This study evaluated the surface microhardness of Lucirin-TPO (TPO) containing resin based composite (RBC) cured with three light-emitting diode (LED) light curing units (LCUs) (two single-peak LED and one multi-peak LED), and two different energy density (ED) (8 J/cm and 16 J/cm). Ninety specimens (8 mm wide and 2 mm thick) (n=5), were prepared with three different shades: translucent (T), A2 dentin (A2d), and A4 dentin (A4d). Specimens were subjected to micro-hardness Vickers measurements (Vickers Hardness Number, VHN) on both top and bottom surfaces. Hardness ratio (rHV) was also calculated. Data were analyzed using multifactorial ANOVA and Bonferroni tests (<=0.05). Results indicated that higher ED performed better than lower ED. Multi-peak LED achieved higher VHNs and rHV than single-peak LED when curing a TPO-containing RBC. A4d invariably achieved lower rHV and VHN than T and A2d. Single-peak LED achieved comparable VHNs and rHVs with multi-peak LED only curing A2d and T shades with 16J/cm.
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http://dx.doi.org/10.11138/orl/2017.10.2.140 | DOI Listing |
Oper Dent
November 2024
*Luís Henrique Araújo Raposo, DDS, MSc, PhD, associate professor, Department of Occlusion, Fixed Prosthodontics and Dental Materials, School of Dentistry, Federal University of Uberlândia, MG, Brazil.
Objectives: This study aimed to evaluate the impact of battery levels on the emission of a multi-peak cordless LED light-curing unit (LCU) and the effect on the degree of conversion (DC) and Knoop hardness (KH) of a light-cure resin luting agent activated through varying lithium disilicate (LiS2) ceramic thicknesses and translucencies.
Methods: High and low translucency LiS2 discs (IPS e.max Press HT and LT, respectively; shade A1) with thickness of 0.
J Dent
November 2024
Department of Restorative Dentistry, State University of Ponta Grossa, Rua General Carlos Cavalcanti, 4748, Uvaranas, Ponta Grossa, 84030-900, Parana, Brazil.
Objective: This study was designed to show that the commonly reported irradiance values that are quoted in most publications inadequately describe the light output from light curing units (LCUs).
Methods: The total spectral radiant power (mW) output from 12 contemporary LCUs was measured with a fiberoptic spectroradiometer and a calibrated integrating sphere. Five recordings were taken for each LCU and exposure mode.
Oper Dent
September 2024
*Luís Henrique Araújo Raposo, DDS, MSc, PhD, associate professor, Department of Occlusion, Fixed Prosthodontics and Dental Materials, School of Dentistry, Federal University of Uberlândia, MG, Brazil.
Purpose: This study aimed to assess the impact of battery levels in single-peak and multi-peak light-curing units (LCUs) on irradiance, and their effects on glass fiber post push-out bond strength to root dentin and the degree of conversion of dual-cure universal resin cement.
Methods And Materials: Sixty bovine roots underwent endodontic treatment and were randomly distributed into 6 groups (n=10), formed by combining two LCUs (single-peak and multipeak) and three battery levels (100%, 50%, and 10%). A spectrophotometer measured irradiance (mW/ cm2) and spectral irradiance (mW/cm2/nm).
Huan Jing Ke Xue
July 2024
College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
The spatial-temporal distribution pattern of surface O over the Qinghai-Xizang Plateau (QXP) was analyzed based on air quality monitoring data and meteorological data from 12 cities on the QXP from 2015 to 2021. Kolmogorov-Zurbenko (KZ) filtering was employed to separate the original O-8h series into components at different time scales. Then, multiple linear regression of meteorological variables was used to quantitatively isolate the effects of meteorology and emissions.
View Article and Find Full Text PDFJ Mater Chem B
July 2024
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P. R. China.
Fluorescence-based LB (liquid biopsy) offers a rapid means of detecting cancer non-invasively. However, the widespread issue of sample loss during purification steps will diminish the accuracy of detection results. Therefore, in this study, we introduce a magnetic lanthanide sensor (MLS) designed for sensitive detection of the characteristic protein, epithelial cell adhesion molecule (EpCAM), on epithelial tumor exosomes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!