scholarly journals Surface Geometry of Four Conventional Nanohybrid Resin-Based Composites and Four Regular Viscosity Bulk Fill Resin-Based Composites after Two-Step Polishing Procedure

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mateusz Granat ◽  
Janusz Cieloszyk ◽  
Urszula Kowalska ◽  
Jadwiga Buczkowska-Radlińska ◽  
Ryta Łagocka
Keyword(s):  
Surface Roughness ◽  
Surface Structure ◽  
Smooth Surface ◽  
Nonparametric Tests ◽  
Matched Pair ◽  
Surface Geometry ◽  
Sem Images ◽  
Posterior Teeth ◽  
Cylindrical Mold ◽  
Slight Damage

Objectives. The aim of the study was to determine the quantitative and qualitative surface structure of contemporary RBCs in posterior teeth reconstructions: regular viscosity bulk fill and conventional composites, obtained after two-stage polishing procedure. Materials and Methods. Four conventional nanohybrid composites (Tetric EvoCeram, GrandioSO, Filtek Z550, and Ceram·X Mono) and four regular viscosity bulk fill composites (Tetric EvoCeram Bulk Fill, X-tra fil, Filtek Bulk Fill Posterior, and QuixFil) were tested. Samples of each RBC were prepared using PMMA cylindrical mold. After two-step polishing procedure, a surface geometry was evaluated under profilometry (Turbowave v. 7.36, Hommel-Etamic) and SEM (VEGA 3, Tescan Analytics). To evaluate differences between values, the following nonparametric tests were used: Friedman’s ANOVA, Wilcoxon’s matched-pair test, ANOVA Kruskal-Wallis, and Mann-Whitney U. Results. All conventional RBCs showed Ra values in the range of 0.20-0.26 μm. Bulk fill showed higher values in range of 0.49-1.36 μm except for Filtek Bulk Fill Posterior, which achieved 0.23 μm Ra value. SEM images of conventional RBCs were described as smooth surfaces with slight damage except for TEC, which presented smooth surface with no damage. Bulk fill composites showed rough surface, except for TBF, which presented smooth surface with slight damage. Conclusions. Regular viscosity bulk fill composites do not constitute a homogeneous group regarding surface roughness after polishing. They obtain, for the most part, poorer smoothness values after polishing than conventional RBCs.

A Parametric Analysis of the Gear Surface Roughness After Hobbing

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Lars Vedmar
Keyword(s):  
Surface Roughness ◽  
Smooth Surface ◽  
Three Dimensional ◽  
Surface Topology ◽  
Roughness Parameters ◽  
Surface Geometry ◽  
Manufacturing Method ◽  
Differentiable Functions ◽  
Involute Gears ◽  
Dimensional Surface

Hobbing is a common manufacturing method when producing helical, involute gears. In order to give the manufactured gear a controlled surface smoothness, a method to, very accurately, determine the achieved surface geometry is needed. In this report, the cutting surfaces of the tool, of which the cutting edges are the boundaries, are assumed to be plane in arbitrary directions. They are mathematically described using parametric and analytically differentiable functions. These functions give the possibility to determine the geometry of the three-dimensional surface of the manufactured gear, without any additional numeric approximations. By comparing this surface with the smooth surface of an ideal gear, the roughness of the surface can be determined. An example is given in which the surface topology and the characteristic surface roughness parameters are determined.

Monolithic Ceramics: Effect of Finishing Techniques on Surface Properties, Bacterial Adhesion and Cell Viability

2018 ◽  
Vol 43 (3) ◽  
pp. 315-325 ◽  
Author(s):  
AMO Dal Piva ◽  
LPC Contreras ◽  
FC Ribeiro ◽  
LC Anami ◽  
SEA Camargo ◽  
...  
Keyword(s):  
Mtt Assay ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Nonparametric Tests ◽  
Lithium Silicate ◽  
Gingival Fibroblasts ◽  
Sem Images ◽  
High Profile ◽  
Colony Forming Units ◽  
Monolithic Ceramics

SUMMARY Introduction: This study evaluated the morphology, biofilm formation, and viability of human gingival fibroblasts in contact with two monolithic ceramics after two different finishing techniques: polishing or glazing. For this, 92 blocks (4.5 × 4.5 × 1.5 mm) of each ceramic were made using high translucency zirconia partially stabilized by yttrium (YZHT) and lithium silicate reinforced by zirconium (ZLS). Methods and Materials: Blocks were sintered and then divided into glazing (g) or polishing (p) surface finish. Surface roughness (Ra and RSm) was evaluated through a contact rugosimeter and profilometry. Specimens were contaminated for heterotypic biofilm formation with Streptococcus mutans, Streptococcus sanguinis and Candida albicans for 16 hours. Biofilm was quantified by counting the colony forming units (CFU/mL) and analyzed by scanning electron microscopy (SEM). Fibroblast viability was evaluated by MTT assay. Surface free energy (SFE) was also determined. Roughness data were evaluated using nonparametric tests, while SFE, MTT and CFU results were evaluated by analysis of variance and Tukey test, and MTT data were also submitted to t-test (all, α=0.05). Results: Results showed that polished samples presented a lower high profile mean (p<0.001); however, YZHTg presented less space between defects (p=0.0002). SFE showed that YZHT presented higher SFE than ZLS. Profilometry evidenced more homogeneity on polished surfaces. The interaction of finishing technique and microorganisms influenced the CFU (p=0.00). MTT assay demonstrated initial severe cytotoxic behavior for polished surfaces. SEM images showed homogeneous surfaces, except for glazed YZHT. Conclusion: Glazed surfaces have a greater roughness and tend to accumulate more biofilm. Polished surfaces have higher SFE; however, they are temporarily cytotoxic.

scholarly journals Deformation-Induced Roughening by Contact Compression in the Presence of Oils with Different Viscosity: Experiment and Numerical Simulation

2020 ◽  
Vol 68 (4) ◽  
Author(s):  
Grzegorz Starzynski ◽  
Ryszard Buczkowski ◽  
Bartlomiej Zylinski
Keyword(s):  
Numerical Simulation ◽  
Surface Roughness ◽  
Smooth Surface ◽  
Steel Sample ◽  
Normal Contact ◽  
Contact Loading ◽  
Uniaxial Stretching ◽  
Structure Interaction ◽  
Finite Element Calculations ◽  
Similarities And Differences

AbstractThe aim of the work is to show both the similarities and differences in the formation of deformation-induced roughness in contact compression in the presence of oil and the problem of free surface roughing during uniaxial stretching in a plastic area. The relationships between changes in the roughness are caused by the deformation of the sample and the viscosity of oil at the contact area. It has been shown that normal contact loading with the presence of oil initially leads to an increase in surface roughness, then to its smoothening. The results of the experimental research have been compared with numerical simulation made using FSI (Fluid Structure Interaction) and ABAQUS systems. Using finite element calculations, it was possible to explain the phenomenon of roughness formation on the surface of a smooth steel sample. The changes in the structure of the smooth surface resulting from compression in the presence of oil are caused by the rotation and deformation of surface grains. The roughness of this structure is dependent on the viscosity of oil: the more viscous the liquid is, the rougher texture is formed.

Capillary Forces Described by Effective Contact Angle Distributions via Simulations of the Centrifuge Technique

MRS Advances ◽  
2016 ◽  
Vol 1 (31) ◽  
pp. 2237-2245
Author(s):  
Myles Thomas ◽  
Elizabeth Krenek ◽  
Stephen Beaudoin
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Smooth Surface ◽  
Adhesion Force ◽  
Capillary Forces ◽  
Angle Distribution ◽  
Particle Adhesion ◽  
Multiple Factors ◽  
Effective Contact ◽  
Condensed Moisture

ABSTRACTUnderstanding particle adhesion is vital to any industry where particulate systems are involved. There are multiple factors that affect the strength of the adhesion force, including the physical properties of the interacting materials and the system conditions. Surface roughness on the particles and the surfaces to which they adhere, including roughness at the nanoscale, is critically important to the adhesion force. The focus of this work is on the capillary force that dominates the adhesion whenever condensed moisture is present. Theoretical capillary forces were calculated for smooth particles adhered to smooth and rough surfaces. Simulations of the classical centrifuge technique used to describe particle adhesion to surfaces were performed based on these forces. A model was developed to describe the adhesion of the particles to the rough surface in terms of the adhesion to a smooth surface and an ‘effective’ contact angle distribution.

scholarly journals Surface Roughness of SiGe/Si(110) Formed by Stress-Induced Twins and the Solution to Produce Smooth Surface

2018 ◽  
Vol 06 (01) ◽  
pp. 25-31 ◽  
Author(s):  
Junji Yamanaka ◽  
Mai Shirakura ◽  
Chiaya Yamamoto ◽  
Naoto Utsuyama ◽  
Kei Sato ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Smooth Surface

Mechanochemical Polishing of Single Crystal Diamond with Mixture of Oxidizing Agents

2006 ◽  
Vol 315-316 ◽  
pp. 852-855 ◽  
Author(s):  
Cheng Yong Wang ◽  
C. Chen ◽  
Yue Xian Song
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Smooth Surface ◽  
Removal Rate ◽  
Polishing Process ◽  
Iron Plate ◽  
Oxidizing Agents ◽  
Single Crystal Diamond ◽  
Lower Temperature ◽  
And Control

In order to achieve the smooth surface of diamond, several kinds of mixture oxidizing agents have been used to polish the single crystal diamond by a designed polishing apparatus. The existing of graphite and amorphous carbon has been found in the surface of diamond after polishing. The mechanochemical actions of oxidizing agents and the polishing iron plate have been proved. The mixture of oxidizing agents can decrease the polishing temperature so that the super-smooth surface of single crystal diamond can be achieved at lower temperature. The method provided is benefit not only to simplify polishing device and control the polishing process, but also to improve the removal rate and surface roughness.

Surface Structure Curves: Toward a Smooth Surface Descriptor

1990 ◽  
Author(s):  
Hiromi T. Tanaka ◽  
Daniel T. L. Lee ◽  
Yukio Kobayashi
Keyword(s):  
Surface Structure ◽  
Smooth Surface

THE EFFECT OF ALUMINUM ELECTROPOLISHING ON NANO-PORES ARRANGEMENT IN ANODIC ALUMINA MEMBRANES

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3267-3277 ◽  
Author(s):  
M. H. RAHIMI ◽  
S. H. TABAIAN ◽  
S. P. HOVEYDA MARASHI ◽  
M. AMIRI ◽  
M. M. DALALY ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Pure Aluminum ◽  
Optical Microscope ◽  
Anodic Alumina ◽  
The Other ◽  
Sem Images ◽  
Current Time ◽  
Nanoporous Anodic Alumina ◽  
Alumina Membranes ◽  
Stress Relieving

Surface conditions of aluminum can influence the final arrangement of nano-pores in fabrication of ordered nanoporous anodic alumina membranes (AAMs). This study is mainly focused on the different applied voltages of aluminum electropolishing by keeping all the other parameters constant. After heat treatment (stress relieving and annealing at 500°C) of pure aluminum sheets, the samples were electropolished at different voltages (10-60V) to obtain desirable surface smoothness, while the temperature of the container was kept constant. The current-time curves were recorded during electropolishing process. The surface roughness obtained in each applied voltage was examined using optical microscope and atomic force microscope (AFM). The process was followed by two-step anodization in order to reach ordered nano-pores. Finally, the influence of surface roughness on regularity of nano-pores was observed using scanning electron microscope (SEM). The SEM images were analyzed to investigate the morphology and the degree of self ordering of pores of the samples by using a new designed analytical method aiming MATLAB and fast Fourier transform (FFT) technique. It was concluded that the electropolishing voltage and the resulted surface roughness and also formed defects can competitively affect the arrangement of membrane's nano-pores. A desired smoothness obtained from electropolishing voltage of 30V. Also 40V provided the best order with respect to the other voltages.

scholarly journals Properties of the Surface Layer After Trochoidal Milling and Brushing: Experimental Study and Artificial Neural Network Simulation

2019 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Monika Kulisz ◽  
Ireneusz Zagórski ◽  
Jakub Matuszak ◽  
Mariusz Kłonica
Keyword(s):  
Neural Networks ◽  
Surface Roughness ◽  
Artificial Neural Networks ◽  
Cutting Speed ◽  
Mg Alloy ◽  
Polar Component ◽  
Maximum Height ◽  
Roughness Parameters ◽  
Surface Geometry ◽  
Artificial Neural

The aim of this study was to investigate the effect of milling and brushing cutting data settings on the surface geometry and energy parameters of two Mg alloy substrates: AZ91D and AZ31. In milling, the cutting speed and the trochoidal step were modified (vc = 400–1200 m/min and str = 5–30%) to investigate how they affect selected 2D (Rz, Rku, Rsk, RSm, Ra) and 3D (Sa, Sz, Sku, Ssk) roughness parameters. The brushing treatment was carried out at constant parameters: n = 5000 rev/min, vf = 300 mm/min, ap = 0.5 mm. The surface roughness of specimens was assessed with the Ra, Rz, and RSm parameters. The effects of the two treatments on the workpiece surface were analyzed comparatively. It was found that the roughness properties of the machined surface may be improved by the application of a carbide milling cutter and ceramic brush. The use of different machining data was also shown to impact the surface free energy and its polar component of Mg alloy specimens. Complementary to the results from the experimental part of the study, the investigated machining processes were modelled by means of statistical artificial neural networks (the radial basis function and multi-layered perceptron). The artificial neural networks (ANNs) were shown to perform well as a tool for the prediction of Mg alloy surface roughness parameters and the maximum height of the profile (Rz) after milling and brushing.

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