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EN
Purpose: The aim of this work is to characterize the surface geometry of the orthodontic archiwire and their influence of the pitting corrosion resistance and bacterial adhesion. Design/methodology/approach: In the paper, the results of the SEM/EDS analysis and microscopic observation of the samples surface and analysis of geometrical structure with the use Atomic Force Microscope (AFM) and Confocal Microscopy were presented as well as the pitting corrosion test and surface roughness and microhardness measurements were performed. Additionally the microbiological study after bacterial breeding with the use Scanning Electron Microscope was carried out. Findings: In the basis of the investigation, it can be concluded that the surface geometry of archwire has a significant impact on their pitting corrosion resistance in artificial saliva solution and on the bacterial adhesion. The obtained results show satisfactory properties and surface geometry of the tested orthodontic wires for use in the human oral environment. Research limitations/implications: In the future, it is planned to extend the research with physicochemical properties and the influence of oral hygiene products on the corrosive behaviour of the material. Limitations in the conducted tests refer to archwire design – a small diameter making measurements difficult. Practical implications: The oral environment is an extremely aggressive corrosive environment. The orthodontic elements should have very good corrosion resistance and biocompatibility. The focus should be on continuously improving orthodontic wires in terms of material quality and topography of its surface topography. Originality/value: The research is conducted in the field of biomedical engineering, which is part of material engineering and is used for the field of dentistry and microbiology.
EN
The paper presents the effect of ZrO2 layer deposition by the ALD process on the physicochemical properties of cobalt-based alloys (Realloy C and EOS CoCr SP2) intended for application in prosthetic dentistry. The paper shows the results of the surface roughness measurements made by the AFM method as well as the wettability and free surface energy measurements. Additionally, potentiodynamic tests of pitting corrosion resistance and electrochemical impedance spectroscopy in a solution of artificial saliva were carried out. Tests were carried out on the samples in the initial state and after surface modification with the ZrO2 layer. Based on these results, the usefulness (e.g. enhancement of corrosion resistance and biocompatibility) of the proposed ZrO2 layer on the cobalt alloys was assessed.
EN
The paper contains the results of the initial surface treatment influence on the properties of the medical Ti-6Al-7Nb alloy with a modified zirconium oxide layer deposited on its surface by sol-gel method. In the paper, the analysis of results of potentiodynamic studies is presented as well as its resistance to pitting corrosion and electrochemical impedance spectroscopy (EIS), macroscopic observation of the surface of samples and analysis of geometrical structure with the use Atomic Force Microscope (AFM) were performed. The studies were performed on two groups of samples depending on the graduation of the sand used in sandblasted process – 50 μm and 250 μm. Based on the obtained results it can be concluded that the type of the initial surface treatment preceding the surface modification of the Ti-6Al-7Nb has a significant effect on its properties.
4
Content available remote Microstructure and properties of CoCr alloys used in prosthetics procedure
EN
Purpose: The aim of this work was to define the influence of manufacturing technology on the chemical composition, surface topography, physicochemical and electrochemical properties of CoCr alloys obtained by casting technology and Direct Metal Laser Sintering. Design/methodology/approach: This work presents microstructural and chemical compositions obtained by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS). Additionally, corrosion pitting analysis and roughness measurement were conducted on the samples. Findings: On the basis of the investigations, it can be stated that the prosthetic restorations are different depending on the type manufacturing technology. Based on the obtained results it was found that the structures of both materials are chemically inhomogeneous. The investigated alloy exhibited similar polarization curve character. Practical implications: The rapid prototyping methods are a new technology used for getting details e.g. by CAD/CAM procedure. Using Direct Metal Laser Sintering (DMLS) method can simplify the technology of producing prosthetics restrictions and is an alternate way for standard casting technology. Originality/value: The paper presents comparative research of two Co-Cr alloys, from which the samples were obtained in conventional casting and DMLS technology.
EN
Full-ceramic dental restorations made from ZrO2 have become increasingly popular due to their aesthetics and mechanical strength, and are gradually replacing prostheses made of porcelain fused to metal. Nevertheless, due to the variability in the physicochemical properties in a wet environment at elevated temperature, zirconia is quite a controversial material, the use of which in the environment of the mouth is questionable and raises many concerns. The reason for the variability in the physicochemical changes is the martensitic transformation in which metastable phases (b, g) change into the stable phase (a). For biomedical applications, the most desired is the b-phase. A very unfavourable phenomenon accompanying the martensitic transformation in a wet environment is low temperature degradation, which is an autocatalytic process accelerating negative changes in ZrO2. The aim of this review is a comprehensive study of the degradation phenomenon problems according to prosthetic treatment with a fixed prosthesis and ways to reduce it.
PL
Celem pracy była ocena jakości stanu powierzchni implantu, która mogłaby wskazywać na przyczynę utraty integracji wszczepu śródkostnego. Badania obejmowały obserwacje mikroskopowe oraz analizę składu chemicznego wszczepu śródkostnego w mikroskopie skaningowym firmy ZEISS SUPRA 35 wyposażonego w detektor SE. Potwierdziły one wykonanie implantu ze stopu Ti- 6Al-4V oraz wskazały na zaistniały proces osteointegracji. Powodem utraty zintegrowanego wszczepu było prawdopodobnie przeciążenie mechaniczne oraz złe nawyki higieniczne, palenie tytoniu oraz współistniejąca choroba przyzębia i wywołane nią periimplantitis.
EN
The aim of the study was the quality assessment of the state of the surface of the implant. The study included microscopic observations and analysis of the chemical composition of the implant intraosseous scanning microscope ZEISS SUPRA 35 equipped with a detector SE. They confirmed the execution of the implant alloy Ti-6Al-4V, and pointed to an apparent process of osseointegration. The reason of incorrect implants integration was probably mechanical overload or poor hygiene habits, smoking and periodontal disease – periimplantitis.
EN
Biomechanical analysis of individual all-ceramic abutments used in dental implantology The paper presents the results of finite element analysis and experimental testing under simulated physiological loading conditions on issues shaping the functional properties of individual all-ceramic abutments manufactured by CAD'CAM technology The conducted research have cognitive significance showing the all-ceramic abutment behavior, as a key element of the implantological system, under the action of cyclic load. The aim of this study was evaluation the fatigue behavior of yttria-stabilized zirconia abutment submitted to cyclic stresses, conducted in accordance with EN ISO 14801 applies to dynamic fatigue tests of endosseous dental implants.
PL
W implantologii zdarzają się przypadki braku osteointegracji wszczepu śródkostnego z tkanką kostną. Celem przeprowadzonych badań była ocena własności mechanicznych oraz struktury elementów systemu implantologicznego - wydzielonego z tkanek żuchwy po sześciu miesiącach od jego wszczepienia. Dla celów pracy przeprowadzono analizę składu chemicznego SEM, pomiary ultra-nanotwardości i modułu Younga oraz obserwacje mikroskopowe struktury materiału.
EN
There are some cases in implantology connected with osseointegration problem of intraosseous implant and bone tissue. Scientists are still looking for the reason of this complication, at the same time developing new methods of implants systems, that are made with more biocompatible biomaterials. The aim of the study was to evaluate the mechanical properties and structure of components dedicated for implant system. For the purposes of operating an analysis of the chemical composition (SEM), measurements of ultra-nanohardness and Young's modulus and microscopic observations structure of the material were made.
EN
Purpose: This paper presents results of studies on the effect of the sterilization process and aging process (for comparison) on the mechanical properties and the surface quality of low density polyethylene PE-LD used in biomedical applications. Design/methodology/approach: In order to determine the changes in the surface structure of polyethylene PE-LD measurement of angle and roughness of samples were made. There were also measured mechanical properties - Shore hardness and tensile strength of PE-LD samples. Findings: Results of this study indicate that the sterilization process and the aging process does not significantly affect the mechanical properties of polyethylene. These processes influence the structure of its surface, which is very important due to the its use in medical. Practical implications: Low density polyethylene PE-LD is used in the manufacturing of laboratory equipment, such as syringes, gloves, laboratory dishes, catheters used in hemodialysis, connectors for the surgical drains, the surgical drains used in the treatment of sinuses, tracheostomy tubes. Originality/value: Results are the base for further investigations of biomedical materials. Research are essential to search for new biomedical applications for polyethylene.
PL
Destrukcje koron zębów, będące wynikiem złamań lub zaawansowanej próchnicy z towarzyszącym im stanem zapalnym miazgi stanowią szczególny problem stomatologii zachowawczej. W praktyce klinicznej takie zęby leczone są endodontycznie, czyli kanałowo. Wynikiem takiego leczenia jest ząb martwy, bez miazgi, przygotowany do odbudowy. Jedną z metod stosowanych w procesie rekonstrukcji koron zębów po leczeniu endodontycznym, jest stosowanie metalowych wkładów koronowo-korzeniowych, które należą do grupy protez stałych jednoczłonowych oraz stanowią podbudowę pod uzupełnienie protetyczne. Na rynku dostępnych jest wiele rodzajów cementów stomatologicznych [1]. Aby ułatwić ich wybór, przeprowadzono analizę numeryczną układu wkład koronowokorzeniowy – ząb z wykorzystaniem trzech różnych rodzajów stosowanych cementów dentystycznych. Do analizy wytypowano wkład koronowo-korzeniowy Flexi-Post (wykonany ze stopu Ti6Al4V) ze względu na jego dużą retencję w kanale korzeniowym oraz mały nacisk na ścianę korzenia. Zakres przeprowadzonej analizy obejmował wyznaczenie stanu przemieszczeń, odkształceń i naprężeń w elementach analizowanego układu w zależności od zastosowanego cementu stomatologicznego. Na podstawie uzyskanych wyników stwierdzono, że największe wartości naprężeń zredukowanych występują w przypadku zastosowania cementu fosforanowo-cynkowego, gdzie wartość ta była 3-krotnie większa w porównaniu do cementu szklanojonomerowego oraz kompozytowego. Dodatkowo nie stwierdzono istotnego wpływu zastosowanego cementu na pozostałe elementy analizowanego układu wkład-ząb. Uzyskane wyniki analizy numerycznej układu wkład-ząb z wykorzystaniem metody elementów skończonych stanowią cenną metodykę dla prawidłowego zaprojektowania jego postaci, cech geometrycznych, doboru własności mechanicznych oraz stopnia umocnienia biomateriału metalowego.
EN
The destruction of tooth crowns, resulting from fractures or advanced decay with an accompanying inflammation of the pulp is a particular problem in conservative dentistry. In clinical practice, these teeth are treated endodontically that is root canal therapy. The result of such treatment is inanimate tooth, without pulp, prepared for a reconstruction. One of the methods used in the process of reconstruction of the teeth crowns after endodontic treatment, is the use of metal endodontic posts-and-cores that belong to the group of monosegmental fixed dentures and constitute a foundation for restoration. There are a lot of different kinds of dental cements on the market [1]. In order to facilitate selection of the optimal system, numerical analysis of the dental post-and-core – tooth system (for three variants of dental cements) was carried out. The main aim of the present work was numerical analysis of the dental post-and-core – tooth system using finite element method. For the analysis the Flexi-Post was selected (made of Ti6Al4V alloy) because of its high retention in the root canal and a small pressure on the root’s wall. The scope of the analysis included calculation of displacements, strains and stresses in the analyzed elements – depending on the applied dental cement. Based on the obtained results, it was found that the largest value of the equivalent stress occurred for zinc-phosphate cement. The value in this case was three times higher in comparison to the glass ionomer cement as well as composite cement. In addition, there was no significant influence of the cement used for other elements of the dental post-and-core – tooth system. The results of the analyzed system provide a valuable methodology for proper designing of its form, geometrical characteristics, the selection of the mechanical properties and an optimal degree of metallic biomaterial strengthening.
11
EN
Purpose: The goal of the study is to investigate the corrosion resistance of hard magnetic composite materials Nd-Fe-B with 5%, 10% and 15% by weight of iron powder, casting copper alloy with tin CuSn10, steel corrosion-resistant X2CrNiMo17-12-2 and Epidian100 (2.5% by mass) as a binder in a humid environment at 40°C and 5% NaCl solution at 35°C and to determine their current-voltage characteristics. Design/methodology/approach: The investigations of corrosion resistance of hard magnetic composite materials in climate chambers were carried out : test 1 (temperature 40°C, relative humidity 93%, duration 96 h), test 2 (temperature 35°C, 5% NaCl solution, duration 6 h). Pitting corrosion were made in an environment of 5% NaCl solution at 35°C. Findings: The results of corrosion tests allows to determinate that the best corrosion show composite materials with addition of 15% of CuSn10 or X2CrNiMo17-12-2. Practical implications: Composite materials Nd-Fe-B – polymer matrix can greatly expand the application possibilities of hard magnetic materials however further examination to obtain materials with improved properties are still needed. Originality/value: Results show corrosion resistance of Nd-Fe-B - polymer matrix composite materials determined by different methods. Results are the base for further investigations of the impact of corrosion environment on the magnetic properties of such composite materials
12
Content available remote FEM used in improvement of quality of medical devices
EN
Purpose: The fundamental aim of this research was to determine the biomechanical characteristics of the medical bed made of carbon steel and an assessment of its stability. To define the biomechanical characteristics of the bed design, the finite element method (FEM) was applied. Additionally, the risk analysis was conducted according to the directives of ISO 14971 standard. Design/methodology/approach: The research was carried out on the typical rehabilitation bed. To define the biomechanical characteristics of this equipment, the finite element method was applied. Geometric model of medical bed, was discretized by means of SOLID 95 element. Appropriate boundary conditions imitating phenomena in the real system with appropriate accuracy were established. The aim of biomechanical analysis was calculation of displacements and stresses in the bed’s construction elements in a function of the applied loading. In order to carry out calculations, 3 models of diverse variants of loading were selected – safe working load - model 1, transverse stability - model 2 and longitudinal stability - model 3. Findings: The analyses showed the difference in displacements, strains and stresses in the characteristic points depending on the selected loading. That also helped to determine maximal loading causing the exceeding of the yield stress of the bed’s components. Research limitations/implications: The limitations were connected with simplification of numerical model of femur as well as with the selected boundary conditions. Practical implications: The obtained results can be useful in the designing process (modification of requirements regarding design and construction, as well as materials used in the production of the device, and reduction of risk as far as possible to the patient). They prove that 3D geometrical analysis works quite well for assistive medical devices design. Originality/value: Stress-strain-displacement characteristics of the medical bed’s elements, obtained from the numerical analysis were presented in the work.
14
Content available remote Corrosion behaviour of metallic biomaterials used as orthodontic wires
EN
Purpose: The aim of the work was evaluation of the corrosion resistance of the commercial metallic orthodontic wires from different manufacturers in simulated intra-oral environment. Design/methodology/approach: Corrosion resistance tests were carried out in artificial saliva at the temperature 37 ± 1° C with the use of the VoltaLab ® PGP 201 system for electrochemical tests. The saturated calomel electrode (SCE) was applied as the reference electrode and the auxiliary electrode was a platinum foil. The evaluation of pitting corrosion was realized by recording of anodic polarization curves with the use of the potentiodynamic method. In order to evaluate crevice corrosion resistance the samples were polarized in the potential equal to 0.8 V by 900 seconds. Findings: Results of corrosion resistance tests of the CrNi, NiTi and CuNiTi wires showed comparable data of parameters obtained in the artificial saliva. Research limitations/implications: The obtained results show the influence of artificial saliva on the electrochemical corrosion of orthodontic wires. In order to demonstrate the higher risk of corrosion, which can have two consequences: a loss of the physical properties and the release of Ni ions (which have been shown to be toxic and the cause of allergic reactions) - additional research on fatigue corrosion should be carried out. Originality/value: The analysis of the obtained results show that that commonly used materials for making orthodontic wires (because of their interesting properties - elasticity and shape memory) can be used in different orthodontic treatment stages to correct numerous clinical conditions. The most favorable characteristics were observed for the new NiTi samples (American Orthodontics).
15
Content available remote Corrosion behaviour of Co-Cr-W-Ni alloy in diverse body fluids
EN
Purpose: The aim of the work was evaluation of corrosion resistance of implantable Co-Cr-W-Ni alloy in simulated body fluids: human blood (artificial plasma), urine (artificial urine) and bone tissue (Tyrode solution). Design/methodology/approach: Corrosion resistance tests were carried out in the selected physiological body fluids at the temperature 37 ± 1°C with the use of the VoltaLab PGP 201 system for electrochemical tests. The saturated calomel electrode (SCE) was applied as the reference electrode and the auxiliary electrode was a platinum foil. The evaluation of pitting corrosion was realized by recording of anodic polarization curves with the use of the potentiodynamic method. In order to evaluate crevice corrosion resistance the samples were polarized in the potential equal to 0,8 V by 900 seconds. Roughness of all the samples was evaluated with the use of the SURTRONIC 3+(Taylor/Hobson) surface analyzer. Findings: Results of corrosion resistance tests of the Co-Cr-W-Ni alloy showed the diverse values of parameters obtained in the individual solutions. The suggested surface treatments ensure good crevice corrosion resistance of the Co-Cr-W-Ni alloy in all the tested physiological fluids. Research limitations/implications: The obtained results show the necessity of selection of the appropriate physiological solution, reflecting the specificity of body environment. In order to fully characterize the material in the human body environment, additional research on stress and fatigue corrosion should be carried out. Originality/value: The analysis of the obtained results show favorable influence of the suggested surface treatment of the Co-Cr-W-Ni alloy. Regardless of the selected physiological solution, the most favorable characteristics was observed for the electropolished and passivated samples.
EN
Stainless steels are the most common metallic biomaterial, used mainly as implants, for example in maxillo-facial surgery. In the work the corrosion resistance of implants, made of Cr-Ni-Mo steels, with the passive-carbon layer was tested. This has been investigated in laboratory test under simulated tissue environments. Moreover, biotolerance of implants, which have served as the internal fixation devices of mandibular fractures in clinical examinations, have been evaluated.
PL
W grupie metod inżynierii powierzchni, które wykorzystywane są do przygotowania powierzchni implantów wymienić możemy między innymi polerowanie elektrochemiczne oraz utlenianie anodowe. Metody te przyczyniają się głównie do poprawy chropowatości powierzchni oraz wzrostu odporności korozyjnej. Dobór obróbki powierzchniowych powinien odbywać się na podstawie wcześniej przeprowadzonych analiz biomechanicznych. Uwarunkowania biomechaniczne dotyczące naprężeń i przemieszczeń muszą być uwzględnione szczególnie w strefach kontaktów implantów. W pracy przedstawiono wyniki badań nad sposobami polerowania elektrochemicznego oraz utleniania anodowego dwufazowych stopów tytanu Ti6Al4V ELl, Ti6Al7Nb. Przeprowadzone badania wykazały, że polerowanie elektrochemiczne i utlenianie anodowe zapewniają dobrą odporność korozyjną stopów tytanu oraz wymaganą chropowatość powierzchni. Głównym składnikiem warstwy tlenkowej był dwutlenek tytanu. Aluminium oraz wanad, których stężenie obniżyło się w warstwie powierzchniowej w stosunku do materiału podłoża występowały w formie utlenionej. Badania przy pomocy mikroskopu AFM wykazały, iż warstwa jest ciągła.
EN
In the group of surface treatments which are commonly used for preparing implants surface we can enumerate electropolishing and anodic oxidation. These methods increase roughness of the surfaces and corrosion resistance of the implants. Nevertheless, choosing a right method for any particular implant should be preceded by biomechanical investigations. In the biomechanical test strain, stress and displacements distributions are determined and on this base we can project a new layer. In the paper results of the research that concern influence of electropolishing and anodic oxidation of titanium alloys Ti6AlV ELl, Ti6Al7Nb on corrosion resistance, surface chemistry and structure were presented. It was shown that electropolishing and following anodic oxidation ensure required roughness for the implants and good corrosion resistance. The oxide layer of Ti6Al4V ELl was predominantly composed of titanium dioxide. Aluminum and vanadium were present in the layer in oxide form and their concentration was lower then in the bulk material. AFM observation showed that the layer is uniform.
PL
W artykule przedstawione zostały wyniki wieloletnich badań. nad zastosowaniem warstw pasywno-węglowych na implantach ze stali Cr-Ni-Mo. Warstwy te wytwarzane są dwuetapowo: poprzez polerowanie elektrolityczne i pasywację chemiczną i kolejno przez wytworzenie warstwy węglowej w procesie RF PCVD. Zbadano strukturę warstw metodami spektroskopii Auger'a, Ramann'a i fotoelektronów oraz metodami wysokorozdzielczej mikroskopii elektronowej transmisyjnej i skaningowej. Ponadto zbadano własności fizykochemiczne warstw w celu określenia ich odporności na korozję wżerową, szczelinową, naprężeniową i zmęczeniową. Korzystny zespół właściwości implantów z warstwami pasywno - węglowymi w zastosowaniu w chirurgii rekonstrukcyjnej (traumatologii, szczękowo twarzowej i wewnątrznaczyniowej) potwierdzony został w badaniach ,,in vivo" - przedklinicznych i klinicznych.
EN
The paper presents results of long-term research on passive - carbon layers on Cr-Ni-Mo steel implants. The layers are created in two stages: first - the electrolytic polishing and the chemical passivation, second - deposition of the carbon layer in the RP PCVD process. In order to evaluate the structure of the layers the Auger, the Ramann and the photoelectron spectroscopy as well as the high resolution transmission and scanning electron microscopy were applied. Furthermore, the physical and the chemical properties of the layers were tested in order to determine their resistance to pitting, crevice, stress and fatigue corrosion. Favorable properties of implants with passive - carbon layers applied in the reconstruction surgery (traumatology, maxillo-facial and intravascular) were confirmed in preclinical and clinical "in vivo" tests.
EN
The paper presents the results of research on the choice of optimal metallic biomaterials (Cr-Ni-Mo steel and titanium) for implants applied in maxillofacial part of cranium. Based on literature the range of coenitive problems has been determined, the solution of which is of prospective importance for the de- velopment of new techniques of the osteosynthesis of mandible bone. A program of investigations comprised an analysis of the slate of stresses and strains in the mandible and stabilization of miniplates applying the holographic interferemetry and the finite element methods. The aim of these investigations was to check whether such implants might warrant a controlled stabilization of the broken elements and whether the yield stresses of both biomaterials are not exceeded.
EN
The paper presents the result of researches concerning the choice ofoptimal metallic biomaterials (Cr-Ni-Mo steel and titanium) for implants applied in maxillo-facial surgery. Basing on literature the range of cognitive problems has been determined, the solution of which is of perspective importance for the development of new techniques of the osteosynthesis mandible bone. A program of investigations has been set up comprising an analysis of the state ofstresses and strains in the mandible and stabilising miniplates applying the finite element method. The aim of these uwestigations was to check whether such implants might warrant a controlled stabilisation of the broken elements and whether deformations of interelements are possible.
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