Mechanical Cleaning Research Articles

Phytochemical constituents and antibacterial activities of indigenous chewing stick (Anogeissus leiocarpus) stem

The stems from Anogeissus leiocarpus are commonly used as chewing sticks in Northern Nigeria. If properly used, the chewing sticks have proven to be effective in removing dental plaque due to mechanical cleaning and enhanced salivation. Chewing sticks from other plants have been shown to display antimicrobial activities against a broad spectrum of microorganisms. However, there is limited information available in Northern Nigeria on the chemical composition, antimicrobial properties and the ability of the plants under study to prevent bacterial adhesion to tooth surface. Therefore, the purpose of this study was to ascertain the phytochemical and antibacterial properties of Anogeissus leiocarpus and correlate the results obtained to their ethnomedicinal uses as chewing sticks. Powdered stem was exhaustively extracted using methanol at room temperature for 72 hours. Antibacterial activities of the methanol extract was assessed using the agar well diffusion methods against the oral pathogens, Staphylococcus aureus, Streptococcus salivarius, Streptococcus pyogenes, Streptococcus mutans and Streptococcus sanguinis. Acute toxicity study was achieved using Lorke method. Phytochemicals which include flavonoid, steroid, triterpenes, alkaloids, tannins, carbohydrate, glycoside, phenols were detected in the extracts while anthraquinones was absent. The antibacterial results revealed that, the methanol extract had promising antibacterial activity. S. aureuswas found to be the most susceptible bacteria at 500mg/ml with inhibition of 22 mm, Streptococcus salivarius, Streptococcus pyogenes and Streptococcus sanguinis were inhibited at 16 mm while Streptococcus mutans showed inhibition of 14 mm. The extract have MIC and MBC of 31.25 mg/ml and 62.5 mg/ml respectively against all the tested clinical isolates. The LD50 of Anogeissus leiocarpus was found to be greater than 5000 mg/kg and could be considered safe for consumption.

A Study on the Laser Removal of Epoxy Coatings on SS400 Surface by Beam Scanning Patterns

Shipyards are very interested in improving their working environment and resolving environmental pollution issues by replacing mechanical cleaning technologies used before and after painting processes with laser cleaning technology. Because epoxy paint is thickly coated, with a thickness of 200 μm or greater, it is difficult to remove using both laser cleaning and mechanical cleaning technologies. Therefore, this study tried to obtain effective cleaning results by controlling the process parameters when removing the thick epoxy coating using a Q-switching fiber laser cleaning system with an average power of 100 W developed by our research team. The pulse duration time of the laser is 150 ns. Additionally, in order to determine whether the cleaning was sufficient, the difference in laser-induced plume/plasma was compared. By controlling the beam scanning patterns, line overlap rate, and pulse overlap rate, it was possible to obtain effective cleaning results without introducing removal deviation. In addition, the NOP increased when the laser beam overlap rate increased. This increased the amount of heat input to the material and reduced the number of scans required to remove the epoxy paint. As a result of the plume/plasma analysis, less plume/plasma was generated as the paint was removed if the epoxy paint remained on the surface. On the other hand, when all of the paint was removed, a higher brightness of plume/plasma generated by evaporation of the bare metal was observed.

ОПТОЕЛЕКТРОННИЙ АПАРАТНО-ПРОГРАМНИЙ МОНОМОДУЛЬНИЙ ДАТЧИК МЕТЕОРОЛОГІЧНОЇ ДАЛЬНОСТІ ВИДИМОСТІ ТА ПРОЗОРОСТІ АТМОСФЕРИ З АВТОМАТИЧНОЮ КОРЕКЦІЄЮ ВПЛИВУ ЗОВНІШНЬОГО ЗАБРУДНЕННЯ ОПТИЧНИХ СИСТЕМ

A model sample of a monomodular hardware-software optoelectronic sensor of k-factor, meteorological range of visibility and atmosphere transparency with high technical and operational characteristics of small -sized execution is developed and created. The combination in the algorithm of functioning of the developed hardware-software methods of sensor creation provided increase of accuracy and invariance of results of measurement concerning external background illumination and self-testing with automatic correction of pollution effect of optical windows of the sensor. Continuous monitoring of the degree of contamination of optical windows provides an opportunity in case of detection of exceeding the permissible level of pollution to provide the operator with information about the need for preventive work. The proposed method of automatic correction of contamination of optical windows either completely eliminates or significantly increases the time interval of their mechanical cleaning operations, which reduces labour costs for maintenance of the sensor. The analysis of technical capabilities of the nodes of the model sample of the sensor allowed to estimate its basic meteorological parameters: the k-factor – (0.17÷1.11∙10-4) m-1, the meteorological visibility – (18÷27∙103 ) m and the atmosphere transparency per 1 km of the layer – (0÷0.895). The developed meteorological sensor can be used as a basic remote-controlled instrument for measuring meteorological parameters of the state of the atmosphere at the hydrometeorological stations of the country, mobile meteorological stations, stationary meteorological stations of road and air services to ensure guaranteed safety of workers.

Reducing non-residential asset sanitisation water footprint for improved public health in water-deficient cities

• Access to water-based sanitisation is disproportionately distributed in cities. • UV-based technology offers sustainable solution for sanitising public assets. • Long-term pandemic preparation requires alternative to water-based sanitisation. • Balancing public health sanitisation water footprint needs strategic planning. This paper evaluates the potential for reconfiguring city-scale clean water demand by reducing the non-residential asset sanitsation water footprint. A novel methodological framework is proposed for assessing the feasibility of a mix of three surface sanitisation measures (Manual surface wiping, Mechanical cleaning/Rapid disinfectant spraying, Ultraviolet germicidal irradiation-UVGI treatment) in terms of a Sanitisation waterfootprint index (SWI); three typical application scenarios are considered – high risk-high frequency, moderate risk-moderate frequency, moderate risk-low frequency. The UVGI treatment outperforms the other two surface treatment methods, particularly in high risk-high frequency scenario in the healthcare setting, with SWI as low as 2%. Further, case-study evidence from a ward-level spatial analysis using real-world data estimates SWI ranging between 0-30% in those wards with greater commercial/public assets, showing clear merit of this framework in re-configuring city-scale public health sanitisation water footprint. A cost-benefit analysis (involving resources – staffing, water and chemicals; capital expenditure, and energy costs) shows superior performance of UVGI treatment over the other two methods from the second year onwards, surpassing the initial cost-effectiveness for corresponding manual or mechanical cleaning. Wider implementation of this framework can foster strategic transformation of city-scale water footprint, which is deemed essential for ensuring sustainable growth of water deficient cities globally.

Laser-assisted removal of weld heat tints from stainless steel surface

The heat generated during the welding of stainless steel results in the oxidation of the surface that, apart from aesthetics, adversely affects its corrosion property too. This communication reports the successful removal of heat tint generated by the gas tungsten arc welding process off a stainless steel surface in addition to an improvement in its pitting corrosion resistance by exposure to the emission of a nanosecond pulsed fiber laser. The laser cleaning experiments, conducted with six different laser pulses having different temporal shapes and duration that varied from 20 to 1020 ns, revealed that removal of the weld heat tint was possible in all conditions provided the effective laser fluence exceeded a definite threshold value. This threshold value, in turn, was found to increase with an increase in pulse duration. The laser cleaned specimens were subsequently analyzed for surface morphology, roughness, and pitting corrosion resistance. The pitting corrosion resistance of the laser-treated specimens was compared with the as-welded specimens and welded specimens with heat tint removed using conventional methods like wire brush cleaning and chemical pickling. The superior quality of tint removal, improved pitting corrosion resistance, and the ease of noncontact operation indicates the significant potential of the fiber laser-based weld tint removal method to substitute the conventional mechanical or chemical cleaning methods currently in use in the manufacturing industry.

تقنيات ترميم صينية نحاسية أثرية بمتحف الفن الإسلامي بالقاهرة

A copper tray dating back to the Mamluk era, kept in the stores of the Museum of Islamic Art in Cairo, registered under No. 9315. It was broken into six separate parts with several holes. Its edge is serrated by a line in the prominent Naskh script. The tray suffers from various deterioration factors, such as pits and holes in different places of the tray, and the wrong restoration, as it was welded incorrectly with the aim of assembling some of its separate parts. Various examinations and analyses were carried out. The results of the X-ray diffraction analysis showed the presence of Cuprite (Cu2O), Atacamite and Paratacamite. Treatment and conservation of the tray was carried out, including mechanical cleaning and chemical cleaning. The assembly process was carried out for the separate parts. The holes were completed using mixture of epoxy with natural oxides and calcium carbonate with microballoon as a filler. The tray was also isolated using 3% benzotriazole to protect it from exposure to corrosion.

Multicenter comparative study of three "non-destructive" methods of detecting the cleanliness of the da Vinci surgical robotic instrument.

The robotic instrument of the da Vinci surgical system determines the accuracy of robotic-assisted surgery, However, the most effective cleaning method of robotic equipment is a challenge for healthcare professionals. This study compared three da Vinci robot-assisted surgery manipulators to detect the effect of "non-destructive" testing of the cleaning effect by two different methods. The post-surgical cleaning of the da Vinci robotic instruments in the Sun Yat-sen University Cancer Center, The First Affiliated Hospital of Guangzhou Medical University and the Shenzhen Second People's Hospital was performed using two different processes from January 2019 to January 2020: manual joint automatic ultrasonic cleaning and automatic mechanical cleaning. The efficacy of visual estimation, the residual protein assay (quantitative) and adenosine triphosphate (ATP) biological biofluorescence detection of the cleanliness of the mechanical instrument's work (distal working end) surface and the shaft's inner chamber was compared. If the cleaning effect of any position on the surface or inner cavity of the manipulator did not qualify, the entire robotic instrument was judged as disqualified. A total of 198 cases of da Vinci robotic instrument postoperative cleanliness data were collected. The qualifying rates of automatic ultrasonic cleaning were 96.97% by visual estimation, 93.94% by residual protein assay and 60.61% by ATP biological fluorescence detection. The respective rates for automatic mechanical cleaning were 100% by visual estimation, 90.91% by residual protein assay and 66.67% by ATP biological fluorescence detection. The cleaning of the da Vinci robotic instrument detected by "non-destructive" residual protein assay or ATP biological fluorescence detection is more accurate than visual estimation.

Antibacterial potential of strawberries and basil extracts combination against Streptococcus sanguinis (ATCC 10556)

Introduction: Streptococcus sanguinis is a commensal microorganism as well as a pioneer colony in forming dental plaque. Oral biofilm formation can be prevented by a mechanical cleaning procedure followed by the use of mouthwash. The current gold standard for mouthwash is chlorhexidine. Nevertheless, it has side effects that are not recommended for long-term use. Previous studies had proven that herbal-based mouthwashes such as basil leaves (Ocimum basilicum) and strawberry fruit (Fragaria x ananassa) have been shown to have antibacterial properties. The effectivity of antibacterial activity phenomenon in combined extracts has been reported in other studies. This research aims to observe the antibacterial potential of the F. x ananassa and O. basilicum extract combinations against S. sanguinis (ATCC 10556). Methods: The sample of this study was a combination of F. x ananassa and O. basilicum extract, which initially screened for their antibacterial activities. Antibacterial activities of F. x ananassa and O. basilicum extracts against S. sanguinis were observed using Kirby Bauer method, while Minimum Inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) by serial microdilution method. The 2% concentration from each extract was combined in 1:1, 1:2, and 2:1 volume ratio variations then tested for inhibitory zones, MIC, and MBC. Results: F. x ananassa extract had 0.125% and 0.25% for MIC and MBC respectively, while O. basilicum extract showed the value of MIC and MBC as 0.031% and 0.063% against S. sanguinis (ATCC 10556). The extract combinations in 1:1, 1:2, and 2:1 volume ratio variations showed 0.016% for MIC and 0.031% for MBC. Conclusions: It was concluded that combining extracts of 2 % F. x ananassa and 2% O. basilicum in various ratios were observably to have the antibacterial potential against S. sanguinis (ATCC 10556).

Efficacy and safety of a device used to prevent fogging and residue buildup on surgical optics during video-assisted thoracic surgical procedures (LacrimaSurg): a pilot in vivo study in 30 patients.

Nowadays the majority of the surgical procedures are video surgeries. Despite technological advances, some problems remain. The buildup of residues in front of the lens is an example of this problem. To solve it, Abreu et al. (Surg Technol Int 26:43-47, 2015) developed LacrimaSurg, which works as a lacrimal duct in the optics preventing fogging and residues buildup on it. This had 98.1% of efficiency in an experimental study. Study feasibility and safety of the device under real surgical conditions. A pilot study included 30 patients undergoing thoracic procedures using LacrimaSurg. Procedures were recorded for further analysis by investigators. The characteristics of patients (age, sex, body mass index, Charlton comorbidity index), data of environment (Temperatures variances), and data of procedures (type of surgery and duration of it) were recorded. The investigators watched the videos and recorded the residue buildup and fogging events that impaired surgeon's vision. The number of times the optics got dirty, need for further jets of crystalloid solution, and need for mechanical cleaning were collected to evaluate efficacy. Comparative serum measurements of electrolytes before and after surgery were studied. Data were organized and analyzed by simple linear correlations and t test for continuous variables and Fisher's test for categorical variables. The use of the device allowed 97% of the procedures to be performed without interruption. No characteristics inherent to the patients or to the procedures that lead to fogging or filth of the optics were identified. There were no statistically significant differences between pre- and postoperative serum ions, and no postoperative complications related to the use of the device were observed. The device was effective in preventing interruption of surgical procedures due to dirt or fogging, its use was considered safe, and did not cause postoperative complications.

Professional Mechanical Tooth Cleaning Method for Dental Implant Surface by Agar Particle Blasting.

Oral dysfunction due to peri-implantitis and shortened life of implants has become a major concern. Self-care and removal of oral biofilms by professional mechanical tooth cleaning (PMTC) are indispensable for its prevention. However, if the surface roughness of the implant is increased, it may result in the adhesion of biofilm in the oral cavity. Therefore, the PMTC method can serve for long-term implant management. Calcium carbonate (CaCO3) has been used as a cleaning method for implant surfaces; however, there is concern that the implant surface roughness could increase due to particle collision. Therefore, in this study, to establish a blasting cleaning method that does not adversely affect the implant surface, a new blasting cleaning method using agar particles was devised and its practical application examined. When the simulated stains were blasted with white alumina (WA) abrasive grains and CaCO3 particles, the simulated stains were almost removed, the surface roughness changed to a satin-finished surface—which was thought to be due to fine scratches—and the surface roughness increased. Most of the simulated stains were removed on the surface of the sample blasted with glycine particles and agar particles. Conversely, the gloss of the sample surface was maintained after cleaning, and the increase in surface roughness was slight.

Analytical Study and Conservation of New Kingdom Period Pottery Jars from Saqqara Excavation, Egypt

Ancient archaeological sites contain numerous pottery objects that suffered from different deterioration factors. This study aims to use different analytical methods to study the chemical and mineralogical composition and identification of deterioration aspects of some ancient Egyptian pottery jars from Saqqara excavation. Thus, to explain the deterioration factors' mechanisms and apply the proper conservation methods to the deteriorated pottery jars. AutoCAD, digital microscope, scanning electron microscope (SEM-EDX), and x-ray diffraction (XRD) were used to clarify the preservation states of pottery jars. The results of the investigation revealed that the selected jars suffered from different cracks, salts crystallization, some surface black spots, separation of the slip layer, and heterogeneity in the grains size. XRD analysis revealed that quartz, diopside, illite, muscovite, orthoclase, anorthite, and hematite are the main components of the jars. SEM-EDX analysis showed high concentrations of chlorides and sulfate salts, besides the presence of manganese oxide. Different treatments were performed for the pottery jars include mechanical and chemical cleaning. Additionally, the completion process was done by using a mixture of dental gypsum with grog. Moreover, the consolidation process was achieved by using paraloid B-72.

Carbon dioxide snow cleaning of paper

The cleaning of particles from smooth and rough paper surfaces using a high-speed CO2 snow jet was investigated. The measurements included characterization of the jet properties, determination of the cleaning efficiency, and evaluation of any possible adverse effects. The method was compared with nitrogen jet cleaning and dry cleaning by commercial materials. The results showed that the CO2 snow jet is able to effectively remove particles from the paper surface and did not cause any observable degradation. The CO2 snow jet cleaning compared with the mechanical dry cleaning showed similar effectiveness without any adverse effects on the paper surface. It was proved that the CO2 snow technique is a suitable method for cleaning common types of paper materials.

Enhanced anti-fouling performance in Membrane Bioreactors using a novel cellulose nanofiber-coated membrane

• The fouling of TFNC-CNF membranes is reversible when filtering wastewater. • Enhanced flux was achieved in the submerged TFNC-CNF membrane bioreactor. • TFNC-CNF membranes showed higher rejection potential of bio-foulants. • Air scouring enhanced the flux of TFNC-CNF membranes when filtering wastewater. The filtration performance, fouling and flux recovery efficiency of a novel thin film nanofibrous composite-cellulose nanofiber (TFNC-CNF) coated membrane was studied and compared with polyvinylidene fluoride (PVDF) membranes treating domestic wastewater. The enhanced anti-fouling property of the TFNC-CNF membrane was associated with the super-hydrophilic nature and negative charge on the membrane surface. The dead-end cell filtration tests demonstrated the TFNC-CNF membrane recovered more than 90% of the initial flux after mechanical cleaning, compared with 26–43% recovery by PVDF membranes. Continuous wastewater ultrafiltration tests with mechanical air scouring confirmed the outstanding permeability (71.3–138.9 LMH/bar) and the superior anti-fouling characteristics (59.2–86.8% recovery of the initial flux) of the TFNC-CNF membrane. Furthermore, higher total organic carbon rejection rates were also observed in the TFNC-CNF membrane (>83.2%) than the PVDF membrane (<69.8%). Collectively, the superior flux recovery and high permeability makes the TFNC-CNF membrane a promising material for membrane bioreactors.

Missing seashells: a subtle detail of an inadequate policy

In Santos Beach, southwest coast of Brazil, cleaning operations are intensified during the summer using manual and mechanical techniques, driven mainly by sanitary and aesthetic aspects that neglect basic ecological standards. This study evaluated the abundance, richness, and diversity of dead shells, after spring and neap tides, found in two strips of sandy beaches: the "damp" and the "wet "sectors, where only the former undergoes mechanical cleaning. We collected and counted all fragmented and whole shells, identified each down to the species levels, and measured their weight. We used mixed statistical modeling to evaluate the effect of the sector over the abundance (in weight and number), richness, and Shannon-Wiener diversity (). We found a significantly greater abundance of fragmented shells in the damp sector. Since this is the sector where mechanical cleaning is applied, we understand such a strategy promotes potential harmful impacts over the conchological structure in Santos Beach, requiring mitigatory measures to protect empty shells. Finally, we fathom incorrectly discarded litter is brought from the surrounding mangrove to the beach after the spring tides; thus, integrated cleaning management with the participation of the local population, are also required to reduce the mechanical cleaning and its impacts.

Randomised methodology development study to investigate plaque removal efficacy of manual toothbrushes

ObjectivesThis study aimed to evaluate plaque removal efficacy of toothbrushes to guide clinical model development. MethodsThis single-centre, randomised, controlled, examiner-blind, method development study included 80 healthy participants. Over 28 days, participants brushed twice-daily using a fluoride toothpaste and one of four marketed toothbrushes: Toothbrushes A (compact head) and B (regular head): medium-hard; flat trim; end-rounded bristles; Toothbrush C: medium-hard; end-rounded bristles; silky, tapered filaments; compact head; Toothbrush D: soft; tapered filaments; compact head. Supra-gingival plaque removal was evaluated immediately after single brushing events (Days 0, 7, 28, at study centre) and following 7- and 28-days’ home use via Rustogi modified Navy Plaque Index (RPI) and Turesky modified Quigley Hein Plaque Index (TPI). ResultsAll toothbrushes provided significant plaque removal after single-brushing events with change from Day 0 pre-brushing scores on RPI ranging from -0.10 to -0.16 (p<.0001) and on TPI ranging from -0.61 to -0.89 (p<.0001). Toothbrushes A and B showed significant (p<.05) pre-brushing RPI/TPI plaque reductions after 7- (-0.04/-0.06, respectively for RPI; -0.16/-0.20, respectively for TPI) and 28-days (-0.04/-0.03, respectively for RPI; -0.20/-0.11, respectively for TPI) use versus Day 0 pre-brushing (except Toothbrush B, Day 28, non-significant TPI). There were no significant differences with Toothbrush C. Toothbrush D TPI was significantly lower at both timepoints versus Day 0 pre-brushing (p<.05). Study toothbrushes were generally well-tolerated. ConclusionThe observations from this study showed how various aspects of a study design could impact toothbrushes performance. These data will inform the design of future clinical studies of plaque removal efficacy using manual toothbrushes. Clinical Significance StatementRegular effective oral hygiene can help prevent and treat gingivitis, principally via twice-daily mechanical cleaning with a toothbrush. Data generated from this methodology development study will help to identify the key aspects which impact toothbrushes’ performance and understand which one would be more suitable to answer questions of scientific interest. This study provides useful information for the design of future clinical trials to assess plaque removal efficacy of manual toothbrushes and generate results to inform clinical recommendations.

Microbial Biofilm Decontamination on Dental Implant Surfaces: A Mini Review.

IntroductionAfter insertion into the bone, implants osseointegrate, which is required for their long-term success. However, inflammation and infection around the implants may lead to implant failure leading to peri-implantitis and loss of supporting bone, which may eventually lead to failure of implant. Surface chemistry of the implant and lack of cleanliness on the part of the patient are related to peri-implantitis. The only way to get rid of this infection is decontamination of dental implants.ObjectiveThis systematic review intended to study decontamination of microbial biofilm methods on titanium implant surfaces used in dentistry.MethodsThe electronic databases Springer Link, Science Direct, and PubMed were explored from their inception until December 2020 to identify relevant studies. Studies included had to evaluate the efficiency of new strategies either to prevent formation of biofilm or to treat matured biofilm on dental implant surfaces.Results and DiscussionIn this systematic review, 17 different groups of decontamination methods were summarized from 116 studies. The decontamination methods included coating materials, mechanical cleaning, laser treatment, photodynamic therapy, air polishing, anodizing treatment, radiation, sonication, thermal treatment, ultrasound treatment, chemical treatment, electrochemical treatment, antimicrobial drugs, argon treatment, and probiotics.ConclusionThe findings suggest that most of the decontamination methods were effective in preventing the formation of biofilm and in decontaminating established biofilm on dental implants. This narrative review provides a summary of methods for future research in the development of new dental implants and decontamination techniques.

Оценка биосовместимости очищенного говяжьего сухожилия на модели гетеротопической имплантации

Damage to the tendon-ligamentous apparatus places serious limitations on a personʼs physical activity. Injuries are especially common in physically healthy people leading an active lifestyle, such as athletes. To treat such injuries in orthopaedics and traumatology, autoplastic operations are performed or prostheses made of synthetic or biological materials are installed. The known treatment methods, in spite of their effectiveness, have a number of serious drawbacks, which often limit their use. Therefore, the search for new approaches and materials for plastic ligaments is an urgent task. Today, biotissue prostheses are accumulating advantages over their synthetic counterparts. The most promising raw material for biological ligament prostheses, due to its availability in the required quantity and optimal size, is the flexor and extensor calf tendons. This paper aimed to develop a method for treating xenogenic tendon to manufacture ligament prostheses and assessing its biocompatibility in a heterotopic implantation model. To manufacture a ligament prosthesis, the raw material was subjected to mechanical cleaning and chemical-physical treatment, as well as treatment with supercritical carbon dioxide fluid with the addition of the nonionic surfactant Tween 80, which together contributed to effective decellularization and removal of other biologically active components, while maintaining the physical and mechanical parameters and natural fiberarchitectonics of native raw materials. The biocompatible properties of ligament prosthesis specimens made from the flexor and extensor calf tendons using this method were evaluated in a model of heterotopic implantation into the subcutaneous adipose tissue of rats. The results obtained confirm the promising use of this material, treated according to the proposed method, in clinical practice.

Effectiveness of Chemical Disinfection in Discarding Pathogenic Bacteria of Human Particulate Tooth Graft

Introduction: Extracted teeth are utilized in dentistry as particulate autologous dentin for immediate grafting of the extraction site after mechanical cleaning and chemical disinfection. The objective of this study was to determine the effectiveness of 0.5M sodium hydroxide in 20% ethanol (Dentin Cleanser™) in eliminating three different types of pathogenic bacteria in comparison to ethylenediaminetetraacetic acid (EDTA) or citric acid. Seven naive extracted teeth were mechanically cleaned, dried, and sectioned to separate the crown from the roots. Each tooth was separately crushed using the Smart Dentin Grinder® device. The sterile particles of crown or root were subdivided into three equal-size groups where each was then contaminated and incubated in an oven at 37°C under low pressure and oxygen flow over 48 h for Escherichia coli (Group A) and Enterococcus faecalis (Group B) and over 72 h for Porphyromonas gingivalis (Group C), respectively. On each agar Petri dish, four paper discs, each loaded with one of the following solutions: Dentin Cleanser (sodium hydroxide plus ethanol), 10% EDTA, phosphate-buffered saline (PBS), or 10% citric acid, were placed in the safe distance for not interfering with disinfectant agent activity. All pathogenic bacteria were highly sensitive to Dentin Cleanser and EDTA disinfectant activity while citric acid or PBS exhibited low or no sensitivity. No difference in sensitivity was found between crown and root particulate or particle size. Our findings show that Dentin Cleanser is most effective in eliminating those pathogenic bacteria without demineralizing the particulate. Context: The experiment was done in the University Laboratory. Aims: The objective of this study was to determine the effectiveness of 0.5M sodium hydroxide in 20% ethanol (Dentin Cleanser™) in eliminating three different types of pathogenic bacteria in comparison to EDTA or citric acid, before tooth graft will be used as a biomaterial. Settings and Design: The study protocol was approved by the Catholic University of Murcia Ethics Committee (UCAM; registration number 6781; July 21, 2017). Seven human teeth were extracted from a 60-year-old patient due to advanced periodontal disease (two central upper incisors, one upper canine, one upper premolar, two lower molars, and one lower canine). The patient received no financial compensation for participating in this study. Materials and Methods: Seven naïve extracted teeth were mechanically cleaned, dried, and sectioned to separate the crown from the roots. Each tooth was separately crushed using the Smart Dentin Grinder® device (KometaBio Inc., Cresskill, NJ, USA). The particles were sieved to obtain particles ranging from 400 to 600 um and 800–1200 um in size, all sterilized using an autoclave. The sterile particles of crown or root were subdivided into three equal-size groups where each was then contaminated and incubated in an oven at 37°C under low pressure and oxygen flow over 48 h for E. coli (Group A) and E. faecalis (Group B) and over 72 h for P. gingivalis (Group C), respectively. Then, each subgroup was immersed in 15 agar Petri dishes and again each was inoculated with the same bacteria allowing full growth of bacteria. On each agar Petri dish, four paper discs, each loaded with one of the following solutions: Dentin Cleanser (sodium hydroxide plus ethanol), 10% EDTA, PBS, or 10% citric acid, were placed in the safe distance for not interfering with disinfectant agent activity. Statistical Analysis Used: Statistical analysis was performed using PASW Statistics v. 18.0.0 software (SPSS). One-way analysis of variance was applied for the comparison of the means for halos, assuming a level of significance of 95% (P &lt; 0.05). Kolmogorov–Smirnov and Shapiro–Wilk tests were applied for normality. Results: The results of the present study show that the 0.5M sodium hydroxide with 20% ethanol also termed as Dentin Cleanser presented the widest diameter halo of free bacterial growth, most effective against P. gingivalis (15.76 ± 0.28), less effective against E. faecalis (13.21 ± 0.72) and E. coli (12.14 ± 0.12). Similarly, EDTA was effective in eliminating the same strains of bacteria, while citric acid was not effective according to the Duraffourd halo inhibition scale. PBS had no effect in inhibiting bacterial growth. Both the Dentin Cleanser and EDTA were significantly effective in inhibiting bacterial growth in comparison to PBS and citric acid. No significant differences were observed between the dentin particulate and the dentin–enamel mix particulate or human bone marrow related to the level of sensitivity measured for each of the disinfectants tested. Conclusions: The use of the Dentin Cleanser (sodium hydroxide plus ethanol) or EDTA 10% appears to be an effective disinfectant method of tooth particulate prior to use of such particulate as autologous grafting material. Although E. coli, P. gingivalis, and E. faecalis were found to be sensitive to the presence of these disinfectants, additional bacterial types should be further investigated.

Membrane Fouling and Cleaning in Anaerobic Flat-Sheet Ceramic Membrane Bioreactor for Sewage Treatment

AbstractIn this study, the feasibility of an anaerobic flat-sheet ceramic membrane reactor for sewage treatment was evaluated, and the membrane fouling mechanism and membrane cleaning methods were ...

THE USE OF LOW-INTENSITY RADIATION IN TREATMENT OF PERIODONTAL TISSUE DISEASES (LITERATURE REVIEW)

Topic relevance. Periodontal tissue diseases currently take a significant place among infectious diseases, both in dentistry and in medicine in general. Traditional methods of treatment of inflammatorydystrophic periodontal diseases do not bring the desired results, so the question arises of finding alternative, non-drug treatments. Among such means, special attention is paid to the use of various types of low-intensity radiation, as well as the cumulative effect of light and photosensitizers.&#x0D; The aim of the study is to analyze literary sources regarding the use of various types of low-intensity radiation in the treatment of periodontal tissue diseases.&#x0D; Materials and methods. The research and analysis of scientific literature on the basis of Google Scholar, Research Gate, Wiley Online Library and Academia.edu on the use of various types of radiation in the treatment of periodontal tissue diseases was carried out.&#x0D; Results and discussion. Laser radiation shows anti-inflammatory, antimicrobial, immunomodulatory and&#x0D; desensitizing effect, stimulates tissue reparation, and also reduces histohemmatic barriers in the inflammatory process, reduces gum hyperemia, which indicates the high efficiency of this method in optimizing the processes of restoring periodontal structures. With wavelengths of 630 and 870 nm, laser radiation at certain parameters increases the sensitivity of S. aureus and P.aeruginosa to commonly used antibiotics.&#x0D; With long-term exposure, PILER (polychromatic polarized incoherent low-energy radiation) has a similar effect on soft tissues, which improves the results of treatment of chronic catarrhal gingivitis in complex therapy, activates regenerative processes, reduces the spread and pain, normalizes immune processes. Polychromatic and monochromatic PILER shows a pronounced antimicrobial effect against opportunistic pathogens, although complete data on its use in periodontology is not yet available.&#x0D; LED radiation, in turn, also increases the sensitivity of conditionally pathogenic microorganisms to some antibiotics, causes improvement of oral hygiene indicators, bleeding of gums and stabilization of tooth mobility, inhibits the activation of pro-inflammatory cytokins, has a biostimulating effect on gum fibroblast and antiinflammatory effect.&#x0D; Experimental studies show that the use of low-intensity radiation and photosensitizers for photodynamic treatment (PDT) show significant improvement of treatment outcomes in periodontal patients. Thus, PDT in combination with mechanical cleaning of periodontal pockets leads to a significant decrease in their depth compared to traditional treatment methods.&#x0D; Conclusion. Application of various methods of irradiation of periodontal tissues using a certain dose of low-intensity radiation, wavelength and exposure, both individually and in combination with photosensitizers, can be employed in the treatment of inflammatory and inflammatory-dystrophic periodontal diseases as an effective antimicrobial method.