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Light activated bleaching

Akiko Haruyama, Atsushi Kameyama, Junji Kato, Shinji Takemoto, Yutaka Oda, Eiji Kawada, Toshiyuki Takahashi, Masahiro Furusawa
This study evaluated the microtensile bond strength (μTBS) of 1-step self-etch adhesives (1-SEAs) and 2-step self-etch adhesives (2-SEAs) to pulp chamber dentin immediately after bleaching with 2 types of common bleaching techniques. Pulp chamber dentin of bovine teeth was bleached using 30% hydrogen peroxide (H2O2) solution with quartz-tungsten-halogen light-curing unit (Group 1) and 3.5% H2O2-containing titanium dioxide (TiO2) (Pyrenees®) activated with 405-nm violet diode laser for 15 min (Group 2). Unbleached specimens were placed in distilled water for 15 min and used as controls...
2016: BioMed Research International
Guacyra M Lisboa, Verónica L Guedes, Maria do R Ml Luna, Américo M Carneiro-Jr, Roberto C Stegun
Sickle cell disease (SCD) is a monogenic disease that affects millions of people worldwide. This study analyzed the effectiveness of bleaching and tooth sensitivity after in-office bleaching in patients with SCD. Forty volunteers were randomly assigned to four groups of 10 patients each (five with the SCD and five healthy controls) and treated using in-office bleaching with 35% hydrogen peroxide and different light activation protocols. No statistically significant difference was observed with relation to presence of tooth sensitivity, with or without use of a source of light for peroxide activation, and all bleaching therapies were effective, regardless of the technique employed and the presence/absence of sickle cell disease...
April 2016: Acta Odontológica Latinoamericana: AOL
Ana Bárbara Araújo Loiola, Aline Evangelista Souza-Gabriel, Renata Siqueira Scatolin, Silmara Aparecida Milori Corona
BACKGROUND: Hydrogen peroxide (HP) at lower concentration can provide less alteration on enamel surface and when combined with laser therapy, could decrease tooth sensitivity. This in situ study evaluated the influence of 15% and 35% HP gel activated by lighting-emitting diode (LED)/laser light for in-office tooth bleaching. MATERIALS AND METHODS: Forty-four bovine enamel slabs were polished and subjected to surface microhardness (load of 25 g for 5 s). The specimens were placed in intraoral palatal devices of 11 volunteers (n = 11)...
July 2016: Contemporary Clinical Dentistry
Iris Beatriz Vega Erramuspe, Elnaz Fazeli, Tuomas Näreoja, Jani Trygg, Pekka Hänninen, Thomas Heinze, Pedro Fardim
Biocatalytic pulp fibers were prepared using surface functionalization of bleached kraft pulp with amino groups (F) and further immobilization of a cross-linked glucose oxidase (G*) from Aspergillus niger. The cross-linked enzymes (G*) were characterized using X-ray spectroscopy, Fourier transform infrared spectroscopy, dynamic scanning calorimetry, and dynamic light scattering. According to standard assays, the G* content on the resulting fibers (FG*) was of 11 mg/g of fiber, and enzyme activity was of 215 U/g...
October 10, 2016: Biomacromolecules
Angelo Calderini, Simona Sciara, Chiara Semeria, Giuseppe Pantaleo, Elisabetta Polizzi
Tooth bleaching is a widespread dental treatment with important psychosocial antecedents and outcomes involved. In the activation of in-office bleaching agents, a selective light radiation, that is, a diode laser seems to be a positive choice to decrease the time of bleaching without surface modification and with no residual tooth sensitivity for maximum effect and minimal clinical and psychological side effects.
August 2016: Clinical Case Reports
Janina Hanne, Fabian Göttfert, Jiří Schimer, Maria Anders-Össwein, Jan Konvalinka, Johann Engelhardt, Barbara Müller, Stefan W Hell, Hans-Georg Kräusslich
Concomitant with human immunodeficiency virus type 1 (HIV-1) budding from a host cell, cleavage of the structural Gag polyproteins by the viral protease (PR) triggers complete remodeling of virion architecture. This maturation process is essential for virus infectivity. Electron tomography provided structures of immature and mature HIV-1 with a diameter of 120-140 nm, but information about the sequence and dynamics of structural rearrangements is lacking. Here, we employed super-resolution STED (stimulated emission depletion) fluorescence nanoscopy of HIV-1 carrying labeled Gag to visualize the virion architecture...
September 27, 2016: ACS Nano
Carmen Llena, Leopoldo Forner, María Vazquez
OBJECTIVE: The aim of this study was to assess the dental bleaching efficacy of 37.5% hydrogen peroxide (HP), with and without light activation, in HP-exposed and unexposed areas. METHOD: 28 bovine teeth were selected and divided into two groups (n = 14). Crowns were detached and stained with tea. The gingival half was covered with a gingival barrier. In the incisal half, 37.5% HP (Pola Office+, SDI) was applied three times, with a 1-week interval between applications...
2016: International Journal of Esthetic Dentistry
Justin Berry, Rikard Frederiksen, Yun Yao, Soile Nymark, Jeannie Chen, Carter Cornwall
UNLABELLED: Rhodopsin is a prototypical G-protein-coupled receptor (GPCR) that is activated when its 11-cis-retinal moiety is photoisomerized to all-trans retinal. This step initiates a cascade of reactions by which rods signal changes in light intensity. Like other GPCRs, rhodopsin is deactivated through receptor phosphorylation and arrestin binding. Full recovery of receptor sensitivity is then achieved when rhodopsin is regenerated through a series of steps that return the receptor to its ground state...
June 29, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
A P Mena-Serrano, E Garcia, I Luque-Martinez, Rhm Grande, A D Loguercio, A Reis
OBJECTIVE: To compare the bleaching efficacy and tooth sensitivity (TS) of two hydrogen peroxide (HP) concentrations (20% and 35%) used for in-office bleaching associated or not with a light-emitting diode (LED)/laser light activation. METHOD: Seventy-seven patients with a right maxillary canine darker than A3 were selected for this single-blind randomized trial. The participants were distributed in four groups: bleaching with 35% HP, 35% HP + LED/laser, 20% HP, and 20% HP + LED/laser...
June 28, 2016: Operative Dentistry
Zhili Han, Fang Li, Jiangnan Shu, Lingfeng Gao, Xiaoying Liu, Hua Cui
In this work, three different kinds of acridinium ester (AE)-functionalized carbon nanomaterials, including AE-functionalized carbon nanoparticles (AE-CNPs), AE-functionalized graphene oxide (AE-GO), and AE-functionalized multiwalled carbon nanotubes (AE-MCNTs), were synthesized for the first time via a simple, general, and noncovalent strategy. AE molecules were assembled on the surface of carbon nanomaterials by electrostatic interaction, π-π stacking interaction, and amide bond. The synthesized AE-CNPs, AE-GO, and AE-MCNTs with 5...
July 13, 2016: ACS Applied Materials & Interfaces
Luigi Tarpani, Daja Ruhlandt, Loredana Latterini, Dirk Haehnel, Ingo Gregor, Jörg Enderlein, Alexey I Chizhik
Photobleaching of fluorophores is one of the key problems in fluorescence microscopy. Overcoming the limitation of the maximum number of photons, which can be detected from a single emitter, would allow one to enhance the signal-to-noise ratio and thus the temporal and spatial resolution in fluorescence imaging. It would be a breakthrough for many applications of fluorescence spectroscopy, which are unachievable up to now. So far, the only approach for diminishing the effect of photobleaching has been to enhance the photostability of an emitter...
July 13, 2016: Nano Letters
Neha Bhutani, Bhuvan Shome Venigalla, Jaya Prakash Patil, Thakur Veerandar Singh, Sistla Venkata Jyotsna, Abhilasha Jain
INTRODUCTION: The aim of this in vitro study is to evaluate the role of light and laser sources in the bleaching ability of 37.5% H2 O2 on extracted human teeth. MATERIALS AND METHODS: About 30 caries-free single-rooted maxillary central incisors were used for the study. Specimens were prepared by sectioning the crown portion of teeth mesiodistally, and labial surface was used for the study. Specimens were then immersed in coffee solution for staining. Color of each tooth was analyzed using Shadestar, a digital shademeter...
May 2016: Journal of Conservative Dentistry: JCD
Rafael Francisco Lia Mondelli, Ana Flávia Soares, Eugenio Gabriel Kegler Pangrazio, Linda Wang, Sergio Kiyoshi Ishikiriama, Juliana Fraga Soares Bombonatti
The use of light sources in the bleaching process reduces the time required and promotes satisfactory results. However, these light sources can cause an increase in the pulp temperature. Objective The purpose of the present study was to measure the increase in intrapulpal temperature induced by different light-activated bleaching procedures with and without the use of a bleaching gel. Material and Methods A human maxillary central incisor was sectioned 2 mm below the cementoenamel junction. A K-type thermocouple probe was introduced into the pulp chamber...
April 2016: Journal of Applied Oral Science: Revista FOB
James W A Murphy, Robert H Richmond
On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration...
2016: PeerJ
Nathalia Luiza Andreazza, Caroline Caramano de Lourenço, Álvaro José Hernandez-Tasco, Maria Lúcia B Pinheiro, Maria Élida Alves Stefanello, Emmanoel Vilaça Costa, Marcos José Salvador
Photodynamic Therapy, a tumor therapy idealized at the beginning of the last century, emerges nowadays as a promising treatment alternative against infectious diseases. In this study we report a bioguided study of Guatteria blepharophylla phytoderivatives for antimicrobial PDT. Crude extracts and fraction from the species bark were obtained and further fractionated for substances isolation. All samples were evaluated in relation to their photophysical (absorbance and fluorescence) and photochemical properties (1,3-DPBF bleaching method)...
July 2016: Journal of Photochemistry and Photobiology. B, Biology
Rickard Hansson, Camilla Lindqvist, Leif K E Ericsson, Andreas Opitz, Ergang Wang, Ellen Moons
We have studied the photo-degradation in air of a blend of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1), and how the photo-degradation affects the solar cell performance. Using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, changes to the electronic structure of TQ1 and PCBM caused by illumination in ambient air are investigated and compared between the pristine materials and the blend. The NEXAFS spectra show that the unoccupied molecular orbitals of TQ1 are not significantly changed by the exposure of pristine TQ1 to light in air, whereas those of PCBM are severely affected as a result of photo-induced degradation of PCBM...
April 28, 2016: Physical Chemistry Chemical Physics: PCCP
Vinod K Kannaujiya, Rajeshwar P Sinha
The effects of diurnal variation of photosynthetically active radiation (PAR; 400-700 nm) and ultraviolet-B (UV-B; 280-315 nm) radiation on phycobiliproteins (PBPs) and photosynthetic pigments (PP) have been studied in the hot-spring cyanobacterium Nostoc sp. strain HKAR-2. The variations in PBPs and PP were monitored by alternating light and dark under PAR, UV-B, and PAR + UV-B radiations over a period of 25 h. There was a decline in the amount of Chl a and PBPs during light periods of UV-B and PAR + UV-B and an increase during dark periods showing a circadian rhythm by destruction and resynthesis of pigment-protein complex...
March 30, 2016: Protoplasma
Ana Flávia Soares, Juliana Fraga Soares Bombonatti, Marina Studart Alencar, Elaine Cristina Consolmagno, Heitor Marques Honório, Rafael Francisco Lia Mondelli
UNLABELLED: Development of new materials for tooth bleaching justifies the need for studies to evaluate the changes in the enamel surface caused by different bleaching protocols. OBJECTIVE: The aim of this study was to evaluate the bovine dental enamel wear in function of different bleaching gel protocols, acid etching and pH variation. MATERIAL AND METHODS: Sixty fragments of bovine teeth were cut, obtaining a control and test areas. In the test area, one half received etching followed by a bleaching gel application, and the other half, only the bleaching gel...
January 2016: Journal of Applied Oral Science: Revista FOB
Chavdar Slavov, Verena Schrameyer, Michael Reus, Peter J Ralph, Ross Hill, Claudia Büchel, Anthony W D Larkum, Alfred R Holzwarth
The global rise in sea surface temperatures causes regular exposure of corals to high temperature and high light stress, leading to worldwide disastrous coral bleaching events (loss of symbiotic dinoflagellates (Symbiodinium) from reef-building corals). Our picosecond chlorophyll fluorescence experiments on cultured Symbiodinium clade C cells exposed to coral bleaching conditions uncovered the transformations of the alga's photosynthetic apparatus (PSA) that activate an extremely efficient non-photochemical "super-quenching" mechanism...
June 2016: Biochimica et Biophysica Acta
Brian P English, Robert H Singer
Our aim is to develop quantitative single-molecule assays to study when and where molecules are interacting inside living cells and where enzymes are active. To this end we present a three-camera imaging microscope for fast tracking of multiple interacting molecules simultaneously, with high spatiotemporal resolution. The system was designed around an ASI RAMM frame using three separate tube lenses and custom multi-band dichroics to allow for enhanced detection efficiency. The frame times of the three Andor iXon Ultra EMCCD cameras are hardware synchronized to the laser excitation pulses of the three excitation lasers, such that the fluorophores are effectively immobilized during frame acquisitions and do not yield detections that are motion-blurred...
August 21, 2015: Proceedings of SPIE
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