Excessive Ozonation Stress Triggers Severe Membrane Biofilm Accumulation and Fouling.

The established benefits of ozone on microbial pathogen inactivation, natural organic matter degradation, and inorganic/organic contaminant oxidation have favored its application in drinking water treatment. However, viable bacteria are still present after the ozonation of raw water, bringing a potential risk to membrane filtration systems in terms of biofilm accumulation and fouling. In this study, we shed light on the role of the specific ozone dose (0.5 mg-O3/mg-C) in biofilm accumulation during long-term membrane ultrafiltration. Results demonstrated that ozonation transformed the molecular structure of influent dissolved organic matter (DOM), producing fractions that were highly bioavailable at a specific ozone dose of 0.5, which was inferred to be a turning point. With the increase of the specific ozone dose, the biofilm microbial consortium was substantially shifted, demonstrating a decrease in richness and diversity. Unexpectedly, the opportunistic pathogen Legionella was stimulated and occurred in approximately 40% relative abundance at the higher specific ozone dose of 1. Accordingly, the membrane filtration system with a specific ozone dose of 0.5 presented a lower biofilm thickness, a weaker fluorescence intensity, smaller concentrations of polysaccharides and proteins, and a lower Raman activity, leading to a lower hydraulic resistance, compared to that with a specific ozone dose of 1. Our findings highlight the interaction mechanism between molecular-level DOM composition, biofilm microbial consortium, and membrane filtration performance, which provides an in-depth understanding of the impact of ozonation on biofilm accumulation.

Efficacy of ozonated olive oil against peri-implant microbes isolated from peri-implantitis.

This study aimed to investigate the antibacterial and antimicrobial activity of ozone gel against oral biofilms grown on titanium dental implant discs. The experiment used medical grade five titanium discs on which peri-implant isolated biofilms were grown. The experimental groups were control, Streptococcus mutans (S. mutans) and Granulicatella adiacens (G. adiacens), (n = 6). The oral microbes grown on titanium discs were exposed to ozone gel for 3 minutes and the antibacterial activity was assessed by turbidity test and adherence test for the antibiofilm activity test. Bacterial morphology and confluence were investigated by scanning electron microscopy (SEM), (n=3). Two bacterial species were identified from the peri-implant sample, S. mutans and G. adiacens. The results showed that adding ozone to the bacterial biofilm on titanium dental implants did not exhibit significant antibacterial activity against S. mutans. Moreover, there was no significant difference in antibiofilm activity between control and treatment groups. However, significant antibacterial and antibiofilm effect was exhibited by ozone gel against G. adiacens. Ozonated olive oil can be considered as a potential antimicrobial agent for disinfecting dental implant surfaces and treating peri-implantitis.

Ozone and photodynamic inactivation of norovirus surrogate bacteriophage MS2 in fresh Brazilian berries and surfaces.

This study assessed the efficacy of ozone (bubble diffusion in water; 6.25 ppm) and photodynamic inactivation (PDT) using curcumin (75 µM) as photosensitizer (LED emission 430-470 nm; 33.6 mW/cm2 irradiance; 16.1, 20.2, and 24.2 J/cm2 light dose) against the Norovirus surrogate bacteriophage MS2 in Brazilian berries (black mulberry and pitanga) and surfaces (glass and stainless steel). Contaminated berries and surfaces were immersed in ozonized water or exposed to PDT-curcumin for different time intervals. Transmission electron microscopy was used to assess the effects of the treatments on MS2 viral particles. The MS2 inactivation by ozone and PDT-curcumin varied with the fruit and the surface tested. Ozone reduced the MS2 titer up to 3.6 log PFU/g in black mulberry and 4.1 log PFU/g in pitanga. On surfaces, the MS2 reduction by ozone reached 3.6 and 4.8 log PFU/cm2 on glass and stainless steel, respectively. PDT-curcumin reduced the MS2 3.2 and 4.8 log PFU/g in black mulberry and pitanga and 2.7 and 3.3 log PFU/cm2 on glass and stainless steel, respectively. MS2 particles were disintegrated by exposure of MS2 to ozone and PDT-curcumin on pitanga. Results can contribute to establishing effective practices for controlling NoV in fruits and surfaces, estimated based on MS2 bacteriophage behavior.

The adjunctive use of antimicrobial photodynamic therapy, light-emitting-diode photobiomodulation and ozone therapy in regenerative treatment of stage III/IV grade C periodontitis: a randomized controlled clinical trial.

OBJECTIVES: To assess the short-term efficacy of multiple sessions of antimicrobial photodynamic therapy (aPDT), light-emitting-diode (LED) photobiomodulation, and topical ozone therapy applications following surgical regenerative treatments on clinical parameters, patient-centered outcomes, and mRNA expression levels of VEGF, IL-6, RunX2, Nell-1, and osterix in gingival crevicular fluid samples in patients with stage III/IV, grade C periodontitis. MATERIALS AND METHODS: Forty-eight systemically healthy patients were assigned into four groups to receive adjunctive modalities with regenerative periodontal surgical treatment. A 970 ± 15 nm diode laser plus indocyanine-green for aPDT group, a 626 nm LED for photobiomodulation group, and topical gaseous ozone were applied at 0, 1, 3, and 7 postoperative days and compared to control group. The clinical periodontal parameters, early wound healing index (EHI), and postoperative patients' morbidity were evaluated. The mRNA levels of biomarkers were assessed by real-time polymerase chain reaction. RESULTS: No significant difference in the clinical parameters except gingival recession (GR) was identified among the groups. For group-by-time interactions, plaque index (PI) and probing pocket depths (PD) showed significant differences (p = 0.034; p = 0.022). In sites with initial PD > 7 mm, significant differences were observed between control and photobiomodulation groups in PD (p = 0.011), between control and aPDT, and control and photobiomodulation groups in CAL at 6-month follow-up (p = 0.007; p = 0.022). The relative osterix mRNA levels showed a statistically significant difference among the treatment groups (p = 0.014). CONCLUSIONS: The additional applications of aPDT and LED after regenerative treatment of stage III/IV grade C periodontitis exhibited a more pronounced beneficial effect on clinical outcomes in deep periodontal pockets.

Anti-Inflammatory Activity of No-Ozone Cold Plasma in Porphyromonas gingivalis Lipopolysaccharide-Induced Periodontitis Rats.

Periodontitis is an inflammatory disease caused by Porphyromonas gingivalis (P. gingivalis) in the oral cavity. This periodontal disease causes damage to the periodontal ligament and alveolar bone and can cause tooth loss, but there is no definite treatment yet. In this study, we investigated the possibility of using no-ozone cold plasma to safely treat periodontitis in the oral cavity. First, human gingival fibroblasts (HGFs) were treated with P. gingivalis-derived lipopolysaccharide (PG-LPS) to induce an inflammatory response, and then the anti-inflammatory effect of NCP was examined, and a study was conducted to identify the mechanism of action. Additionally, the anti-inflammatory effect of NCP was verified in rats that developed an inflammatory response similar to periodontitis. When NCP was applied to PG-LPS-treated HGFs, the activities of inflammatory proteins and cytokines were effectively inhibited. It was confirmed that the process of denaturing the medium by charged particles of NCP is essential for the anti-inflammatory effect of NCP. Also, it was confirmed that repeated treatment of periodontitis rats with NCP effectively reduced the inflammatory cells and osteoclast activity. As a result, this study suggests that NCP can be directly helpful in the treatment of periodontitis in the future.

Environmental impacts of carbon fiber production and decarbonization performance in wind turbine blades.

The application of carbon fiber in the wind power industry is of great interest in declining CO2 emissions but the carbon fiber manufacturing process is still a long way heading cleaner production. Since little to no information clarifies the dual effects from carbon fiber production to application, this study carried out a life cycle assessment (LCA) to recognize the environmental performances of polyacrylonitrile (PAN)-based carbon fiber production and explore the decarbonization effects of carbon fiber application in wind turbine blades. Based on on-site data from a leading carbon fiber production chain in China, potential environmental impacts of carbon fiber production predominantly originated from the precursor spinning stage (accounted for 13-91%). Fossil depletion (20.24 kg oil eq.), climate change (67.79 kg CO2 eq.), terrestrial ecotoxicity (165.63 kg 1,4-DCB eq.) and photochemical ozone formation (0.14 kg NOx eq.) were the four noteworthy areas to improve the sustainable development. Different scenarios in energy and advanced technology were set to explore the potential improvement of the environmental performance of carbon fiber products. Energy structure (wind power) can improve an average of 22.58% environmental benefit compared with the background scenarios. Regarding the decarbonization effects, the energy payback time and the carbon payback time were estimated to be 0.73 and 0.37 months respectively. Therefore, carbon fiber is a trustworthy material in the strategy to achieve sustainable development from a life cycle perspective.

The Synergetic Reduction of the Condensation Degree of Dissolved Lignin (DL) during the Refining Process of Wheat Straw Biomass Based on the MA/O3 System.

Lignin, a natural pol2ymer with a complex structure that is difficult to separate, is prone to C-C bond condensation during the separation process. To reduce the condensation of lignin, here, a novel method is proposed for separating the components by using a combination of maleic acid (MA)/ozone (O3) to co-treat wheat straw. The removal of lignin, glucan, and xylan was 38.07 ± 0.2%, 31.44 ± 0.1%, and 71.98 ± 0.1%, respectively, under the conditions of ball-milling of wheat straw for 6 h, reaction temperature of 60 °C, and O3 holding time of 9 min. Lignin-rich solutions were collected to extract the dissolved lignin (DL) after washing the treated samples. The DL obtained under MA/O3 conditions had a carboxyl group (-COOH) content of 2.96 mmol/g. The carboxyl group of MA underwent esterification with the hydroxyl group (-OH) at the γ position of lignin and O3 reacted on the positions of the lignin side chain or the phenolic ring, resulting in a break in the side chain and the opening of the phenolic ring to introduce the carboxyl group. The 2D-HSQC-NMR results revealed that the phenolic ring-opening reaction of lignin in the presence of O3 was essentially free of ß-ß and ß-5 condensation bonds.

The response of aquatic ecosystems to the interactive effects of stratospheric ozone depletion, UV radiation, and climate change.

Variations in stratospheric ozone and changes in the aquatic environment by climate change and human activity are modifying the exposure of aquatic ecosystems to UV radiation. These shifts in exposure have consequences for the distributions of species, biogeochemical cycles, and services provided by aquatic ecosystems. This Quadrennial Assessment presents the latest knowledge on the multi-faceted interactions between the effects of UV irradiation and climate change, and other anthropogenic activities, and how these conditions are changing aquatic ecosystems. Climate change results in variations in the depth of mixing, the thickness of ice cover, the duration of ice-free conditions and inputs of dissolved organic matter, all of which can either increase or decrease exposure to UV radiation. Anthropogenic activities release oil, UV filters in sunscreens, and microplastics into the aquatic environment that are then modified by UV radiation, frequently amplifying adverse effects on aquatic organisms and their environments. The impacts of these changes in combination with factors such as warming and ocean acidification are considered for aquatic micro-organisms, macroalgae, plants, and animals (floating, swimming, and attached). Minimising the disruptive consequences of these effects on critical services provided by the world's rivers, lakes and oceans (freshwater supply, recreation, transport, and food security) will not only require continued adherence to the Montreal Protocol but also a wider inclusion of solar UV radiation and its effects in studies and/or models of aquatic ecosystems under conditions of the future global climate.

HONO Measurement by Catalytic Conversion to NO on Nafion Surfaces.

A selective catalytic converter has been developed to quantify nitrous acid (HONO), a photochemical precursor to NO and OH radicals that drives the formation of ozone and other pollutants in the troposphere. The converter is made from a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer (Nafion) that was found to convert HONO to NO with unity yield under specific conditions. When coupled to a commercially available NOx (=NO + NO2) chemiluminescence (CL) analyzer, the system measures HONO with a limit of detection as low as 64 parts-per-trillion (ppt) (1 min average) in addition to NOx. The converter is selective for HONO when tested against other common gas-phase reactive nitrogen species, although loss of O3 on Nafion is a potential interference. The sensitivity and selectivity of this method allow for accurate measurement of atmospherically relevant concentrations of HONO. This was demonstrated by good agreement between HONO measurements made with the Nafion-CL method and those made with chemical ionization mass spectrometry in a simulation chamber and in indoor air. The observed reactivity of HONO on Nafion also has significant implications for the accuracy of CL NOx analyzers that use Nafion to remove water from sampling lines.

Computational Studies of Rubber Ozonation Explain the Effectiveness of 6PPD as an Antidegradant and the Mechanism of Its Quinone Formation.

The discovery that the commercial rubber antidegradant 6PPD reacts with ozone (O3) to produce a highly toxic quinone (6PPDQ) spurred a significant research effort into nontoxic alternatives. This work has been hampered by lack of a detailed understanding of the mechanism of protection that 6PPD affords rubber compounds against ozone. Herein, we report high-level density functional theory studies into early steps of rubber and PPD (p-phenylenediamine) ozonation, identifying key steps that contribute to the antiozonant activity of PPDs. In this, we establish that our density functional theory approach can achieve chemical accuracy for many ozonation reactions, which are notoriously difficult to model. Using adiabatic energy decomposition analysis, we examine and dispel the notion that one-electron charge transfer initiates ozonation in these systems, as is sometimes argued. Instead, we find direct interaction between O3 and the PPD aromatic ring is kinetically accessible and that this motif is more significant than interactions with PPD nitrogens. The former pathway results in a hydroxylated PPD intermediate, which reacts further with O3 to afford 6PPD hydroquinone and, ultimately, 6PPDQ. This mechanism directly links the toxicity of 6PPDQ to the antiozonant function of 6PPD. These results have significant implications for development of alternative antiozonants, which are discussed.

Transformation Products of Tire Rubber Antioxidant 6PPD in Heterogeneous Gas-Phase Ozonation: Identification and Environmental Occurrence.

6PPD, a tire rubber antioxidant, poses substantial ecological risks because it can form a highly toxic quinone transformation product (TP), 6PPD-quinone (6PPDQ), during exposure to gas-phase ozone. Important data gaps exist regarding the structures, reaction mechanisms, and environmental occurrence of TPs from 6PPD ozonation. To address these data gaps, gas-phase ozonation of 6PPD was conducted over 24-168 h and ozonation TPs were characterized using high-resolution mass spectrometry. The probable structures were proposed for 23 TPs with 5 subsequently standard-verified. Consistent with prior findings, 6PPDQ (C18H22N2O2) was one of the major TPs in 6PPD ozonation (∼1 to 19% yield). Notably, 6PPDQ was not observed during ozonation of 6QDI (N-(1,3-dimethylbutyl)-N'-phenyl-p-quinonediimine), indicating that 6PPDQ formation does not proceed through 6QDI or associated 6QDI TPs. Other major 6PPD TPs included multiple C18H22N2O and C18H22N2O2 isomers, with presumptive N-oxide, N,N'-dioxide, and orthoquinone structures. Standard-verified TPs were quantified in roadway-impacted environmental samples, with total concentrations of 130 ± 3.2 µg/g in methanol extracts of tire tread wear particles (TWPs), 34 ± 4 µg/g-TWP in aqueous TWP leachates, 2700 ± 1500 ng/L in roadway runoff, and 1900 ± 1200 ng/L in roadway-impacted creeks. These data demonstrate that 6PPD TPs are likely an important and ubiquitous class of contaminants in roadway-impacted environments.

Enhanced ozonation of polystyrene nanoplastics in water with CeOx@MnOx catalyst.

The nanoplastics released into the environment pose a critical threat to creatures, and thus it is necessary to remove them. However, their natural decomposition usually takes years or even decades, which raises an imminent demand for an efficient removal technology. Herein we report a core-shell CeOx@MnOx catalyst for enhancing ozonation of polystyrene nanoplastics in water. Ozonation achieves 31.67% molecular weight removal of polystyrene nanoplastics in the first 10 min reaction, which is increased to 51.67% in catalytic ozonation by MnOx and further improved to 73.33% in catalytic ozonation via CeOx@MnOx. The remarkable thing is the CeOx@MnOx could achieve almost 96.70% molecular weight removal after 50 min reaction. The specific catalytic mechanism is ozone decomposes into reactive oxygen radicals (•OH, •O2- and 1O2) after capturing electrons from MnOx, improving the polystyrene nanoplastics removal. Meanwhile, the Mn averaged valence state increases, making it harder to donate electrons to ozone. This can be alleviated by encapsulating the CeOx core in the MnOx, enabling electrons replenishment from the CeOx core to the MnOx shell, which is verified by the experiment and density functional theory calculations. The repeated experiment demonstrates the CeOx@MnOx possesses excellent stability, maintaining 95.25-96.70% removal efficiency of polystyrene nanoplastics. This research provides a possibility for the efficient removal of nanoplastics in water.

Effectiveness of adjunct therapy for the treatment of apical periodontitis: A systematic review and meta-analysis.

BACKGROUND: Adjunct therapy refers to any intracanal procedure going beyond chemomechanical preparation with instruments and traditionally delivered irrigants (excluding interim dressings). It is not clear whether and which of these adjunct therapies have a significant impact on the outcome of root canal treatment [healing of apical periodontitis (AP) and other patient-related outcomes]. OBJECTIVES: This systematic review aimed to analyse available evidence on the effectiveness of adjunct therapy for the treatment of AP in permanent teeth, according to a population, intervention, comparison, outcome, time and study design framework formulated a priori by the European Society of Endodontology. METHODS: Five electronic databases (PubMed, Embase, Scopus, Cochrane and Web of Science) were searched up to October 2021 to identify clinical studies comparing adjunct therapy to no adjunct therapy in adult patients with AP. Animal studies, reviews, studies with less than 10 patients per arm and studies with a follow-up time of less than 1 year, or less than 7 days for postoperative pain, were excluded. The quality of the included studies was appraised by the appropriate tools [Risk of Bias 2 (RoB2) for randomized clinical trials (RCTs) and Newcastle-Ottawa Scale for observational studies]. Meta-analysis was performed using a random-effects model. The certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: Fourteen studies (13 RCTs and one retrospective cohort) fulfilled the inclusion criteria for this review. They evaluated different types of adjunct therapy: antimicrobial photodynamic therapy (aPDT; three studies), diode laser canal irradiation (3), Nd:YAG laser canal irradiation (2), Er;Cr:YSGG laser canal irradiation (1), ozone therapy (2) and ultrasonically activated irrigation (UAI) (4). Radiographical healing was reported in seven studies, but meta-analysis was only possible for UAI (two studies), showing no statistically significant difference in healing after 12 months. Pain after 7 days was reported in seven studies. Meta-analysis on three studies that used aPDT and on two studies using diode laser irradiation showed no significant difference in the prevalence of pain after 7 days between the control and adjunct therapy. According to RoB2 tool, six studies had a high risk of bias, five studies had some concerns, and two studies low risk of bias. The GRADE assessment revealed a very low strength of evidence for diode laser, and low strength of evidence for PDT, ozone and UAI studies. DISCUSSION: The included studies displayed significant heterogeneity in terms of type of adjunct therapy, technical details per adjunct therapy, outcome reporting and several combinations of these, limiting the potential for meta-analysis. CONCLUSIONS: There is insufficient evidence to recommend any adjunctive therapy for the treatment of apical periodontitis. REGISTRATION: Prospero CRD42021261869.

Investigation of the bleaching efficiencies of different office type bleaching techniques and the changes caused on the enamel surface.

The aim of this in vitro study is to evaluate the bleaching efficiency of 5 different office bleaching methods and the changes in enamel morphology after bleaching. In this study, 75 human molar teeth are used. The teeth are divided in half in the mesiodistal direction, and a total of 150 enamel samples are obtained. The obtained samples are split into 3 main groups to evaluate the bleaching efficiency, surface roughness, and enamel surface hardness, and each group is composed of 50 samples. Then, each main group was divided into 5 separate subgroups (n = 10) containing 5 varied bleaching techniques. Before the bleaching, color measurement with a spectrophotometer, surface roughness with a profilometer, and microhardness measurement with Vickers test device are performed. After that, different bleaching procedures are applied to the 5 subgroups formed. As a result of the statistical evaluation, it is found that there is a significant level of bleaching in all groups (p < 0.05). In the comparison between the groups, there is no remarkable divergence in terms of hardness and roughness levels (p˃0.05). In light of the findings obtained from our study, we suggest that ozone can be used as an alternative bleaching agent to hydrogen peroxide. In addition, it is discovered that the use of light activation is not necessary to increase bleaching effectiveness. Finally, we believe that enamel surface morphology may be affected after office bleaching methods; therefore, various precautions should be taken before and after bleaching.

Comparison of intracanal ozone and low-level laser therapy on postoperative pain in vital teeth with symptomatic apical periodontitis:placebo-controlled randomize trial.

The aim of this study was to compare the effect of ozone and low-level-laser therapy (LLLT) on postoperative pain after root canal treatment in symptomatic apical periodontitis on vital teeth. Eighty patients were divided into four groups using a web program as follows: LLLT placebo (mock laser therapy), LLLT, Ozone placebo (mock ozonated water irrigation), and Ozone. Postoperative pain levels for 7 days after treatment and percussion pain levels at the 7th day were recorded on the visual analog scale. A regression analysis, Cochran's Q test, Chi-square test, Kruskal-Wallis tests were performed to analyze the data (P=.05). A regression analysis demonstrated that the most effective variables are "group" and "jaw" (P=0.01). Pain in the lower jaw is higher than the upper jaw. There was difference between the groups on postoperative pain at the days 1, 2, and 3; however, there was no significant difference on other days. LLLT and ozone groups had less postoperative pain and pain on percussion. Low-level laser and ozone therapy are useful methods on postoperative-pain in vital symptomatic teeth ,but they don't have superiority to each other.

Recent advances on microplastics pollution and removal from wastewater systems: A critical review.

Microplastics (MPs) (plastic particles <5 mm) are globally acknowledged as a serious emerging micropollutant, which passes through various pathways in natural habitats and eventually ends up in our food chain. In this context, the present study critically reviews recent advances in MPs sampling and detection, occurrence, fate, and removal in wastewater treatment plants (WWTPs) by delineating their characteristics that manifest toxicity in the environment via effluent discharge. While there is currently no standard protocol in place, this work examined and compared the latest approaches adopted for improved sampling, sample processing, and characterization of MPs via fluorescence imaging and certified reference materials for method validation. MPs concentration from different sources in the WWTPs varies considerably ranging between 0.28 and 18285 MPs/L (raw wastewater), 0.004-750 MPs/L (effluent), and 0.00023-10380 MPs/kg (sludge). Assessment of MPs removal efficiency across different treatment stages in various in WWTPs has been performed and elucidated their removal mechanisms. The overall MPs removal efficiency in primary, secondary, and tertiary treatment stages in WWTPs reported to be around 57-99%, 78.1-99.4%, and 90-99.2%, respectively. Moreover, the review covers advanced treatment methods for removing MPs, including membrane bioreactors, coagulation/flocculation, ultrafiltration, rapid sand filtration, ozonation, disc filtration, and reverse osmosis, which have been found to be highly effective (>99%). Membrane bioreactors have been proclaimed to be the most reliable secondary treatment technique for MPs removal. Coagulation (92.2-95.7%) followed by ozonation (99.2%) as a tertiary treatment chain has been demonstrated to be the most efficient in removing MPs from secondary-treated wastewater effluent. Further, the review delineates the effect of different treatment stages on the physical and chemical characteristics of MPs, associated toxicity, and potential impact factors that can influence the MPs removal efficiency in WWTPs. Conclusively, the merits and demerits of advanced treatment techniques to mitigate MPs pollution from the wastewater system, research gaps, and future perspectives have been highlighted.

Gravity-driven membrane coupled with oxidation technology to modify the surface properties and biofilm formation: Biofouling mitigation.

Biofilms caused by biological fouling play an essential role in gravity-driven membranes' (GDMs) flux decline and rejection rate. The effects of ozone, permanganate, and ferrate (VI) in-situ pretreatment on membrane properties and biofilm formation were systematically studied. Due to the selective retention and adsorption of algal organic matter by biofilms and oxidative degradation, the rejection efficiency of dissolved organic carbon (DOC) in algae-laden water pretreated with permanganate by GDM was up to 23.63%. Pre-oxidation extraordinarily postponed flux decline and biofilm formation of GDM and reduced membrane fouling. The total membrane resistance decreased by 87.22%-90.30% within 72 h after pre-ozonation. Permanganate was more effective than ozone and ferrate (VI) in alleviating secondary membrane fouling caused by algal cells destroyed by pre-oxidation. Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory revealed that the distribution of electrostatic force (EL), acid-base (AB), and Lifshitz-van der Waals forces (LW) interactions between M. aeruginosa and the released intracellular algogenic organic matter (IOM) and ceramic membrane surface was similar. The membrane and foulants are always attracted to each other by LW interaction at different separation distances. The dominant fouling mechanism of GDM combined with pre-oxidation technology shifts from complete pore blocking to cake layer filtration during operation. After pre-oxidation of algae-laden water by ozone, permanganate, and ferrate (VI), GDM can treat at least 131.8%, 37.0%, and 61.5% more feed solution before forming a complete cake layer. This study provides new insights into the biological fouling control strategies and mechanisms for GDM coupled with oxidation technology, which is expected to alleviate membrane fouling and optimize the feed liquid pretreatment procedure.

Efficacy of surgical methods for peri-implantitis: a systematic review and network meta-analysis.

BACKGROUND: Peri-implantitis is the most difficult biological complication associated with dental implants, often requiring surgical treatments in advanced stages. This study compares the effectiveness of different surgical methods for peri-implantitis. METHODS: Randomized controlled trials (RCTs) of different surgical treatments for peri-implantitis were extracted from EMBASE, Web of Science, Cochrane Library databases, and PubMed systematically. Pairwise comparisons and network meta-analyses (NMA) were conducted to analyze the effect of surgical treatments on probing depth (PD), radiographic bone fill (RBF), mucosal recession (MR), bleeding on probing (BOP), and clinical attachment level (CAL). In addition, risk of bias, quality of evidence, and statistical heterogeneity of the selected studies were evaluated. A total of 13 articles were included in this study, involving open flap debridement (OFD), resective therapy (RT), and augmentative therapy (AT) with and without adjunctive treatments (laser therapy, photodynamic therapy, local antibiotics, phosphoric acid, and ozone therapy). RESULTS: AT improved RBF and CAL more than OFD, but does not outperform OFD in reducing peri-implant soft-tissue inflammation. AT, OFD and RT did not significantly alter the levels of MR. Addition of ozone therapy improved the effect of AT, but addition of photodynamic therapy did not affect PD reduction and CAL gain significantly. Similarly, adjuvant treatment with phosphoric acid during RT did not significantly change the outcome of BOP. CONCLUSIONS: Within the limitation of this systematic review and NMA, AT was superior to OFD in improving peri-implantitis outcomes. While adjunct use of ozone therapy may further improve the efficacy of AT, the limited evidence supporting this combination therapy argues for cautionary interpretation of these results.

Research efficacy of gaseous ozone therapy as an adjuvant to periodontal treatment on oxidative stress mediators in patients with type 2 diabetes: a randomized clinical trial.

BACKGROUND: Chronic inflammation and cumulative oxidative stress have been theorized as two common pathways of the interconnection between periodontitis and diabetes. Improvement in oxidizing status has been demonstrated in periodontal patients with diabetes treated with proper non-surgical periodontal treatment. In addition to periodontal treatment, Gaseous ozone therapy has been reported to possess anti-inflammatory properties and the ability to stimulate the endogenous antioxidant defence mechanism. To date, the antioxidant effect of gaseous ozone, in addition with periodontal treatment in diabetic patients, has been examined in only one study. The aim of this study was to determine the efficacy of gaseous ozone therapy as an alternative approach to supporting non-surgical periodontal therapy (NSPT), aimed at improving antioxidant machinery and interfering with ROS production on plasma levels in diabetic individuals diagnosed with moderate or severe periodontitis. METHODS: One hundred and eighty patients with periodontitis and type 2 diabetes mellitus were randomly assigned to receive non-surgical periodontal treatment (NSPT) plus gaseous ozone therapy (A) NSPT alone (B). Clinical and periodontal parameters -Bleeding on probing (BOP), Periodontal pocket depth (PPD), and Clinical attachment Level (CAL)- and plasma levels of oxidant-antioxidant (TOS- TAOS) levels, glutathione (GSH), and malondialdehyde (MDA) were recorded at baseline and at 3- (T1) and at 6-months (T2) after treatment. RESULTS: Both treatments were efficacious in reducing clinical parameters. However, there were no significant differences regarding oxidative stress parameters in group A compared to group B. CONCLUSIONS: In the present study, gaseous ozone therapy did not enhance the effect of periodontal treatment in reducing oxidative stress in plasma levels of periodontitis patients with type II diabetes. TRIAL REGISTRATION: The study was registered with ISRCTN1728169 (23/07/2022).

Effectiveness of Topical Ozone Gel Application in the Management of Postextraction Wound Healing: An In Vivo Study.

AIM: The purpose of the current study was to determine the effectiveness of topical ozone gel application in the management of postextraction wound healing. MATERIALS AND METHODS: The current study involved a total of 40 participants. The patients were randomly placed into two groups with sample size estimated as n = 20 in each group. Group A: Control: patients received only saline irrigation and group B: patients receiving topical ozone gel. The surgical procedure was standardized for all groups, and local anesthesia was used during the procedure. After the removal of the mandibular third molar, the control group irrigated the socket with saline, whereas in the study group, the socket was filled with ozone gel. On the first, third, fifth, and seventh postoperative days, a single examiner evaluated each participant for postoperative mouth opening, discomfort, and patient satisfaction. The t-test was used to analyze quantitative data, whereas the Fisher exact test was employed to analyze qualitative data. Statistical significance was defined as a p value less than 0.05. RESULTS: On comparison of patient satisfaction, in the ozone gel group, 13 patients were very satisfied but in the control group, 8 patients were very satisfied. On comparison of pain intensity, on the 5th day, the complete absence of pain patients was more in the ozone gel group (12 patients) compared with the control group (4 patients). There was a statistically significant difference found between these two groups (p < 0.001). On comparison of mouth opening, on the 3rd and 5th day, mouth opening was better in the ozone gel group (29.22 ± 1.28 and 34.06 ± 0.09) compared with the control group (27.38 ± 1.03 and 31.14 ± 0.82), respectively. And there was a statistically significant difference found between these two groups (p < 0.001) on both the days. CONCLUSION: The current study came to the conclusion that using ozone gel significantly improves postoperative pain, mouth opening range, and promotes faster wound healing. CLINICAL SIGNIFICANCE: The primary goals of postoperative care for exodontia patients have always been pain management and infection control. The most frequent postoperative consequences are pain and edema. Hence, ozone therapy can be used as an effective topical agent to manage postextraction pain and swelling in healthy patients without the need for excess medications. How to cite this article: Varghese LJ, Lahiri B, Penumatsa NV, et al. Effectiveness of Topical Ozone Gel Application in the Management of Postextraction Wound Healing: An In Vivo Study. J Contemp Dent Pract 2023;24(11):887-890.