scholarly journals Ultrastructural analysis of the surface of stainless steel endodontic instruments before and after use

2014 ◽  
Vol 61 (4) ◽  
pp. 175-182
Author(s):  
Jelena Popovic ◽  
Jovanka Gasic ◽  
Slavoljub Zivkovic ◽  
Aleksandar Mitic ◽  
Marija Nikolic ◽  
...  

Introduction. Although many studies have reported various advantages of nickel-titanium endodontic instruments, the use of stainless steel endodontic files still presents a standard in everyday practice. The aim of this study was to evaluate ultrastructure of the surface of stainless steel endodontic instruments before and after their use. Material and Methods. Fourteen sets of non-used stainless steel endodontic reamers and files were included in the study. Each set of instruments was used one, three or six times in simulated clinical conditions on extracted maxillary premolars. After their use the instruments were subjected to cleaning and sterilization procedures. Ultrastructure of the surface of instruments was observed under scanning electron microscope (SEM). Surface analysis was performed based on the number of uses and size of instruments. The following characteristics were analyzed: defects of instrument flutes, defects of cutting edges and instrument deformations. Results. SEM analysis showed defects on the surface of non-used instruments as a result of the manufacturing process. Surface defects, defects of cutting edges as well as flutes deformations were observed after a single use and were more often noticed in small sized instruments. After three uses, flutes deformations were observed in all small sized instruments and some of the medium size. After six uses all groups of instruments showed defects of cutting edges. Conclusion. Non-used stainless steel endodontic instruments showed surface defects created by the manufacturing process. Defects of cutting edges and flutes can be observed after a single use. To minimize complications and mistakes during clinical preparation it is recommended to limit the number of instrument uses.

2021 ◽  
Vol 38 (3) ◽  
pp. 291-298
Author(s):  
Nenad Stošić ◽  
Jelena Popović ◽  
Marija Anđelković-Apostolović ◽  
Aleksandar Mitić ◽  
Marija Nikolić ◽  
...  

One of the primary goals in endodontics is efficient cleaning and shaping of the root canal while maintaining its original configuration. Numerous studies highlight the advantage of using nickel-titanium instruments and the most important is their high flexibility and the ability to penetrate the curved canals. The aim of this study was to analyze the ultrastructure of the surface of nickel-titanium endodontic files before and after use. Eighty-four instruments were included in this study. The instruments were used one, three and six times for root canal preparation on extracted upper premolars. The analysis was performed based on the number of uses and the size of the instruments. Changes on flat surfaces in the grooves of the instruments, defects of the cutting edges and fractures were evaluated. The surface ultrastructure was analyzed on a scanning electron microscope (SEM). SEM analysis showed irregularities on the surfaces of the new instruments. Surface defects and damage of the cutting edges were present after the first use. After three uses, the damage was more evident in instruments of all sizes. After six uses, all instruments showed damage of the cutting edges, and a significant number of fractures were observed. Irregularities on the working parts are already noticed on the new endodontic instruments and originate from the production process. The first signs of damage appear after the first use. In order to prevent errors in clinical work during root canal preparation, it is recommended that the number of instruments uses should be limited.


2013 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Marisa Mifta Huda ◽  
Erwin Siregar ◽  
Nada Ismah

Deformasi slot braket Stainless Steel akan mempengaruhi gaya yang diaplikasikan kepada gigi.Tujuan penelitian adalah untuk mengetahui deformasi slot braket dari lima merek braket yaitu 3M, Biom, Versadent, Ormco dan Shinye akibat gaya torque kawat Beta Titanium 0.021x0.025 inci dengan sudut puntir 45° dan besar gaya torque dengan sudut puntir 30° dan 45°. Penelitian juga bertujuan untuk membandingkan deformasi dan besar gaya torque antara kelima merek braket. Penelitian dilakukan pada 50 braket Stainless Steel Edgewise dari lima kelompok merek braket (n=10) dilem ke akrilik. Masing-masing braket dilakukan dua tahapan pengukuran yaitu pengukuran deformasi braket dengan menghitung rerata tinggi slot braket dengan mikroskop stereoskopi sebelum dan sesudah uji torque dan pengukuran besar gaya torque dengan alat uji torque. Hasil analisa statistik menunjukkan terdapat deformasi slot braket pada kelima merek braket dengan deformasi permanen secara klinis pada braket Biom (2,79 µm) dan Shinye (2,29 µm). Besar gaya torque pada kelima braket dari yang paling besar yaitu 3M, Ormco, Versadent, Shinye dan Biom. Perbandingan deformasi slot braket dan besar gaya torque antara kelima braket adalah terdapat perbedaan deformasi slot braket antara kelima merek braket kecuali antara 3M dan Ormco dan Biom dan Shinye dan terdapat perbedaan besar gaya torque antara kelima braket dengan sudut puntir 30° (kecuali 3M dan Ormco) dan 45°. Kesimpulan, Komposisi logam dan proses pembuatan braket merupakan faktor yang mempengaruhi terjadinya deformasi slot braket dan besar gaya torque. Proses pembuatan dengan metode MIM dan komposisi logam AISI 303 dan 17-4PH menurunkan risiko deformasi.Slot Deformation in Various Stainless Steel Bracket Products due to The Torqueing Force of Beta Titanium Wire. Stainless Steel bracket slot deformation affects force applied to teeth. The research aims to determine slot deformation of five different bracket brands namely, 3M, Biom, Versadent, Ormco and Shinye due to torque of Beta Titanium wire 0.021 x 0.025 inch with torsional angle of 45° and the amount of torque with torsional angle of 30° and 45°. The research also attempts to compare the deformation and amount of torque among all five bracket brands. Fifity Stainless Steel Edgewise brackets from five bracket group brands (n=10) were attached on acrylic. Bracket slot measurement was carried out in two stages: firstly, deformation measurement by calculating average bracket slot height with stereoscopy microscope before and after application of torque; and secondly, measurement of torque with a torque measurement apparatus. Statistical analysis showed that there are slot deformations on the five bracket brands with clinical permanent deformation on Biom (2,79 µm) and Shinye (2,29 µm). The amount of torque on the five bracket brands from the highest is 3M, Ormco, Versadent, Shinye and Biom. From correlation assessment between bracket slot deformation and amount of torque in the five brands, a difference is found in the deformation in five brands except 3M, Ormco, Biom and Shinye. There is a difference in the amount of torque between the five brands with torsional angle of 30° (except 3M and Ormco) and 45°. It is concluded that metal compositions and manufacturing process are the factors that influence the occurrence of deformation bracket slot and the amount of torque. Manufacturing process using MIM and metal compositions of AISI 303 and 17-4 PH reduce the risk of deformation.


2016 ◽  
Vol 04 (01) ◽  
pp. 018-022
Author(s):  
Dhwani Bakhai ◽  
Vibha Hegde

AbstractClinically, there is a real potential for rotary NiTi instruments to separate in the canal; hence increasing the resistance to fracture has been a focus in the designing of new NiTi rotary systems. NiTi alloys go through various transitional phases and these have been utilized by manufacturers in different file systems. Aim: To evaluate and compare the surface changes of rotary nickel-titanium instruments manufactured from the Austenite phase, M-wire technology and R- phase before and after multiple uses. Materials and Methodology: 60 freshly extracted human mandibular premolars with a single, straight canal were selected. They were divided into 3 groups of 20 teeth each. Cleaning and Shaping was carried out using the crown down technique. All instruments were evaluated for defects under Scanning Electron Microscope (SEM) before and after multiple uses and scored for the defects. Results were statistically analyzed using Kruskal Wallis and Mann Whitney U test. Results: The p-value was <0.0001, indicating a statistically significant difference between the three groups in terms of resistance to surface defects. Conclusion: R-phase technology had superior resistance to surface defects, followed by M-wire and the austenitic phase.


Author(s):  
Muna I Khalaf ◽  
Khulood A Saleh ◽  
Khalil S Khalil

Electro polymerization of N-benzothiazolyl maleamic acid (NBM) was carried out on stainless steel plate electrode in a protic medium of monomer aqueous solution using electrochemical oxidation procedure in electrochemical cell.Spectroscopic characterization techniques were investigated to obtain information about the chemical structure of polymer. The anti-corrosion action of polymer was investigated on stainless steel by electrochemical polarization method. In addition, the effect of adding nanomaterial (TiO2, ZnO (bulk-nano)) to monomer solution on the corrosion behavior of stainless steel was investigated. The results obtained showed that the corrosion rate of S-steel increased with temperature increase from 293K to 323K and the values of inhibition efficiency by coating polymer increase with nanomaterial addition. Apparent energies of activation have been calculated for the corrosion process of S-steel in acidic medium before and after polymeric coating. Furthermore were studied the effect of the preparing polymer on some strain of bacteria.


2003 ◽  
Vol 44 (3) ◽  
pp. 414-420 ◽  
Author(s):  
Daisuke Kuroda ◽  
Takao Hanawa ◽  
Takaaki Hibaru ◽  
Syuji Kuroda ◽  
Masaki Kobayashi ◽  
...  

Author(s):  
L. Carvalho ◽  
W. Pacquentin ◽  
M. Tabarant ◽  
J. Lambert ◽  
A. Semerok ◽  
...  

Laser cleaning study was performed on prepared samples using a nanosecond pulsed ytterbium fiber laser. To prepare samples, AISI 304L stainless steel samples were oxidized and implemented with non-radioactive contaminants in a controlled manner. In order to validate the cleaning process for metallic equipment polluted in nuclear installations, two types of contamination with europium (Eu) and with cobalt (Co) were studied. Eu was used as a simulator-product resulting from uranium fission, while Co — as an activation-product of nickel, which is a composing element of a primary coolant system of a reactor. The oxide layers have suffered laser scanning which was followed by the furnace treatment to obtain thicknesses in the range of 100 nm to 1 μm depending on the oxidation parameters [1] with a mean weight percentage of 1% of Eu and 1 % of Co in the volume of the oxide layer. Glow Discharge Optical Emission (GD-OES) and Mass Spectrometry (GD-MS) analyses have been performed to assess the efficiency of the cleaning treatment and to follow the distribution of residual contamination with a detection limit of 0.1mg/kg of Eu and Co. Decontamination rates up to 95.5 % were obtained. One of the identified reasons for this limitation is that the radionuclides are trapped in surface defects like micro cracks [2, 3]. Therefore, cleaning treatments have been applied on surface defects with controlled geometry and a micrometric aperture obtained by laser engraving and juxtaposition of polished sheets of AISI 304L stainless steel. The goal of this study is surface decontamination without either welding or inducing penetration of contamination into the cracks. GD-MS analysis and Scanning Electron Microscopy (SEM) were performed to analyze the efficiency of the treatment and the diffusion of contaminants in this complex geometry.


2008 ◽  
Vol 55-57 ◽  
pp. 413-416 ◽  
Author(s):  
C.I. Huang ◽  
C.I. Su ◽  
Ching Wen Lou ◽  
Wen Hao Hsing ◽  
Jia Horng Lin

Recently, development of technology increases human life quality and gradually raises the value of health protection in human’s concept. Bamboo has multi-functional including far infrared radiation, deodorization and anion generation. Therefore, bamboo charcoal has been widely used in textile industry. Moreover, development of technology also increased the electromagnetic hazard in human’s daily life. This study aims to develop a manufacturing process of functional composite yarn-dyed woven fabrics. In the manufacturing process, the materials included pure cotton yarn, stainless steel fiber(called metallic yarn) and viscose rayon yarn containing bamboo charcoal (called bamboo charcoal yarn) were used for making the bamboo charcoal/stainless steel composite woven fabric. The composite woven fabrics were woven by using same warp yarn and two kinds of weft yarn that contained bamboo charcoal and stainless steel. The composite fabrics had two different structures. Those fabrics were changed the order of bamboo charcoal yarn and metallic yarn. The ratios of weft yarn were 1 end of bamboo charcoal yarn to 1 end of metallic yarn and 3 ends of bamboo charcoal yarn to 1 end of metallic yarn. Furthermore, the fabrication of composite fabrics that included plain, 2/2 twill and dobby were changed. The composite woven fabrics were finished and laminated by TPU film to enhance the waterproof and vapor permeable functions. The laminated composite fabrics were evaluated by far-infrared coefficient, anion generation rate, water vapor permeability, water resistance, surface electric resistance and electromagnetic shelter property to obtained optimal manufacturing process.


Sign in / Sign up

Export Citation Format

Share Document