This study evaluated the effect of physical and chemical activation on the diffusion time of different concentrations of hydrogen peroxide (HP) bleaching agents through enamel and dentin. One hundred and twenty bovine cylindrical specimens were divided into six groups (n = 20): 20% HP; 20% HP with light activation; 20% HP with manganese gluconate; 35% HP; 35% HP with light activation; and 35% HP with manganese gluconate. The specimens were fixed over transparent epoxy wells with internal cavities to simulate a pulpal chamber. This chamber was filled with an enzymatic reagent to simulate pulpal fluid. The bleaching gels were applied on enamel surface and the image of the pulpal fluid was captured by a video camera to monitor the time of peroxide penetration in each specimen. ANOVA analysis showed that concentration and type of activation of bleaching gel significantly influenced the diffusion time of HP (P < 0.05). 35% HP showed the lowest diffusion times compared to the groups with 20% HP gel. The light activation of HP decreased significantly the diffusion time compared to chemical activation. The highest diffusion time was obtained with 20% HP chemically activated. The diffusion time of HP was dependent on activation and concentration of HP. The higher concentration of HP diffused through dental tissues more quickly.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3791642 | PMC |
| http://dx.doi.org/10.1155/2013/193241 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Motion-Compensated Multishot Pancreatic Diffusion-Weighted Imaging With Deep Learning-Based Denoising.
Invest Radiol
January 2025
From the Department of Radiology, Stanford University, Stanford, CA (K.W., M.J.M., A.M.L., A.B.S., A.J.H., D.B.E., R.L.B.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA (K.W.); GE HealthCare, Houston, TX (X.W.); GE HealthCare, Boston, MA (A.G.); and GE HealthCare, Menlo Park, CA (P.L.).
Objectives: Pancreatic diffusion-weighted imaging (DWI) has numerous clinical applications, but conventional single-shot methods suffer from off resonance-induced artifacts like distortion and blurring while cardiovascular motion-induced phase inconsistency leads to quantitative errors and signal loss, limiting its utility. Multishot DWI (msDWI) offers reduced image distortion and blurring relative to single-shot methods but increases sensitivity to motion artifacts. Motion-compensated diffusion-encoding gradients (MCGs) reduce motion artifacts and could improve motion robustness of msDWI but come with the cost of extended echo time, further reducing signal.
View Article and Find Full Text PDFPermeability Benchmarking: Guidelines for Comparing , , and Measurements.
J Chem Inf Model
January 2025
Dept. of Engineering, King's College London, London WC2R 2LS, U.K.
Permeability is a measure of the degree to which cells can transport molecules across biological barriers. Units of permeability are distance per unit time (typically cm/s), where accurate measurements are needed to define drug delivery in homeostasis and to model dysfunction occurring during disease. This perspective offers a set of community-led guidelines to benchmark permeability data across multidisciplinary approaches and different biological contexts.
View Article and Find Full Text PDFEnhancement of Transdermal Drug Delivery: Integrating Microneedles with Biodegradable Microparticles.
Mol Pharm
January 2025
Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, Georgia 30341, United States.
This investigation aimed to enhance transdermal methotrexate delivery through human skin by employing Dr. Pen microneedles and poly(d,l-lactide--glycolide) acid microparticles formulated from eight polymer grades (Expansorb DLG 95-4A, DLG 75-5A, DLG 50-2A, DLG 50-5A, DLG 50-8A, DLG 50-6P, DLG 50-7P, and DLL 10-15A). A comprehensive characterization of the microparticles was performed, encompassing various parameters such as size, charge, morphology, microencapsulation efficiency, yield, release kinetics, and chemical composition.
View Article and Find Full Text PDFEstimating Earphone Level and Dose Using Real-Ear Measures and Ecological Momentary Assessment.
Am J Audiol
January 2025
Department of Communication Sciences and Disorders, University of Wisconsin-Madison.
Purpose: Prior work estimating sound exposure dose from earphone use has typically measured earphone use time with retrospective questionnaires or device-based tracking, both of which have limitations. This research note presents an exploratory analysis of sound exposure dose from earphone use among college-aged adults using real-ear measures to estimate exposure level and ecological momentary assessment (EMA) to estimate use time.
Method: Earphone levels were measured at the ear drum of 53 college students using their own devices, earphones, and preferred music and speech stimuli at their normal listening volume.
Long Time Scale Molecular Dynamics Simulation of Magnesium Hydride Dehydrogenation Enabled by Machine Learning Interatomic Potentials.
ACS Appl Energy Mater
January 2025
Advanced Materials Research Group, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Magnesium hydride (MgH) is a promising material for solid-state hydrogen storage due to its high gravimetric hydrogen capacity as well as the abundance and low cost of magnesium. The material's limiting factor is the high dehydrogenation temperature (over 300 °C) and sluggish (de)hydrogenation kinetics when no catalyst is present, making it impractical for onboard applications. Catalysts and physical restructuring (e.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!