Steam Cleaning Research Articles

Technical assessment of shear bond strength at ceramo-alloy interface after various surface treatment combinations and application of metal bonding agent.

Bonding between metal and ceramic is one of the most important aspects of a successful prosthesis. Various methods have been recommended for preparing the metal surface to enhance the bond between metal and ceramic including the use of a metal bonding agent. This study aims to evaluate and compare the shear bond strength of the metal-ceramic (M-C) interface after combinations of various surface treatments including the application of a metal bonding agent. 40 Ni-Cr alloy specimens were made and divided into 4 groups of 10 each based on the combination of surface treatments. Sandblasting, surface grinding, and Oxidation heat treatment (OHT) were performed on specimens from Group 1 (Control). In addition, Group 2 specimens received ultrasonic cleaning, Group 3 steam cleaning, and Group 4 metal bonding agent application. Following surface treatments on all specimens, porcelain build-up was performed, and shear bond strength was tested in a Digital Universal testing machine. The statistical tests used were independent t-test and ANOVA. Results revealed that Group 4 specimens had the highest mean value of shear bond strength of 39.087 MPa while Group 3 specimens showed the least mean shear bond strength of 18.154 MPa with highly statistically significant results (p< 0.001). The surface treatments and application of bonding agent to metal prior to porcelain application resulted in increased shear bond strength of the metal-ceramic interface.

Effects of header design on thermal characteristics of multi-nozzle steam spraying

The distribution header of small-scale steam systems, commonly employed in household items like steam cleaners, is pivotal for dictating the spray characteristics of the steam generated. For uniform spray performance across multiple outlets, it's imperative to discern the design factors influencing this outcome. We numerically assessed the flow characteristics of steam in a spraying system with three nozzle outlets and scrutinized the impact of header design parameters on uniformity. Through a multiphase numerical model, numerical simulations were conducted. Our analysis revealed that decreasing the diameter of the three outlets promoted a more even mass flow rate of the sprayed steam from each outlet, having a minimal effect on temperature consistency. In contrast, enlarging the tapering angle of the header improved temperature uniformity up to 62.5 % but negatively influenced the uniformity of the steam spray amount when outlet diameters were consistent. Notably, when the combined area of the outlets was increased, there was a decline of up to 85 % in the uniformity of the discharged steam mass among the outlets with an increased tapering. This research offers insights that are anticipated to inform future studies and advancements in steam spraying system optimization, enhancing performance and efficiency for applications such as steam cleaning and sterilization processes.

Biocompatibility, Surface Morphology, and Bacterial Load of Dental Implant Abutments following Decontamination Protocols: An In-Vitro Study.

The long-term success of dental implant rehabilitation depends significantly on proper peri-implant soft tissue integration. Therefore, decontamination of abutments prior to their connection to the implant is beneficial to enhance soft tissue attachment and to aid in maintaining marginal bone around the implant. Consequently, different implant abutment decontamination protocols were evaluated regarding biocompatibility, surface morphology, and bacterial load. The protocols evaluated were autoclave sterilization, ultrasonic washing, steam cleaning, chlorhexidine chemical decontamination, and sodium hypochlorite chemical decontamination. The control groups included: (1) implant abutments prepared and polished in a dental lab without decontamination and (2) unprepared implant abutments obtained directly from the company. Surface analysis was performed using scanning electron microscopy (SEM). Biocompatibility was evaluated using XTT cell viability and proliferation assays. Biofilm biomass and viable counts (CFU/mL) (n = 5 for each test) were used for surface bacterial load evaluation. Surface analysis revealed areas of debris and accumulation of materials, such as iron, cobalt, chromium, and other metals, in all abutments prepared by the lab and with all decontamination protocols. Steam cleaning was the most efficient method for reducing contamination. Chlorhexidine and sodium hypochlorite left residual materials on the abutments. XTT results showed that the chlorhexidine group (M = 0.7005, SD = 0.2995) had the lowest values (p < 0.001) (autoclave: M = 3.6354, SD = 0.1510; ultrasonic: M = 3.4077, SD = 0.3730; steam: M = 3.2903, SD = 0.2172; NaOCl: M = 3.5377, SD = 0.0927; prep non-decont.: M = 3.4815, SD = 0.2326; factory: M = 3.6173, SD = 0.0392). Bacterial growth (CFU/mL) was high in the abutments treated with steam cleaning and ultrasonic bath: 2.93 × 109, SD = 1.68 × 1012 and 1.83 × 109, SD = 3.95 × 1010, respectively. Abutments treated with chlorhexidine showed higher toxicity to cells, while all other samples showed similar effects to the control. In conclusion, steam cleaning seemed to be the most efficient method for reducing debris and metallic contamination. Bacterial load can be reduced using autoclaving, chlorhexidine, and NaOCl.

Research on the Role of Surface Treatment of the Metal Surface on the Strength of the Metal-Ceramic Bond.

The aim of the present study is to investigate the metal-ceramic bond strength as a result of three different surface treatment methods: (1) oxidation, (2) oxidation and sandblasting, and (3) double oxidation on the metal substrate. A total of 72 metal substrates were made from two different types of metal-ceramic alloys (n = 36): group I, Ni-Cr and group II, Co-Cr alloys. Each group was further divided and subjected to three different surface treatments (n = 12): (1) oxidation in accordance with the manufacturer's instructions; (2) oxidation according to the manufacturer's instructions and then sandblasting with Al2O3, with a grain size of 110 μm, a pressure of 75 psi for 10 sec with a distance of 5 cm and steam cleaning; and (3) double oxidation. The bond strength of the specimens was evaluated with the three-point bending process. The data were recorded, tabulated, and statistically analyzed. For group I, the materials with oxidation based on the specifications, show mean value of 64.02 Nt. The oxidation and sandblasting materials have mean 55.92 Nt. The double oxidation materials have mean 55.47. For group II, the materials with oxidation based on the specifications, show mean value of 58.46 Nt. The oxidation and sandblasting materials have a mean value of 42.56 Nt. The double oxidation materials have mean 42.96 Nt. The best method of treatment of the metal substrate is specification oxidation, in terms of the strength of the metal-ceramic bond. Further treatment of the metal substrate reduces the strength of the metal-ceramic bond. A prerequisite for clinical success of metal-ceramic prosthetic restorations is the increased strength of the bond between ceramic material and metal substrate. With that in mind, the present research gives important insight into best practices for prosthetic restorations.

Quantification of surface changes and volume losses of selected rock types due to different cleaning processes

The restorative cleaning of natural stones has a special significance for the preservation of important cultural assets or the slowing of their deterioration. Organisms such as fungi, lichens or mosses, but also emission dirt such as soot soften and otherwise damage both the surface and the internal structure of the building stone. In order to quantify the effects and in particular the abrasiveness of selected cleaning methods, cleaning experiments were carried out on six different naturally and artificially weathered rocks using cold water under high pressure, hot water under high pressure as well as hot-water steam. The types of rocks studied include marble, limestone, granite, sandstone and tuff. Surface changes in roughness and topography were quantified using two surface-sensitive methods: confocal microscopy as well as 3D shadow triangulation. The two high-pressure cleaning methods were found to have a significantly stronger abrasive effect than steam cleaning when the distances were too small. The cleaning performance, which was compared using biologically weathered samples, was lowest for steam cleaning. However, the high temperatures of the steam also permanently eliminate much of the biological matter on and under the surface, as observed in the field test. The results presented should make it possible for the conservator to assess, which cleaning procedures to use for the different rock varieties depending on the degree of weathering.

One-Year Outcomes of Subcrestal Platform-Switched Implants With and Without Sterile Prosthetic Abutments: A Randomized Controlled Trial.

Surface contaminants on customized implant abutments could trigger an inflammatory response in the peri-implant tissues. The aim of this randomized controlled study was to assess the radiographic bone changes around implants restored with customized, platform-switched abutments, with and without autoclave treatment, 12 months after definitive restoration. Dental implants were placed 1 mm subcrestally in 64 systemically healthy patients (mean age: 63.3 ± 10.0 years; 31 patients had a history of periodontitis) to replace single or multiple missing teeth. According to a randomization list, abutments were subjected to steam and autoclave sterilization (43 implants, test group) or steam cleaning alone (44 implants, control group). Periapical standardized radiographs were taken at implant placement, prosthetic abutment connection, and 12 months after definitive cement-retained restoration. All implants were clinically stable without any sign of infection at the 12-month follow-up. An average marginal bone loss of 0.25 ± 0.19 mm was found in the test group compared to 0.35 ± 0.23 mm in the control group (no statistically significant difference), while the percentage of bleeding sites was significantly higher in the control group (8.7% ± 13.1% vs 19.1% ± 19.8%; P &#61; .035). Autoclave treatment of customized abutments seems to reduce the inflammatory response around subcrestally placed implants.

Formation of the Working Flux in an Abrasive Jet for Steam Cleaning

Formation of the Working Flux in an Abrasive Jet for Steam Cleaning

Numerical Simulation of Vapor-Liquid Two-Phase Saturated Steam Fluent Flow and Atomizing Jet Cleaning

In order to reduce the serious impact of polluting particles on the performance and quality of high-precision machinery and equipment, a cleaning system that uses saturated steam to clean the surface of parts and components is designed to achieve high cleanliness requirements. Based on the standard k-ε model, the large-scale fluid simulation software ANSYS is used to simulate the flow pattern of the steam nozzle to obtain the best distance for steam cleaning. According to the simulation results, a steam cleaning machine was developed and put into an automated cleaning production line to clean three different types of aviation parts. The residual masses of the parts were 0.1 mg, 0.1 mg, and 0.2 mg, and the maximum particle diameters were 549.461 μm, 275.464 μm, and 399.660 μm. The cleaning results show that the saturated steam cleaner can meet the cleaning requirements and get better surface quality parts after cleaning.

Mathematical model of the process of forming the working flow of a thermodynamic abrasive jet tool for surface treatment

A mathematical model of heat transfer during steam cleaning of surfaces with an abrasive jet tool is developed, taking into account its design features and heat flow power. Keywords: thermo-steam-jet tool, vaporization, heat transfer, transformation ratio, water consumption. kravchenko-in71@yandex.ru

Color and translucency of milled polymethyl methacrylate crowns on non–tooth-colored interim abutments with different surface treatments

Statement of problemThe interim rehabilitation of implants has become a necessity, particularly for those placed in the esthetic regions. However, the optical properties of computer-aided design and computer-aided manufacturing (CAD-CAM) polymethyl methacrylate (PMMA) crowns on interim abutments with different surface treatments are unclear. PurposeThe purpose of this in vitro study was to investigate the color and translucency of CAD-CAM PMMA crowns when different surface treatments were used on titanium interim abutments. Material and methodsA maxillary dentate stone cast with a narrow-diameter implant analog at the left lateral incisor site was used. Three titanium interim abutments (blue) were divided into 3 groups according to the surface treatment they received: control (steam cleaning), opaqued (120-μm Al2O3 airborne-particle abrasion and opaque application), and airborne-particle abraded (120-μm Al2O3). Thirty PMMA crowns (A2 shade) were milled (n=10). The color coordinates of the crown-interim abutment pairs and a shade tab (A2) were measured by using a colorimeter. The color differences (ΔE00) between the crowns and the shade tab and the relative translucency parameter (RTP) values of the crowns were calculated by using the CIEDE2000 formula. One-way ANOVA was used to analyze the ΔE00 and RTP values with subsequent Tukey honestly significant difference tests (α=.05). ResultsThe abutment surface treatment significantly affected the ΔE00 of interim crowns from the shade tab (P<.001), but no significant effect was found on RTP (P=.26). The control group had the highest ΔE00 from the shade tab (P≤.011). No significant difference (P=.14) was found between the opaqued and the ΔE00 of the airborne-particle abraded groups from the shade tab. ConclusionsThe surface treatments of interim abutments affected the color of CAD-CAM PMMA crowns, which differed from that of the shade tab. The color of crowns on opaqued or airborne-particle abraded interim abutments was closer to the color of the shade tab. Abutment surface treatments did not affect the translucency of crown-interim abutment pairs.

Water-mediated adhesion of oil sands on solid surfaces at low temperature

Frozen oil sands adhere to the walls of mining fleets in winter, which is an undesirable phenomenon that reduces the delivery capacity of vehicles and wastes fuel for in-land transportation. For automated surface mining, an effective and scalable approach is needed to replace the current method for removing adhered oil sands by shovelling or steam cleaning. In this work, we identify ice formation at the interface of oil sands and the different substrates (steel, rubber, and bitumen/asphaltene coated steel) as the primary reason for the observed high adhesion strength of more than 1,000 kPa; in absence of ice formation, the adhesion strength of oil sand is smaller than 2 kPa. At temperature of −2.5 °C to −20 °C, the adhesion strength was measured by a force apparatus with thermal control as water content in oil sands matrix was varied from 4 to 14 wt%. The adhesion strength was found to increase linearly with water content. At a fixed water content, the adhesion strength was stronger at a lower temperature after a short freezing time of 5 min. The relationship between water content and the adhesion strength was rationalized by a theoretical model, based on the contact area between ice and the substrate. X-ray micro-computed tomography confirmed that water formed more capillary bridges with the substrate at a higher water content. To effectively reduce the adhesion of oil sands on the substrate, a method was proposed based on anti-icing by spraying a small amount of anti-freezing liquid (0.3 L/m2) on the substrate, which effectively reduced the adhesion strength to <2 kPa. The insights and proposed anti-freezing approach in this study may be applied to reducing adhesion of not only frozen oil sands, but wet granular materials in general.

The impact of different cleaning protocols on resin bond strength to polymer-infiltrated ceramic material

Purpose: This study measured and compared shear bond strength (SBS) of a composite resin cement with that of PICN material after different surface cleaning methods. Materials and Methods: Forty Vita-Enamic plates (10x7x2 mm) were fabricated using of a low speed, water-cooled diamond saw. All plates were air-borne particle abraded using 50µm Al2O3 then contaminated with saliva, after that all plates were classified into four groups (n=10): control group (CG) in which conventional cleaning with air-water spry was used, and three test groups as follow: ultrasonic cleaning (UCG), steam cleaning (SCG), Ivoclean cleaning (ICG). Composite resin discs (Nexcomp) were cemented to ceramic plates using self-adhesive resin cement (Charm Supercem). All bonded specimens were stored in 37°C water for 1 month then, thermocycled 1000 times in water baths between 5˚C and 55˚C. Shear bond strength (SBS) test was performed using a universal testing machine. Scanning Electron Microscope (SEM) was used for failure mode examination. Results: Different cleaning methods significantly increased SBS values of tested groups compared to control one (p=0.000). The highest mean SBS (MPa) was reported for (SC) test group (18.41±1.5 MPa) followed by (UC) test group (11.52±.99MPa). While the lowest mean SBS was observed for (CG) (4.00 ±.59 MPa). There was statistically significant difference between (SCG) and other groups (CG, UCG, ICG) (p=0.0001). There was no statistically significant difference between IC and UC test groups (p=0.2941). Conclusion: Within the limitation of the present study, the bond strength of self-adhesive resin cement to hybrid ceramics increased by different surface cleaning protocols.

Effects of Heat Source Temperature, Nanostructure, and Wettability on Explosive Boiling of Ultra-Thin Liquid Argon Film Over Graphene Substrate: A Molecular Dynamics Study

Background: The study on explosive boiling phenomenon has received increasing attention because it involves many industries, such as advanced micro-, nano-electromechanical and nano-electronic cooling systems, laser steam cleaning, and so on. Objective: In the present work, the explosive boiling of ultra-thin liquid film over two-dimensional nanomaterial surface in confined space with particular emphasis under the three different influencing factors: various heights of nanostructures, various wetting conditions of solid-liquid interface as well as various heat source temperatures. Methods: Molecular Dynamics simulations (MDs) in present work have been adopted to simulate the whole explosive boiling process. Results: For different heat source temperature case, the higher the heat temperature is, the less time the explosive boiling spends after relaxation. For nanostructure case, nanostructure surface significantly increases heat transfer rate and then leads to the increase of phase transition rate of explosive boiling. For different wetting property case, the increase of surface wettability results in an increase of phase transition to some degree. Conclusion: The addition of nanostructures, the higher heat source temperature and good wettability between thin liquid film and substrate surface dramatically improve thermal heat transfer from solid surface to liquid film, which will give rise to explosive boiling occur. In addition, the non-vaporized argon layer still exists in these three factors despite continuous thermal transmission from the substrate surface to liquid argon film adjacent to the solid surface even other vaporized argon atoms.

The efficacy of convenient cleaning methods applicable for customized abutments: an in vitro study

BackgroundThe demand for implant dentistry, which includes customized abutments, is increasing. A lot of pollutions are generated on the customized abutment surface following milling procedure. This study evaluated the surface topography and cleanliness of customized abutments after cleaning procedures, which are simply applicable in the dental clinic.MethodsThirty computer-aided design and computer-aided manufacturing internal connection type titanium abutments were produced, milled, and randomly divided into 3 groups: steam cleaning (control group), chlorhexidine (CHX) scrubbing (test group 1), and ultrasonic cleaning with CHX solution, acetone, and ethyl alcohol (test group 2). Each group was evaluated using microscopic and microbial analysis.ResultsForeign bodies were observed on the abutment surfaces in control group and test group 1, but not in test group 2. Bacteria were observed on 40% of the agar plates following steam cleaning; most of the colonies consisted of Bacillus cereus and Staphylococcus warneri. Colony growth was absent following test group 1 and 2.ConclusionFor customized abutments, cleaning with steam is ineffective. CHX scrubbing effectively eliminates only bacteria. Ultrasonic cleaning with CHX solution, acetone, and ethyl alcohol successfully removes both foreign bodies and bacteria. Thus, the ultrasonic cleaning method is conveniently applicable in the dental clinic for eliminating contamination of the customized abutment surface.

Enjoyment of watching pimple popping videos: An fMRI investigation

BackgroundMillions of people enjoy watching videos of pimple treatments. The underlying neural mechanisms of this enjoyment have not been investigated so far. MethodWe administered a total of 96 video clips from three categories: Pimple Popping (PP), Water Fountains (WF), and Steam Cleaning (SC). The PP videos showed a pimple or blackhead that was opened to squeeze out the pus or sebum. The female participants (mean age: 24 years) were assigned to one of two groups: females who reported to enjoy watching PP (PPE_high; n = 38) and those with little enjoyment (PPE_low; n = 42). We analyzed brain activity in regions of interest (ROI) involved in the encoding of pleasure and aversion (e.g., nucleus accumbens (NAc), insula). ResultsThe PPE_high group showed less deactivation of the NAc (ROI finding), more frontopolar activation (whole-brain finding), and stronger accumbens-insula coupling than the PPE_low group. ConclusionsA specific pattern of brain activity and connectivity that involves the NAc and insula (coding of aversion/pleasure) and the frontopolar region (prediction of outcomes of motor decisions) is associated with the enjoyment of PP videos.

Effect of 5 Popular Disinfection Methods on Microflora of Laboratory: Customized Implant Abutments.

To compare the efficacy of 5 different decontamination methods of titanium abutments and to assess their possible effects on surface roughness of titanium. Micrococcus luteus, Acinetobacter baumannii, Enterococcus faecalis, and Candida albicans were cocultured to form a multispecies biofilm on 18 titanium discs. In another group, Bacillus subtilis, a spore-forming species, was cultivated on another set of 18 titanium discs. Each group was further divided into 5 test groups: high-pressure steam cleaning (4 Mpa, 5 seconds), NaOCl (1% active chlorine, 5 minutes), H2O2 (3%, 5 minutes), GaAlAs laser (810 nm, CW, 1 W, 400-μm fiber, 1-mm distance, 1 minute), Er:YAG laser (2940 nm, pulse mode, 100 mJ, 10 Hz, 230-μm noncontact handpiece, 4-mm distance, 50/50% air/water, 1 minute), and a control group of no treatment. After each decontamination procedure, the remaining microbial load was reported as colony-forming unit/disc. To evaluate the effect of each treatment on titanium discs, surface roughness parameters including Sa, Sq, Ssk, Sku, Sal, and Sdr were measured at 6 points of each disc using an atomic force microscope. Complete disinfection was achieved using high-pressure steam, NaOCl, H2O2, and Er:YAG laser. GaAlAs laser was able to reduce microbial count over 90%. Sa and Sq parameters were only increased significantly in diluted NaOCl group in comparison with control group, whereas Sdr was increased significantly in both absolute and diluted NaOCl groups. All the methods could decontaminate machined titanium surfaces, although complete microbial elimination was not achieved by diode laser. None of the treatments altered surface roughness significantly, except for sodium hypochlorite (NaOCl).

In-Process Steam Cleaning of Ceramic Membranes Used in the Treatment of Oil Sands Produced Water

Current oil sands extraction technologies expend a significant amount of energy in the treatment and recycling of the oily process waters that are generated during the extraction process. Ceramic membranes are promising candidates for enhancing the energy efficiency of the produced water deoiling process due to their low energy requirements. However, membrane fouling by bituminous solids remains a significant barrier to the widespread acceptance of membranes in this application. As an alternative to chemical membrane cleaning, a steam regeneration technique was applied to ceramic membranes in the filtration of steam-assisted gravity drainage (SAGD) produced water. This technique involved the periodic injection of steam directly into the membrane feed channels, and was applied in conjunction with conventional permeate backflushing. Tubular multilumen ceramic membranes with titania selective layers having pore sizes of 5 or 10 nm were used. Support layers were composed of either alumina or titania. Optimal transmembrane pressure and crossflow velocity settings were found to be 50 psi and 1 m/s over the investigated ranges. Membrane permeate fluxes increased from 50 to 200 Lmh when the steam regeneration method was activated. Flux enhancement was found to depend on the initial duration of filtration without steam injection, which results in significant irreversible fouling. Steam regeneration also improved membrane separation performance, increasing total organic carbon, sulfate and chloride retention by as much as 19%, 17% and 10%, respectively. Steam regeneration is a continuous in-process method that offers the possibility of recycling the oleophilic cake released from the surface of the membrane. The cake can be sent to a flotation unit upstream of the membrane system, allowing bituminous fines to be entrained in the main oil stream. This offers many possibilities for waste minimization, particularly in remote areas where cleaning fluids that are produced when membranes are chemically cleaned would need to be transported and treated off-site.

Occupational asthma; the limited role of air-fed respiratory protective equipment

Evidence-based reviews have found that evidence for the efficacy of respiratory protective equipment (RPE) in the management of occupational asthma (OA) is lacking. To quantify the effectiveness of air-fed RPE in workers with sensitizer-induced OA exposed to metal-working fluid aerosols in a car engine and transmission manufacturing facility. All workers from an outbreak of metal-working fluid-induced OA who had continuing peak expiratory flow (PEF) evidence of sensitizer-induced OA after steam cleaning and replacement of all metal-working fluid were included. Workers kept 2-hourly PEF measurements at home and work, before and after a strictly enforced programme of RPE with air-fed respirators with charcoal filters. The area-between-curve (ABC) score from the Oasys plotter was used to assess the effectiveness of the RPE. Twenty workers met the inclusion criteria. Records were kept for a mean of 24.6 day shifts and rest days before and 24.7 after the institution of RPE. The ABC score improved from 26.6 (SD 16.2) to 17.7 (SD 25.4) l/min/h (P > 0.05) post-RPE; however, work-related decline was <15 l/min/h in only 12 of 20 workers, despite increased asthma treatment in 5 workers. Serial PEF measurements assessed with the ABC score from the Oasys system allowed quantification of the effect of RPE in sensitized workers. The RPE reduced falls in PEF associated with work exposure, but this was rarely complete. This study suggests that RPE use cannot be relied on to replace source control in workers with OA, and that monitoring post-RPE introduction is needed.

The Influence of an Ultrasonic Cleaning Protocol for CAD/CAM Abutment Surfaces on Cell Viability and Inflammatory Response In Vitro.

To evaluate the effect of an ultrasonic cleaning and disinfection method for CAD/CAM abutment surfaces on cell viability and inflammatory response in vitro. Untreated and manually polished surfaces of CAD/CAM generated titanium and zirconia disks were randomly assigned, either to a 3-step ultrasonic cleaning and disinfection process (test: TiUF, TiPF, ZrUF, ZrPF) or to 30 sec steam cleaning (control: TiUS, TiPS, ZrUS, ZrPS). Pre-cleaning surface analyses using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and surface profilometry were performed. Human gingival fibroblasts (HGFs) were cultured on test and control specimens and subsequently examined for cell viability and inflammatory response. Expression of acute inflammatory cytokine interleukin (IL)-6 and vascular endothelial growth factor A (VEGFA) were assessed by means of RT-qPCR. Cells on all specimens exhibited a satisfactory viability, indicating firm attachment. Cells on polished zirconia samples, cleaned by means of sonication (ZrPF), exhibited significantly higher viability than cells on the same material cleaned by steam (ZrPS), p=0.019. For all other three material/ surface treatment combinations (TiU, TiP, ZrU), no such difference was observed between the cleaning methods. The messenger ribonucleic acid (mRNA) levels of IL-6 and VEGFA were between 50 and 105% of that of the control cells on the non-toxic control surface. mRNA levels of IL-6 and VEGFA correlated well with each other. Except for higher viability of cells cultured on polished zirconia specimens, no universally applicable advantage could be found for the ultrasonic cleaning procedure for zirconia and titanium abutment surfaces regarding cell viability, IL-6 expression or VEGFA expression. The cleaning procedures did not have any negative effect either.

정수처리용 세라믹 분리막의 막오염 물질의 제거 효율 향상을 위한 스팀세정 기법 개발

정수처리용 세라믹 분리막의 막오염 물질의 제거 효율 향상을 위한 스팀세정 기법 개발