Effect Of Polishing Research Articles

Concealing Meets Healing in the Treatment of Toenail Onychomycosis: A Review of Concurrent Nail Polish Use With Topical Efinaconazole 10% Solution

Introduction: Females are more likely than males to seek help or treatment for onychomycosis and are more likely to camouflage affected nails with nail polish. Between 2016 and 2022, over half of prescriptions for topical efinaconazole 10% solution were written for females, suggesting that there may be particular interest in the interaction between nail polish use concurrent with efinaconazole treatment for onychomycosis.
 Methods: Review in vitro data on effects of nail polish on nail penetration of efinaconazole 10% solution and clinical studies on the impact of nail polish use on efficacy of topical efinaconazole in the treatment of toenail onychomycosis.
 Results: Only 4 small studies have assessed interactions between efinaconazole 10% solution and concurrent nail polish use. In vitro, penetration of efinaconazole 10% solution through cadaverous human nails coated with traditional nail polish was similar to penetration through uncoated nails. In a 1-year clinical study, once-daily efinaconazole treatment for 48 weeks was associated with improvements in onychomycosis severity and clear toenail growth that were similar for participants who used traditional nail polish and those who did not use nail polish. In a second, 6-month clinical study, participants received once-daily efinaconazole treatment concurrent with monthly gel nail polish pedicures. After 6 months, 100% of participants tested negative for fungal infection (mycological cure) and all participants experienced visible improvements in their treated toenails. In clinical and in vitro studies, efinaconazole application was associated with degradation of traditional nail polish texture and appearance as well as color transfer to the applicator and unused medication. In contrast, efinaconazole did not affect the duration, quality, or texture of gel nail polish.
 Conclusions: Application of nail polish did not prevent penetration of efinaconazole 10% solution through human nails or its successful use in the treatment of toenail onychomycosis. Further, efinaconazole did not impact the texture or appearance of gel-polished nails. To our knowledge, these findings represent the only available data on topical treatment of toenail onychomycosis with concurrent nail polish use, and may be of particular importance when selecting treatment options for female patients with onychomycosis.
 Funding: Ortho Dermatologics

Impact of thermo-oxidative aging on the dry tribological performance and wear mechanisms of UHMWPE/ZrO2 friction pairs

Ultra-high molecular weight polyethylene (UHMWPE) is esteemed for its superior wear resistance, making it a preferred material in various applications, including artificial joints, dental materials, and mechanical components. This study elucidates the effects of thermo-oxidative aging on the dry tribological performance and wear mechanisms of UHMWPE and zirconia (ZrO2) friction pairs using dynamic friction wear tests, scanning electron microscopy, and energy-dispersive x-ray spectroscopy. Results reveal that thermo-oxidative aging significantly compromises wear resistance and alters the degradation mechanisms of UHMWPE. The unaged UHMWPE exhibits exceptional wear resistance, indicated by minimal wear and pronounced polishing effects. Post-aging at 40 °C leads to the formation of fine scratches and rougher wear marks on UHMWPE surfaces, with the predominant wear mechanism transitioning from abrasive wear to fatigue wear as the number of cycles increases. Upon aging at 70 °C, more extensive spalling and pitting damages occur on UHMWPE, indicating more severe thermo-oxidative and wear damages that primarily exhibit fatigue wear and oxidative wear patterns. Notably, aging at 40 °C results in a friction coefficient increase to ∼0.165, whereas aging at 70 °C decreases the friction coefficient to around 0.118, indicating a complex relationship between aging temperature and tribological behavior. This research provides valuable insights into predicting and improving the durability of UHMWPE components used in orthopedic applications, thereby contributing to optimizing orthopedic implant materials for enhanced patient outcomes.

Effect of dry and wet finishing and polishing on color change and opacity of nanofill and nanohybrid composites

BackgroundAs superior esthetic is one of the main reasons for using composite resins, it is very important to be familiar with factors and techniques affecting their optical properties and appearance.AimThe aim of this study was comparing the effect of finishing and polishing with and without water coolant, on the color change and opacity of composite resin materials.MethodsComposites used for preparing samples were Z250 (microhybrid), Z350XT (nanofilled), and Z550 (nanohybrid). Then divided into 4 groups of 5 depending on finishing and polishing technique (dry or wet) and time (immediate and after twenty-four hours). After polishing, samples were assessed using a spectrophotometer. Color change and opacity were determined. Data was analyzed using Kolmogorov-Smirnov, ANOVA and Tukey HSD tests.ResultsType of material at both time had a significant effect on ΔE and opacity. Our results in dry and wet technique immediately(T0) showed that the highest and lowest ΔE and opacity belong to Z350XT (p < 0.001). After Twenty-four hours (T24), opacity of Z250 in wet condition was higher than dry condition (p < 0.001).ConclusionsWet or dry technique was only effective on color in immediate polishing. Regarding opacity, technique was only effective in case of delayed polishing.

Pulsed Laser Manufactured Heteroatom Doped Carbon Dots via Heterocyclic Aromatic Hydrocarbons for Improved Tribology Performance.

Traditional laser-assisted method (top-down synthesis strategy) is applied in the preparation of carbon dots (CDs) by cutting larger carbon materials, which requires harsh conditions, and the size distribution of the CDs is seldom monodisperse. In this work, heteroatom-doped CDs, represented by N,S co-doped CDs (N,S-CDs), can be prepared successfully by pulsed laser irradiation of heterocyclic aromatic hydrocarbons-based small molecule compound solution. The friction coefficient (COF) of base oil PAO decreases from 0.650 to 0.093, and the wear volume reduces by 92.0% accompanied by 1 wt.% N,S-CDs addition, while the load-bearing capacity is improved from 100 to 950 N. The excellent lubrication performance is mainly attributed to the formation of a robust tribofilm via a tribochemical reaction between N,S-CDs and friction pairs, and the N,S-CDs can play a mending effect and polishing effect for worn surfaces. Furthermore, the lubricant containing heteroatom doped CDs are capable of being prepared in situ via pulsed laser irradiation of heterocyclic aromatic hydrocarbons in base oil, which can avoid the redispersed problem of nano-additive in base oil to maintain long-term dispersion, with COF of 0.103 and low wear volume ≈1.99 × 105 µm3 (76.9% reduction) even after standing for 9 months.

Evaluation of the effectiveness of polishing pastes used in teeth whitening

INTRODUCTION. To increase the effectiveness of preventive procedures, it is important to choose the right professional hygiene products. The most common complaint after professional oral hygiene is hypersensitivity of the teeth.AIM. To study the effectiveness of various polishing pastes.MATERIALS AND METHODS. The research was conducted on the basis of the Department of Therapeutic Dentistry of the Research Medical University, Nizhny Novgorod, the cytological laboratory, Dental Polyclinic No. 1 (Ryazan). A dental examination was performed on 39 patients of both sexes aged 18 to 45 years with discoloritis of hard tissues, who were exposed to harmful industrial factors and did not have dental hyperesthesia. The control consisted of 13 practically healthy people who do not work in hazardous industries from Ryazan. The patients underwent professional hygiene using 3 types of polishing pastes (based on corundum, perlite, R.O.C.S. PRO POLISHING toothpaste), depending on which the patients were divided into 3 groups of 13 people each.RESULTS. In all 3 groups, there was a significant difference in the values of IGZ, IRGZ, Schiff and VAS samples from the initial ones (p &lt; 0.05), i. e. hyperesthesia of varying degrees appeared after professional hygiene. The most significant differences between IIGZ, IRGZ, Schiff’s sample and VAS were revealed in groups 1 and 3, the Schiff sample revealed significant differences between groups 1 and 2, differences in the values of IIGZ, IRGZ and VAS were also recorded in groups 1 and 2 of observation. The most pronounced hyperesthesia was observed when using Corundum–based polishing paste, and the minimum was R.O.C.S. paste PRO POLISHING.CONCLUSION. The existing harmful production factors in workers lead to structural changes in the enamel. When carrying out occupational hygiene for people working in hazardous industries, the most preferable is the use of a paste based on ultrafine silicon dioxide.

Effect of Polymerization Unit, Polishing, and Coffee Thermocycling on the Color and Translucency of Additively Manufactured Resins Used for Definitive Prostheses.

To evaluate the effect of polymerization unit, polishing, and coffee thermocycling on the color and translucency of additively manufactured polyurethane-based resins with different viscosities. In addition, their color behavior was compared with the color of the shade tab throughout the fabrication steps and aging. Disk-shaped specimens (Ø10 × 2 mm) were fabricated from polyurethane-based resins with different viscosities (Tera Harz TC-80DP and C&B permanent; n = 30 per material). Baseline color coordinates were measured after cleaning. The specimens in each resin group were divided into three subgroups (n = 10 per subgroup) to be polymerized with different polymerization units (Otoflash G171 [FLN], Wash and Cure 2.0 [CLED1], and P Cure [CLED2]), polished, and subjected to coffee thermocycling. Color coordinates were remeasured after each process. Color differences (ΔE00) and relative translucency parameter (RTP) values were calculated. Data were statistically analyzed (α = .05). Time points and polymerization units affected the ΔE00 for each material (P ≤ .049). ΔE00 of each polymerization unit pair had significant differences within and among different time points within each material (P ≤ .024). ΔE00 (when compared with the shade tab) and RTP were mostly affected by polymerization units and time points within both materials (P ≤ .042). Tested polymerization units, polishing, and coffee thermocycling affected the color difference and translucency of tested resins. Color differences ranged from moderately unacceptable to extremely unacceptable, and the differences in translucency values mostly ranged from perceptible to unacceptable, according to previous thresholds. In addition, tested resin-polymerization unit pairs had unacceptable color differences when compared to the shade tab. CLED1 may enable higher color stability for tested resins.

Trivalent lanthanum and ytterbium doped meso-silica/ceria abrasive systems toward chemical mechanical polishing (CMP) and ultraviolet irradiation-assisted photochemical mechanical polishing (PCMP)

Ceria (CeO2)-based abrasives are widely utilized in ultra-precision grinding and chemical mechanical polishing (CMP) applications over silica materials due to their unique physicochemical properties. Both mechanical and chemical contributions to polishing processes are highly affected by the size, shape, structure, component, defect of CeO2 abrasives. Herein, the composites involved mesoporous silica (mSiO2) cores and La- or Yb-doped CeO2 shells were synthesized and characterized in terms of X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, scanning transmission electron microscopy–energy dispersive X-ray mapping methods. The polishing effectiveness of the proposed composites toward quartz glass was experimentally evaluated under both CMP and ultraviolet irradiation-assisted photochemical mechanical polishing (PCMP) conditions. The polishing results indicated that the low-modulus mSiO2 cores strongly exerted the cushion effects for the friction and abrasion to substrates. Consequently, the heterostructured mSiO2/La-CeO2 and mSiO2/Yb-CeO2 abrasive systems offered nearly non-damage and ultra-smooth surfaces with angstrom-level roughness compared to conventional rigid abrasives. The enriched Ce3+ and oxygen vacancy defects at La- and Yb- doped CeO2 surfaces were responsible for the improvements of tribochemical and photochemical activities, thus allowing evidently enhanced removal efficiency with the assistance of ultraviolet irradiation. A possible polishing mechanism on the multi-component abrasive systems was also proposed.

Effect of different finishing and polishing systems on surface properties of universal single shade resin-based composites

BackgroundRecently, universal single-shade resin composites have become increasingly available in the dental market. The modification of their composition can have an inadvertent effect on their physical and surface properties, and subsequently determinantal effect on their clinical function and longevity. Therefore, this study aimed to evaluate the effect of different finishing and polishing (F/P) systems on surface roughness (Ra), surface gloss (GU), and Vickers microhardness (VMH) of universal single-shade RBCs.Materials and methodsFour commercial RBCs were used; the universal single-shade RBCs were Omnichroma, Charisma® Diamond ONE, and Vittra APS Unique, and a conventional nanocomposite Filtek™ Z250 XT was used as a control. The 3 F/P systems were Sof-Lex™ XT, Enhance®/PoGo®, and Diacomp® Plus Twist. A total of 160 discs were used for the 3 F/P system groups for all RBCs (n = 10). After F/P, the Ra, GU, and VMH were assessed. The data were analyzed using 2-way ANOVA at p-value < 0.05.ResultsSignificant differences were found among the four RBCs and the 3 F/P systems (p < .000). Omnichroma showed the lowest Ra and acceptable GU, but the lowest VMH. Charisma showed the highest Ra, acceptable GU, and VMH. Vittra showed acceptable Ra, GU, and VMH and Filtek showed the highest GU, VMH, and acceptable Ra.ConclusionAlthough conventional nanohybrid RBC (Filtek Z250 XT) showed better GU and VMH values, the universal single-shade RBCs demonstrated comparable surface properties. The highest GU & VMH and lowest Ra were achieved by Diacomp followed by Enhance and Soflex.

Effect of polishing versus glazing of CAD-CAM ceramics on wear and surface roughness of opposing composite resin

Background: This study aimed to assess the effect of polishing versus glazing of computer-aided design-computer-aided manufacturing (CAD-CAM) ceramics on depth of wear and surface roughness of opposing composite resin. Materials and Methods: This in vitro study was conducted on 40 Z250 composite and 40 CAD-CAM ceramic specimens including Celtra Duo, Vita Mark II, e.max CAD, and Vita Suprinity ceramics. All ceramic specimens were roughened by a fine-grit bur after primary glazing to simulate an adjusted surface in the clinical setting. They were then randomly assigned to two subgroups and underwent reglazing or polishing. All composite and ceramic specimens underwent profilometry after surface treatment and prior to the wear test, and the results were recorded quantitatively. Composite specimens were then subjected to 120,000 wear cycles against ceramic specimens in a chewing simulator, and the depth of wear was measured by a scanner. Data were statistically analyzed by repeated measures two-way analysis of variance (ANOVA) and one-way ANOVA (α = 0.05). Results: Comparison of the surface roughness of composite specimens before and after the wear test revealed significant differences in both glazed Suprinity (P = 0.048) and Vita Mark II (P = 0.026) ceramics groups. The change in surface roughness after the wear test (compared with baseline) was significant in glazed (P = 0.000) and polished (P = 0.013) Vita Mark II and polished Suprinity (P = 0.037) ceramics, but this change was not significant in other ceramics (P &gt; 0.05). The depth of wear after the wear test was not significantly different among the ceramic and composite subgroups (P &gt; 0.05). Conclusion: Assessment of depth of wear and surface roughness of composite specimens showed that the polishing kits of CAD-CAM ceramics can serve as a suitable alternative to reglazing.

Comparative study on the effects of different polishing methods on tooth surface microstructure and roughness following initial periodontal treatment.

To investigate the effects of different polishing methods on the surface microstructure and roughness of teeth following initial periodontal treatment. Teeth were divided into three groups (silica onegloss, polishing disc, and polishing strip) in vitro. Tooth surface microstructure was characterized via scanning electron microscopy. Roughness was measured by profilometry and laser scanning confocal microscopy (LSCM). According to the in vitro results, one group was chosen for further clinical trials. Effects of the chosen polishing method on patient plaque control and satisfaction were assessed via plaque staining and visual analog scale (VAS). Electron microscopy results revealed that the polishing disc group had smoother roots and crowns than did the other two groups. Roughness analysis revealed that the crown roughness with the polishing disc and silica onegloss was lower, and the root roughness with the polishing disc was the lowest (p < .05) The LSCM results showed that the pigment deposition depth with the polishing disc and silicon onegloss in the crowns and roots were significantly lower than those with the other two methods (p = .000). The polishing effect of the polishing disc was best among the three groups. Clinical trials were performed to verify the polishing disc effects. Plaque staining results showed that the decrease in plaque in the polishing disc group was greater than that ofthe rubber cup group (p = .020), which was similar to the results of LSCM. The VAS results showed that the polishing disc made teeth feel smoother, similar to the results of the roughness detection, and the procedure was more comfortable (p < .05). However, there was no significant difference between the two groups regarding foreign body sensation during pronunciation (p = .178). Combining in vitro and in vivo evaluations, the use of a polishing disc following periodontal treatment yielded superior polishing effects on teeth and was better accepted by patients.

Investigation on Enhanced Machinability of SiC Ceramics through Photocatalytic Vibration Composite Polishing.

The problems of low polishing efficiency and serious surface damage in the processing of silicon carbide (SiC) ceramics are well-known. In view of the above problems, a new method of photocatalytic vibration composite polishing (PVCP) combined with a compound control strategy was proposed. A vibration-assisted device was developed, and a compound control system was designed for the device to improve the trajectory tracking accuracy. Experiments were carried out to verify the effectiveness of the vibration-assisted device and the compound control system. In addition, methyl orange degradation and fading experiments, redox potential measurement experiments, and SiC ceramic surface hardness characterization experiments were carried out to reveal the effects of vibration and photocatalytic parameters on polishing solution oxidation and SiC ceramic surface mechanical properties. Finally, the effects of photocatalysis, vibration frequency, amplitude, and the compound control system on the polishing effect were analyzed. The results show that when the UV intensity is 100%, the polishing force is 3-4N, the vibration frequency is 400 Hz, the amplitude is 15 μm, and the surface roughness of SiC ceramics is reduced by about 11 nm after the introduction of the compound control system, which verifies the effectiveness of the combination of the compound control system and PVCP.

Effects of air abrasive polishing on chromium ion release from different metal self-ligating orthodontic brackets

Treatment with fixed orthodontic appliances compromises the oral hygiene and increases the risk of plaque related disorders and dental staining in addition to corrosion and corrosion byproduct: ions. The aims this study was assessment the effects of air polishing on Chromium ion (Cr) release from stainless steel self-ligating brackets.&#x0D; one hundred and sixty self-ligating stainless-steel brackets of four brands Damon® Q™ (Damon® Q™, Ormco, Orange, CA, USA), Discovery® SL 2.0 (Dentaraum, Ispringen, Germany), Leone® F1000 (SLB; F1000, Leone SpA, Sesto Florentino, Florentino, Italy) and Lotus Plus® (Lotus plus, Orthotechnology co., Brazil) were exposed to different time of air abrasion polishing (0, 5, 10, 20 seconds) then immersed in artificial saliva with pH value 6.75 and incubated at 37°C for 28 days. Cr ion release was assessed using atomic absorption spectrophotometer at 7, 14 and 28 days and accumulative effect was calculated. Scanning electron microscope (SEM) were used to assess the surface changes and microtopography after polishing for randomly selected sample. Analysis of variance test (ANOVA), and Tukey’s (HSD) test were used to identify the significant difference among the studied groups where the level of significance set as P ≤ 0.05.&#x0D; The results revealed that all brands showed significant increase in Cr ion release concomitant with an increase in the polishing time. Damon® Q™ show the greatest amount of Cr ion release&#x0D; Conclusion: The air polishing procedure enhanced the amount of Cr ion release to a subtoxic level and could be used in adult patients using 5 sec. recommended time of polishing with prolonged intervals between the visits.

Anode surface pretreatment to optimize electrochemical performance of aqueous zinc-ion batteries

The aqueous zinc-ion batteries (AZIBs) exhibit promising potential as a viable solution for large energy storage. Solving dendrite growth the surface of zinc metal anode in AZIBs is of great significance for its application in energy storage field. Among the many strategies for solving the zinc anode problem, the influence of zinc anode pretreatment is often ignored. The effect of sandpaper physical polishing on the performance of zinc anode was studied in this paper. The striated grooves formed on the surface of the zinc anode after sandpaper treatment make the zinc anode have a large specific surface area and a high zinc plating/stripping kinetics. It was found that sandpaper with larger mesh count (the finer the sandpaper) could reduce roughness and had the higher the electrochemical performance of zinc anodes. Consequently, the cycle life of 2000 M-Zn symmetric battery can reach 900 h under the current density of 0.5 mA cm−2. In the application of energy storage, the full battery composed of 2000 M-Zn and sodium doped V2O5 cathode (NVO) still has a specific capacity of 148.6 mAh g−1 after 500 cycles, and has a stable rate performance. The pretreatment strategy of zinc anode holds significant importance in the applications of AZIBs.

Evaluation of tribological efficacy and EP lubricity properties of gear oil (EP90) energized with molybdenum disulfide (MoS2) nano-additives

The practice of employing efficient lubricants involving functional additives has become imperative in order to enhance engine efficiency, to say the least. The span of an engine’s life can be greatly enhanced by gear oil’s tribological and thermo-physical properties. Addressing the tribological management of gearbox components within the mechanical sector is a dire necessity. In a quest for exceptional nanolubricants with improved serviceability, present manuscript deals with the dispersion of metallic-sulphide nano dispersants in gear oil lubricant. Nanolubricants were prepared by dispersing molybdenum disulfide nanoparticles (MoS2 Nps) in gear oil with varying concentrations of 0.1%, 0.3%, and 0.5% by volume (v/v). Then nanolubricants’ thermo-physical properties were assessed and contrasted with those of plain gear oil. This was followed by the measurement of the tribological and extreme pressure properties of the nanolubricant samples on a four-ball tester. According to the findings, as compared to gear oil, the prepared nanolubricant yielded a maximum reduction of 9.21% and 9.38% in coefficient of friction and an average wear scar diameter, respectively. A maximum augmentation of 12% in weld load was obtained with 0.3% nanolubricant sample. The wear scar on the steel balls was examined using field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscope (EDS). The investigations revealed the presence of ball bearing and surface polishing effects as dominant lubricating mechanisms, which potentially contribute to the enhanced tribological properties of the oil. Hence, adding MoS2 Nps in gear oil may solve many engineering problems related to the lubricity of the base oil.

Electrolic plasma polishing of complex parts in magnetic field

The article discusses a new technology of electrolyte-plasma polishing (EPP) of turbomachine parts with the imposition of an external magnetic field, which improves the quality of the surface layer. The results of experimental studies of the effect of electrolytic-plasma polishing of blades made of titanium alloy VT6 with the imposition of an external magnetic field are presented, indicating the prospects of using the proposed EPP method for processing parts of complex configuration, as well as the possibility of increasing the stability of the EPP process with the introduction of a magnetic field as an additional technological factor.

Large-area single-crystal TMD growth modulated by sapphire substrates.

Transition metal dichalcogenides (TMDs) have recently attracted extensive attention due to their unique physical and chemical properties; however, the preparation of large-area TMD single crystals is still a great challenge. Chemical vapor deposition (CVD) is an effective method to synthesize large-area and high-quality TMD films, in which sapphires as suitable substrates play a crucial role in anchoring the source material, promoting nucleation and modulating epitaxial growth. In this review, we provide an insightful overview of different epitaxial mechanisms and growth behaviors associated with the atomic structure of sapphire surfaces and the growth parameters. First, we summarize three epitaxial growth mechanisms of TMDs on sapphire substrates, namely, van der Waals epitaxy, step-guided epitaxy, and dual-coupling-guided epitaxy. Second, we introduce the effects of polishing, cutting, and annealing processing of the sapphire surface on the TMD growth. Finally, we discuss the influence of other growth parameters, such as temperature, pressure, carrier gas, and substrate position, on the growth kinetics of TMDs. This review might provide deep insights into the controllable growth of large-area single-crystal TMDs on sapphires, which will propel their practical applications in high-performance nanoelectronics and optoelectronics.

Effect of abrasive on tribological behavior and polishing effect of β-Ga2O3(100) substrate

Given the problems of easy cleavage and unfavorable surface integrity in the processing of β-Ga2O3(100), the effects of abrasive type (diamond, silicon carbide, alumina, cerium oxide) and abrasive particle size (W3, W2, W1, W0.5) on substrate processing were investigated via friction and polishing experiments. The results demonstrated that a strong correlation exists between the surface integrity of the β-Ga2O3(100) substrate and abrasive type, and it was determined that the diamond abrasive with sharp cutting edges was optimal. The abrasive particle size significantly affected the friction wear and polishing effect of β-Ga2O3(100). The use of fine abrasive particles can effectively inhibit the formation of cleavage pits and scratches. After polishing with the W0.5 diamond, the surface roughness (Ra) of the substrate decreased to 3.8 nm, and the scratch depth decreased to 18 nm. The abrasive particle size significantly affected the friction wear and polishing effect of β-Ga2O3(100). The shape and size of the abrasive are crucial factors affecting the processing of the β-Ga2O3(100) substrate. The diamond abrasive particle size distribution was uniform, and the axial ratio of the abrasive was predominantly between 0.6 and 0.9. The surface material of the substrate was removed via the “three-body rolling” method, so the polishing effect was optimal.

Effect of air abrasive polishing on nickel release, stainless steel corrosion, and nickel-titanium archwires.

Orthodontic treatment is becoming more and more popular. However, using fixed orthodontic devices for treatment affects oral hygiene and raises the risk of corrosion, plaque-related illnesses, and dental discoloration-related issues. Air abrasive polishing has a superior effect over the conventional method in removing dental deposits. Using fixed orthodontic appliances affects oral hygiene and raises the risk of diseases caused by plaque, tooth discoloration, and corrosion, as well as corrosion by ions. This study evaluated the impact of air polishing on nickel ion release and corrosion from stainless steel, nickel-titanium, coated stainless steel, and coated nickel-titanium. A total of 288 (stainless steel, coated stainless-steel, nickel-titanium, and coated nickel-titanium rectangular archwires) of one brand were subjected to varying air abrasion polishing times (5, 10, and 20 seconds). Then, they were submerged in artificial saliva with a pH of 6.75 and incubated for 28 days at 37 °C. The release of nickel ions (Ni2+) was measured using an atomic absorption spectrophotometer at 7, 14, and 28 days to estimate the cumulative effect. The corrosion of the test-selected samples and surface alterations was evaluated using scanning electron microscopy (SEM). Prolonged polishing significantly increased Ni2+ release and corrosion. Archwires made of coated stainless steel exhibited the least amount of Ni2+ release. The air polishing process increased the Ni2+ release at a subtoxic level and could be used on adult patients with long gaps between visits with a polishing period of 5 seconds.

Tribological Properties and Lubrication Mechanisms of Water-Based Nanolubricants Containing TiO2 Nanoparticles during Micro Rolling of Titanium Foils.

The tribological behavior of traditional oil-in-water (O/W) lubricants (1.0 wt.%) and nano-TiO2 additive lubricants (1.0-9.0 wt.%) during micro rolling of titanium foils were analyzed. In this study, the surface morphologies of titanium foils under various lubrication conditions were assessed, and the corresponding lubrication mechanisms were revealed. The tribological behavior of nano-TiO2 additive lubricants during micro rolling of titanium foils was also explored through a series of characterization methods. The utilization of nano-TiO2 additive lubricants in micro rolling reduces the surface roughness of titanium foils. Moreover, it effectively inhibits the generation of indentations and cracks during rolling processes, enhancing the surface quality of rolled specimens. Additionally, owing to the synergism of rolling, tribo-film, mending and polishing effects of the nanoparticles, both the rolling force and surface roughness were minimized by using lubricants containing 3.0 wt.% TiO2 nanoparticles. Overall, an optimal concentration (3.0 wt.%) of TiO2 nanoparticles in water-based nanolubricants was obtained with enhanced tribological properties and lubrication performance during micro rolling of titanium foils.

Interface smoothing in short-period W/B4C multilayers using neon ion beam polishing

Short-period 2.5 nm W/B4C multilayers are useful as dispersive Bragg reflectors in wavelength-dispersive x-ray fluorescence. However, high roughness at the W–B4C interfaces deteriorates optical performance. To improve this, low-energy neon ion beam polishing (IBP) has been applied in sputter-deposited 2.5 nm W/B4C multilayers. Two energies, 200 and 50 eV, were investigated to study the effects of polishing by sputter removal (200 eV) and polishing by the mobilization of weakly bound surface atoms (50 eV). Atomic force microscopy and x-ray scattering showed reduced interface roughness for both IBP energies. However, the optical constant profile of 200 eV IBP showed strong W–B4C intermixing and interface asymmetry, leading to significant reflectance loss. In contrast, 50 eV IBP resulted in sharp, symmetric interfaces and increased optical contrast. A 43% peak reflectance at θ = ⁓9.7° grazing for W/B4C with 50 eV IBP was measured at λ = 0.834 nm—a 6.4% increase relative to non-polished W/B4C, corresponding to a 25% increase in integrated reflectance. These results highlight the necessity of using low-energy ion polishing by the mobilization of weakly bound surface atoms in short-period multilayers—rather than polishing by sputter removal.