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This study evaluates the analysis of round inserts (Fixed and Self-Propelled Rotary Tools) when machining hardened steel. Self-propelled rotary Tools (SPRTs) exploit the entire perimeter of the insert rather than a specific cutting edge, minimizing insert wear and maximizing insert life. It is considered an environmentally friendly process. Tool and insert geometry have a direct effect on the surface roughness. Previous studies highlighted the significant effects of one inclination angle on surface roughness. Despite previous research that investigated only one inclination angle, in this research, the effect of both inclination angles has been investigated, and a new method for simultaneous application has been used. The optimal use of both inclination angles has significantly improved the quality of the machined surface. Therefore, an optimal holder has been designed and fabricated based on the cutting forces and component shapes, allowing inclination angle changes. The full factorial design of the experiment is adopted, and the effects of the horizontal and vertical inclination angles and feed rate in fixed tool and SPRT turning have been evaluated, each in 3 levels with a total of 54 experiments. The equivalent insert radius is defined using the inclination angles and an analytical model is developed concerning the equivalent insert radius to predict surface roughness. The proposed model accurately estimated roughness in fixed tool turning for an R-square of 0.81 and 0.76 for SPRT turning. In the best condition, the surface roughness has been measured at 0.472 μm in the fixed tool turning and 0.409 μm in SPRT turning.

In Laser Powder Bed Fusion (L-PBF), surface roughness is pivotal for controlling the mechanical and functional performances, as well as the geometrical accuracy of the final product. This study extensively investigated the interactions of hatch and contour processing parameters, along with contour offset distance, on vertical surface roughness for 316L stainless steel in L-PBF. Melt pool morphology and surface arithmetic average roughness (Sa) were quantified using confocal microscopy, while scanning electron microscopy was employed to interpret the detailed microstructure of surface features. Under low volumetric energy density (VED) hatch conditions (e.g., 66.7 J/mm3), varying the contour offset distance has a negatable effect on the surface roughness when the contour VED is lower than 121.6 J/mm3, remaining relatively smooth surfaces dominated by bare melt tracks with sparely attached partially melted particles. Increasing the hatch or contour VED (e.g., 166.7 J/mm3), dross formation, identified by the microstructural differences and explained by the melt pool instability and migration, is inevitable, which dictates the surface roughness with higher Sa values. The larger contour offset distance further promotes the dross occurrence with irregularity and increases Sa. Employing a low contour VED with an appropriate offset distance and adopting the contour-first scan strategy was demonstrated as an effective solution to reduce the dross formation. Through the analysis of melt pool behavior, surface topography, and microstructure, this study elucidates the mechanisms governing dominant surface characteristics under the combined influence of hatch and contour parameters. It lays the foundation for precise control of surface roughness without altering hatching parameters, enabling the tailored manipulation of performance in additively manufactured structures.

Due to their homogeneity and excellent ratio between load capacity and weight, thin-walled aluminum structures are used as structural parts in the aerospace, automotive and military industries. The manufacture of these thin-walled structures is mainly done by removing a large amount of material from full raw pieces, sometimes up to 95% of their initial mass. Because of a large volume of material removing, it is necessary to achieve high productivity, which is limited by the lack of rigidity of the thin walls of these structures. As a result, errors occur, while reducing accuracy and machining quality. The main subject and objective of this paper is related to the optimization of high-speed machining parameters of linear thin-walled structures made of aluminum alloy Al7075 from the aspect of surface quality of processed superficial as a goal function. For this purpose, experiments were carried out based on which conclusions were made of the influence of input parameters on the surface roughness.

The most frequently used method for measuring surface roughness is profilographometry. However, with complex and non-homogeneous surfaces, this method may be subject to large errors because of its contact nature and limitations related to the geometry of the measuring head. In this study, the surface topography was examined on polypropylene injection moldings produced using an injection mold with a complex molding cavity surface. The moldings were modified using a Nd:YAG laser, and the obtained structures were examined using two measurement methods, i.e. contact (profilographometry) and optical (3D digital microscopy). Researchers performed a statistical analysis to determine the differences between the measurement results obtained for the two methods. Additionally, the impact of the laser parameters on the modified surface was determined. The obtained results showed significant differences between the values of measurements made using different methods, especially in the case of surfaces that were modified by the laser beam to the greatest extent (laser A parameters). In all cases where a statistically significant difference was found between the measurement results, the mechanical method showed lower roughness values than the optical method, and the average difference between these results was 15%.

Abstract Backgrounds This study aimed to compare the effects of different energy drinks on the surface roughness, weight loss, and color change of various bioactive restorative materials. Methods Charisma Diamond One, Activa™ BioActive Restorative, Activa™ Presto™ and Equia Forte HT Fil samples were prepared using plastic molds (8 × 2 mm) (n = 10/groups). After polishing, the samples were weighed, their colors were recorded using a spectrophotometer according to the CIEDE2000 system, and their surface roughness was measured using a profilometer. The samples were immersed in Powerade, Burn, Monster and distilled water for 7 days. After immersion, all the measurements were repeated. Statistical analyses were performed using the Wilcoxon signed-rank test and the Mann‒Whitney U test (p

Abstract The energy efficiency identification of machining process plays an indispensable part in achieving energy-efficient manufacturing and improving energy utilization as well as productivity and surface quality. However, there is a great difficulty to track energy efficiency in real-time based on one kind of traditional power signal. Because energy consumption is affected by many factors such as machine tool current performance, tool wear conditions and cutting parameters selection. This paper puts forward an energy efficiency recognition method as well as surface roughness prediction model based on the cutting force signals. The CEEMDAN (Complete Ensemble Empirical Mode Decomposition with Adaptive Noise) algorithm is employed to decompose the cutting force signal into multiple IMF (intrinsic mode function) components; and characterization of energy efficiency of machining process is recognized through proportion of components based on PCA—Fast ICA algorithm. Then, a surface roughness prediction model is proposed using support vector regression (SVR) based on specific cutting energy consumption (SCEC). The orthogonal test is designed considering spindle speed, feed rate, depth of cutting and width of cutting in 3 levels to obtain the influence degree of cutting parameters on cutting force, specific energy consumption, and the surface roughness. The energy efficiency of 27 group experiments is classified into high, medium and low levels according to energy efficiency value. Finally, using the data of orthogonal test, energy efficiency state was identified. The result show that time–frequency of cutting force signals for high, medium and low energy efficiency could be extracted, and the average absolute error of surface roughness predict is 0.058. That illustrated that the proposed method could meet the industry requirement for energy efficiency monitoring and surface roughness prediction to achieve sustainable manufacturing.

Abstract Rehabilitation of pulpotomized primary molars with an appropriate restoration is essential for recovering function and safeguarding the durability of the treatment. This study aimed to assess and compare the surface roughness of stainless steel (ST) crowns, zirconia (ZR) crowns, fiberglass (FG) crowns, and lithium disilicate (LD) endo-crowns as a restoration for pulpotomized primary molars also, evaluating the surface roughness of their antagonists. Sixty pulpotomized primary mandibular first molars were used for qualitative surface roughness evaluation and divided into four groups (n = 15/group) according to the crown type (group-ST, group-ZR, group-FG, group-LD). While the other sixty sound, unprepared primary maxillary first molars were used for evaluation of their surface roughness against the tested crowns. Specimens’ preparation and cementation were carried out according to each crown type and manufacturer’s instructions. The surface roughness was done using a two-body wear test. The data were statistically analyzed. All tested crowns showed an increased change in surface roughness, except group-ZR, which had the least change in surface roughness after mechanical wear with no statistically significant difference(P = 0.681). All crown types significantly increased the surface roughness of their antagonists after mechanical wear, except group-ST which showed insignificant affection (p ≥ 0.05). Zirconia crowns and lithium disilicate endo-crowns had the least change in surface roughness compared to other groups while SSCs showed the least tooth loss in the antagonist enamel.

Abstract Achieving optimal bonding to translucent zirconia poses certain challenges as there is no consensus on ideal surface treatment method. Therefore, the aim of present investigation is to evaluate effect of Er:YAG laser treatment on wettability, surface roughness and shear-bond strength of three Yttrium oxide-stabilized zirconium-oxide polycrystal translucent zirconias. 120 specimens (n = 40/zirconia type) were prepared from three commercially-available translucent zirconias (Dentsply Sirona, USA); Translucent, High-Translucent and Ultra-Translucent zirconia. Specimens were sub-divided (n = 20/surface-treatment) into control and Er:YAG laser surface-treated groups. Regarding water wettability test; goniometer was used to measure contact angle before and after laser treatment. Surface roughness was measured using atomic force microscope. For shear-bond strength (SBS) test; the control group was sandblasted. All resin-bonded zirconia specimens were thermocycled for 5000 cycle and subjected to shear force using universal testing machine with 0.5 mm/min crosshead-speed. Results were statistically analyzed using two-way-analysis-of- variance (p ≤ 0.05). There was significant decrease in average contact angles (p-value

Abstract Resin cement integrated with zein-incorporated magnesium oxide nanoparticles has previously been found to inhibit oral microbes and decrease bacterial biofilm. However, the bond strength and surface features of this biomaterial have yet to be investigated. The objective of this study was to evaluate the shear bond strength, mode of fracture, and surface roughness of resin cement modified with zein-incorporated magnesium oxide nanoparticles. Characterization of the cement was performed by X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy. 126 human teeth were divided into 3 groups and cemented to lithium disilicate ceramic using resin cement with zein-incorporated magnesium oxide nanoparticles at concentrations of 0%, 1%, and 2% (n = 42). 21 samples of each group were subjected to the shear bond strength test, while the other 21 underwent thermocycling for 10,000 cycles before the test, after which all samples were evaluated for the mode of fracture. To assess surface roughness, resin cement disks were analyzed by a profilometer before and after undergoing thermocycling for 10,000 cycles. The shear bond strength of the cement with 1% and 2% nanoparticles was significantly higher than the control before thermocycling. The mode of fracture was found to be mainly adhesive with all groups, with the unmodified cement presenting the highest cohesive failure. There was no significant difference in surface roughness between the groups before or after thermocycling. The addition of zein-incorporated magnesium oxide nanoparticles to resin cement improved or maintained the shear bond strength and surface roughness of the resin cement. Graphical abstract

Abstract Background Patients tend to favor the whitening mouthwashes as they are easily applied and affordable. This study aimed to evaluate the effect of hydrogen peroxide versus charcoal-based whitening mouthwashes on color, surface roughness, and color stability of enamel. In the current study, the whitening mouthwashes used have the ability to stop future stains due to their white seal technology. Methods A total of 21 permanent central incisor teeth extracted for periodontal reasons were used in the present study. Teeth roots were sectioned and crowns were mounted in self-cured acrylic resin blocks. The specimens were randomly divided into three groups (n = 7) according to the tested whitening mouthwash: Control group ‟ DW” (Distilled water), ‟OW” group: Peroxide-based mouthwash (Colgate Optic White) and ‟CP” group: Charcoal-based mouthwash (Colgate® Plax Charcoal). Regarding ‟OW” and ‟CP” groups, the specimens were immersed in 20 ml of the tested mouthwash in each corresponding group for 1 min twice daily (morning and evening) for a total of 12 uninterrupted weeks. Color change was assessed using VITA Easyshade spectrophotometer and surface roughness (Ra) was measured using a white light interferometer. The specimens were stained using black tea solution and color was measured after 24 h of immersion for assessment of color stability. Results Color change results revealed that both whitening mouthwashes were able to restore color comparable to the control group with no significant difference between them. Regarding surface roughness, the control group showed the highest mean Ra value, followed by ‟OW” group while ‟CP” group showed the lowest mean Ra value. While color stability after staining, the control group showed a significantly higher value than the ‟CP” and ‟OW” groups. Conclusion Hydrogen peroxide and charcoal-based whitening mouthwashes improve the color of enamel with no adverse effect on the surface roughness. Both whitening mouthwashes were beneficial to maintain the color after staining and prevent future enamel stains.

Abstract Background The temperature changes, chemical agents, and brushing activity that resin composite restorations are exposed to in the oral environment can cause changes in surface roughness. In this study, the aim was to investigate in vitro the clinical one-year surface roughness changes of different types of composites (flowable or conventional) from the same companies by subjecting them to immersion in solutions, brushing, and thermal cycling procedures to simulate intraoral conditions. Methods Four different resin composite brands were included in the study using both their conventional (Charisma Smart, 3M Filtek Ultimate Universal, Omnichroma, Beautifil II) and flowable resin composites (Charisma Flow, 3M Filtek Ultimate Flowable, Omnichroma Flow, Beautifil Flow Plus F00), giving 4 groups with 2 types of resin composite in each. 40 samples were prepared for each group/resin type, for a total of 320 samples. After initial surface roughness measurements by a mechanical profilometer, the samples were divided into 4 subgroups (n = 10) and immersed in solutions (distilled water, tea, coffee, or wine) for 12 days. The samples were then subjected to 10,000 cycles of brushing simulation and 10,000 cycles of thermal aging. Surface roughness measurements were repeated after the procedures. For statistical analysis, the 3-way analysis of variance and the Tukey test were used (p

The implementation of three-dimensional (3D) printing technology has culminated in a notable rise in productivity and operational effectiveness for manufacturers. Additive manufacturing (AM) is a manufacturing technology that implies an alteration from the conventional approach of material removal. The fundamental idea underlying the AM technique is the gradual buildup of layers (layer-on-layer accumulation). In conventional approaches, every component can have detrimental implications due to the direct interaction between the tool and the workpiece, leading to the loss of heat through friction. The utilisation of 3D printing as a way to surpass conventional processing methods signifies a novel development in several sectors. This method involves the utilisation of unconventional techniques for the fabrication of components. The primary objective of this research is to investigate the chemical vapour jet drilling technique specifically applied to acrylonitrile butadiene styrene (ABS) materials. The intent is to enhance the surface characteristics, or surface finish (SF), and the dimensional accuracy (DA) of ABS workpieces. An evaluation regarding the reliability, repeatability, as well as preciseness of the vapour jet drilling (VJD) process is conducted via the utilisation of experiment and data analysis. The study employed a Taguchi L9 design of experiments to carry out a series of tests aimed at analysing the implications of three independent variables: pressure, flow rate, and standoff distance. The researchers employed a multiresponse optimisation approach to attain an optimal combination of parameters that resulted in a superior SF with DA. Consequently, the overall appeal of the outcome was reached. The process’s capabilities and dependability were assessed by conducting tests on the substrates at their optimal settings. Surface roughness and circularity were measured at numerous locations on the substrates. The study determined that the process capability indices (C p and C pk) had values over 1.33 for each of the response parameters, with C pk values also exceeding 1. The analysis of histograms and capability indices demonstrates that the VJD method, when conducted under optimised conditions, may be categorised as statistically controlled for the processing of ABS materials.

This study was conducted to investigate some characteristics of thermally treated Scots pine (Pinus sylvestris L.) wood specimens such as air-dried density, color change, average surface roughness, and sound absorption capacity. Heat treatment of Scots pine wood was performed at atmospheric pressure at 140, 160, 180, and 200 °C for 2 h. As a result, the air-dried density values of the thermally treated wood decreased as the temperature of the thermal treatment increased. With the increase of thermal treatment temperature, an increase in total color change values was detected on the surfaces of the samples and the color of the samples became darker. The average surface roughness (Ra) value of samples improved due to thermal treatment conditions and the highest value was determined in thermally treated samples at 200 °C as 3.59 μm. At 140 °C the value of maximum sound absorption coefficient was observed to be 0.48 at 2500 Hz and the highest sound transmission loss value, which was 36.7 dB, was measured at 6300 Hz and at 200 °C.

Abstract Background This study aimed to investigate the effect of whitening toothpastes on the color stability and surface roughness of resin composites stained with coffee and cigarette smoke. Methods Seventy-two disk-shaped specimens (6 × 2 mm) of suprananohybrid resin composite were randomly divided into two groups and exposed to coffee and cigarette smoke (n = 36). After staining, the samples randomly divided into four groups according to whitening toothpastes and were brushed for 4 min: Opalescence Whitening (OW); Colgate Optic White (COW); Curaprox Black is White (CPX) and, distilled water (control) (n = 9). Color was measured with spectrophotometer at the initial, after staining, and after brushing, and surface roughness was measured with profilometer at the initial and after brushing. A surface morphology analysis was examined using scanning electron microscopy and atomic force microscopy. The obtained data were statistically analyzed. (p

Abstract TC21 alloy is a high-strength titanium alloy that has been gaining attention in various industries for its excellent combination of strength, toughness, and corrosion resistance. Given that this alloy is hard to cut material, therefore this study aims to optimize the process parameters of Turing this alloy under different conditions (i.e. as-received alloy, and heat-treated alloy). The L9 Taguchi approach-base orthogonal array is used to determine the optimum cutting parameters and the least number of experimental trials required. The achievement of this target, three different cutting parameters are used in the experimental work; each cutting parameter has three levels. The cutting speeds are chosen as 120, 100, and 80 m/min. The feed rates’ values are 0.15, 0.1, and 0.05, mm/rev, and the depth of cut values are 0.6, 0.4, and 0.2 mm. After applying three steps of heat treatment (First step: is heating the sample to 920 °C for 1 h then decreasing to 820 °C also for 1 h, second step: cooling the sample to room temperature by water quenching (WQ), the third step: holding the sample at 600 °C for 4 h (Aging process)). The results revealed that the triple heat treatment led to the change in the microstructure from (α + β) to (α + β) with secondary α platelets (αs) formed in residual β matrix leading to a decreased surface roughness by 56.25% and tool wear by 24.18%. The two most critical factors that affect the tool insert wear and surface roughness are the death of cut and cutting speed, which contribute 46.6% and 46.7% of the total, respectively. Feed rate, on the other hand, has the least importance, contributing 20.2% and 31.9% respectively.

Abstract In order to develop a method for the production of crack-free cladding layers, we combined surface texturing technology with laser cladding, establishing a multi-field coupled numerical simulation model. A separate investigation was conducted into the temperature, stress, and fluid fields in laser cladding processes with and without texturing, seeking optimal cladding parameters, and conducted experiments. The results of the numerical simulations indicate that pre-set texturing effectively reduces the temperature gradient during the cladding process, thereby making the thermal cycle curve smoother. The residual stresses in the X, Y, and Z directions are reduced by 34.84%, 3.94%, and 50.22%, respectively. The introduction of texturing reduces the internal flow velocity of the melt pool, preventing the occurrence of a double vortex effect. Experimental results show that the residual stresses in the X, Y, and Z directions of the predefined textured cladding layer are reduced by approximately 41%, 8%, and 47%, respectively, compared to the non-textured cladding layer. This effectively improves the surface roughness and internal grain size of the cladding layer, with no significant defects at the metallurgical bonding positions, providing a reference for future improvements in cladding layer quality.

Abstract Background Currently, the advantages of monochromatic universal composite resin restorative materials have increased their use in dentistry. Accordingly, the optical, surface and mechanical properties of these materials have become more important. This study aimed to evaluate the effect of detox solution on discoloration, surface roughness (SR), and microhardness of different monochromatic universal composite resins (Omnichroma [O], Zenchroma [Z], Vittra [V], and Charisma Diamond One [CDO]). Another aim of this study was to evaluate the monomer conversion degree (DC) of the materials. Methods A total of 80 specimens were prepared to evaluate the materials (n = 10). After the initial measurements, the specimens were immersed in a red detox solution for 21 days. Statistical data analysis was performed using one-way ANOVA and Tukey’s multiple comparisons. Results The ∆E values of Z were highest on the 21st day. There was an increase in the SR values of the materials immersed in the detox solution. On the 21st day, top surface microhardness of O was lower than the other materials. There was no statistically significant difference at DC values among material groups. Conclusions The use of detox solutions for a commercially recommended period of 21 days is suggested. However, this usage period can cause discoloration in restorative materials. Furthermore, especially in the initial one-week period, detox solution may have a negative impact on the microhardness of the materials. In light of all these data, we recommend the cautious use of detox solutions to prevent adverse effects on restorative materials.

Abstract Replacing the conventional endodontic irrigants with herbal agents could avoid complications associated with using sodium hypochlorite (NaOCl). Endodontic irrigants alter the surface roughness of the dentinal wall surface, which affects sealer mechanical retention. This study aimed to assess the effect of experimental herbal Moringa oleifera and orange peel extract irrigant on intraradicular dentin (IRD) surface roughness using quantitative 3D surface analysis by scanning electron microscopy (SEM) regarding the smear layer assessment. Sixty human root sections were divided into four groups (n = 15): NaOCl combined with 17% ethylenediaminetetraacetic acid (EDTA); negative control (saline); moringa extract (MO); and orange oil (OO). SEM images were assessed quantitatively for surface roughness (Ra) in the coronal, middle, and apical IRD. The data were analysed by Kruskal–Wallis, Friedman, and Dunn’s tests. All groups showed statistically significant differences (P = 0.007). MO exhibited significantly greater Ra values at the coronal, middle, and apical root levels than OO (P = 0.007, 0.009, and 0.046, respectively). There was no significant change in Ra values at various root levels within each group at P = 0.091, 0.819, 0.819, and 0.549 for the EDTA, saline, MO, and OO groups. Considerable (IRD) surface roughness analysis makes Moringa extract a promising herbal endodontic irrigant alternative to the NaOCl plus EDTA regimen.

Abstract Objective To determine the effects of conventional cigarette smoking (CS) and recent heated tobacco products (HTPs) on the surface roughness and color stability of different indirect restorative materials. Materials and methods One hundred disc-shaped samples were constructed of three different restorative CAD/CAM materials: lithium disilicate glass–ceramic (IPS e.max CAD; Ivoclar Vivadent, Liechtenstein), zirconia (BruxZir® Zirconia, Glidewell, USA) and polyetheretherketone (BioHPP® bredent GmbH, Germany). Of the IPS e.max CAD and the Bruxzir samples, 20 samples were glazed, and 20 samples were polished, while the BioHPP samples were all polished according to the manufacturer’s instructions. Fifty samples were subjected to conventional cigarette smoking (LM, Philip Morris International Inc., Egypt) (Groups: IPS e.max CAD_Glazed exposed to CS (LD_G_Cig), IPS e.max CAD_Polished exposed to CS (LD_P_Cig), Bruxzir_Glazed exposed to CS (Zr_G_Cig), Bruxzir _Polished exposed to CS (Zr_P_Cig) and BioHPP exposed to CS (PEEK_Cig) and fifty samples were exposed to heated tobacco product smoking (Heets, Russet selection, Philip Morris International Inc., Italy) (Groups: IPS e.max CAD_Glazed exposed to HTP (LD_G_HTP), IPS e.max CAD_Polished exposed to HTP (LD_P_HTP), Bruxzir_Glazed exposed to HTP (Zr_G_HTP), Bruxzir CAD_Polished exposed to HTP (Zr_P_HTP) and BioHPP exposed to HTP (PEEK_HTP).. Six hundred cigarettes/heets representing 30 days of medium smoking behavior (20 cigarettes/day) were used. Before and after exposure to smoke, the surface roughness of all the samples was measured using JITAI8101 surface roughness tester (Beijing Jitai Tech Detection Device Co., Ltd, China, and the color parameters were assessed using VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA). The data were analyzed using One-way ANOVA, paired sample t-test and independent sample t-test. The significance level was set at α

This study was conducted to investigate some characteristics of thermally treated Scots pine (Pinus sylvestris L.) wood specimens such as air-dried density, color change, average surface roughness, and sound absorption capacity. Heat treatment of Scots pine wood was performed at atmospheric pressure at 140, 160, 180, and 200 °C for 2 h. As a result, the air-dried density values of the thermally treated wood decreased as the temperature of the thermal treatment increased. With the increase of thermal treatment temperature, an increase in total color change values was detected on the surfaces of the samples and the color of the samples became darker. The average surface roughness (Ra) value of samples improved due to thermal treatment conditions and the highest value was determined in thermally treated samples at 200 °C as 3.59 μm. At 140 °C the value of maximum sound absorption coefficient was observed to be 0.48 at 2500 Hz and the highest sound transmission loss value, which was 36.7 dB, was measured at 6300 Hz and at 200 °C.

The examination of the machining of 7075-T6 aluminum alloy polymer mold cavities using Taguchi optimization and analysis of variance is presented in this paper. This study identified the best CNC milling cutting parameters and used a mathematical model to quantify the surface roughness of the machined cavities. The findings showed that while using a flat endmill, the spindle speed multiplied by feed rate contributed 28.01% to surface roughness, and when using a ball endmill, the squared depth of cut contributed 41.27%. Using both flat and ball endmills, the depth of the cut contributed 98.53% to the material removal rate. A refined second-order linear regression model was employed to forecast the endmill-machined surface roughness. The Warp Surf Portable tester measured values that were outside the error range of approximately 0.257% and 2.8%, respectively, for the expected values. Surface roughness has a 99.97% correlation coefficient in the regression model, indicating a very significant link. Additionally, the study improved the cutting parameters for a ball endmill, which were 3005 Rpm, 726.7 mm/min, and 0.43 mm, and for a flat endmill, these were spindle speed (2500 Rpm), feed rate (650 mm/min), and axial cut depth (0.5 mm). The outcomes demonstrated how well the techniques enhanced mold cavity machining and cost estimation using Ra and MRR data. Consequently, these results can be applied to future academic studies and industrial applications.

The publication presents the results of research on the influence of hydrostatic burnishing process on the value of selected parameters of surface roughness, material ratio and surface hardness. The process was carried out on shafts made of X5CrNi18-10 stainless steel. The prepared samples were subjected to a finishing turning process with constant cutting parameters, and then hydrostatic burnishing was performed on the surface. The tests determined the influence of the variable pressure exerted by the ball on the shaft surface. The evaluation of the research results showed a significant increase in hardness in the surface layer and an improvement in surface roughness parameters and material ratio. The machining process was carried out on a conventional lathe.

This paper presents a study of the turning of titanium alloy Ti6Al4V with uncoated and physically or chemically coated carbide blades. The indicators studied and measured were 3D surface roughness, cutting force, the shape of the resulting chips and the degree of blade wear. It was found that coating the cutting blades increased the cutting forces. More blade wear mechanisms also occur, including thermal and adhesive wear. The chemically applied coating makes it possible to obtain the best roughness of Sq and Sz. The coating of the cutting blades had no effect on the form of the chips produced. The Grey Relational Analysis (GRA) confirmed that the recommended blades for the machining of superalloys warranted better technological results for the machining Ti6Al4V alloy.

[Objective] The extensive development of biological soil crusts driven by the project of “Grain for Green” on the Loess Plateau can significantly inhibit soil erosion, but the characteristics of soil erosion resistance and the response mechanism with the growth and development of biological soil crusts are still unclear. [Methods] Algal crusts, moss crusts, and natural succession crusts were cultivated for 176 days to systematically study the effects of different developmental stages and types of biological soil crusts on loessial soil erosion resistance. [Results] (1)The coverage, thickness, biomass, chlorophyll and roughness of the biological soil crusts increased significantly with growth time, and the moss crusts were higher at the beginning of cultivation and the natural succession crusts were highest at the end of cultivation. (2) With the development of biological soil crusts, the cohesion increased as a power function, which increased by 39.8%~60.3% compared with the initial period; the mass loss rate decreased exponentially, which decreased by 45.6%~57.3% compared with the initial period; and the saturated hydraulic conductivity (Ks) was more complex, but the Ks was lowest at the end of cultivation (0.08~0.12 mm/min). (3) Soil cohesion increased as a power function with the increase of coverage, thickness, chlorophyll, biomass and roughness, and the mass loss rate decreased exponentially with the increase of coverage, thickness, chlorophyll, biomass and roughness. (4) The comprehensive index of soil erosion resistance (Cser) constructed based on soil properties can effectively show the effect of biological soil crusts development on soil erosion resistance. And the Cser can be expressed as a power function of coverage (Cov), thickness (T) and biomass (B) (Cser=0.279 Cov0.194T0.188B0.119, R2=0.73, p

Background. Taking into account temperature, soil composition, surface roughness and the dependence of effective dielectric constant on frequency allows a more accurate assessment of soil moisture and other important parameters, which can be used in various fields such as agriculture, geology, ecology and hydrology. Aim. In this work, we calculate the reflection of a linearly polarized electromagnetic wave from wet soil, taking into account such physical factors as heterogeneity of soil structure, surface roughness and dispersion. Methods. Based on a heterogeneous mathematical model of wet soil, taking into account the dispersion of the dielectric constant of water and surface roughness, expressions are derived for the complex reflection coefficients of electromagnetic waves of vertical and horizontal polarization. Results. The model of loose wet soil with the standard deviation of roughness on the surface was chosen as the object of study. An analysis of the frequency and angular characteristics of the modules of the reflection coefficients was carried out at a fixed level of soil moisture. Conclusion. The data obtained as a result of the calculations is a valuable tool for further improving methods of remote sensing of the Earth and contributes to the development of new technologies for monitoring soil parameters using unmanned aerial vehicles, which opens up prospects for more accurate and efficient analysis of the state of land resources and ecosystems.

Understanding the interface shear strength is crucial for the design of geotechnical structures. This study investigates the effect of surface roughness on the interface friction angle, peak interface friction coefficient, and interface shear strength through direct interface shear tests. The experiments were performed on 10 samples of concrete and steel with the level of roughness varying and soil. The objective is to provide soil parameters for a site that is located around 6 km away to the south of Al-Amarah city, Southeast of Iraq where earthquakes hit frequently. The research is intended to investigate the effect of earthquakes on objects that are built in that particular region, by putting emphasis on the interaction between the soil structure and the roughness of the contact surface between the structural parts and the soil. In order to evaluate the roughness nature of structural materials, a test program was conducted using the SRT-6210 Digital Surface Roughness Tester. The average roughness parameter (R a) had the strongest association with shear parameters, and so it is the indicator to explain the shear behavior of sand‒concrete and sand‒steel interfaces. The direct shear box test was employed to find out the soil’s shear strength parameters as well as the interface shear strength parameters. The test shows a profound change in the shear strength characteristics of sand‒concrete and sand‒steel indispensable interfaces. As the roughness index increased. It depicted an upward slope of apparent shear strength and friction coefficient taken at the interface. The shear strength had increased by 25.13% when the roughness of the concrete was below 20 μm20{\rm{\mu }}{\rm{m}} and by 36.26% when the roughness of the steel was below 30 μm.\hspace{0.25em}30{\rm{\mu }}{\rm{m}}.\hspace{0.25em} Moreover, sand‒steel samples interface friction angle increased by approximately 31.5% with increasing surface roughness and sand‒concrete samples by 21.54%. The results also revealed that the peak interface friction coefficient (μp)\left(\mu p) increased with the increase in R a.

The interactions between soil-structure are largely governed by the shear strength at the soil-structure interface, particularly in situations involving large displacements, known as shear residual strength. This latter can be influenced by a range of factors, including normal stress, physical properties, surface roughness, wall friction. The main objective of this study is to investigate clogging related to surface roughness form, in addition to wall friction arises from consolidation. In order to investigate the impact of wall friction, experiments involving ring shear tests were carried out on kaolin. Four different consolidation durations were employed to induce varying settlements of the upper platen, while three distinct testing procedures, including single stage, multistage, and preshearing, were utilized. Additionally, different levels of surface roughness were incorporated to investigate the effect of clogging. The test results obtained from various testing procedures indicate that employing a single stage procedure with zero consolidation time is the most suitable approach for mitigating the influence of wall friction. For clogging effect, is dependent on the materials used, namely, the kaolin and the mixture, as well as, the interfaces involved.

The intend of current study was focused on the prediction of material removal rate (MRR) and surface roughness (SR) for the AA7050-SiO2 composite during wire electric erosion or discharge machining (WEDM) process using a brass (Br) wire electrode. Here, stir casting process was employed to develop the AA7050 matrix composite with inclusion of 10wt.% SiO2 particle reinforcement. The multi-objective optimization method of Technique for order preference by similarity to ideal solution (TOPSIS) approach has been applied to find out the optimal setting of input machining parameters such as peak current (Ip), pulse-on time (Ton) and pulse-off time (Toff). Furthermore, the significant effects of parameters were identified by analysis of variance (ANOVA). Taguchi L9 (33) orthogonal design has been formulated to perform the experimental work. TOP SIS results stated that the optimal setting of Ip at 30 amps, Ton of 130 μs and Toff of 55 μs provide the better MRR with lesser SR. The ANOVA results noticed that Ip has the prime noteworthy parameter over the adopted responses having a contribution of 45.67%, followed by Ton (32.34%) and Toff (12.26%), respectively. The confirmation test was carried out by the optimal parameters setting to verify the predicted results. Finally, the scanning electron microscopy (SEM) test was carried out for the machined surface of the composite specimen and it was reveals that the formation of craters and recast layer thickness in the machined surfaces.

Background: The use of diverse transparent Vacuum-Formed Retainers (VFR) is widespread. However, there is a lack of detailed instructions regarding the proper cleaning methods for patients to ensure optimal longevity and plaque removal from their retainers. The objective of our study was to investigate the alteration in surface roughness of polypropylene (PP), thermoplastic polyurethane (TPU), polyethylene terephthalate glycol (PET-G), and co-polyester (COP) materials exposed to different cleaning procedures. Methods: In the initial phase of our study, we distributed a questionnaire to individuals who utilize vacuum-formed retainers to gain insight into their cleaning practices. After consolidating the results, we established six different cleaning categories. A toothbrush simulator, designed and built by one of the authors (B.M.), was used to simulate brushing for 30 days. A profilometer was used to quantify the inner surface roughness (Ra). Statistical analysis included Kruskal-Wallis, ANOVA, Post hoc analysis and t-tests. Results: The findings of our study demonstrated that distinct cleaning protocols had varying effects on the retainer materials. TPU samples typically exhibited a reduction in surface roughness following most cleaning procedures, but PP samples demonstrated an elevation in roughness. COP proved to be the most resistant material, and TPU the least. Medium and electric toothbrushes and whitening toothpaste should be used with caution. Conclusions: These findings emphasize the significance of choosing the appropriate cleaning procedures to preserve the integrity and hygiene of VFR materials, ultimately enhancing patient satisfaction.

Abstract In this work, the surface of polyvinyl chloride PVC sheet was modified by blending it with sunflower seed oil SSO to obtain PVC sheet/SSO films of ratios 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (v/v)% using the solution casting method. Various techniques were used to characterize the prepared films, besides the use of hemolysis assays and blood clot formation tests. FTIR spectra revealed that there was a good interaction between the PVC sheet and the oil. The dielectric measurement indicated that SSO addition enhanced the dielectric properties of the sheet. The study of dielectric relaxation times confirmed the interaction between SSO and the sheet. DC conductivity increased to 6 × 10–6 S/m, so it could be applied in antistatic applications. Also, SSO addition increased the value of the thermal stability. According to SEM micrographs, the film was roughened at a ratio of 60/40 and smoothed out at 50/50. This behavior was confirmed with roughness and contact angle measurement results, in which the film of ratio 60/40 had the highest value equal to (72.03°) and then decreased at 50/50 to (59.62°). These results were confirmed by XRD measurement as the crystallinity increased at the film ratio of 60/40 and decreased again at 50/50. Also, the ratio of 60/40 demonstrated a large decrease in thrombus weights along with a slight increase in hemolysis, which is within the acceptable range and has a high degree of biocompatibility, so this concentration is recommended to be used in blood bags applications.

Abstract Titanium (Ti) dental scaffolds are widely used in dental prosthetics due to their excellent mechanical properties and biocompatibility. However, conventional Ti scaffolds manufactured through machining often do not fit perfectly with the bone defect site. Laser powder bed fusion (LPBF) technology enables the personalised manufacturing of custom‐made Ti scaffolds. A custom‐made Ti scaffold was prepared using LPBF and its surface roughness was improved through chemical polishing. To enhance the surface roughness, a nitric acid mixed solution with a specific composition of HF: HNO3:C3H6O3 = 2:2:3 was used. The polishing mechanism was investigated by adjusting the F/Ti ratio to control the formation and dissolution of the oxide film. As a result, the surface of the Ti scaffold after polishing exhibited a smooth and flat appearance compared to the LPBF part, with a reduced surface roughness (Ra) of 1.23 ± 0.19 μm. The custom‐made Ti scaffold also demonstrated favourable mechanical properties, with a bending strength of 335.18 ± 33.62 MPa and stiffness of 2.13 ± 0.21 GPa. Furthermore, in vitro cell tests confirmed the excellent biocompatibility of the custom‐made Ti scaffold. The authors present a feasible strategy for the further clinical application of custom‐made Ti scaffolds, offering enhanced surface properties and addressing the limitations of conventional machining methods.

The present work deals with the enhancement of the surface characteristics of stainless steel 316L as a result of shot peening treatment using ceramic balls. In accordance with our own research and information available in literature, as a result of shot peening process, the shot balls can penetrate to the surface layer (permanently depositing) and modify the mechanical performance and the corrosion resistance in the products being treated in this way. Shot peening leads to a significant change to the surface hardness and topography, and consequently, to the change in corrosion behaviour dependent on the choice of processing parameters. Therefore, in this paper, steel samples were treated using two variable parameters of peening pressure (0.3 and 0.4 MPa) and peening time (30 and 60s). In the research, the reference surface were the samples subjected to mechanical polishing. The surface morphology of the samples was investigated by scanning electron microscopy (SEM). The potentiodynamic polarization tests were performed with 1 mV/s scan rate in 0.9% NalCl solution. The improved corrosion resistance (lowest current density Icorr=0.35µA/cm2 and highest corrosion potential Ecorr=-0.164V) was obtained for specimens with longer time (60s) and higher pressure of shot peening treatment (0.4MPa). Greater changes in surface roughness were observed with an increase in peening pressure than with an increase in the processing time. The treatment of the surface with ceramic shots results in an increase in the hardness of the treated surface by more than 110% (for sample 316L/0.4/60) compared to the reference surface. Moreover, an increase in average hardness values was recorded for all surfaces after shot peening (by more than 42% relative to reference samples).

Under low-speed or start/stop conditions, the rubbing of top foil in foil journal bearing (FJB) prompting the application of heat treatment to improve the rubbing behavior of the foil bearing. During heat treatment, various factors can influence the thermo-physical properties of foil. Therefore, the present study is carried out to analyze the impact of heat treatment variables on the rubbing behavior of FJB. To obtain it, bump-type FJBs are fabricated using SS 316 foil material with a corrugated die. Subsequently, experimental investigations of the developed bump-type FJB are conducted based on response surface methodology. The rubbing behavior of the FJB, including wear rate and surface roughness, is evaluated under various heat treatment conditions. The results indicate that both the wear rate and surface roughness of bump-type FJB decrease with increasing HT time duration. Furthermore, it is observed that the temperature distribution of the heated foil becomes more uniform with longer HT time durations. At the optimal HT variables of 500°C and 3 hours, the surface roughness and rubbing temperature of bump-type FJB are measured at 1.295 μm and 55.20°C, respectively. Additionally, the rubbing temperature of bump-type FJB is thoroughly evaluated.

This paper presents the process of digital data flow in RE/CAD/RP/CAI systems to develop models for planning surgical procedures in the craniofacial area. At the first RE modeling stage, digital data processing, segmentation, and the reconstruction of the geometry of the anatomical structures were performed. During the CAD modeling stage, three different concepts were utilized. The first concept was used to create a tool that could mold the geometry of the cranial vault. The second concept was created to prepare a prototype implant that would complement the anterior part of the mandibular geometry. And finally, the third concept was used to design a customized prototype surgical plate that would match the mandibular geometry accurately. Physical models were made using a rapid prototyping technique. A Bambu Lab X1 3D printer was used for this purpose. The process of geometric accuracy evaluation was carried out on manufactured prototypes of surgical plates made of ABS+, CPE, PLA+, and PETG material. In the geometric accuracy evaluation process, the smallest deviation values were obtained for the ABS plus material, within a tolerance of ±0.1 mm, and the largest were obtained for CPE (±0.2 mm) and PLA plus (±0.18 mm). In terms of the surface roughness evaluation, the highest value of the Sa parameter was obtained for the PLA plus material, which was 4.15 µm, and the lowest was obtained for the CPE material, equal to 3.62 µm. The knowledge of the flow of digital data and the identification of factors determining the accuracy of mapping the geometry of anatomical structures allowed for the development of a procedure that improves the modeling and manufacturing of anatomical structures within the craniofacial region.

Improvement of the surface quality of machined parts is essential in order to avoid excessive and costly post-processing. Although non-conventional processes can efficiently carry out the machining of difficult-to-cut materials with high productivity, they may also, for various reasons, be related to increased surface roughness. In order to optimize the surface quality of generated surfaces in a reliable way, surface profiles obtained during these processes must be adequately modeled. However, given that most studies have focused on Ra or Rz indicators or are based on the assumption of a normal distribution for the profile heights, relevant models cannot accurately represent the surface characteristics that exist in a real machined surface with a high degree of accuracy. Thus, in the present study, a new modeling approach based on the use of a statistical probability distribution for the surface profile height is proposed. After six different distributions were evaluated on the basis of a three-stage procedure involving different roughness indicators pertaining to the abrasive waterjet (AWJ) milling of pockets, it was found that, although it is not possible to model the nominal values of every roughness parameter simultaneously, in several cases, it is possible to approximate the values of critical indicators such as Ra, Rz, Rsk, Rku and Rp/Rv ratio by Weibull distribution with a sufficient degree of accuracy.

The rotating scanning strategy is a critical factor for top surface roughness in laser-powder bed fusion (L-PBF), yet the underlying mechanism remains elusive. This study introduces an integrated L-PBF model, encompassing powder packing and molten pool fluid dynamics analysis, to investigate how surface roughness accumulates across layers with non-rotating scans but is mitigated with rotating scans. To address computational complexity and prediction errors associated with multi-layer simulations, the model utilizes an experimentally built part as substrate and simulates single-layer depositions with varying scanning rotation angles. Additionally, an as-machined surface representing ideal flat substrate is included for comparative analysis. Results indicate that on as-built surfaces featuring alternating peak-valley patterns, both powder packing structure and fusion zone shape are location-dependent. To effectively characterize the packing structure on such non-flat surfaces, an effective packing density is proposed. Specifically, peak locations exhibit a thinner powder layer, a 14.5% increase in effective packing density, and a 7% decrease in penetration depth compared to valley locations. The circulation flow, driven by recoil pressure and Marangoni force, is responsible for the reduced surface roughness with rotating scans. Specifically, the circulation flow intersects with multiple peaks and valleys, effectively promoting material redistribution among these tracks and disrupting the peak-valley patterns. Conversely, the peak-valley patterns are preserved and may propagate to subsequent layers with non-rotating scans.

The purpose of this study was to determine the effect of variations in the angle and distance of sandblasting on paint coating quality and corrosion properties of low carbon steel. The success of a coating is highly dependent on surface roughness, so sandblasting is needed to clean and create a surface roughness profile with the aim that the paint can coat the surface perfectly. The test method used in this research is the pull off test method for testing the adhesive strength of paint and open circuit potential (OCP) for testing the corrosion potential. The sandblasting variations used are angles of 45⁰, 60⁰, 75⁰ and nozzle distances of 15 cm, 35 and 50 cm. The tests carried out were roughness, paint thickness, paint adhesive strength and corrosion potential. From the test results it can be concluded that the greater the angle and the closer the sandblasting nozzle distance, the greater the surface roughness. The greater surface roughness affects the paint layer to be thicker and has a high paint adhesion strength, resulting in a smaller corrosion potential. In this study, the highest test results were obtained at an angle of 75⁰ and a distance of 15 cm with a surface roughness value of 5.981 µm, a paint thickness of 115 µm, a paint adhesive strength of 7.28 MPa and an initial corrosion potential position of -0.101 V then a final position of -0.063 V.

The use of vegetable oil-based cutting fluids under minimum quantity lubrication (MQL) lubrication has been suggested as a potential alternative. The cutting fluid is conveyed in the form of fine droplets with compressed air delivered precisely to the cutting zone. This study aims to determine the effect of variations of rubber seed oil and coconut oil as a cutting fluid on the surface roughness of the machining process using the MQL method. Researchers used the parameters of cutting fluid flow rate of 120 ml/hour and 180 ml/hour, cutting speed of 500 rpm, feed rate of 0.011 mm/rev, depth of cut of 0.5 mm with variations of coconut oil 10%, 20%, 30%. The results showed that the lowest surface roughness value was at a flow rate of 180 ml/hour with a 30% variation of 0.886 µm, while the highest surface roughness value was at a flow rate of 120 ml/hour with a 10% variation of 1.164 µm, meaning that the greater the flow rate and variation cutting fluid results in a decrease in surface roughness, this is due to the influence of the addition of coconut oil, the more coconut oil is added, the surface roughness value decreases. The surface roughness value decreases as the viscosity decreases, because the viscosity of coconut oil is lower than that of rubber seed oil, so that the flow rate of the cutting fluid is able to work optimally to lubricate the contact area.

Ultrasonic shot peening (USP) is widely used for materials surface strengthening and metal sheet forming as a novel mechanical surface treatment technology. The USP-caused surface roughness is usually viewed as an unfavorable factor influencing the service performance of the mechanical components treated by USP. Taking advantages of the experimental investigation, analytical calculation and finite element simulation, the correlation between the USP-caused surface roughness and the USP-induced metal sheet forming deformation is studied comprehensively. Firstly, the USP intensity was experimentally tested by USP of Almen strips. In accordance with the USP intensity, the experimental investigations on the evolutions of surface roughness caused by USP of 2024 aluminum alloy sheets with the thicknesses of 1 mm, 2 mm and 3 mm were carried out, respectively. An analytical calculation model (ACM) was then proposed to account for the effects of the USP-induced metal sheet forming deformation on the USP-caused surface roughness. The analytically-calculated results are in good agreement with the experimentally-measured surface roughness caused by USP of 2024 aluminum alloy sheets. Lastly, linking the finite element simulation of the USP-induced metal sheet forming with the analytical calculation model, an innovative FEM-ACM coupling approach was presented for predicting the evolutions of surface roughness caused by USP of metal sheets. It has been experimentally validated with USP of 2024 aluminum alloy sheets, and would be of great significance for the development and industrial application of USP technology.

The aim of this paper is to investigate the grinding characteristics and mechanism of 2D- SiC/SiC composites with 0°/90° orthogonal anisotropic structured surfaces under different scratching fiber angles (angle between scratch direction and fiber orientation, SFA). A series of surface single abrasive scratching tests were conducted. The effects of the scratch fiber angle on the grinding force, surface morphology and roughness were investigated. The results show that the scratch force and surface roughness at different scratch fiber angles are in the order of 0° > 30°> 45°; SFA also has an important effect on the surface microstructure. The grinding mechanism of 2D-SiCf/SiC composites was analyzed by single-particle scratching test. The results of the scratch force and surface morphology provide strong evidence of the differences produced during the grinding process. The advantages of ultrasonic vibration over conventional machining were further identified by comparing specific scratch energies. This study elucidates the damage behavior of 2D-Sicf/sic composites in correlation with the influence of angle, and these results provide a new guideline for ultrasonic vibratory grinding of woven fiber-reinforced ceramic matrix composites for machining quality.

Abstract Textured surfaces with certain micro/nano structures have been proven to possess some advanced functions, such as reducing friction, improving wear and increasing wettability. Accurate prediction of micro/nano surface textures is of great significance for the design, fabrication and application of functional textured surfaces. In this paper, based on the kinematic analysis of cutter teeth, the discretization of ultrasonic machining process, transformation method of coordinate systems and the cubic spline data interpolation, an integrated theoretical model was established to characterize the distribution and geometric features of micro textures on the surfaces machined by different types of ultrasonic vibration-assisted milling (UVAM). Based on the theoretical model, the effect of key process parameters (vibration directions, vibration dimensions, cutting parameters and vibration parameters) on tool trajectories and microtextured surface morphology in UVAM is investigated. Besides, the effect of phase difference on the elliptical shape in 2D/3D ultrasonic elliptical vibration-assisted milling (UEVAM) was analyzed. Compared to conventional numerical models, the method of the cubic spline data interpolation is applied to the simulation of microtextured surface morphology in UVAM, which is more suitable for characterizing the morphological features of microtextured surfaces than traditional methods due to the presence of numerous micro textures. The prediction of surface roughness indicates that the magnitude of ultrasonic amplitude in z-direction should be strictly limited in 1D rotary UVAM, 2D and 3D UEVAM due to the unfavorable effect of axial ultrasonic vibration on the surface quality. This study can provide theoretical guidance for the design and fabrication of microtextured surfaces in UVAM.

Leveraging a fresh comprehension of electrolytic polishing (EP) mechanisms, this study introduces a pivotal factor - viscosity/water content ratio (VWR) - for the first time, rooted in acidity ratio theory. The present study aligns with published works to affirm the validity of the VWR indicator and its correlation with surface roughness. A noteworthy contribution lies in the design of EP solutions that can serve as a guide for stainless steels. It strikes a balance between low cost, high efficiency, long service life and desirable surface roughness. This involves regulating the dissolution-ionization-deposition process at the metal/solution interface.

Abstract Background Recently, a new generation of high-strength flowable dental composites has been introduced by manufacturers. The manufacturers claim that these materials have enhanced mechanical and physical properties and are suitable for use in a wide range of direct anterior and posterior restorations, even in high-stress bearing areas. Aim The objective of this study was to assess certain physical and mechanical properties of these recently introduced high-strength flowable composites in comparison to conventional multipurpose dental composites. Methods Four types of high-strength flowable composites (Genial Universal FLO, Gaenial Universal Injectable, Beautifil Injectable, and Beautifil Flow Plus) were tested in experimental groups, while a nanohybrid conventional composite (Filtek Z350 XT) was used as the control. For flexure properties, ten rectangular samples (2 × 2 × 25 mm) were prepared from each composite material and subjected to 5000 cycles of thermocycling. Samples were then subjected to flexural strength testing using the universal testing machine. Another twenty disc-shaped specimens of dimensions (5 mm diameter × 2 mm thickness) were fabricated from each composite material for surface roughness (Ra) (n = 10) and hardness (VHN) test (n = 10). All samples underwent 5000 cycles of thermocycling before testing. Additionally, microleakage testing was conducted on 60 standardized class V cavities prepared on molar teeth and divided randomly into five groups (n = 12). Cavities were then filled with composite according to the manufacturer’s instructions and subjected to thermocycling for 1000 cycles before testing using methylene blue solution and a stereomicroscope. Results All tested materials were comparable to the control group in terms of flexural strength and surface roughness (p > 0.05), with Gaenial Universal FLO exhibiting significantly higher flexural strength compared to the other flowable composite materials tested. However, all tested materials demonstrated significantly lower elastic modulus and surface hardness than the control group (p

The aim of the work – to study the peculiarities of the shape and surface relief of the main types of dental implants. Materials and methods. 12 dental implants used in the medical practice of Ukrainian dental clinics were studied. The study of the shape and surface relief of the implants was carried out using a scanning electron microscope GSM-649 (Japan). Results. All implants in the apical part have the shape of a cone with threads and cutting grooves. The thread with a large profile is located in the apical part of the implant, has an average pitch of turns of 1.1±0.05 mm and a profile height of 0.3±0.02 mm. The thread with a small profile is located in the part of the implant near the neck, has a pitch of 0.4±0.02 mm and a profile height of 0.1±0.02 mm. The thread pitch of implants with a single profile is 0.8±0.05 mm, and the height of the profile is 0.2±0.01 mm. Threads with a triangular profile have a profile angle of 50.0±2.9 degrees. The highest roughness is the surface of the top of the fine profile thread with the height of micro-uniformities from 7.0±2.2 to 36.0±8.3 μm, the smallest roughness with the height of micro-uniformities from 3.0±1.1 to 14.0±6.1 μm have surface areas in the area of the implant neck. Conclusions. 50% of the examined implants were made with two thread profiles: a large one in the apical side and a small one closer to the neck, 50% – with the same thread profile from the apical end to the neck. In most implants, the thread with a small profile is made in the form of annular grooves. The large thread of the implants had a rectangular, rounded and triangular profile with one or two steps. In some implants, as they approach the neck, the shape changes and the height of the thread profile decreases. The shape of the profile of small threads in all implants was close to rounded. The implants had different surface roughness. The highest roughness was recorded on the surface of the top of the small profile thread, and the lowest – in the area without a thread in the area of the implant neck.

Titanium is widely acknowledged as a challenging metal due to its inherent characteristics. Manufacturers often encounter challenges such as tool wear, reduced tool lifecycle, and increased cutting heat when working with Ti64. This research investigates the cutting characteristics of additively manufactured (AMed) Ti64 under dry cutting, Minimum Quantity Lubrication (MQL), Cryogenic Carbon dioxide (CO2), and a hybrid approach combining MQL and CO2 conditions. Surface roughness, flank wear, temperature, chip morphology, and microhardness were analyzed to assess the impact of cooling strategies. Results indicate that the hybrid approach outperforms individual methods, showing superior surface finish and reduced tool wear. Machined Surface roughness (Ra) measurements reveal a substantial improvement in the hybrid condition, reducing Ra values by 62.44–67.02%, 35.65–41.38%, and 18.68–27.59% compared to dry, MQL, and CO2. Tool wear assessments exhibit significantly lower flank wear values in the hybrid condition, emphasizing the synergistic benefits of lubrication and cryogenic cooling. This research provides valuable insights into tailoring cooling strategies for optimal precision in machining AMed-Ti64 material, which is crucial for achieving high-quality manufacturing outcomes.

Abstract In fractured reservoirs, the fracture network provides the main path for fluid flow. Appropriate estimation of the fracture permeability influences the precise prediction of the reservoir’s future performance. Commonly, for a known geometry of natural or induced fracture, the permeability is estimated by applying local cubic law. One major drawback of this approach is that the fracture surface roughness, which has a significant effect on fracture permeability, is not considered. Moreover, the knowledge about the impact of fracture surface roughness on fracture permeability is not currently sufficient. In this research, the fluid flow in fractures with rough-walled surfaces was studied using computational fluid dynamics. For this purpose, the fluid flow through fractures was simulated by applying appropriate roughness for fracture walls. Furthermore, two correlations, based on response surface methodology and power-law models, were proposed to predict fracture permeability as a function of four independent variables (surface roughness, fracture aperture, angle, and porosity). The results of the two presented correlations were validated, and the statistical analysis indicates that both models are appropriate to predict fracture permeability. The findings of this study will be of great assistance with understanding and characterization of the fluid flow in rough fractures and can be used in future works.

(1) Background: The presence of various dental ceramic materials with different chemical compositions complicates clinicians’ decision making, especially in cases with a highly acidic environment appearing in patients suffering from gastroesophageal reflux disease or other eating disorders. Thermal alterations in the oral cavity can also affect surface structure and roughness, resulting in variations in both degradation mechanisms and/or bacteria adhesion. The aim of the present in vitro study was to evaluate the effect of thermal cycling and exposure to simulated gastric acid on the surface roughness of different ceramics; (2) Methods: Five groups of different ceramics were utilized, and twenty specimens were fabricated for each group. Specimens were either thermocycled for 10,000 cycles in distilled water or immersed in simulated gastric acid for 91 h. The evaluation of surface roughness was performed with optical profilometry, while scanning electron microscopy, X-ray diffraction analysis and inductively coupled plasma atomic emission spectroscopy were also performed; (4) Conclusions: Based on the combination of the surface roughness profile and structural integrity, zirconia specimens presented the smallest changes after immersion in simulated gastric acid followed by lithium disilicate materials. Zirconia-reinforced lithium silicate ceramic presented the most notable changes in microstructure and roughness after both treatments.

Frequent and prolonged exposure to high levels of vibration and shock can cause neck and back pain and discomfort for many wheelchair users. Current methods to attenuate the vibration have shown to be ineffective and, in some cases, detrimental to health. Novel in-wheel suspension systems claim to offer a solution by replacing traditional spokes of the rear wheels with dampening elements or springs. The objective of this study was to investigate the effects of in-wheel suspension on reducing vibration and shock and improving comfort in manual wheelchair users. Twenty-four manual wheelchair users were propelled over nine different surfaces using a standard spoked wheel, a Spinergy CLX, and Loopwheels while accelerometry data was collected at the footrest, seat, and backrest. Loopwheels lowered vibrations by 10% at the backrest compared to the standard and CLX wheels (p-value < 0.001) and by 7% at the footrest compared to the CLX (p-value < 0.05). They also reduced shocks by 7% at the backrest compared to the standard wheel and CLX (p-value < 0.001). No significant differences were found in comfort between the wheels. Results indicate that Loopwheels is effective at reducing vibration and shock, but more long-term testing is required to determine effects on health.

Aluminum Alloy 6061 is widely used in various engineering applications, including automotive vehicle wheels. The selection of aluminum alloy wheels involves aspects such as corrosion resistance. To enhance corrosion resistance, there are several methods, one of which is anodizing. Anodizing is a process that involves an electrolytic coating process that transforms the surface of aluminum into aluminum oxide (Al2O3), which the main process of aluminum anodizing requires a solution of sulfuric acid, chromic acid, or a mixture of sulfuric acid and oxalic acid. The sulfuric acid used must be concentrated acid, and acid is an oxidizing substance. The thickness of the oxide is approximately twice the thickness of the lost aluminum. The purpose of this research is to determine the characteristic such as surface roughness values, corrosion rates, and changes in morphology in Aluminum 6061 after undergoing anodizing. In this study, various current strengths were used, namely 0.75 Amperes, 1.5 Amperes, 2.25 Amperes, and 3 Amperes. The highest surface roughness value was obtained at 0.447 μm in the third specimen of the 0.75 Ampere variation, while the lowest was 0.075 μm in the first specimen of the 3 Ampere variation. The highest corrosion rate was observed in the 0.75 Ampere variation, with a rate of 17.724004 mpy, and the lowest was 0.0731653 mpy in the 3 Ampere variation. SEM results show that, in general, Aluminum 6061 tends to have a bright gray color, which is a surface that has been coated by cathode.

Aim of the StudyThe aim of this in vitro study was to evaluate the effect of the resin infiltration technique and remineralization of induced enamel caries with fluoride solution on the color masking of white spot lesions and surface roughness. Materials and MethodsA total of 45 sound teeth were used in this study. All the teeth were sectioned along the long axes into two halves, lingual and buccal to get 90 specimens. All specimens were immersed in a demineralized solution for 7 days. The specimens were divided randomly into three equal groups (n = 30) according to the type of treatment; Group 1 (n = 30) was treated with fluoride varnish (Clinpro); Group 2 (n = 30) was treated by resin infiltration (Icon); and Group 3 (n = 30) was used as a control group with no treatment. The color and surface roughness were measured three times at baseline (T1), directly after induction of artificial white spot lesions (WSLs) (T2), and directly after application of the treatment options (T3). The colors were measured using a portable reflective spectrophotometer and the 3D surface roughness was measured using a Light Sectioning Vision System. Data were collected and statistically analyzed using T test and Mann–Whitney U test. The ResultsSurface roughness was almost equal in the study groups with no statistically significant differences reported. Icon showed slightly higher color scores than that of ClinPro. ConclusionsThe Icon produced favorable esthetic results compared to the fluoride therapy while no significant differences were reported regarding the surface roughness.