The purpose of this study was to determine colour changes in a composite cured with tungsten-halogen, light-emitting diode (LED) or a plasma arc after 5 years. Five specimens 10 mm in diameter and 2 mm in height were prepared using Hybrid (Clearfil AP-X) composite for each test group. The corresponding specimens were cured with a tungsten-halogen curing light, a LED unit or with a plasma arc. Specimens were stored in light-proof boxes for 5 years after the curing procedure to avoid further exposure to light and stored in 37 degrees C in 100% humidity. Colorimetric values of the specimens immediately after curing and after 5 years were measured using colorimeter. The DeltaE*( ab ) values varied significantly depending on the curing unit used (p < 0.001). Curing time did not affect the colour changes of the specimens (p = 0.4). The results of this study suggest that composite materials undergo measurable changes due to the curing unit exposure.
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http://dx.doi.org/10.1007/s00784-008-0221-9 | DOI Listing |
J Cent Nerv Syst Dis
January 2025
CRCSEP, Université Nice Cote d'Azur, Nice, France.
Multiple sclerosis (MS) falls within the spectrum of central nervous system (CNS) demyelinating diseases that may lead to permanent neurological disability. Fundamental to the diagnosis and clinical surveillance is magnetic resonance imaging (MRI) that allows for the identification of T2-hyperintensities associated with autoimmune injury that demonstrate distinct spatial distribution patterns. Here, we describe the clinical experience of a 31-year-old, right-handed, White man seen in consultation at The University of Texas Southwestern Medical Center in Dallas, Texas, following complaints of headaches that began after head trauma related to military service.
View Article and Find Full Text PDFOper Dent
January 2025
*Roberta Tarkany Basting, DDS, MSc, PhD, Professor, Restorative Dentistry Department, Faculdade São Leopoldo Mandic, São Paulo, Brazil.
This study evaluated the influence of six resin composite coating agents on color stability and surface roughness after toothbrushing abrasion. Discs (Ø6 mm x 2 mm) of nanofilled resin composite (Filtek Z350XT) were prepared for application of coating agents (n=10): control (absence), two surface sealants (PermaSeal and BisCover LV), two adhesive systems (Scotchbond Multi-Purpose Adhesive/3M Oral Care and Single Bond Universal), and two modeling liquids (Modeling Resin and Composite Wetting Resin). CIELab*, WID, and color change (ΔEab, ΔE00, and ΔWID) were analyzed at baseline, after finishing and polishing, after application of coating agents, after coffee staining (simulating 30 days and one year of staining), and after toothbrushing abrasion.
View Article and Find Full Text PDFInorg Chem
January 2025
High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, Trombay 400085, India.
Determining the dissociation mechanism of perchlorate materials remains a top priority to address sustainability, handling, processing, and synthesis issues of new and existing high-energy density materials vital to many industrial processes. We determined the dissociation mechanism of diglycine perchlorate (DGPCl) using vibrational spectroscopy, which unveiled the formation of ammonium perchlorate (AP) and carbon at high temperatures. Our studies establish that DGPCl shows multiple phase transitions upon heating.
View Article and Find Full Text PDFPLoS Biol
January 2025
Department of Forest and Conservation Sciences, Department of Botany, University of British Columbia, Vancouver, Canada.
The discipline of ecology and evolutionary biology (EEB) has long grappled with issues of inclusivity and representation, particularly for individuals with systematically excluded and marginalized backgrounds or identities. For example, significant representation disparities still persist that disproportionately affect women and gender minorities; Black, Indigenous, and People of Color (BIPOC); individuals with disabilities; and people who are LGBTQIA+. Recent calls for action have urged the EEB community to directly address issues of representation, inclusion, justice, and equity.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Department of Basic Sciences, Sari University of Agricultural Sciences and Natural Resources, P.O.Box 578, Sari, Iran.
Among the various cations, the Fe ion is one of the most critical transition metal ions in living cells for many cellular functions and enzymatic activities. The decrease or overloading of Fe can lead to different disruptions in humans. Also, Fe, highly toxic, is very common in all industrial wastewater.
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