Search

Purpose: To compare the color dimensions, color discrepancies (E00), and surface roughness of milled materials before and after application of a bleaching agent. Materials and Methods: A total of 10 extracted molars were obtained. Each tooth was cut in transverse sections to create disks (3-mm thick, 10-mm diameter; control group). Disk specimens of eight materials (n = 10 per group) were fabricated: polymethyl methacrylate (PMMA) interim material (PMMA-Telio group), two resin nanoceramics (RNC-Ultimate group and RNC-Cerasmart group), two hybrid ceramics (HC-Shofu group and HC-Enamic group), lithium disilicate (LD-Emax group), zirconia-reinforced glass ceramic (ZGC-Suprinity group), and zirconia (Zr-InCeram group). Color measurements were obtained using a spectrophotometer before and after applying 35% hydrogen peroxide-based bleaching agent. Pre- and postbleaching surface roughness (Sa) analyses were completed using a profilometer. Results: Significant L*, a*, b*, and E00 value differences were found (P < .05). Color discrepancies (E00) ranged from 0.30 ± 0.14 to 4.82 ± 0.10. The highest color discrepancies were measured on the PMMA-Telio group, while the lowest color discrepancies were computed for ZGC-Suprinity, RNCUltimate, and RNC-Cerasmart. Significant surface roughness differences were found (P < .05). The largest increase of surface roughness values between the pre- and postbleaching measurements was obtained in the PMMA-Telio group with a mean Sa value of 4.73 ± 3.02, while the largest decrease of surface roughness values between the pre- and postbleaching measurements was obtained in the Zr-InCeram group with a mean Sa value of -1.58 ± 0.10. Conclusions: The milled materials showed significant pre- and postbleaching color and surface roughness discrepancies. [ABSTRACT FROM AUTHOR]

Introduction: Non Carious Cervical Lesions (NCCLs) represent a prevalent dental condition characterised by the erosion of tooth structure at the cementoenamel junction without the involvement of dental caries. These lesions pose significant challenges due to their aesthetic impact, potential for dentinal hypersensitivity, plaque accumulation, pulpal complications and compromised structural integrity of the teeth. Tooth preparation traditionally uses diamond abrasive points and tungsten carbide burs for micromechanical adhesion. Newer methods, like ultrasonic tips, offer a more conservative approach, but limited research has compared their effects on bond strength, particularly in cervical cavity restorations with nanohybrid composites. Aim: To compare the surface roughness of cervical cavity preparations utilising diamond abrasive points and ultrasonic tips, and to evaluate the shear bond strength of restorations with composite resin. Materials and Methods: The present in-vitro comparative study was conducted in the Department of Conservative Dentistry and Endodontics, Guru Nanak Institute of Dental Sciences and Research, Panihati, Kolkata, West Bengal, India, from October 2023 to December 2023. The study included 52 freshly extracted maxillary 1st premolar teeth extracted for orthodontic reasons. These teeth were divided into two groups: Group-I (n=26) underwent surface preparation using a diamond abrasive point (No. 835-012, Piranha, SS White, USA), while Group-II (n=26) was prepared using an ultrasonic tip (Woodpecker G 20, Guilin Woodpecker, China). Teeth were cleaned, disinfected and stored in 0.1% thymol solution before being prepared with diamond abrasive points or ultrasonic tips, following which the specimens were restored using nanohybrid composite material (Solare X, GC Corporation, Japan). Surface roughness was assessed using a digital profilometer before the restoration, and the shear bond strength of repaired specimens was measured with a Universal Testing Machine. Statistical analysis was performed using GraphPad Prism, with independent samples t-tests applied to compare results between groups, and a significance level set at 5%. Results: Group-I exhibited greater surface roughness (6.33±2.18 μm) compared to Group-II (4.91±1.57 μm). Group-I also showed higher shear bond strength (62±13 MPa) than Group-II (59.3±19.9 MPa), though this variation was not statistically significant (p-value=0.56). Conclusion: Within the present study's limitations, diamond abrasive points created significantly greater surface roughness compared to ultrasonic tips. However, no statistically significant variations have been observed in shear bond strength among the two methods, suggesting that ultrasonic tips may be considered as an alternative to diamond abrasive points in clinical settings, avoiding their drawbacks while achieving adequate restoration retention. [ABSTRACT FROM AUTHOR]

This research explores the scratch resistance of polymer composites reinforced with hybrid glass and basalt fibers under repeated loadings. By examining the behavior across 1–10 repetitions using Rockwell and Vickers indenters, the study delves into the complex interplay between composite matrices and the fibers' configurations. Through Scanning Electron Microscope (SEM) imaging and 3D profilometry, it reveals how different fibers influence the composite's surface post‐scratch tests. Basalt fibers are found to offer superior scratch protection over glass fibers, although both types' of effectiveness declines with increased loading cycles, showing significant material loss and surface damage respectively. Composites with these fibers display enhanced resistance, especially when basalt fibers are optimally positioned on the surface. The study underscores the critical role of fiber‐matrix bonding in scratch resistance and the significant impact of mechanical stress. It was found that the scratch hardness values reduced with more repeats in the scratch tests utilizing Vickers and Rockwell indenters. The sample with the label G4B6G4 has the greatest hardness values, which is noteworthy. After 10 repeats, the scratch hardness values for this sample reduced to 225 N/mm2 and 75 N/mm2, respectively, from roughly 340 N/mm2 and 225 N/mm2 at both ends for a single repetition. In addition, ANOVA for penetration depth is dominated (66.01%) by the repetition factor. The most common kind is indenter (42.79%), with low p‐values. Despite material and indenter effects, groove area study confirms the significance of repetition (65.72%). Highlights: Basalt fibers enhance scratch resistance more than glass fibers.Increased scratch repetitions lead to fiber breakage and material loss.Hybrid fiber layers distribute load and minimize surface damage.Strong fiber‐matrix adhesion is crucial for reducing damage severity.Research informs the design of durable, fiber‐reinforced composites. [ABSTRACT FROM AUTHOR]

Introduction: Dentinal Hypersensitivity (DH) is a common clinical condition usually associated with exposed dentinal surfaces. Desensitising agents are regularly used by patients experiencing hypersensitivity, which can affect the physical properties of the existing restorative material. Aim: To evaluate the surface roughness and colour stability of four different types of composite resin restorations after exposure to a desensitising agent. Materials and Methods: The in-vitro study was conducted in the Department of Conservative Dentistry and Endodontics at Ranjeet Deshmukh Dental College and Research Centre, Nagpur, Maharashtra, India from January 2024 to March 2024. Total 56 standardised composite resin discs of size 8×2 mm thickness were prepared using four different types of composites: microhybrid, nanofilled, nanohybrid, and flowable. They were further divided into control and experimental groups based on the application of a desensitising agent, with seven samples in each subgroup. The desensitising agent was applied twice a day for three minutes for one month. Surface roughness was evaluated using a surface profilometer, and colour stability was assessed using a spectrophotometer with the Commision on Ilumination (CIE) L*a*b* formula. The data were analysed using Student's t-test for pair-wise comparison and One-way Analysis of Variance (ANOVA), with Tukey post-hoc tests for intergroup comparison. Results: The application of a desensitising agent on the samples resulted in a significantly greater effect on the surface roughness of the experimental subgroup than their control counterparts (p=0.05). Among all groups, the nanofilled group exhibited the lowest surface roughness (0.418±0.047), and the colour change (1.87±0.00) was clinically acceptable. However, the flowable group had the maximum colour change amongst all the other groups (3.16±0.00). Conclusion: Within the limitations of the study, nanofilled composite resin restorative material has minimal surface roughness and colour change after exposure to the desensitising agent. It can be considered the material of choice for restoration in patients with DH. [ABSTRACT FROM AUTHOR]

Abrasion acts to smooth glacial terrains and leaves behind linear scratch-like features (striations) on bedrock landscapes. Striations are often used as measures of glacier flow directions, but their morphology can also provide information about the subglacial stress conditions that produced the features. While striations are often abundant in the field, the processes that create them can be opaque and hard to examine in situ because they occur under thick layers of flowing ice. To alleviate that difficulty and provide information for interpretation of the populations of striations that are observed in the field, we conducted a set of laboratory experiments in which a ring of temperate debris-laden ice was slid atop a planar marble bed under various contact force conditions that led to the creation of hundreds of striations. During the experiment, numerous glaciological properties were continuously measured, including the resistive drag. Following the completion of the experiments, the marble beds were extracted, and the striations were measured for length and categorized by morphological type, and a subset was measured using a highresolution white-light profilometer. These experiments showed that, similar to field observations, type 2 striations were initially the most abundant; however, we found that type 3 striations became the most abundant at large displacements. We found good correlation between the abundance of striations as a function of displacement and measured drag as a function of displacement. When taken together, these results suggest that, in natural settings, ice flow around small roughness elements in glacier beds can “reset” the basal debris field, causing striations to become more abundant in their wake. As roughness is linked to quarrying, abrasion rates may increase in areas of increased quarrying. [ABSTRACT FROM AUTHOR]

This study investigated the effects of bleaching and microabrasion on the color and shear bond strength (SBS) of stained-remineralized caries-like lesions (s-RCLs). Human enamel specimens were demineralized, stained (coffee/tea), then remineralized (2% NaF and artificial saliva [AS]) to create s-RCLs. Specimens were randomly divided into five groups (n = 18): G1, demineralized/AS; G2, s-RCLs/AS; G3, s-RCLs/at-home bleaching (15% carbamide peroxide [CP)], 6 h/d×7)/AS; G4, s-RCLs/microabrasion (6.6% hydrochloric acid, [1min/3cycles]/AS; and G5, s-RCLs/microabrasion and at-home bleaching/AS. Color was spectrophotometrically measured at baseline, after demineralization, after staining, and after treatment. After two weeks, the SBS was tested using a universal testing machine. Outcomes were analyzed using ANOVA models followed by Tukey's test (α = 0.05). The mean colors (ΔE) for demineralization and staining were significant (ΔE ≤ 5.9 and ≤14.4, respectively). G3 (ΔE 23.9) and G5 (ΔE 25.2) were significantly improved compared to G4 (ΔE 12.3). The SBS in G5 had the highest significant value (25.2 MPa), followed by G4 and G3 (21.5–20.6 MPa), which were significantly higher than G2 (16.8 MPa). G2, in turn, was more significant than G1 (10.9 MPa). At-home bleaching (15% CP) for seven days eliminated and improved organic stains on RCLs. Faster results were achieved when combined with microabrasion. All surface treatments resulted in high SBS. [ABSTRACT FROM AUTHOR]

The surface roughness of wood mortise and tenon seriously influence the strength of mortise-and-tenon joints. However, it is difficult to obtain the whole surface roughness of mortise and tenon due to the limitation in measuring range of most profilometers. Therefore, the selection of measured position is critical to measuring the roughness of mortise and tenon. This study mainly aimed to investigate the effects of measured position in the thickness direction (T1, T2, and T3) and length direction (L1, L2, and L3), and assembly condition (unassembled and assembled) on the surface roughness of wood mortise and tenon to characterize their surface roughness. Roughness profile results showed that the average roughness of mortise (4.53 µm) was greater than that of tenon (3.89 µm), and the roughness of unassembled ones was greater than that of assembled ones. The roughness at all measured positions of unassembled mortise was nearly identical, while for unassembled tenon, roughness in the thickness direction varied. T2 was significantly greater than those of T1 and T3. Statistical analysis results showed that for an unassembled sample, sample type and measured position in the thickness direction significantly influenced roughness, but measured position in the length direction was not significant. Assembly condition significantly influenced the roughness of tenon; the roughness of assembled tenon decreased significantly compared with unassembled tenon. The roughness at T2L1 decreased so much compared with T2L2 and T2L3. It can be concluded that the roughness of mortise was mainly dominated by its grain orientation of the measured surface, which was perpendicular to the grain. The roughness of unassembled tenon varied and resulted from the tangential feeding speed of the machine changing during the manufacturing of the curved part of the tenon. The cutting speed at T2 of wood tenon was faster than those of T1 and T3, so the roughness at T2 was greater than those of T1 and T3. [ABSTRACT FROM AUTHOR]

Introduction: Non Carious Cervical Lesions (NCCLs) represent a prevalent dental condition characterised by the erosion of tooth structure at the cementoenamel junction without the involvement of dental caries. These lesions pose significant challenges due to their aesthetic impact, potential for dentinal hypersensitivity, plaque accumulation, pulpal complications and compromised structural integrity of the teeth. Tooth preparation traditionally uses diamond abrasive points and tungsten carbide burs for micromechanical adhesion. Newer methods, like ultrasonic tips, offer a more conservative approach, but limited research has compared their effects on bond strength, particularly in cervical cavity restorations with nanohybrid composites. Aim: To compare the surface roughness of cervical cavity preparations utilising diamond abrasive points and ultrasonic tips, and to evaluate the shear bond strength of restorations with composite resin. Materials and Methods: The present in-vitro comparative study was conducted in the Department of Conservative Dentistry and Endodontics, Guru Nanak Institute of Dental Sciences and Research, Panihati, Kolkata, West Bengal, India, from October 2023 to December 2023. The study included 52 freshly extracted maxillary 1st premolar teeth extracted for orthodontic reasons. These teeth were divided into two groups: Group-I (n=26) underwent surface preparation using a diamond abrasive point (No. 835-012, Piranha, SS White, USA), while Group-II (n=26) was prepared using an ultrasonic tip (Woodpecker G 20, Guilin Woodpecker, China). Teeth were cleaned, disinfected and stored in 0.1% thymol solution before being prepared with diamond abrasive points or ultrasonic tips, following which the specimens were restored using nanohybrid composite material (Solare X, GC Corporation, Japan). Surface roughness was assessed using a digital profilometer before the restoration, and the shear bond strength of repaired specimens was measured with a Universal Testing Machine. Statistical analysis was performed using GraphPad Prism, with independent samples t-tests applied to compare results between groups, and a significance level set at 5%. Results: Group-I exhibited greater surface roughness (6.33±2.18 μm) compared to Group-II (4.91±1.57 μm). Group-I also showed higher shear bond strength (62±13 MPa) than Group-II (59.3±19.9 MPa), though this variation was not statistically significant (p-value=0.56). Conclusion: Within the present study’s limitations, diamond abrasive points created significantly greater surface roughness compared to ultrasonic tips. However, no statistically significant variations have been observed in shear bond strength among the two methods, suggesting that ultrasonic tips may be considered as an alternative to diamond abrasive points in clinical settings, avoiding their drawbacks while achieving adequate restoration retention.

Introduction: Dentinal Hypersensitivity (DH) is a common clinical condition usually associated with exposed dentinal surfaces. Desensitising agents are regularly used by patients experiencing hypersensitivity, which can affect the physical properties of the existing restorative material. Aim: To evaluate the surface roughness and colour stability of four different types of composite resin restorations after exposure to a desensitising agent. Materials and Methods: The in-vitro study was conducted in the Department of Conservative Dentistry and Endodontics at Ranjeet Deshmukh Dental College and Research Centre, Nagpur, Maharashtra, India from January 2024 to March 2024. Total 56 standardised composite resin discs of size 8×2 mm thickness were prepared using four different types of composites: microhybrid, nanofilled, nanohybrid, and flowable. They were further divided into control and experimental groups based on the application of a desensitising agent, with seven samples in each subgroup. The desensitising agent was applied twice a day for three minutes for one month. Surface roughness was evaluated using a surface profilometer, and colour stability was assessed using a spectrophotometer with the Commision on Ilumination (CIE) L*a*b* formula. The data were analysed using Student’s t-test for pair-wise comparison and One-way Analysis of Variance (ANOVA), with Tukey post-hoc tests for intergroup comparison. Results: The application of a desensitising agent on the samples resulted in a significantly greater effect on the surface roughness of the experimental subgroup than their control counterparts (p≤0.05). Among all groups, the nanofilled group exhibited the lowest surface roughness (0.418±0.047), and the colour change (1.87±0.00) was clinically acceptable. However, the flowable group had the maximum colour change amongst all the other groups (3.16±0.00). Conclusion: Within the limitations of the study, nanofilled composite resin restorative material has minimal surface roughness and colour change after exposure to the desensitising agent. It can be considered the material of choice for restoration in patients with DH.

This paper presents issues related to the assessment of the texture of aggregate concrete (EAC) surfaces using various methods for its verification. Microtexture was assessed using the British Pendulum Tester (BPT) and Dynamic Friction Tester (DFT). Two laser profilometers were used to assess macrotexture, circular texture meter (CTM) and stationary laser profilograph (SPL), as well as the commonly known volumetric method. Measurements were carried out on left and right tracks and in between them on five test sections of expressways. Based on the analyses performed, it was found that the results obtained by the DFT were less sensitive to changes in microtexture between individual tracks compared to the results obtained by the BPT. The BPN values in the left track were lower than those in the right track. However, the difference between the DFT20 results in these spots was insignificant. Both MPD and MTD values did not show significant differences between the right and left tracks. However, some differences were observed between the MPD parameters obtained using the CTM and SPL. This resulted from the different frequency and length of the scanned surface profile. However, the differences were at an acceptable level. A very high linear correlation was obtained in the case of BPN and DFT20 values (r − 0.719), and in the case of MPD and MTD values, the correlation was almost certain (r above 0.900). Based on a comparative analysis of the models estimating mean texture depth (MTD/ETD), a significant difference was observed between models based on EAC pavement results and those based on asphalt surfaces. [ABSTRACT FROM AUTHOR]

This article discusses a comparative analysis of the wear and quality of planer knife blades used in wood planers. The novelty in this work is the use of a simple coordinate measuring machine with a vision system to assess the wear of the cutting edges of planer knives. The primary objective of the research described in this paper was to verify whether the wear of the cutting edge of planer knives can be measured quickly and accurately using an optical coordinate measuring machine with a vision system. To date, contact profilometry methods have been used for this purpose, which require a specialist apparatus and qualified measuring equipment operators and are expensive and time-consuming. The research presented in this work was conducted on twelve planer knives. The condition and wear of the working surfaces of the tested knives were assessed using an optical digital microscope. The wear of the cutting edge of the knives was measured using two methods: the contact profilometry method and an optical coordinate measuring machine equipped with a vision system. The edge profiles and their parameters obtained by the optical method were compared to the results of measurements with a stylus profilometer. Based on the research and analyses conducted, it was found that the optical method used in this research significantly shortens the time of measuring the wear of the cutting edges of planer knives. In addition, this method has a wider measurement range, and the obtained measurement results are characterized by lower measurement uncertainty. [ABSTRACT FROM AUTHOR]

Wearable technology excels in estimating kinematic and physiological data, but estimating biological torques remains an open challenge. Deformation of the skin above contracting muscles—surface‐level muscle deformation—has emerged as a promising signal for joint torque estimation. However, a lack of ground‐truth measures of surface‐level muscle deformation has complicated the evaluation of wearable sensors designed to measure surface‐level muscle deformation. A non‐contact methodology is proposed for ground‐truth measurement of surface‐level muscle deformation using a 2D laser profilometer. It shows how three metrics of surface‐level muscle deformation—peak radial displacement: r = 0.94 ± 0.05, surface curvature: r= 0.78 ± 0.10, surface strain: r = 0.83 ± 0.12—correlate strongly to changes in volitional elbow torque, further exploring the impact of measurement location or joint angle on these relationships. A nonlinear, lead‐lag relationship between surface‐level muscle deformation and torque is also found. The findings suggest that surface‐level muscle deformation is a promising signal for non‐invasive, real‐time estimates of torque. By standardizing measurement, the methodology can help inform the design of future wearable sensors. [ABSTRACT FROM AUTHOR]

Applications for an antenna structure produced with additive manufacturing technology are numerous and promising. This study focuses explicitly on utilizing micro‐laser sintering (MLS) three‐dimensional (3D) printing technology to fabricate two rectangular horn antennas identical to a standard Pasternack® horn antenna, making the fabrication straightforward. The objective is to investigate how surface roughness affects antenna performance in a frequency range of 18 to 26.5 GHz. One antenna is polished and the other is left untouched, resulting in surface roughness of 4 and 6 µm, respectively, measured using a profilometer. Then, a vector network analyzer was used to assess their reflection coefficient, transmission characteristics, and radiation pattern and determine gains of 8.83 and 9.14 dBi for the polished and unpolished antennas, respectively. The study finds that both polished and unpolished antennas perform similarly, and their characteristics closely resembling simulated and standard antennas. Finally, the performance of the MLS‐printed metallic antennas is compared with horn antennas created using other 3D printing techniques. It reveals that the MLS‐printed metallic structures exhibit better performance, indicating that the MLS technology has great potential to print 3D metallic electromagnetic designs. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate how two different polishing techniques affect the color stability, surface roughness, and changes in surface morphology of aged and coffee-stained bulk-fill resin composites. A total of 112 disc-shaped samples were prepared using Omnichroma Flow Bulk (OB), Charisma Bulk Flow One (CB), Estelite Bulk Fill Flow (EB), and Estelite Sigma Quick (control). Samples were divided into two subgroups (n = 16) and aged using thermocycling. A profilometer was used to measure the surface roughness (Ra) and a spectrophotometer was used for color stability (ΔE00). The EB group had the highest Ra values both before aging (disc: 0.23 ± 0.05, twist: 0.42 ± 0.05) and after aging (discs: 0.28 ± 0.04, twist: 0.46 ± 0.05). The OB group had the highest ΔE00 values before and after aging (discs: 3.06 ± 0.54, twist 3.05 ± 0.41) and the highest after coffee-staining (discs: 3.75 ± 0.70, twist: 3.91 ± 0.57). Re-polishing reduced the ΔE00 values in all materials but did not restore all to clinically acceptable levels. According to the results of this study, it can be concluded that the surface roughness and color stability of resin composites are notably influenced by the polishing technique, aging process, and coffee staining. Specimens that were polished using the multi-stage Super-Snap discs consistently exhibited smoother surfaces across all bulk-fill resin composites compared to those polished with the two-stage Diacomp plus Twist. [ABSTRACT FROM AUTHOR]

The article attempts to analyze the possible effects of using Ti−C:H DLC carbon coatings produced by pulsed magnetron sputtering (PVD) to reduce friction coefficient and wear in kinematic pairs found in internal combustion engines and powertrain systems used in automotive vehicles. The aim of such action is primarily to reduce internal losses in the aforementioned units. The coatings were deposited on heat-treated bearing steel 100Cr6, and examined using a scanning electron microscope FEI Quanta 200 Mark II with the chemical analyzer EDS EDAX Genesis XM 2i, tribotester T−01M examining the friction coefficient in the ball-disc correlation and Hommel Werke T8000 profilometers, additionally, in order to check the coating thickness, studies were carried out using the Calotest method. The results obtained indicate that both the friction coefficient and wear are drastically reduced concerning samples on which no DLC coatings were applied. [ABSTRACT FROM AUTHOR]

Background Metal-free ceramic veneers exhibit many desirable properties. However, low fracture strength is a major disadvantage. The success of the veneers depends on optimal tooth preparation and intaglio surface preparation techniques for bonding porcelain substrates to the tooth to ensure clinical success. This study was conducted to evaluate the influence of acid etching technique on surface roughness and fracture strength of veneers. Methods The in vitro study was conducted on maxillary central incisors that were prepared to receive the veneers; the specimens were divided into two groups—group A and group B. The intaglio surface of veneer in both groups was etched with 4.6 % of the hydrofluoric acid solution for 30 seconds, in group B specimens were further treated with 33% sodium hypochlorite solution treatment following which the surface roughness was measured and calculated with scanning electron microscope at a magnification of 3000X and profilometer, respectively. The fracture strength of the specimens in both groups was determined by subjecting the tooth with veneer to a universal testing machine; the force was applied until the fracture occurred. Results There was a significant difference observed in the surface roughness, fracture strength, and bond strength of the heat-pressed lithium-disilicate veneers treated solely with hydrofluoric acid and samples treated with hydrofluoric acid and phosphoric acid. Conclusion Optimizing porcelain surfaces before treatment with various adhesives and luting resins requires an understanding of the involved substrates and materials, as well as a logical and systematic methodology in their manipulation. The intaglio surface of the veneers treated with hydrofluoric acid followed with phosphoric acid has no significant difference observed in the properties of the veneers but has better bonding with the tooth structure. [ABSTRACT FROM AUTHOR]

Due to their contactless and fast measuring capabilities, laser interferometers represent an interesting alternative to tactile stylus instruments for surface profilometry. In addition to these outstanding attributes, acquisition costs play a major role in industry, limiting the frequent use of optical profilometers, which are significantly more expensive than tactile profilometers. We present a low-cost laser distance-measuring interferometer featuring axial repeatability below 1 nm at acquisition rates of 38,000 height values per second. The sensor's performance is validated on several surface standards, achieving lateral scan velocities up to 160 mm/s. Further to high scan velocities, the high acquisition rate enables improved measurement accuracy by averaging measured height values. For example, the standard deviation of 625 pm for repeated measurements can be reduced to 265 pm at the expense of the data rate. However, the sensor concept provides the potential for further improvements in data rate and measurement repeatability. [ABSTRACT FROM AUTHOR]

The engineering behavior of rock masses is controlled more by the strength of the discontinuity surfaces than by the strength of the intact rock. Asperity angles play a very important role in the shear strength of discontinuity surfaces. The strength of discontinuity surfaces can be determined by direct shear tests in the laboratory. However, it is not always possible to obtain suitable discontinuity surfaces from natural discontinuities in the field and place them in the shear test device. In this study, in addition to direct shear tests on 9 different rocks, basic friction angles (φb ) were determined with a tiltmeter device and the second degree asperity angles (i) on the discontinuity surfaces were determined with an electromechanical profilometer device. From these two values, the total friction angles were obtained (φ1 = φb + i). These values were compared with the results of φb andφ1 obtained from Patton’s bilinear failure envelope by direct shear tests under different normal stresses and their compatibility was evaluated. It was determined that the failure envelopes obtained from direct shear tests performed at different normal stress levels comply with the Patton bi-linear failure model for all 9 specimens. According to the results obtained, when the basic friction angles and total friction angles obtained from direct shear tests were compared with the values obtained from profilometer and tiltmeter tests; it was determined that the basic friction angles were in a very high level of agreement for all 9 rocks tested (R² = 0.91). Total friction angles can be obtained with high accuracy except for two rocks (granodiorite and marble) with high strength (R² = 0.86). It was concluded that basic friction angles and total friction angles can also be obtained by profilometer and tiltmeter tests whenever it is not possible to direct shear tests. [ABSTRACT FROM AUTHOR]

ABSTRACTThe surface roughness of the textile materials is one of the crucial features influencing the appearance and functionality of fabrics and products made of them. The surface roughness of textile materials can be measured using the contact or non-contact methods. In the presented work, the non-contact method using the MicroSpy® Profile profilometer was applied to assess the quality of surface of the cotton woven fabrics of plain and 3/1S twill weave. Determination of surface geometry parameters and functions was done using the Mark III software according to the DIN EN ISO 4287 standard. Results showed that the twill woven fabric is characterized by greater roughness than the plain woven fabric. The profiles created along the warp and weft have different shapes dependably on fabric weave. The autocorrelation function reflects the weave pattern of the woven fabrics. Performed investigations confirmed that the non-contact method of measurement of fabric surface geometry by means of the profilometer provides very detailed and complex data about the fabrics’ surface quality.

The precision requirements for aeroengine blade machining are exceedingly stringent. This study aims to improve the accuracy of existing aeroengine blade measurement methods while achieving comprehensive measurement. Therefore, this study proposes a new concentric ring calibration method and designs a multi-layer concentric ring calibration plate. The effectiveness of this calibration method was verified through actual testing of standard ball gauges. Compared with the checkerboard-grid calibration method, the average deviation of the multilayer concentric ring calibration method for measuring the center distance of the standard sphere is 0.02352, which improves the measurement accuracy by 3–4 times. On the basis of multi-layer concentric ring calibration, this study builds a fringe projection profiler based on the three-frequency twelve-step phase shift method. Compared with the CMM, the average deviation of the blade chord length measured by this solution is 0.064, which meets the measurement index requirements of aeroengine fan blades. [ABSTRACT FROM AUTHOR]

Resin infiltration is an effective method to mask vestibular white spots. If needed, external bleaching is usually recommended before infiltration, whilst in clinical practice, this sequence may not always be feasible. This in vitro study evaluated the effect of bleaching after resin infiltration regarding surface roughness and color using bovine incisors. Unlike for the untreated specimens (control, n = 25), artificial caries lesions were created within the test group (n = 25) using a demineralization solution at 37 °C for five days (pH = 4.95). The lesions were subsequently infiltrated using a resin infiltrant (Icon, DMG, Hamburg, Germany), followed by polishing. Afterwards, all specimens were bleached with a 10% carbamide peroxide gel (Opalescence, Ultradent, South Jordan, UT, USA) for 8 h/day over a ten-day period. Between bleaching treatments, specimens were stored in an opaque container with moistened paper tissues at 37 °C. Surface roughness was measured using a profilometer, and color in the L*a*b* space was assessed spectrophotometrically before and after bleaching. Bleaching increased the L*-values of both infiltrated (mean ± SD; ΔL* = 3.52 ± 1.98) and untreated (control) specimens (ΔL* = 3.53 ± 2.30) without any significant difference between the groups (p = 0.983). Bleaching also induced a significant increase in the mean surface roughness of both infiltrated (p < 0.001) and untreated (p = 0.0134) teeth. In terms of clinical relevance; it can be concluded that bleaching resin-infiltrated enamel is as effective as bleaching sound enamel. [ABSTRACT FROM AUTHOR]

In this work, a novel approach involving coating fine PEEK powder on prepreg is introduced to improve wedge peel strength and reduce interlaminar voids. CF/PEEK laminates with resin interleaving are in situ consolidated by laser-assisted fiber placement. The morphology of the powdered surface is obtained using an optical profilometer, and the surface roughness and volume of added resin are calculated accordingly. Interface and surface temperature are measured during the layup process. Thermal history indicates that very short bonding time is the dominating factor for voids and limited interlayer strength. Laminate porosity and microscopic features are characterized with an optical microscope. The porosity of resin-interleaved laminates decreases to 3.7%, while the resin content only increases by 4.5% in the meantime. This is because interlayer resin particles rapidly melt under laser heating and quickly fill the voids between layers. The wedge peel strength of resin-interleaved laminates can increase by 30.1% without a repass treatment. This could be attributed to the increase in resin intimate contact and reduction in interlayer voids. [ABSTRACT FROM AUTHOR]

The measurement of the longitudinal rail profile is relevant to the condition monitoring of the rail infrastructure. The running surface is recognizable as a shiny metallic area on top of the rail head. The detection of the running surface is crucial for vehicle-based rail profile measurements, as well as for defect detection. This paper presents a methodology for the automatic detection of the running surface based on a laser profilometer. The detection of the running surface is performed based on the light reflected from the rail surface. Three rail surfaces with different surface conditions are considered. Supervised machine learning is applied to classify individual surface elements as part of the running surface. Detection by a linear support vector machine is performed with accuracy of > 90 % . The lateral position of the running surface and its width are calculated. The average deviation from the labeled widths varies between − 1.2 m m and 5.6 m m. The proposed measurement approach could be installed on a train for the future onboard monitoring of the rail network. [ABSTRACT FROM AUTHOR]

In this work, a number of geometrical parameters related to the microgeometry of the cutting edge, such as rounding radius r, maximum clearance wear VBmax and a number of others, were determined. Tools for processing wood materials made of WC-Co cemented carbide with a PVD coating based on Ti and Al. were blunted until the wear indicator VBmax reached the value of 0.2 mm. The cutting blades prepared in this way were tested using a contact profilometer. Based on the data obtained in this way, an analysis of the blade contour over a length of 10 mm was carried out in the AutoCad environment. This section included both the blunted part and the part not involved in the cutting process. Correlations obtained using a procedure written in Visual Basic for Applications using elements of statistical data analysis built into the Excel program, between the selected rounding asymmetry coefficients denoted with letter K and the blade wear indicators proposed in the tests were analyzed. Geometric indicators were also determined, taking into account the working conditions of the tool, affecting the process of its blunting, such as e.g. h (uncut chip thicknesses). [ABSTRACT FROM AUTHOR]

Hard alloy end mills are commonly employed for milling zirconia prostheses in dentistry. Nano-diamond-coated milling bits ensure high processing efficiency, accuracy, extended tool life, and reduced processing costs. This study aims at comparing various effects of cutting dental zirconia with nano-diamond-coated and ordinary milling bits. Two types of milling bits, one with nano-diamond coating and one without, were used to cut the dental zirconia green blanks (Ø98.5 mm, thickness: 25 mm) at three different speeds (1000, 1500, and 2000 rpm) in a dental milling machine. The unsintered and sintered zirconia surfaces were evaluated with glossmeter, optical profilometer for surface roughness, SEM, and EDX. The glossiness of the sintered zirconia block was statistically higher than that of the unsintered block (p < 0.05). For sintered zirconia, the nano-diamond-coated milling bit yielded a statistically (p < 0.05) higher glossiness in all spindle speeds than uncoated, save for the uncoated milling bit used at 1500 rpm. However, in terms of roughness, only sintering showed to be a statistically significant factor (p < 0.001) outweighing other two factors, and sintered zirconia always yielded lower surface roughness than the unsintered counterpart. Overall, the nano-diamond-coated milling bit can be operated at various speeds, resulting in a higher gloss on the sintered zirconia block, while an ordinary, uncoated milling bit can only achieve the same glossiness at a designated speed. The type of milling bits and the speeds have no significant effect on the surface roughness. [ABSTRACT FROM AUTHOR]

This study was motivated by the need for a road profile monitoring concept that can provide frequent measurements over large areas across all weather conditions. A profile inversion method was proposed in this context, based on measured in-vehicle accelerations alongside speed and location information. The method combined a quarter-car response model, a proportional-integral-derivative controller, and a nonlinear error minimization algorithm. In general terms, the underlying idea for profile inversion was centred around best-matching measured accelerations with accelerations calculated in a precalibrated quarter-car response model. The new method was first verified with synthetic/manufactured acceleration traces. Next, it was applied to real data obtained from 10 nominally identical electric cars that were driven over highways and urban roads. Inverted road profiles were compared to those measured by a standard laser profilometer. Very good match and reproducibility metrics were obtained, especially for highways, indicating that the new method is potentially useful as a large-scale road profile monitoring concept. [ABSTRACT FROM AUTHOR]

Composite is usually a mixture of two phases. The composites used in dentistry have high durability. The individual properties of each phase are important to increase the mechanical property of the composite. This study aimed to determine the surface roughness changes of two composite resin restorative materials after thermocycling. Two of the commercially available composites were chosen (Nanocomposite 3M Z350 and Nanohybrid composite 3M Z250). The composite disks of dimension 10mm diameter and 3mm height were prepared using silicone molds, and every increment was light cured for 30s. A stylus profilometer was used to assess the surface roughness pre thermocycling, and then, the disks were subjected to an integrated thermocycler (T.S-4.4) for 1000 cycles. The post surface roughness was obtained after the thermocycling process using the same stylus profilometer. The surface parameter values before and after thermocycling of the 3M Z350 sample is less than that of 3M Z250. There was a significant difference between the Rz and Rq values of the two different commercially available composite materials. Thus, the present study concludes that thermocycling influenced the surface roughness of composite resin and increased the surface roughness of both the 3M Z250 & Z350 composites. [ABSTRACT FROM AUTHOR]

Fused Deposition Modeling (FDM) finds extensive application across various fields due to its cost-effectiveness and user-friendly nature. However, it does come with certain limitations, including challenges in achieving high surface quality, precise dimensional tolerance, and the characteristic anisotropic mechanical properties it exhibits. The aim of this paper is to investigate the machinability of 3D-printed PETG and analyze the roughness and burr formation that occurs as a result. A Design of Experiments (DoE) was developed with three factors: rotational speed, feed rate, and depth of cut. Each factor had different levels: rotational speed at 3000, 5500, and 8000 rpm; feed rate at 400, 600, and 800 mm/min; and depth of cut at 0.2, 0.4, 0.6, and 0.8 mm. The machinability was evaluated based on two response parameters: roughness (Sa), determined on the milled surface, and burr height, measured using a profilometer on both sides of the milled surface. The findings indicate that milling parameters strongly affect roughness and burr formation. However, the optimal conditions for minimizing roughness and burr formation are not coincident. The results were also compared to the machinability of PLA machined under similar conditions. [ABSTRACT FROM AUTHOR]

This study introduces a metrological approach to measure the aerodynamic shape and the twist of a wind turbine blade. The optical profilometer measurement technique used is laser triangulation. A camera records the image of a line projected onto a section of the blade and, by reconstructing the airfoil shape, the twist angular position of the profile with respect to the axial line of the blade is determined. This methodology is applied to test different sections of a Wortmann FX 63-137 airfoil with a length of 1700 mm. The results of the aerodynamic shape and twist angle are quantitatively verified by comparing them with the ideal or design values. The reconstruction process achieved a resolution of 0.06 mm, and measurement errors in the twist angular position were less than 0.1°. The presented method is efficient, accurate, and low cost to evaluate the blade profiles of low-power wind turbines. However, due to its easy implementation, it is expected to be able to measure any full-scale wind blade profile up to several meters in length. [ABSTRACT FROM AUTHOR]

Purpose This study aimed to evaluate the effects of different polishing protocols on the surface properties and color stability of the polyetheretherketone (PEEK). Materials and Methods A total of 96 disc-shaped specimens were fabricated from PEEK material and divided into 6 different groups: control (CN), "Abraso-Starglanz" polishing paste (A), "Yildiz" polishing paste (Y), "Enhance" polishing system (EN), "Super snap" polishing kit (SS), and silicone polisher (SP). Surface roughness (Ra) were measured with a profilometer and the surface topography was examined under scanning electron microscope. Color differences were measured with a spectrophotometer according to the CIEDE2000 (ΔE00) formulation before and after coffee immersion. Data were statistically analyzed with Kruskall-Wallis and Spearman's correlation analysis (p<0.05, p<0.001). Results A statistically significant difference was observed between the Ra measurements of the polishing protocols (p<0.001). Ra measurements except A, Y, and SS groups were found to be higher than the clinical acceptable threshold of surface roughness (0.20 µm). In ΔE00 measurements, statistically significant differences were observed between the CN and SP (p=0.041), EN (p=0.001), and A (p=0.002) polishing protocols. No correlation was found between Ra and color stability. Conclusion Only in the A, Y and SS polishing protocols, Ra measurements were not found to be risky in terms of acceptable threshold of surface roughness. Polishing protocols have also generally failed to maintain the color stability. Considering the surface roughness and color stability, the "Abraso-Starglanz" paste may be suitable method for PEEK material. [ABSTRACT FROM AUTHOR]

Copyright of Materials & Technologies / Materiali in Tehnologije is the property of Institute of Metals & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe the use of geomorphometric methods for studying thin-film structures in microelectronics. In particular, we developed a method for processing data from measuring equipment (optical profilometer and spectral ellipsometer) to calculate maps of mechanical stress distribution considering a complex (i.e., nonspherical) shape of structures (that is, nonuniform deformation) and nonuniform film thickness. The results of calculations for SiO2/Si and GaN/Al2O3 structures are presented. The calculated value of mechanical stresses for SiO2: σ ≤ 300 MPa. A relationship was obtained between the highest values of mechanical stress and volumetric defects for GaN. Geomorphometric methods are effective for (1) preparation of initial experimental data for the purpose of subsequent calculation of second partial derivatives (which are necessary for computation of mechanical stresses from the topographic data of structures); (2) direct calculation of curvature maps for subsequent determination of mechanical stresses; and (3) qualitative assessment of local topographic features poorly manifested on the initial topographic maps, which are directly related to the areas of the highest mechanical stresses. [ABSTRACT FROM AUTHOR]

Due to their contactless and fast measuring capabilities, laser interferometers represent an interesting alternative to tactile stylus instruments for surface profilometry. In addition to these outstanding attributes, acquisition costs play a major role in industry, limiting the frequent use of optical profilometers, which are significantly more expensive than tactile profilometers. We present a low-cost laser distance-measuring interferometer featuring axial repeatability below 1 nm at acquisition rates of 38,000 height values per second. The sensor’s performance is validated on several surface standards, achieving lateral scan velocities up to 160 mm/s. Further to high scan velocities, the high acquisition rate enables improved measurement accuracy by averaging measured height values. For example, the standard deviation of 625 pm for repeated measurements can be reduced to 265 pm at the expense of the data rate. However, the sensor concept provides the potential for further improvements in data rate and measurement repeatability.

Average surface height and maximum amplitude can affect surface functions. In the industry, these parameters can be obtained based on profile measurements. However, variability in maximum profile height is high. A more stable parameter can be obtained from the results of the areal surface topography measurements as the average value of the parallel profiles. The aim of this study is to establish this parameter directly from the result of the areal surface texture by correcting the maximum surface height to material ratios in the range of 0.13–99.87%. This method was tested by measuring 100 surface topographies with a stylus profilometer and a white light interferometer. It can be utilized correctly for deterministic textures and random one- and two-process surfaces for which the correlation between neighboring profile ordinates is not very high. In other cases, the method should be modified. Employing this method, the maximum profile amplitude Pt and parameters characterizing the average profile height Pq, Pa, and the ratios Pq/Pa and Pp/Pt describing the shape of the profile ordinate distribution can be correctly estimated. Pq/Pa and Pp/Pt were more stable than the kurtosis Pku and skewness Psk. The corrected maximum height S±3σ can be adopted as a parameter that characterizes the areal surface texture as more stable than the maximum surface height St. Pq/Pa and Pp/Pt were more steady than kurtosis Pku and skewness Psk. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the delamination of convex-shaped metformin HCl (MF) and evogliptin tartrate (EG) multi-layer tablets depending on the pre-compression and main compression pressures and simultaneously correlate these results with those of a surface roughness analysis. Free-flowing MF and EG (median diameters of 38.3 and 44.7 μm, respectively) granules prepared using the wet granulation method were pre-compressed and subsequently compressed into bilayer and trilayer tablets using a universal testing machine. The compaction force required to break the tablets increased linearly as the main compression pressure increased (30–150 MPa). Conversely, the interfacial strength and compaction breaking force decreased as the pre-compression pressure increased (10–110 MPa). A surface roughness analysis employing a profilometer revealed that the first layer (MF) roughness drastically decreased from 5.89 to 0.51 μm (Ra, arithmetic average of profile height deviations from the mean line) as the pre-compression pressure increased from 10 to 150 MPa in the bilayer tablet. Accordingly, the decrease in the roughness of the first layer reduced the inter-penetration at the interface, as observed via energy dispersive spectrometer (EDS)-equipped scanning electron microscopy, decreasing the interfacial bonding strength and causing delamination of the MF/EG multi-layer tablets. These findings indicate the significance of roughness control in the actual preparation of multi-layer tablets and the usefulness of profilometer- and EDS-based surface analyses for interpreting the delamination of multi-layer tablets. [ABSTRACT FROM AUTHOR]

The main goal of this study was to verify the best combination of density, moisture content, and feed speed on the surface quality of Pinus elliottii boards aimed at deck manufacturing. The secondary goal was to compare three methods of surface quality assessment. Tangential boards were sampled and sorted by density (level 1: 414 kg·m-3 to 525 kg·m-3; level 2: 526 kg·m-3 to 668 kg·m-3) and moisture content (level 1: 13.5% to 17.5%; level 2: 17.6% to 20.0%). A four-side planer molder was used, at three levels of feed speed (15, 20, and 25 m·min-1). Surface quality was assessed immediately after machining by visual-tactile analysis, stylus surface profilometer reading (parameters Ra, Rz, and Rt), and feed per tooth (fz) measurement. The best surface quality results were obtained with denser (526 kg·m-3 to 668 kg·m-3) and wetter boards (17.6% to 20.0% moisture content) at feed speed 20 m•min-1. This recommendation represents an optimal balance between the quality standard of the deck boards and high productivity. Because of the low cost and because it has some correspondence with the stylus surface profilometer readings, visual-tactile analysis is recommended to assess the surface quality. [ABSTRACT FROM AUTHOR]

Statement of Problem: Direct resin composite bonding offers a highly esthetic, minimally invasive option for the treatment of anterior teeth however the challenge to improve their longevity remains. Direct resin composite restorations are limited by the risk of staining which may be influenced by the final surface roughness (Ra) of composite achieved. Purpose: The purpose of this review is to investigate, using a systematic approach, whether the final surface roughness of anterior composite restorations is affected by the interaction between resin composite and polishing systems. Materials and Methods: The review was conducted by 3 independent reviewers and included articles published up to January 21, 2021. Three electronic databases were searched: Medline, Embase, and Web of Science. Studies assessing a quantitative effect of polishing methods on the Ra of direct composite resin materials published after the year 2000 and restricted to the English language were included. Results: The database search for the effect of polishing systems on composite materials retrieved 125 eligible studies. Twelve duplicate records were removed. The resulting records were screened using title and abstract leading to 38 reports which were sought for retrieval. Application of eligibility criteria led to 11 studies included in the review. Hand searching of these studies yielded no additional papers. Conclusions: There is insufficient evidence to determine whether combination of composite and polisher influences final Ra. More research is required to determine if there is an optimum combination of polisher and composite. Clinical Implications: Polishing should be completed following planned finishing procedures. The approximation to the final surface and which finishing burs to use, if any, should be considered when planning a restoration. Durafill VS predictably achieves an acceptable Ra by different polishers. [ABSTRACT FROM AUTHOR]

The present work proposes an innovative method to form microgrooves on a tube's internal surface through new machining based on the principle of the closed magnetic circuit. A newly designed machine with a magnetic grooving tool was fabricated. The tool consists of a pair of magnets positioned in the pipe to be pulled by another pairing magnet set at the pipe's external side, arranged in sequence of N−S−N−S direction so that it creates a closed magnetic field that has a greater pulling force. By controlling the magnet pair at the pipe's external side in the linear and rotational direction, the magnetic grooving tool is moved in both directions and simultaneously pulled towards the pipe surface to form the microgrooves. The experiment was carried out by adjusting the magnet's size combination and its distance to vary the magnetic strengths. The grooving dimension was examined by using an optical microscope and analysed using a 3‐dimensional laser profilometer surface analyser. With N52 class Nd2Fe12B neodymium (40×10×10 mm3), the maximum groove depth of 75.51 μm was recorded and the minimum depth of 2.33 μm was recorded by using magnet size 10×10×10 mm3. The method is capable to produce microgrooves on the copper pipe's internal surface. [ABSTRACT FROM AUTHOR]

For evaluation and comparison of the effect of surface treatment (glazings, polishing with rubber wheel and diamond paste, and polishing with rubber wheel) on pressable porcelain (IPS Emax porcelain) surface roughness in comparison with nontreated surface. Forty-disc shaped specimens of baseplate wax with 10 mm diameter and 2 mm thickness have been prepared. They were invested and subjected to lost wax technique in fabricate the pressable ceramic. Following pressing, they have been divided randomly into four groups: Group A: no surface treatments, Group B: glazing (paste, HT, Ivoclar, Vivadent, Germany) glazing (paste, HT, Ivoclar, Vivadent, Germany), Group C: polishing with burs (DIAPRO TWIST, EVE, GmbH, Germany), and Group D: polishing with burs (DIAPRO TWIST, EVE, GmbH, Germany) and diamond paste (All in one, RENFERT, GmbH, Germany). For each specimen, examination of mean roughness profile (Ra) was performed for total surface roughness description. Specimens were stabilized with the acrylic holder used previously in the initial polishing procedure. A contact stylus profilometer was used to conduct a quantitative measurement of surface roughness in micrometers (µm) for all specimens. The highest (Ra) value was for control group (1.9520), whereas the lowest values were in group D (Polishing by rubber wheel .4670. One-way ANOVA test showed a high significant value at (P <. 000), and LSD test showed a high significant value at (P <. 000) when comparison was established among groups. From the results of the current study, we can conclude the following; polishing procedure for the surface of pressable ceramic with or without diamond paste produced better surface smoothness than glazed surface and non-treated surface and polishing with burs could be an alternative to glazing to provide smooth surface. [ABSTRACT FROM AUTHOR]

Seersucker woven fabrics are characterized by their unique structure and properties. Surface topography is a crucial feature of the seersucker woven fabrics. It influences the appearance and performance of fabrics. Till now, no testing method has been developed to assess the seersucker woven fabrics from the point of view of their surface geometry and to quantify the seersucker effect. In the present work, the non-contact optical method has been used to determine the parameters and functions characterizing the surface geometry of the cotton seersucker woven fabric. The aim of this work was to analyse the possibility of use of the MicroSpy® Profile profilometer in complex characterization of the investigated fabric and separately the flat and puckered areas of the fabric. The obtained results confirmed that the selected surface parameters and functions are able to distinguish both phases of the seersucker woven fabric: flat and puckered. The results are the starting point for further investigations of the seersucker woven fabrics in order to quantify the seersucker effect. [ABSTRACT FROM AUTHOR]

Objectives: To develop and validate a simple approach for building cost-effective imaging phantoms for Cone Beam Computed Tomography (CBCT) using a modified Polyjet additive manufacturing technology where a single material can mimic a range of human soft-tissue radiation attenuation. Materials and Methods: Single material test phantoms using a cubic lattice were designed in 3-Matic 15.0 software . Keeping the individual cubic lattice volume constant, eight different percentage ratio (R) of air: material from 0% to 70% with a 10% increment were assigned to each sample. The phantoms were printed in three materials, namely Vero PureWhite, VeroClear and TangoPlus using Polyjet technology. The CT value analysis, non-contact profile measurement and microCT-based volumetric analysis was performed for all the samples. Results: The printed test phantoms produced a grey value spectrum equivalent to the radiation attenuation of human soft tissues in the range of −757 to +286 HU on CT. The results from dimensional comparison analysis of the printed phantoms with the digital test phantoms using non-contact profile measurement showed a mean accuracy of 99.07 % and that of micro-CT volumetric analysis showed mean volumetric accuracy of 84.80–94.91%. The material and printing costs of developing 24 test phantoms was 83.00 Euro. Conclusions: The study shows that additive manufacturing-guided macrostructure manipulation modifies successfully the radiographic visibility of a material in CBCT imaging with 1 mm3 resolution, helping customization of imaging phantoms.

Abstract Background Dentists started to follow the era of using single-shade resin composite restorations to avoid color shade selection. Our study was done to evaluate and compare the color stability of two single-shade resin composite materials. Methods Sixty samples were randomly allocated into two main groups (n = 30) according to the composite resin used: Group O: (Omnichroma) samples and Group V: (Venus Peral) samples. Each group was then divided into two subgroups (n = 15): group O1 and V1: samples immersed in coffee. Group O2 and V2: samples immersed in distilled water. Color changes (ΔE) and roughness values (Ra) were evaluated at baseline, first, and 14th days of immersion. The color change was assessed using Vita Easyshade V, while surface roughness was assessed using a profilometer and Atomic Force Microscope (AFM). Data were collected and statistically analyzed using two-way variance analysis (ANOVA) and Tukey's post-hoc test (p

Introduction: Surface roughness of the crowns is dependent on the pattern material used for the making as well as the procedure of investing. The study was aimed to examine the impact of various pattern materials and investment procedures on the surface roughness of nickel-chromium alloy raw castings. Materials and Methods: An in-vitro study was piloted at a tertiary care hospital. Eighty samples of inlay wax and pattern resin were divided equally. They were invested in phosphate-bonded investment material and kept under normal atmospheric pressure as well as invested under a pressure of 3 bars. The surface roughness was calculated with a Profilometer. The values obtained were compared using statistical tools keeping P < 0.05 as significant. Results: Lowest surface roughness was seen for the wax pattern invested under positive pressure. While the highest was seen for the resin patterns invested at room pressure. A significant variance between the wax 1 and wax 2 (P < 0.01); as well as between the wax 2 vs. Resin 2 specimens (P < 0.01) was noted. Conclusions: Wax patterns can be suggested as the material and method of choice because they showed the least amount of surface roughness when placed under pressure. Resin patterns when invested under pressure can also be suggested as an alternate as they also exhibited similar surface roughness as that of the wax. [ABSTRACT FROM AUTHOR]

Material Extrusion (MEX) is an Additive Manufacturing technology widely used for the fabrication of polymeric, metallic and composite parts with clear advantages. In the last decades, the growing interest of such industries like aerospace, medical, automotive and R&D has driven technological improvements of MEX to make the technology more reliable and repeatable. Although, defects and geometric dimensional inaccuracies are still known to affect the process, limiting the applicability of MEX for the realization of functional parts. Recently, in-process monitoring methods have been implemented for a rapid detection of defects and process anomalies, activating, eventually, the control of the process. In this work, an innovative layerwise monitoring methodology based on a high-resolution blue laser line profilometer applied to a MEX process, was proposed. By analyzing the point clouds of each layer, with proper quality indexes, it was possible to compute the layer height deviation and to evaluate the surface quality in terms of occurrence of defects. In particular, the quality indexes presented in this work were representative of the layer height accuracy, the occurrence and distribution of defects on the layer surface and the stability of the process (respectively the so-called indexes were ADLH, RAD and the slope s). Different process conditions were generated by varying the raster angle and the sample location on the building platform. [ABSTRACT FROM AUTHOR]

Experimental results in the processing of Scots pine (Pinus sylvestris L.). are presented in the paper. They were conducted under the manufacturing conditions. Three machines are used – two jointers with different knife spindle designs and with flat knives and replaceable rigid alloy plates – a helical cutter head, as well as a planer with flat knives. The measured parameter is Rz, and an electronic profilometer was used to measure its reading. The studies were conducted using the method of planned two-factor regression analysis. The selected factors are fundamental to the milling process – feed speed vf and radial depth of cut ae. Their levels of variation are determined on the basis of preliminary experiments, as well as the practical possibility of their realization. The results obtained with all three machines do not exceed 45 μm, and the ones for the planer make the strongest impression. [ABSTRACT FROM AUTHOR]

Background: The effects of whitening toothpastes containing nanohydroxyapatite on the surfaces of restorative materials are not well known. This study evaluated the changes in surface roughness and color of coffee-stained restorative materials after brushing with nanohydroxyapatite and other whitening toothpastes. Methods: Disc-shaped specimens were formed using microhybrid, nanohybrid, and supra-nano-filled composite (n = 30) and stained with a coffee solution. A brushing simulation was applied with toothpastes containing nanohydroxyapatite (Dentiste Plus White), perlite (Signal White System) and hydrogen peroxide (Colgate Optic White) for 7, 15, and 30 days. Color and surface roughness measurements were taken before and after brushing. Color change (?E00) was calculated using the CIEDE2000 system. Results: Supra-nano-filled composite-Dentiste Plus White, supra-nano-filled composite-Colgate Optic White, and nanohybrid composite-Signal White System were the groups with the greatest color change observed on the 7th, 15th, and 30th days, respectively. The smallest color change was seen in the microhybrid composite-Signal White System, microhybrid composite-Dentiste Plus White, and nanohybrid composite-Dentiste Plus White groups on the 7th, 15th, and 30th days, respectively. No significant surface roughness changes were observed in the nanohybrid composite-Dentiste Plus White, supra-nano-filled composite-Colgate Optic White, supra-nano-filled composite-Dentiste Plus White, or supra-nano-filled composite-Signal White System groups. Conclusions: Whitening toothpaste containing nanohydroxyapatite provided a high degree of color change in the short term and did not create significant surface roughness in nanohybrid or supra-nano-filled composites. [ABSTRACT FROM AUTHOR]

Road Roughness/Unevenness is an important parameter for the evaluation of the surface condition of a road. Roughness affects the vehicle operating cost, speed, riding comfort, safety, fuel consumption, and tire wear and tear. Every road user desires to have a smooth and comfortable riding. Roughness measurement is an important activity on highways based on which maintenance decisions are taken. IRC (Indian Road Congress) manual specifies roughness measurements to be taken at every 6 months on highways and based on the roughness index the functional overlay requirements are decided on highways. Roughness measurements using profilometers, namely Rod and Level, Dipstick, Merlin, Profiler, LiDAR, etc., give detailed surface profile measurements but are time-consuming. An alternative to profilometers is Response Type Road Roughness Measurement Systems (RTRRMS) which are installed on vehicles and measure how the vehicle responds to the pavement profile. A car-mounted fifth wheel Bump Integrator developed by CRRI in India is commonly used to measure roughness. The fifth wheel bump integrator system works through mechanical instruments producing 'bumps,' a binary, 'true or false' information, instead of 'range based' analog information produced by digital accelerometers commonly found in smartphones. Due to the difficulty in the calibration process, towing for longer distances, and complexity in recording, analyzing, and possible manual errors in recording the data, Cell Phone-based systems are becoming popular for their simplicity in measuring roughness using accelerometers embedded in the cell phone. RoadBounce is one such technology using Cell phone-based mobile Apps to measure roughness. This paper intends to present the findings of testing and evaluation of App-based roughness measurement technology for its accuracy and usability using different vehicles and mobile phones under different speeds, tire pressures, gradients, etc. [ABSTRACT FROM AUTHOR]

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article aims to assess the roughness of parting surfaces in the context of abrasive water jet technology for various materials. The evaluation is based on the feed speed of the cutting head, which is adjusted to achieve the desired final roughness, taking into consideration the stiffness of the material being cut. We used non-contact and contact methods to measure selected parameters of the roughness of the dividing surfaces. The study included two materials—namely, structural steel material S235JRG1 and aluminum alloy AW 5754. In addition to the above, the study involved using a cutting head with varying feed rates to achieve different surface roughness levels required by customers. The roughness parameters Ra and Rz of the cut surfaces were measured using a laser profilometer (laser profilometer). To ensure the accuracy of the laser profilometer, a control roughness measurement was conducted using a contact roughness gauge. The roughness values obtained for Ra and Rz from both measurement methods were plotted on a graph to illustrate their dependencies and were subsequently evaluated and compared. By measuring the roughness parameters Ra and Rz, the study was able to provide insights into the effectiveness of the cutting head's feed rates in achieving the desired roughness levels. Additionally, by comparing the results of the laser profilometer and contact roughness gauge, the accuracy of the measurement non-contact method used in the study was verified. [ABSTRACT FROM AUTHOR]