2]½. Enamel morphology and Ca and P compositions were evaluated by confocal laser scanning microscope and environmenta…
Segona cita a la península Ibèrica d'Elasmus nudus (Nees, 1834) (Hymenoptera: Eulophidae), aspectes morfològics i biològics d'aquesta espècie
2011
Es descriu i s'il·lustren els caràcters més importants d'Elasmus nudus (Nees, 1834) amb la finalitat de millorar les descripcions antigues i incompletes d'aquesta espècie. Aquesta troballa representa la primera cita per a la província de València i la segona per a la península Ibèrica. Es destaquen diferents aspectes biològics; així E. nudus ha estat obtingut com a parasitoide secundari de E. chrysorrhoea L., 1758 (Lepidoptera: Lymantriidae) atacant Apanteles lacteicolor (Viereck, 1911) (Hymenoptera: Braconidae), un parasitoide primari del lepidòpter esmentat. Pediobius pyrgo (Walker, 1839) (Hymenoptera: Eulophidae) ataca les pupes de E. nudus, que és un parasitoide terciari del lepidòpter.…
Color Difference Thresholds in Dentistry
2015
Purpose The aim of this prospective multicenter study was to determine 50:50% perceptibility threshold (PT) and 50:50% acceptability threshold (AT) of dental ceramic under simulated clinical settings. Materials and Methods The spectral radiance of 63 monochromatic ceramic specimens was determined using a non-contact spectroradiometer. A total of 60 specimen pairs, divided into 3 sets of 20 specimen pairs (medium to light shades, medium to dark shades, and dark shades), were selected for psychophysical experiment. The coordinating center and seven research sites obtained the Institutional Review Board (IRB) approvals prior the beginning of the experiment. Each research site had 25 observers,…