Influence of Ozone on the Oxidation of Flowable Dental Compomer Restorative Material

This research examines the resilience of polymerized compomer dental restorative to the oxidation effects of ozone (O₃), with exposure times of 60, 180, 1320, and 2880 minutes. Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) is used to observe the release of elemental strontium from the polymer into the aqueous medium, Scanning Electron Microscope (SEM) is used to record the deterioration of the polymer surface and underlying areas of the compomer material, and a microbalance is used to track the mass loss. Ozone can impact a dental polymer in three scenario’s: first is a single disinfections treatment in situ (mouth), second is a multiple treatments in situ, and the third is the immersion of a dental implant that contain the compomer in a disinfecting chamber for cleansing purposes.     

Effect of Different Restorative Materials on Microleakage of Ozone Gas and Traditional Cavity Disinfectant Applied Teeth

The aim of this in vitro study is to investigate the effects of ozone and conventional cavity disinfectant on microleakage at the cavities which are restorated with different restorative materials. Ninety human molar teeth were used in this study. Black V cavities are prepared on buccal surfaces of teeth. Teeth are divided to 3 groups which contains 30 teeth. Group 1: ozone applied; Group 2: 2% chlorhexidine applied; Group 3: any disinfectant is not applied. And then all groups are divided to three subgroups. All subgroups are restored with silorane, ormocer, and traditional composite according to the manufacturer’s directions. Sections were examined under a microscope. Occlusal and gingival microleakage values by a separate researcher and scores were recorded. Statistically results were reviewed with ANOVA and Kruskal–Wallis Tests. Statistically significant difference of microleakage between cavity disinfectant and control groups’ occlusal and gingival lines was not found (p > 0.05). There was no differences at occlusal lines of composite subgroups (p > 0.05) but also significant difference at gingival lines was found (p < 0.05). Statistically significant difference was found among the composite materials, between chlorhexidine and control groups’ gingival lines. The most successful results at gingival lines were found with silorane.     

Research Note: Effects of Ozonated Water Spray Droplet Size and Distance on the Dissolved Ozone Concentration at the Spray Target

Dissolved ozone concentration (DOC) of ozonated water (OW) sprayed from four different distances using three different droplet sizes (expressed in terms of Sauter mean diameter; small, medium, large) was measured at the spray target to obtain fundamental data for improving disease control efficacy when spraying OW onto plants. DOC in the OW at the spray target decreased with decreasing droplet size. DOC was also greatly reduced at the typical spray distances of 0.50 to 0.75 m to less than one-seventh of the initial DOC (2.2 mg/L^?1) in the sprayer reservoir, and DOC one-third lower than the initial DOC was observed even at the shortest spray distance of 0.05 m for all three nozzle sizes used. Based on the results of these experiments, disease control efficacy by spraying OW can be improved by minimizing the spray distance and using a nozzle that produces a larger spray droplet size, within the range such that adhesion efficiency of OW to the leaf surface is not greatly reduced.     

Effects of Some Metals and Chelating Agents on Patulin Degradation by Ozone

The efficiency of ozone treatment for degradation of the mycotoxin patulin in the presence of various metal ions was evaluated in model systems. An initial patulin concentration of 250 μg/L was ozonated and residual ozone concentration was about 0.17±0.01 mg/L at the end of the experiment. Patulin showed a weak resistance to ozone, because up to 98% of this toxin was oxidized in only one minute. Degradation rates in the presence of calcium, aluminum, copper and zinc were almost the same in the absence of these metals. However, degradation of patulin was reduced from 98 to 37% when the concentration of manganese increased from 0 to 3 mg/L. Patulin was almost completely degraded in the absence of iron, while the degradation was only 8.5% in the presence of 0.5 mg/L of iron. These results have revealed that manganese and iron significantly reduce the detoxification of patulin by ozone. Agents such as ethylenediaminetetraacetic acid and sodium polyphosphate effectively chelated iron and increased the degradation rate of patulin. None of the tested agents were able to chelate manganese and to enhance patulin degradation by ozone.     

Comparison of the Effects of Ozone,UV and Combined Ozone/UV Treatment on the Color and Microbial Counts of Wheat Flour

The effects of direct ozone treatment, UV treatment and combined ozone/UV treatment on the color and microbiological count of milled wheat flour were compared. The changes in color and microbiological properties during a 19-week storage period were also examined. Each of the treatments significantly reduced the microbial count of the flour and resulted in whiter flour. The results showed that only the combined treatment furnished flour suitable for consumption. The effect of the combined treatment was similar to, but more pronounced than that of ozone treatment. Changes in the quality of the dough were observable, similar by as in response to other oxidizing agents.     

Pilot Scale Evaluation of Ozone and Other Drinking Water Disinfectants Using Mutagenicity Testing

Mutagenicity produced by the oxidants chlorine, chloramines, chlorine dioxide and ozone when used in drinking water treatment was examined in a pilot scale study conducted at Edmonton, Canada. Both the Ames test, and a yeast assay using Saccharomyces cerevisiae (strain D7144–2) were employed. In the Ames test, chlorination produced utagenicity the most frequently; samples obtained following ozonation rarely were mutagenic. In the yeast assay, utagenicity was seen only infrequently. Granular activated carbon effectively removed mutagenicity for a long period of time.     

An Evaluation of the Antimicrobial Effects of Gas-Phase Ozone

This project evaluated the effects of exposing a variety of microorganisms on porous and non-porous materials to elevated gaseous ozone concentrations ranging from 100 – 1000 ppm. Gypsum wallboard (porous) and glass slide (non-porous) building materials were used. Two fungi organisms, two bacteria organisms and two levels of relative humidity (RH) were tested. Increased humidity and non-porous surface exposure were found to increase the biocidal capability of high levels of ozone. The results of this study indicate that even at relatively high concentrations of ozone, it is difficult to get significant reductions of microorganisms on surfaces, especially on porous materials.     

Effects of Ozone and Ozone/Hydrogen Peroxide on the Degradation of Model and Real Oil-Sands-Process-Affected-Water Naphthenic Acids

Naphthenic acids (NAs) are persistent compounds that contribute to the toxicity of oil sands process-affected water (OSPW). In this study, the effects of ozone and ozone/hydrogen peroxide on the NAs degradation in buffered water and OSPW were examined. Cyclohexanoic acid (CHA) was used as a model NAs compound in buffered water experiments at two different pHs, using radical scavengers. At pH 9, the addition of carbonate did not have any effect on CHA degradation. Additions of tert-butyl alcohol and tetranitromethane decreased the CHA degradation levels. For the OSPW experiments, degradation of acid-extractable fraction (AEF) and NAs was examined. Approximately 90% of AEF was oxidized in a semi-batch system. In a batch system, 99% of OSPW NAs were degraded. This study demonstrated that ozone and ozone/hydrogen peroxide could be suitable treatment processes for OSPW remediation.     

Effects of Atmospheric Chemical and Climate Change on Tropospheric Ozone

Changes in atmospheric levels of certain pollutants (CH₄, CO, NO_X, nonmethane hydrocarbons) have the potential to affect tropospheric O₃ formation and the abundance of the free radical OH on a global scale. Perturbations to stratospheric O₃ and climate (temperature and moisture) also can influence tropospheric O3 and OH. We have used a tropospheric photochemical model with projections of CO, NO_X, and CH₄ to predict tropospheric ozone and OH changes from 1980-2030. The calculations simulate the background chemistry of various global regions and assume that increases in CH₄ and CO will continue at current rates. Predicted changes in tropospheric O₃ and OH are different in urban and nonurban areas, and in marine and continental regions.

Generally, increasing levels of CH₄ and CO at constant NO_X levels will increase O₃ and suppress OH. A rough estimate of possible global changes shows tropospheric O3 increasing ?10% from 1980 to 2030 and OH decreasing ?10% during that period. When calculations are performed assuming that stratospheric ozone depletion and climate warming occur at anticipated rates during the same period, tropospheric O₃ enhancement and OH loss in nonurban areas are both reduced relative to changes assuming that only CH₄ and CO emissions change.

Regional changes in surface-level O₃, OH and the water-soluble oxidant H₂O₂ are estimated for the year 2030. Increases in CO and CH₄ suppress OH and enhance O₃ and H₂O₂ in nonpolluted (low NO_X) areas. In urban environments (background NO_X > 1 ppbv), increases in CO and CH₄ add significantly to all three oxidants, O₃, OH and H₂O₂. Changes in and near urban areas may be of greatest magnitude, but the high levels of OH (and H₂O₂) found in the tropics indicate that perturbations in that region could dominate future global oxidant changes.     

Quantification of the Bactericidal,Fungicidal, and Sporicidal Efficacy of the JLA Ltd. Ozone Laundering System

The objective of this study was to demonstrate the bactericidal, fungicidal, and sporicidal efficacy of the in-use concentration of ozone in solution generated continuously by the JLA Limited OTEX validated ozone laundering system against a range of typical microorganisms associated with laundering applications. The study used the JLA HC 100 laundering machine as the containment vessel. Test microbial suspensions were introduced directly into the drum of the laundering machine containing a known level of water in the presence of soluble ozone. Using standard microbiological techniques, the numbers of surviving bacteria, mold spores or bacterial spores were determined, and reductions in viable counts were calculated. The following test organisms were employed: Pseudomonas aeruginosa, Methicillin-Resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, E. coli, Acinetobacter baumannii, Aspergillus niger (spores), and Clostridium difficile (spores). All tests used multiple contact times of 0, 1, 3, 5, 7, 11 and 15 minutes at 20 °C±2 °C. Levels of ≤0.25 mg/L of dissolved ozone had minimal effect on the bacteria. Levels of >0.45 mg/L ozone showed good biocidal activity, except against Acinetobacter baumannii, which showed strong resistance to ozone. Against fungal spores, dissolved ozone levels of >1.2 mg/L were required to obtain a 2.8 log reduction. For Clostridium difficile spores, a dissolved ozone level between 0.90 and 1.20 mg/L gave >1.6 log reduction with no discernable spore recovery. In every instance, the control tests (no ozone) recovered levels of microorganisms that proved that the action of the laundering machine has no antimicrobial activity, and that the log reductions obtained are solely due to the effects of dissolved ozone.     

Ozone Solubility in Aqueous Solutions of NaCl,Na2SO4, and K2SO4: Application of the Weisenberger-Schumpe Model for Description of Regularities and Calculation of the Ozone Molar Absorption Coefficient

The ozone solubility in aqueous solutions of salts, NaCl (up to 5 М) and Na₂SO₄ (up to 2 М) and their mixtures, was studied. The results are adequately described by the semi-empirical model proposed by Weisenberger and Schumpe for calculation of the solubilities of atmospheric gases in concentrated solutions of electrolytes. By comparing the data obtained experimentally and calculated in terms of the Weisenberger and Schumpe model, the ozone molar absorption coefficient was found to be ε = 2860 ± 200 M^?1 cm^?1 at 260 nm.     

Effects of Ozone-Gas Bubble Size and pH on Ozone/UV Treatment

A series of ozone/UV treatment under injection of ozone with different ozone-gas bubble sizes was performed at pH 1.7 and 7.4. The increase in the bubble size and the decrease in pH enhanced the ozone utilization efficiency. The enhancement of ozone utilization efficiency was caused by the shift of the production pathway of hydroxyl radical (OH) from the OH production via O₃ ^– to the UV photolysis of H₂O₂. The lower pH caused this shift through the chemical equilibrium of H₂O₂ and HO₂ ^–, and the large bubbles caused this shift through the augmentation of H₂O₂ transport from the bubble surface to the bulk solution.     

Ozone in Medicine: Clinical Evaluation and Evidence Classification of the Systemic Ozone Applications,Major Autohemotherapy and Rectal Insufflation,According to the Requirements for Evidence-Based Medicine

Now that indications are clearly defined, applications have mostly become standardized and the active mechanisms have been well confirmed, medical ozone application in the form of the low-dose concept, is established and proven as a complementary medical method in the treatment of chronic inflammations or diseases associated with chronic inflammatory conditions. More than 11,000 systemic ozone treatments in the form of Major Ozone Autohemotherapy (MAH) in 577 patients and ≥ 47,000 Rectal Insufflations (RI) in 716 patients in various clinical studies are subjected to critical clinical assessment and classification according to the criteria of evidence-based medicine (EBM). Statistically significant clinical and/or pharmacological improvements without side-effects or adverse reactions are found in all studies; special attention is drawn to maintaining hygiene when working with blood and to the use of ozone-resistent and biocompatible materials. On summarizing the evidence classification under RCT + CT (Randomized Controlled Trials + Controlled Trials), i.e., Levels Ib and IIa, 12 studies with 657 ozone-treated patients are obtained for MAH and 6 studies with 227 patients for RI. As a result of the evidence here assessed, the two systemic ozone applications, MAH and RI are part of evidence-based medicine. Both applications are effective, safe and economic.     

Effects of Spraying Ozonated Water on the Severity of Powdery Mildew Infection on Cucumber Leaves

Effects of spraying ozonated water on the severity of powdery mildew infection, visible disorder/injury occurrence, and net photosynthesis in cucumbers were investigated. The severity in the ozonated water treatment was contained to almost the same level throughout the 14-day period of the experiment, while the severity steadily increased in the non-treated control and distilled water treatment. Neither visible disorder/injury on the leaves nor a large difference in net photosynthesis between before and after spraying the ozonated water was observed. The results indicate that ozonated water can be at least a partial alternative to agricultural chemical fungicides for powdery mildew on cucumber leaves.     

Application of Ozone Post-Harvest Treatment on Kabkab Date Fruits: Effect on Mortality Rate of Indian Meal Moth and Nutrition Components

Methyl bromide (MB) was used for years to treat infested stored date fruits; however, MB is due to be phased out by 2015. In this study ozone is used for disinfestations of Kabkab date against Indian meal moth in three life stage. They were exposed to four ozone concentrations (300 ± 10, 1050 ± 40, 2000 ± 40, and 4000 ± 50 ppm) during four periods (2, 4, 6, and 8 h). The findings show 2000 ppm of ozone concentration within 8 h resulted in complete mortality of larvae and adult insects and over 90% mortality of eggs. The proposed ozone treatment is a promising approach replacing application of MB for disinfestations of examined date fruits, as no remarkable changes were observed on pH of the date fruits and its chemical compositions (total phenolic content, anti-oxidant activity and free radicals).     

Comparative Analysis of Ozone and Ultrasound Effect on the Elimination of Giardia spp. Cysts from Wastewater

Giardia spp. is a flagellate protozoan that presents two evolution forms, cysts and trophozoites. Cysts are resistant to chlorine, the most employed disinfectant agent in the treatment of water. For this reason, new techniques for the disinfection of waters that contain this parasite are necessary. This work evaluated the efficiency of the disinfection by ozone and ultrasound individually and simultaneously upon wastewater. The data obtained showed that after application, ozone, ultrasound, and combined techniques induced a significant elimination of Giardia spp. cysts. Furthermore, this effect was more accentuated when the two techniques were applied simultaneously.     

Ozone And Biological Treatments – Effects on the Elimination of Cyanides

Since publications concerning theeffect ofozone on biological treatments are contradictory, increasing biodegradation on the onehand, effect of “stress” on bacteria ontheother, we have selected two compounds which are eliminated only by biodegradation: cyanides andammonium ions. Thestudyhas shown that ozone retards their biodegradation significantly.

Concerning the elimination of organic materials, we have noticed two competitive actions: an increase in the possibility of biodegradation and the effect of “stress” on bacteria. The result of these twoactions is in favor of ozone.     

Reduction of Captan,Boscalid and Pyraclostrobin Residues on Apples Using Water Only,Gaseous Ozone,and Ozone Aqueous Solution

Intensive use of plant protection products in modern agriculture and horticulture often results in increasing residue levels of active ingredients of plant protection products in fruits and vegetables. Even if the maximum residue levels are not exceeded, the synergic effects of various compounds may have a serious impact on consumers' health. In particular, more sensitive consumer groups, e.g., children, may be affected. Therefore, it is important to develop an effective method that could be utilized for reduction of pesticide residue levels in food products of plant origin. In this work, possible application of ozone to reduce pesticide residue levels in apples has been investigated. The fruits were treated with ozone in gaseous state, in ozonized water, and in water alone, which was used for rinsing the fruits. The experiments included tests on apples that were subjected to a protection program using captan, boscalid and pyraclostrobin. The ozonized water and treatment with a gaseous ozone were found to be not more efficient in reducing the pesticide content on the fruits than simple washing procedures, e.g., 81–95% reduction of captan residue or 40–67% reduction of boscalid residue and 20–42% reduction of pyraclostrobin residue. Still, ozonation of water used for rinsing prevented fruits from consecutive contamination by pesticide residues present in water after several rinsing cycles. It was proven that application of ozonation process as a part of post-harvest treatment of apples may be beneficial for the fruit quality.     

Effects of Ozone Gas Exposure on Toxigenic Fungi Species from Fusarium,Aspergillus, and Penicillium Genera

The antifungal properties of ozone (O₃) gas exposure towards toxigenic fungi were evaluated in laboratory-scale treatments trials. O₃ gas was utilized at a concentration of 60 μmol/mol at different times of exposure, which efficiently inhibited the fungi colonies growth, especially F. graminearum and P. citrinum. At the concentration applied, O₃ gas exposure was able to inhibit conidia germination, caused hyphae morphological alterations that led to hyphae death and ROS production of all fungi tested. O₃ action can be related to cell metabolism alterations, leading to apoptosis and oxidative stress, showing to be effective on controlling toxigenic fungal development which is one of the main problems regarding food contamination.     

Impact of Ozonated Water on the Quality and Shelf-life of Fresh Citrus Fruit,Stone Fruit,and Table Grapes

Spores of fungi that cause postharvest decay of fresh fruit die rapidly in ozonated water. We determined the impact of sporocidal or higher O₃ doses on fruit shelf-life and quality. Green mold and sour rot on citrus fruit, caused by Penicillium digitatum and Geotrichum citri-aurantii, respectively, were not reduced by 20 min immersion in 10 ppm O₃. These fungi infect through wounds; their spores were placed in shallow wounds (l mm wide by 2 mm deep) 24 hr before treatment. On five peach varieties, the average natural incidence of brown rot, caused by Monilinia fructicola, was reduced from 10.9 to 5.4% by 1 min immersion in 1.5 ppm O₃. A treatment of 15 min with 5 ppm O₃ further reduced decay to 1.7%, but consistent control of brown rot was associated only with this severe treatment and it caused shallow pits on the fruit. Brown rot caused by spores placed in wounds before treatment was not controlled. Immersion for 1 or 5 min in 5 ppm O₃ reduced natural aerobic bacteria populations by 1.1 and 1.6 log₁₀ units, respectively, and yeast and filamentous fungal populations by 0.7 and 1.3 log₁₀ units, respectively. Spores of Botrytis cinerea, cause of gray mold, were sprayed on table grape clusters, the clusters were dried, and then immersed for 1 to 6 min in 10 ppm O₃. In two tests, immersion for 1 min in O₃ reduced gray mold from 35% among untreated grapes to about 10%, while in two other tests the incidence was only reduced from 35 to 26%. Minor injury to the rachis of grape clusters occurred at high O₃ rates. Immersion in ozonated water did not control postharvest decay of citrus fruit, injured peaches and nectarines at doses that reliably controlled decay, and on table grapes control was irregular and caused minor rachis injury at high rates.