Search results for "hydrogen peroxide"

Effects of in-office bleaching on human enamel and dentin. Morphological and mineral changes

2017

Abstract Background The effects of HP-based products upon dental enamel and dentin are inconclusive. Aim To evaluate changes in micromorphology and composition of calcium (Ca) and phosphate (P) in enamel and dentin after the application of 37.5% hydrogen peroxide (HP) and 35% carbamide peroxide (CP) Methods Crowns of 20 human teeth were divided in two halves. One half was used as control specimen and the other as experimental specimen. The control specimens were kept in artificial saliva, and the experimental specimens were divided into four groups (n = 5 each): group 1 (enamel HP for 45 min); group 2 (dentin HP for 45 min); group 3 (enamel CP for 90 min); and group 4 (dentin CP for 90 min)…

Characterization of Hydrothermal Processing Influence on Strontium Substituted Apatite by Investigating Stable Oxygen Isotope Ratio and Antibacterial…

2018

Synthetic hydroxyapatite (HAp) has weak antibacterial and mechanical properties. The antibacterial activity of HAp can be enhanced by strontium cation substitution and incorporation of peroxide ion via hydrothermal processing at 100 °C and 150 °C temperature using 50% H2O2 solution. The starting reagents and products of HAp processing were analyzed by thermal conversion elemental analyser – isotopic ratio mass spectrometer in order to determine the δ18O values. Using different host materials it could be possible to determine differences of δ18O values between untreated and hydrothermally treated HAp samples. The enhanced antibacterial properties of processed HAp samples were investigated us…

Effects of innovative and conventional sanitizing treatments on the reduction of Saccharomycopsis fibuligera defects on industrial durum wheat bread

2016

Wickerhamomyces anomalus, Hyphopichia burtonii and Saccharomycopsis fibuligera are spoilage yeasts causing chalk mold defects on sliced bread packaged under modified atmosphere. The first objective of this study, carried out in a bread-making company for two consecutive years, was to genetically identify yeasts isolated from spoiled sliced bread in Modified Atmosphere Packaging (MAP) and to determine the dominant species among identified strains. The second objective was to evaluate the effects of hydrogen peroxide and silver solution 12% (HPS) treatment in the leavening cells and cooling chambers, in comparison with the conventional Ortho-Phenylphenol (OPP) fumigating treatment, on the inc…

Does comsumption of staining drinks compromise the result of tooth whitening?

2019

Background After dental bleaching procedures dentists commonly advise patients to reduce the consumption of beverages that may cause the teeth to stain, however, the effectiveness of teeth whitening may not be directly affected by diet. Material and methods It was evaluated through in vitro study whether contact with dyes through in-office bleaching sessions with 35% hydrogen peroxide would influence the effectiveness of treatment. Sixty bovine incisors were randomly assigned into 5 groups (n = 12) according to contact frequency and type of dye solutions. All dental elements received three in-office bleaching sessions with 35% hydrogen peroxide one week apart. Except for GCTRL (control), al…

Mechanical stretch on endothelial cells interconnects innate and adaptive immune response in hypertension

2018

The application of casein phosphopeptide and amorphous calcium phosphate with fluoride (CPP-ACPF) for restoring mineral loss after dental bleaching w…

2018

Abstract Objective To conduct an in vitro evaluation of the effect of casein-phosphopeptide and amorphous calcium phosphate with fluoride [CPP-ACPF] upon the calcium [Ca] and phosphorus [P] composition and morphology of dental enamel and dentin after the application of two bleaching agents: 37.5% hydrogen peroxide [HP]) and 35% carbamide peroxide [CP]. Materials and methods The crowns of 40 extracted human teeth were divided into four groups (n = 10 each). The crowns were sectioned along the cervical-incisal axis, and each half was embedded in acrylic resin, leaving a window 3 mm in diameter to explore the enamel or dentin (according to the study group involved). Groups 1a and 1b correspond…

Takotsubo Syndrome: Impact of endothelial dysfunction and oxidative stress

2021

Takotsubo Syndrome (TTS) is characterized by a transient left ventricular dysfunction recovering spontaneously within days or weeks. Although the pathophysiology of TTS remains obscure, there is growing evidence suggesting TTS to be associated with increased production of reactive oxygen species (ROS), which may be involved in causing transient coronary and peripheral endothelial dysfunction leading to a transient impairment of myocardial contraction due to stunning (apical ballooning). Endothelial dysfunction is mainly caused by decreased vascular and myocardial nitric oxide bioavailability in response to increased ROS production. Accordingly, studies in humans and animal models demonstrat…

The effects of fractional CO2 laser, Nano-hydroxyapatite and MI paste on mechanical properties of bovine enamel after bleaching

2017

Background This study investigated the effect of post bleaching treatments to the change of enamel elastic modulus and microhardness after dental bleaching in- vitro. Material and Methods Fifty bovine incisor slab were randomly assigned into five groups (n=10). The samples were bleached for three times; 20 minutes each time, by 40% hydrogen peroxide. Next it was applied fractional CO2 laser for two minutes, Nano- hydroxy apatite (N-HA) and MI-paste for 7 days and 2 minutes per day. The sound enamel and bleached teeth without post treatment remained as control groups. The elastic modulus and microhardness were measured at three times; 24 hours, 1 and 2 months. Data were statistically analyze…

Is there scientific evidence of the mouthwashes effectiveness in reducing viral load in Covid-19? A systematic review.

2020

Background The aim of this research is to verify whether there is evidence in the literature regarding the decrease in viral load present in saliva after using three types of mouthwashes. Material and methods Clinical and/or in vitro experimental studies that have used mouthwashes as a form of intervention to reduce the viral load in saliva were included. Combinations of words and appropriate truncations were adapted for each of the seven selected electronic bases including grey literature. Results The selection of articles was carried out in two phases by two independent reviewers. After removing duplicate articles, 1245 references were maintained, and 2 articles were included in the Syste…

Nanoincorporation of curcumin in polymer-glycerosomes and evaluation of their in vitro–in vivo suitability as pulmonary delivery systems

2015

The aim of this work was to deliver curcumin into the lungs by incorporating it into innovative vesicles obtained using phospholipids and high concentrations of glycerol (50%, v/v), so called glycerosomes, which were then combined with two polymers: sodium hyaluronate and trimethyl chitosan to form polymer-glycerosomes. These systems were prepared without the use of organic solvents or acidic solutions and their physico-chemical properties were fully characterized. Cryogenic transmission electron microscopy and small-angle X-ray scattering showed that both glycerosomes and polymer-glycerosomes were spherical, mainly unilamellar and of nanometric size (65–112 nm). The vesicles were readily n…