scholarly journals Effect of 0.05% Sodium Fluoride Mouthwash on Surface Roughness and Friction Between Ceramic Brackets and Rhodium-Coated and Uncoated Stainless Steel Wires

2019 ◽  
Author(s):  
Tahereh HosseinzadehNik ◽  
Hannaneh Ghadirian ◽  
Tabassom Hooshmand ◽  
Mohammad Javad Kharrazi fard ◽  
Maryam Nasiri ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Sodium Fluoride ◽  
Artificial Saliva ◽  
Testing Machine ◽  
Significance Level ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Ceramic Brackets

Objectives: This study aimed to assess the effect of 0.05% sodium fluoride (NaF) mouthwash on the surface roughness and friction between ceramic brackets and rhodium-coated (RC) and uncoated stainless steel (SS) wires. Materials and Methods: This experimental study was performed on 48 maxillary premolar ceramic brackets. Twenty-four pieces of RC-SS wires were used. Samples were divided into four groups. Groups 1 and 2 were immersed in artificial saliva, and groups 3 and 4 were immersed in a solution consisting of artificial saliva (9%) and mouthwash (91%). To assess surface roughness, images were obtained from the surface of wires and brackets with atomic force microscopy (AFM) and scanning electron microscopy (SEM) before and after the intervention. To assess friction, the wires were ligated into brackets, and friction was measured at a crosshead speed of 0.5 mm/minute using a universal testing machine. Data were analyzed using one-way analysis of variance (ANOVA) at the 0.05 significance level. Results: Friction during sliding in RC wires was significantly less than that in SS wires (P<0.05). Increase in the friction in SS wires by mouthwash was significantly greater compared to RC wires (P<0.05). Surface roughness coefficients of the wires before the intervention were not significantly different. The surface roughness of the wires significantly increased after the intervention and it was greater in SS wires than in RC wires (P<0.05). Conclusion: Considering the lower friction and surface roughness of SS-RC wires compared to SS wires, SS-RC wires may be a better alternative for use with ceramic brackets.

scholarly journals Nonprescription Bleaching versus Home Bleaching with Professional Prescriptions: Which One is Safer? A Comprehensive Review of Color Changes and Their Side Effects on Human Enamel

2019 ◽  
Vol 13 (04) ◽  
pp. 589-598
Author(s):  
Farhana Omar ◽  
Zuryati Ab-Ghani ◽  
Normastura Abd Rahman ◽  
Mohamad Syahrizal Halim
Keyword(s):  
Surface Roughness ◽  
Over The Counter ◽  
Microscopic Appearance ◽  
Significance Level ◽  
Force Microscopy ◽  
Colorimetric Measurement ◽  
Color Changes ◽  
Atomic Force ◽  
Human Enamel ◽  
Before And After

Abstract Objectives This study evaluates the efficacy and safety of the professionally prescribed and nonprescription over-the-counter (OTC) bleaching agents. Materials and Methods Extracted human upper central incisors were prepared and stained with red wine for 14 days before being subjected to four different bleaching agents: professionally prescribed opalescence PF 15%, VOCO Perfect Bleach 10%, nonprescription OTC Crest 3D Whitestrips, and Whitelight Teeth Whitening System. Colorimetric measurement was performed with Vita Easyshade Handheld Spectrophotometer, enamel surface microhardness measured using Vickers Hardness machine, and surface roughness was evaluated with profilometer, before and after bleaching. Scanning electron microscope (SEM) evaluation and atomic force microscopy were conducted postbleaching. Statistical Analysis The data were analyzed with t-test, two-way ANOVA, one-way ANOVA, and Turkey’s test at a significance level of 5%. Results All bleaching products have the same efficacy to whiten stained enamel. Opalescence PF 15% showed significant increase in the microhardness (92.69 ± 68.316). All groups demonstrated significant increase in surface roughness (p < 0.05). SEM evaluation showed that Opalescence PF 15% resulted in same microscopic appearance as unbleached enamel, while VOCO Perfect Bleach 10%, Whitelight Teeth Whitening System and Crest 3D Whitestrips demonstrated mild to moderate irregularities and accentuated irregularities, respectively. Conclusion Professionally prescribed bleaching agent of Opalescence PF 15% is effective tin whitening the teeth, while the other bleaching products may be effective but also have deleterious effects on the enamel.

scholarly journals Effect of Hydrofluoric Acid Surface Treatments on Surface Roughness and Three-Point Flexural Strength of Suprinity Ceramic

2020 ◽  
Author(s):  
Nazanin Keshmiri ◽  
Homayoon Alaghehmand ◽  
Faraneh Mokhtarpour
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Hydrofluoric Acid ◽  
Testing Machine ◽  
Etching Time ◽  
Control Group ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference ◽  
Before And After

Objectives: This study aimed to evaluate the effects of hydrofluoric acid (HF) concentration and etching time on the surface roughness (SR) and three-point flexural strength of Suprinity and to analyze the surface elements before and after etching. Materials and Methods: To measure the SR, 70 specimens of Suprinity (2×4×5mm3) were assigned to seven groups (n=10). Six groups were etched for 20, 60, and 120 seconds with 5% and 10% HF and 7th group was the control group. Specimens were evaluated using atomic force microscopy (AFM). One specimen from each group was used to analyze the surface elements using scanning electron microscopy (SEM). For measuring the three-point flexural strength, 60 specimens were divided into six groups (n=10) and etched as previously described. The flexural strength was measured using a universal testing machine. T-test, one-way analysis of variance (ANOVA), and two-way ANOVA were used for statistical analyses (P<0.05). Results: The 10% concentration of HF caused higher SR compared to the 5% HF. The effect of HF concentration on the flexural strength was significantly different in the 20- and 60-second etching groups. Different etching times had no significantly different effect on the SR. With 5% HF, the flexural strength was significantly higher for 20-second etching time than for the etching times of 60 and 120 seconds. With 10% HF, there was a significant difference in flexural strength between etching times of 20 and 120 seconds. The atomic percentage (at%) of silica was enhanced by increasing the etching time. Conclusions: The best surface etching protocol comprises 10% HF used for 20 seconds.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

Suppression of SiC surface roughening during high-temperature annealing by atmospheric control using purified Ar gas

2010 ◽  
Vol 25 (4) ◽  
pp. 708-710 ◽  
Author(s):  
Atsushi Ogura ◽  
Daisuke Kosemura ◽  
Shingo Kinoshita
Keyword(s):  
Surface Roughness ◽  
High Temperature ◽  
Surface Roughening ◽  
Annealing Atmosphere ◽  
High Temperature Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Furnace Tube ◽  
Ar Gas

4H-silicon carbide (SiC) wafers were annealed at 1300 and 1600 °C for 30 min and 60 min in a conventional and purified Ar atmosphere. The surface roughness before and after annealing was evaluated by atomic force microscopy. The surface roughness before annealing was approximately 2.37 nm in root mean square. The roughness, after annealing for 30 min at 1300 and 1600 °C in a conventional Ar furnace, was increased to 4.53 and 14.9 nm, respectively. The roughness, after annealing for 60 min, was 5.01 and 19.1 nm, respectively. In this study, the G3 grade Ar gas (99.999%) was supplied in the conventional furnace tube. When the Ar gas was purified to an impurity concentration of less than 1 ppb, and it was supplied in the leak-tight furnace tube, the roughness after 30-min annealing improved 4.27 and 6.93 nm at 1300 and 1600 °C, respectively. The roughness after 60-min annealing was also reduced to 3.54 and 9.28 nm, respectively. We assume that a significant reduction of H2O concentration in the annealing atmosphere might play an important role in suppressing surface roughening of SiC during high-temperature annealing.

AFM Study of Untreated and Treated Fibers of Mongolian Goat Cashmere

2009 ◽  
Vol 610-613 ◽  
pp. 175-178 ◽  
Author(s):  
Namsrai Javkhlantugs ◽  
Enkhbaatar Ankhbayar ◽  
Khishigjargal Tegshjargal ◽  
Damdin Enkhjargal ◽  
Chimed Ganzorig
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Fine Structure ◽  
Ambient Conditions ◽  
Bleaching Process ◽  
Surface Change ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
The Difference

The morphological surface change of untreated and treated fibers of the Mongolian goat cashmere was investigated by atomic force microscopy (AFM) at ambient conditions. The cuticle scale heights of the Mongolian goat cashmere fibers were measured by the AFM for the fibers before and after treatment. The experimental results showed that the difference between the fine structure of the cuticle and surface roughness of untreated and treated fibers. We found that the surface morphological change of the cashmere fibers was strongly degraded after the bleaching process.

scholarly journals Comparison of Friction in Sliding Mechanics Using Different Ligation Methods on Ceramic Bracket with Metal Slot and Epoxy Resin-Coated Stainless Steel Esthetic Wire: An in Vitro Study

2019 ◽  
Vol 53 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Hina Desai ◽  
Fenil Manishkumar Gandhi ◽  
Kalpesh Patel ◽  
Sarvesh Agrawal
Keyword(s):  
Stainless Steel ◽  
Epoxy Resin ◽  
Artificial Saliva ◽  
Testing Machine ◽  
Kinetic Friction ◽  
Intergroup Comparison ◽  
Wet Condition ◽  
Ceramic Brackets ◽  
Ceramic Bracket ◽  
Elastic Modules

Introduction: The friction generated during orthodontic treatment seems of concern in terms of anchorage and treatment duration. Different ligation methods have been developed to reduce the friction as compared with regular elastic modules. This study aimed to evaluate and to compare static and kinetic friction generated in ceramic brackets with metal slot and epoxy resin-coated stainless steel esthetic wire by using different ligation materials in wet condition (artificial saliva). Materials and Methods: A total of 40 epoxy-coated stainless steel wires and metal slot ceramic brackets were divided into 4 groups of 10 each and ligated using 4 different methods as follows: (1) super slick elastic modules, (2) slide elastic modules, (3) Teflon-coated esthetic stainless steel wire, and (4) regular elastic modules. They were then immersed in artificial saliva for 1 hour before testing their static and kinetic friction using a universal testing machine. Results: The intergroup comparison showed statistically significant differences for static and kinetic friction among all the 4 groups, where group 2 (slide modules) showed the least static as well as kinetic friction as compared with the other 3 groups. Conclusions: (1) Slide modules produced the least amount of friction compared with all other methods of ligation when epoxy resin-coated stainless steel archwire was used in ceramic bracket with 0.22˝ metal slot in wet condition. (2) Super slick modules produced the least friction in comparison with regular elastomeric and Teflon-coated ligature groups but produced greater friction than slide modules. (3) Teflon-coated stainless steel ligature produced the highest friction; however, it was not statistically significant when compared with the conventional elastic ligature. (4) In all clinical situations during the retraction stage, a large amount of friction is created in the buccal segment; hence, it is advisable to use slide modules in the buccal segment to reduce static and kinetic friction.

Surface Morphology of Nanoscale TiSi2 Epitaxial Islands on Si(00l)

1996 ◽  
Vol 448 ◽  
Author(s):  
Woochul Yang ◽  
F.J. Jedema ◽  
H. Ade ◽  
R.J Nemanich
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Strain Field ◽  
Island Size ◽  
Island Formation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Size Uniformity ◽  
Rough Substrate

AbstractThe morphologies of nanoscale epitaxial islands of TISi2 are studied. The islands are prepared by deposition of ultrathin Ti (3-20Å) on both smooth and roughened.Si(001) substrates. The island formation is initiated by annealing to 800-1000°C. The roughened substrates are prepared by etching with atomic H produced in a plasma. The morphologies of the substrate before and after island formation are examined by atomic force microscopy (AFM). In particular, the influence of surface-roughness on both the formation of islands and the size distribution of islands is investigated. On a rough substrate islands with a lateral dimension of ~350Å and a vertical dimension of ~25Å were observed with size uniformity of ~20%. Also it was observed that the roughness of the surface reduced the island size and affected the island distribution. The results are discussed in terms of surface energy and the strain field around the islands.

Nanoscale Surface Modifications by Magnetic Field-Assisted Finishing

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Raul E. Riveros ◽  
Jared N. Hann ◽  
Curtis R. Taylor ◽  
Hitomi Yamaguchi
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Microelectromechanical Systems ◽  
Clear Understanding ◽  
X Ray ◽  
Surface Features ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Process Material

A magnetic field-assisted finishing (MAF) process has been developed to reduce the sidewall surface roughness of the 5–20 μm wide curvilinear pores of microelectromechanical systems micropore X-ray optics to <1 nm Rq. Although the feasibility of this process has been demonstrated on these optics, a clear understanding of the MAF process' material removal mechanisms has not been attained. In an attempt to discover these mechanisms, the MAF process is applied to a flat workpiece, allowing for direct observation and tracking of changes to distinctive surface features before and after MAF. Atomic force microscopy, field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy are used to analyze the surface morphology and composition with respect to finishing time. These observations suggest that the MAF process modified the surface, reducing surface roughness (from 0.8 nm to 0.6 nm Rz on silicon) by removing relatively low-wavelength surface features. Moreover, the MAF process appears to modify the surface mechanically.

Analysis of Roughness and Surface Hardness of a Dental Composite Using Atomic Force Microscopy and Microhardness Testing

2011 ◽  
Vol 17 (3) ◽  
pp. 446-451 ◽  
Author(s):  
Marcos Aurélio Bomfim da Silva ◽  
Aline Barbirato Fardin ◽  
Renata Carvalho Cabral de Vasconcellos ◽  
Lucineide de Melo Santos ◽  
Josealdo Tonholo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Artificial Saliva ◽  
Soft Drink ◽  
Surface Hardness ◽  
Dental Composite ◽  
Force Microscopy ◽  
Atomic Force ◽  
Group A ◽  
Group B ◽  
Group D

AbstractThe objective of this study was to evaluate the influence of a cola soft drink (CSD) and coffee on the microhardness and surface roughness of composite resin. Fifty cavities were prepared on the vestibular surface of bovine incisors and restored with nanoparticulate resin. The teeth were divided into five groups (n= 10): group A (control), immersion in artificial saliva (AS) for 14 days; group B, immersion in coffee for 15 min (3×/day) for 7 days followed by immersion in AS for another 7 days; group C, immersion in CSD for 15 min (3×/day) for 7 days followed by immersion in AS for another 7 days; group D, immersion in AS for 7 days, immersion in coffee for 15 min (3×/day) for 7 days; group E, immersion in AS for 7 days, immersion in CSD for 15 min (3×/day) for 7 days. After the immersion periods the specimens were analyzed for their microhardness and surface roughness. The data were subjected to analysis of variance (ANOVA) followed byt-test with 5% significance. Group A presented the highest average microhardness and lowest surface roughness, so it was possible to conclude that the consumption of CSD and coffee alters the microhardness and surface roughness of new restorations.

Measuring the Changes in InP Morphological and Electrical Specifications Caused by Oxygen Ion Implantation

2011 ◽  
Vol 264-265 ◽  
pp. 1312-1317
Author(s):  
A.H. Ramezani ◽  
M.R. Hantezadeh ◽  
M. Ghoranneviss ◽  
A.H. Sari
Keyword(s):  
Surface Roughness ◽  
Ion Implantation ◽  
Room Temperature ◽  
Implantation Dose ◽  
Force Microscopy ◽  
Oxygen Ions ◽  
Oxygen Ion ◽  
Atomic Force ◽  
Before And After ◽  
Oxygen Ion Implantation

This paper is the results of oxygen ion implantation on morphological and electrical properties of indium phosphate (InP) semiconductor wafers. The oxygen ions were implanted at 30 keV and various doses in the range between 5×10 15 to 5×10 17 ions/cm2 and at nearly room temperature. The changes in surface roughness and resistivity before and after the implantation is studied using atomic force microscopy (AFM) and four-point probes technique, respectively. The results show that the resistivity is depend on the ion implantation dose. In addition, the RMS roughness of implanted samples dramatically increases by accumulation of oxygen ion dose.

Sign in / Sign up

Export Citation Format

Share Document