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1

Microplasma spraying of hydroxyapatite coatings on additive manufacturing titanium implants with trabecular structures

Kadyroldina Albina, Alontseva Dayra, Voinarovych Sergey, Łatka Leszek, Kyslytsia Oleksandr, Azamatov Bagdat, Khozhanov Aleksandr, Prokhorenkova Nadezhda, Zhilkashinova Almira, Burburska Svitlana

Materials Science Poland

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2022

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Vol. 40, No. 4

28--42

EN

This paper presents new results of microplasma spraying (MPS) of laboratory-synthesized hydroxyapatite (HA) powder coatings onto trabecular substrates obtained by selective laser melting (SLM) of a certified titanium medical alloy powder. The aim of the study was to establish the possibility of combining the technologies of MPS and additive manufacturing (AM) for the possible production of custom-designed implants with increased surface biocompatibility, as well as to establish the MPS parameters that ensure chemical purity of the HA coating and satisfactory adhesion of the coatings to the substrate. The structural-phase compositions of the initial HA powder and the plasma-sprayed HA coating were studied by X-ray diffraction analysis and transmission electron microscopy, and the adhesion strength of the coating was tested according to the F1147 standard of the American Society for Testing and Materials (ASTM). The main results of the study are the following: the application of the MPS technology for HA coating with an average thickness of 150±50 μm on trabecular substrates obtained by the SLM method has been shown. The parameters of MPS of HA coatings onto titanium implants with a trabecular surface have been established. It is also proved that using the appropriate MPS parameters, it is possible to obtain a HA coating with a 95% level of HA phases, 93% level of crystallinity, and the adhesion strength to the trabecular substrate of 24.7±5.7 MPa, which complies with the requirements of the international medical standard (International Organization for Standardization [ISO] 13779-2:2018). These results are of significance for a wide range of researchers developing plasma spray technologies for the manufacture of biocompatible coatings.

2

Tribokorozja jako efekt działania pary trącej w medium płynu synowialnego na przykładzie implantu – endoprotezy stawu biodrowegoTribokorozja jako efekt działania pary trącej w medium płynu synowialnego na przykładzie implantu – endoprotezy stawu biodrowego

Stanek Wiktor

Ochrona przed Korozją

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2021

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nr 12

387--395

PL

Idealny materiał implantu endoprotezy stawu biodrowego powinien mieć elastyczność modułu kości, wysoką odporność na korozję i zużycie oraz doskonałą biokompatybilność. Aby osiągnąć maksymalną wydajność i trwałość implantu, producenci używają różnych materiałów do różnych części implantu. Korozja odgrywa znaczną rolę w uwalnianiu jonów metali, jednak zarówno zużycie (proces mechaniczny) jak i korozja (proces chemiczny) działają synergistycznie („tribokorozja”) w obecności płynu maziowego/synowialnego bogatego w białko. Ta interakcja powoduje generowanie złożonych produktów degradacji. Gdy dwa metale stykają się ze sobą i przechodzą proces trybologiczny (zużycie przez tarcie lub fretting), zużyty materiał w postaci gruzu zostaje uwolniony z ich węzła par trących. Są to cząstki zużycia mechanicznego lub produkty korozji i/lub jony metali. Ogólnie rzecz biorąc, tribokorozja jest procesem nieodwracalnym, skutkującym transformacją/degradacją materiału z wynikającą zmianą funkcji mechanicznej urządzenia. Wynika to z synergicznej interakcji mechanizmów ślizgowych, ściernych, frettingu, korozji szczelinowej i galwanicznej prowadzących do mechanicznej zmiany implantu. Tribokorozja systemów biologicznych jest trudna do przetestowania ze względu na złożoność struktury powierzchni i dużą liczbę zaangażowanych procesów. Odkrycie efektu synergicznego może wnieść wiele istotnych informacji na temat powstawania biotribowarstw, ich struktury i jednorodności na powierzchni implantu oraz wszelkich korzystnych (lub szkodliwych) efektów.

EN

An ideal hip joint endoprosthesis material should have bone module flexibility, high corrosion and wear resistance, and excellent biocompatibility. To achieve maximum implant performance and durability, manufacturers employ different materials for different parts of the implant. Corrosion plays an important role in the release of metal ions, however both wear (mechanical process) and corrosion (chemical process) act synergistically („tribocorrosion”) in the presence of protein-rich synovial fluid. This interaction generates complex degradation products. When two metals come into contact with each other and undergo a tribological process (wear by means of friction or fretting), the waste material is released as debris from the friction pair. These are wear particles or corrosion products and / or metal ions. In general, tribocorrosion is an irreversible process, resulting in the transformation / degradation of material, and leading to a change of the mechanical function of a device. This is due to the synergistic interaction of sliding and abrasive mechanisms, fretting, crevice and galvanic corrosion leading to a mechanical change of the implant. Tribocorrosion of biological systems is difficult to analyse due to surface structure complexity and a large number of processes involved. The discovery of the synergistic effect can provide much important information on the formation of biotribolayers, their structure and uniformity on the implant surface and any beneficial (or harmful) effects. An ideal hip joint endoprosthesis material should have bone module flexibility, high corrosion and wear resistance, and excellent biocompatibility. To achieve maximum implant performance and durability, manufacturers employ different materials for different parts of the implant. Corrosion plays an important role in the release of metal ions, however both wear (mechanical process) and corrosion (chemical process) act synergistically („tribocorrosion”) in the presence of protein-rich synovial fluid. This interaction generates complex degradation products. When two metals come into contact with each other and undergo a tribological process (wear by means of friction or fretting), the waste material is released as debris from the friction pair. These are wear particles or corrosion products and / or metal ions. In general, tribocorrosion is an irreversible process, resulting in the transformation / degradation of material, and leading to a change of the mechanical function of a device. This is due to the synergistic interaction of sliding and abrasive mechanisms, fretting, crevice and galvanic corrosion leading to a mechanical change of the implant. Tribocorrosion of biological systems is difficult to analyse due to surface structure complexity and a large number of processes involved. The discovery of the synergistic effect can provide much important information on the formation of biotribolayers, their structure and uniformity on the implant surface and any beneficial (or harmful) effects.

3

Wydłużanie kości długich – metody i zastosowanie

Grygier Dominika, Słowiński Jakub, Kowalewski Piotr

Inżynier i Fizyk Medyczny

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2020

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Vol. 9, nr 6

458--460

PL

Jednym z głównych przejawów ludzkiej aktywności ruchowej jest lokomocja realizowana jako chód. Jego prawidłowość i stabilna postawa jest pochodną równej długości kończyn dolnych. Badania związane z postawą ciała dzieci prowadzone w latach 50. ubiegłego wieku wskazywały, że ponad 90% dzieci do 13 roku życia miało asymetrię ciała w płaszczyźnie czołowej [1]. Badania z udziałem osób dorosłych wykazują, według różnych źródeł, że nierówność kończyn (ang. limb length discrepancy) (Rys. 1) dotyczy tej populacji w przedziale 40-70% [2-3]. W większości jest to nieznaczna różnica, która kompensowana jest dyskretnymi odchyleniami w budowie anatomicznej w innych regionach ciała. Do skutków znacznej nierówności kończyn zaliczyć można nie tylko ogólne wady postawy, jak skrzywienia kręgosłupa, obniżenie miednicy czy występowanie garbu żebrowego [4]. Wada ta wiąże się także z dolegliwościami bólowymi – ze szczególnym uwzględnieniem odcinka L – S kręgosłupa [5].

4

The effect of hydroxyapatite coating with silver nanoparticles on osseointegration of titanium implants

Sulej-Chojnacka Joanna, Woźniak Waldemar, Andrzejewski Daniel

Engineering of Biomaterials

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2020

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Vol. 23, no. 154

9--15

EN

During the implantation surgery, an infection associated with the biofilm formation may occur. Both the type of the introduced material as well as the implant osseointegration largely determine the effectiveness of bone defect treatment. The materials research is increasingly focusing on improving the osseointegration process. A bacterial biofilm can form on any surface of the artificial organ that has been introduced into the body or surrounding tissues. A bacterial infection is one of the most serious complications of implantology surgery leading to serious physiological damage. As proved in the literature, a solution that can prevent bacterial infections is to modify the implant surface by applying an antibacterial coating, while maintaining the material biocompatibility. The article presents the tests results of prototype implants with hydroxyapatite coatings obtained via plasma spraying on titanium surfaces. The resulting coatings were enriched with silver nanoparticles, the content of which was about 2%. The animal model are New Zealand rabbits. The implants were placed in the femur of the animal. The amount of released ions and the force of pulling the implants from the bone were determined. The binding strength between the joint surface and the implant was determined by the mechanical blocking and biological binding of growing bone tissue. In addition, the surface structure of the obtained implants was evaluated. It has been shown that the surface modification of the implants affected the obtained stabilization value, as compared to the implants surface coated only with hydroxyapatite.

5

Laser-modified PLGA for implants: in vitro degradation and mechanical properties

Kobielarz Magdalena, Tomanik Magdalena, Mroczkowska Katarzyna, Szustakiewicz Konrad, Oryszczak Magdalena, Mazur Anna, Antończak Arkadiusz, Filipiak Jarosław

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 1

179--192

EN

Irradiations of poly(lactic-co-glycolic acid) surface by CO2 laser lead to alterations of physicochemical properties of the copolymer. Effects of PLGA irradiations depend on the process parameters determining different cases of surface modification. Hence the main goal of presented studies was to define the influence of CO2 laser irradiation with different process parameters, inducing three cases of surface modification, on mechanical properties and topography of PLGA during degradation in the aqueous environment. Methods: Hydrolytic degradation of untreated and treated by CO2 laser thin specimens of PLGA was performed in distilled (demineralized) water. Mechanical properties of PLGA specimens before and during incubation were conducted in accordance with the PN-EN ISO 527-3:1998 standard. The pH of incubation solutions, topographies, masses and geometrical dimensions of specimens were controlled during the process. Results: During the hydrolytic degradation, gradual changes in failure mode were observed from ductile failure characteristic for untreated PLGA to brittle failure of incubated PLGA regardless of the case of induced modification. Tensile strength decreased with degradation time regardless of the case of surface modification with insignificant fluctuation Young’s moduli at the level of means. The pH of solutions for each case decreased and topography od specimens become smoother with incubation time. Conclusions: PLGA surface modification by CO2 laser below the ablation threshold (P1) and at the ablation threshold (P2) led to surface functionalization, however, irradiation above the ablation threshold (P3) caused marked degradation of PLGA and accelerated specimens disintegration during incubation in the aquatic environment.

6

The mechanical aspect of titanium ion release after posterior instrumentation for early onset scoliosis

Danielewicz Anna, Fatyga Marek, Wójciak-Kosior Magdalena, Sawicki Jan, Różańska-Boczula Monika, Sowa Ireneusz, Latalski Michał

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1442--1449

EN

Surgical treatment of early onset scoliosis (EOS) is connected with the risk of early and late complications. The aim of the study is to assess influence of the rod fracture on the titanium ion release (TIR) in traditional growing rods instrumentation for EOS.56 patients treated surgically due to EOS were divided into three groups: 1) a control-patients newly operated due to scoliosis, patients treated with the traditional growing rod (TGR) and TGR who had rod fracture (FGR) and required a surgical revision. Titanium quantification in blood sample, skin fragment (CT –clean tissue) andmacrosco-pically contaminated tissue located near the implant (DT –dirty tissue) was performed using high-resolution emission spectrometry with excitation in inductively coupled plasma.The mean serum titanium level in control, TGR, and FGR groups were 1.93 ± 0.8, 5.61 ± 0.23, and 4.43 ± 0.1 μg/dm3, respectively. The mean CT titanium level in control, TGR, and FGR groups were 0.0045 ± 0.001, 0.0035 ± 0.001and 0.0065 ± 6.8 mg/g, respectively. The mean DT titanium level in TGR and FGR groups was 0.59 ± 0.02, and 1.022 ± 0.03 mg/g, respectively.Implant leadsto the TIR into tissues and blood. Increasing the number of anchors increases the titanium content inthe CT TGR group. Mechanical damage to the implant has no significant effect on the increase of TIR

7

Strenghth analysis of hip joint replacement revision implant

Skowronek Paweł, Twardoch Krzysztof, Skawiński Piotr, Żołnierz Marcel

Journal of Theoretical and Applied Mechanics

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2019

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Vol. 57 nr 1

235--248

EN

The subject of the article is the evaluation of the strength of revision implants made of titanium or tantalum alloy, used during bone reconstruction of a hip joint while potentially using additional stabilizing screws, necessary due to significant bone loss. The article provides a preliminary strength analysis of implants, indispensable for further evaluation of strength limitations due to the risk of implant damage depending on the structure and number of additional screw holes. In the human locomotor system, the hip joint is the joint with the most load, hence the main problem is to establish an adequate load model which ought to be assumed for the needs of implant strength analysis. It is found necessary to perform a short, analytical review of the existing hip joint load models from the point of view of choosing the proper one, considering evaluation of implant strength by means of numerical studies using FEM. Differences in the implant load distribution depending on the used material are shown.

8

Characterization of Ca50Mg20Zn12Cu18 Alloy

Hrapkowicz B., Lesz S.T.

Archives of Foundry Engineering

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2019

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iss. 1

75--82

EN

The Ca50Mg20Zn12Cu18 was assessed with different methods in order to characterize its basic characteristics, and to determine whether the amorphous alloy of such composition would be applicable as an implant material. The XRD analysis was conducted to conclude the structure of the initial material. The Ca50Mg20Zn12Cu18 ingot sample demonstrates crystalline structure containing two main intermetallic phases, however as-cast plates show features of an amorphous material, revealing the characteristic amorphous halo on the x-ray patterns. It was confirmed by the scanning electron microscopy method and fracture images revealing chevron pattern morphology with shell type fracture. Corrosion resistance, was studied using the potentiostatic analysis. The amorphous samples show higher resistance than the crystalline one. Post corrosion surface of the Ca50Mg20Zn12Cu18 alloy exhibits high concentration of magnesium and calcium hydroxides, forming the globular structures in large aggregates of spherical units.

9

Projekt i analiza obliczeniowa implantu krążka międzykręgowego odcinka szyjnego kręgosłupa przeznaczonego do wytwarzania za pomocą technologii przyrostowych

Surma Krzysztof, Adach Martyna, Dębowska Martyna, Turlej Patrycja, Szymczyk Patrycja

Aktualne Problemy Biomechaniki

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2019

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z. 17

111--122

PL

Artykuł został poświęcony projektowi spersonalizowanego sztucznego implantu krążka miedzykręgowego odcinka szyjnego kręgosłupa. Praca zawiera analizę wstępną związaną z prawidłowym funkcjonowaniem krążka podczas obciążenia, doborem materiałów oraz metody wykonania implantów z wykorzystaniem technologii addytywnych SLS i SLM. Przy wykorzystaniu analizy MES przeprowadzono symulację wytrzymałościową implantu w warunkach obciążenia odcinka szyjnego wynikającego z zadanej pozycji ciała.

EN

The article is devoted to the design of a personalized artificial implant of the intervertebral disc of the cervical spine. The work contains preliminary analysis related to the proper functioning of the disc during loading, selection of materials and methods of implant preparation using SLS and SLM additive technologies. Using the MES analysis, strength simulation of the implant was carried out under load conditions of the cervical segment resulting from the position of the body.

10

Influence of middle ear disorder in round-window stimulation using a finite element human ear model

Zhou Kai, Liu Houguang, Yang Jianhua, Zhao Yu, Rao Zhushi, Yang Shanguo

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 1

3--12

EN

The aim of this work was to study the effect of middle ear disorder on round window (RW) stimulation, so as to provide references for the optimal design of RW stimulation type middle ear implants (MEIs). Methods: A human ear finite-element model was built by reverse engineering technique based on micro-computed tomography scanning images of human temporal bone, and was validated by three sets of comparisons with experimental data. Then, based on this model, typical disorders in otosclerosis and otitis media were simulated. Finally, their influences on the RW stimulation were analyzed by comparison of the displacements of the basilar membrane. Results: For the otosclerosis, the stapedial abnormal bone growth severely deteriorated the equivalent sound pressure of the RW stimulation at higher frequencies, while the hardening of ligaments and tendons prominently decreased the RW stimulation at lower frequencies. Besides, among the hardening of the studied tissues, the influence of the stapedial annular ligament’s hardening was much more significant. For the otitis media, the round window membrane (RWM)’s thickening mainly decreased the RW stimulation’s performance at lower frequencies. When the elastic modulus’ reduction of the RWM was considered at the same time especially for the acute otitis media, it would raise the lower-frequency performance of the RW stimulation. Conclusions: The influence of the middle ear disorder on the RW stimulation is considerable and variable, it should be considered during the design of the RW stimulation type MEIs.

11

Amorphous materials in the production of new implants

Kiljan A., Liptakova T.

Production Engineering Archives

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2018

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Vol. 18

50--53

EN

Amorphous materials based on magnesium are new materials for potential biomedical application, especially for new implants, as they bear resemblance to titanium implants. Mg66Zn30Ca4 alloy has specific properties, especially mechanical and corrosive, therefore, it has biomedical application as its properties are better than that of other materials. The following paper describes amorphous alloy based on magnesium, properties and shows how to produce amorphous samples of Mg66Zn30Ca4.

12

Bioaktywne powłoki przeciwdrobnoustrojowe na wyrobach medycznych do implantacji nałożone przez plazmowe utlenianie elektrolityczne

Dzhurinskiy D.

Obróbka Plastyczna Metali

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2018

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T. 29, nr 1

65--76

PL

W przedstawionej pracy badawczej wytworzono nowatorską powłokę na bazie TiO2 zawierającą nanocząsteczkowy hydroksyapatyt (n-HA) i cząstki srebra na dostępnych w handlu podłożach stopowych Ti-6Al-4V (Grade 5) i Ti-czysty (Grade 2) za pomocą techniki plazmowego utleniania elektrolitycznego (PEO). Osadzanie powłoki zrealizowano w wodnym roztworze wodorofosforanu disodowego zawierającego zawieszone nanocząsteczki hydroksyapatytowe i wodorotlenek potasu w trybie impulsowym prądu bipolarnego o kontrolowanym cyklu pracy. Włączenie przeciwdrobnoustrojowych cząsteczek srebra było możliwe z wykorzystaniem oddzielnej operacji technologicznej w wodnym roztworze AgNO3 na zasadzie fotokatalizy na powierzchni TiO2 w warunkach obróbki w ultrafiolecie. Morfologię powierzchni utworzonych powłok zbadano za pomocą skaningowej mikroskopii elektronowej (SEM), natomiast skład pierwiastkowy powłok został określony metodą analizy dyspersji energii promieniowania rentgenowskiego (EDS). Obecność nanocząsteczek HA w utworzonych powłokach została określona za pomocą spektroskopii w podczerwieni z transformatą Fouriera (FTIR). Wyniki wskazują, że utworzone powłoki PEO wykazują porowatą strukturę sieciową z osadzonymi cząstkami n-HA i Ag równomiernie rozmieszczonymi na całej powierzchni powłok. Utworzone w technologii PEO warstwy TiO2: n-HA: Ag mogą być stosowane jako bioaktywne powłoki biomimetyczne o właściwościach przeciwdrobnoustrojowych w celu zwiększenia aktywności biologicznej, osteointegacji i stabilności biochemicznej w implantowanych wyrobach medycznych.

EN

In the present study, a novel TiO2-based coating containing nanosized hydroxyapatite (nHA) and Silver particles has been formed on commercially available Ti-6Al-4V (Grade 5) and Ti-pure (Grade 2) alloy substrates by the Plasma Electrolytic Oxidation (PEO) technique. The coating deposition were provided in an aqueous solution of disodium hydrogen phosphate containing suspended hydroxyapatite nanoparticles and potassium hydroxide under a pulsed bipolar current mode with controlled duty cycle. Inclusion of antimicrobial silver particles were possible from a separate technological operation in AgNO3 aqueous solution by the principle of photocatalysis at TiO2 surface under ultraviolet treatment. The surface morphology of the formed coatings has been examined by Scanning Electron Microscopy (SEM), while the element composition of the coatings has been determined by Energy Dispersive X-ray analysis (EDS). The presence of HA nanoparticles within the formed coatings has been analyzed by Fourier Transform Infrared Spectroscopy (FTIR). The results indicate that the formed PEO coatings exhibit a porous network structure with embedded n-HA and Ag particles uniformly distributed over the entire surface of the coatings. The PEO-formed TiO2:n-HA:Ag layers can be used as a bioactive biomimetic coating with antimicrobial properties to enhance surface bioactivity, osseointegration and biochemical stability in implantable medical devices.

13

3D FE analysis of the behavior of elliptical cracks on orthopedic cement of the total hip prosthesis

Benouis A., Zagane M. S., Boulenouar A., Serier B., Belgherras M. E.

Journal of Theoretical and Applied Mechanics

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2018

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Vol. 56 nr 3

803--813

EN

An explicit analysis conducted on the crack behavior in chirurgical cement (Polymethylmethacrylate – PMMA) used for Total Hip Prosthesis (THP) is of great importance in collecting information about the nature of the phenomenon of loosening of the cement application. The rupture of the orthopedic cement is practically the main cause of this loosening. Understanding diﬀerent rupture mechanisms give a great value in advancing the durability of the cemented total prosthesis. The purpose of this study is to analyse cracks behavior, initiated in the cement that links the femoral-stem with the bone, using the Finite Element Analysis Method (FEM). The present study brings into focus the variation of the stress intensity factor in modes I, II and III. This rupture criterion is used according to the nature of crack, its orientation and its location in the orthopedic cement. At ﬁrst, the level and distribution of the equivalent von Mises stress is analysed, which is induced in the medial, proximal and distal parts of the bone cement. Then, the behavior of diﬀerent geometric forms of an elliptical crack is evaluated which are located and initiated within the body of these three parts.

14

Złamanie kości żuchwy : porównanie numeryczne wariantów stabilizacyjnych

Słowiński J. J.

Inżynier i Fizyk Medyczny

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2018

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Vol. 7, nr 6

403--406

PL

Kość żuchwy jest jedną z najczęściej łamanych kości ludzkiego organizmu, a w obrębie twarzoczaszki co trzecie złamanie dotyczy właśnie tej kości. Jej wyeksponowanie i brak naturalnych osłon sprawia, że w momencie urazu twarzoczaszki to właśnie żuchwa stanowi pierwszą linię obrony, która kumuluje dużą część energii. Efektem takich urazów może być dekohezja materiału kostnego żuchwy lub destabilizacja jej położenia. Efekty te mogą występować zarówno łącznie, jak i rozdzielnie. Ze względu na udział żuchwy w procesach komunikacji, odżywiania i oddychania jest niezmiernie istotnym przeprowadzenie korekcji w taki sposób, aby utracone funkcje zostały odzyskane w możliwie największym stopniu. Nie bez znaczenia jest również efekt kosmetyczny, który w dużej mierze rzutuje na późniejsze życie pacjenta [1-3]. Obecny rozwój techniki pozwala na prowadzenie zabiegów w obrębie twarzoczaszki z wykorzystaniem chirurgii małoinwazyjnej w oparciu o zastosowanie implantów w postaci płytek stabilizacyjnych. Zróżnicowanie kształtów i rozmiarów pozwala na właściwy dobór implantu do indywidualnych potrzeb pacjenta. W zakresie przeprowadzonej analizy opracowano modele numeryczne kości żuchwy wraz ze złamaniem oraz dwa warianty stabilizacji: jedno- i dwupłytkowy.

15

Analiza wpływu stabilizacji złamania kości piszczelowej za pomocą gwoździa śródszpikowego na zrost kostny. Cz. 2

Słowiński J. J., Kudłacik K.

Inżynier i Fizyk Medyczny

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2018

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Vol. 7, nr 1

66--68

PL

Ze względu na niepowodzenie prowadzonego leczenia podjęto decyzję o przeprowadzeniu wstępnej analizy numerycznej prezentowanego przypadku klinicznego z wykorzystaniem metody elementów skończonych. W tym celu opracowano modele numeryczne kości, złamania oraz implantu. Analizie poddano dwa przypadki możliwej stabilizacji – jednopłaszczyznową oraz dwupłaszczyznową. Pierwsze rozwiązanie wykorzystuje otwory implantu w płaszczyźnie czołowej, tak w dalszym, jak i bliższym końcu. W wariancie drugim (wykorzystanym w opisywanym przypadku klinicznym), w części bliższej powtórzono mocowanie z przypadku pierwszego, tj. jednopłaszczyznowe, w części dalszej natomiast wykorzystano jeden otwór w płaszczyźnie czołowej, drugi zaś w płaszczyźnie strzałkowej. Celem prowadzonych prac było wykazanie, czy i jak sposób stabilizacji gwoździa w objętości kości, szczególnie w części dalszej, rzutuje na uzyskanie zrostu kostnego.

16

Evaluation of the retention characteristics of various stud attachment systems for implant retained overdenture

Gonuldas F., Tokar E., Ozturk C.

Acta of Bioengineering and Biomechanics

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2018

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Vol. 20, no. 4

135--141

EN

The purpose of the study was to analyze and compare retention characteristics of different stud attachments including a standard and two low profile attachments on two implant embedded test models. Methods: Three different stud attachment systems (Ball attachment and two different low profile stud attachments – Equator and Locator) were used in this study. Two dental implants were placed vertically into a custom-made acrylic resin block within a 22 mm distance. Strong and soft nylon inserts of each attachment system were tested using cyclic dislodgement test for 24 months simulation. Maximum forces during the test were recorded and 10 consecutive data at baseline, 1st to 24th months were analyzed. Repeated measures ANOVA and post-hoc Tukey’s test ( p  0.05) were used for statistical analysis. Results: Retentive forces of the tested attachments varied from 30.7 to 93.75 N at the baseline. The highest initial mean retention (93.75 N) was observed in Group LC (locator attachment with clear nylon inserts) and the lowest initial mean retention (30.7 N) was detected in both Group BO (ball attachment with orange nylon inserts) and Group EY (equator with yellow nylon inserts). After the 24 months simulation, locator groups illustrated more light retention than other tested attachment systems. Conclusions: All tested attachment systems showed a significant decrease in retention value at the end of the simulated period. The locator attachment had significantly higher reduction in retention values compared to other low profile stud attachment equator and ball attachment.

17

Numerical analysis of the foods nature effect on the mechanical behavior of dental implants

Sifi M., Serier B., Merdji A., Benaissa A, Mootanah R.

Mechanics and Mechanical Engineering

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2017

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Vol. 21, nr 4

1021--1032

EN

This study focuses on a three-dimensional numerical analysis by the finite element method, the mechanical behavior of the dental prosthesis implant composed of a single implant. The effect of the nature of food on the level and distribution of the Von Mises equivalent stress generated in the bone and the elements that constitute this prosthesis have been highlighted. It has been shown that this level is particularly important that the Crushed masticated foods are rigid. This work was carried out to answer questions whose purpose was to analyze the risk of overload in the mandibular region. Loads transfer mechanisms and the possible failure of osseointegrated implants, the shape of the implant, the geometrical and mechanical properties of the placement site and bone resorption of the crest. A proper estimation of these effects allows the correct design of the implant.

18

Surface Modification of Self-Consolidated Microporous Ti Implant Compacts Fabricated by Electro-Discharge-Sintering in Air

Jo Y. J., Yoon Y. H., Kim Y. H., Chang S. Y., Kim J. Y., Lee Y. K., Van Tyne C. J., Lee W. H.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2B

1287--1291

EN

A single pulse of 0.75-2.0 kJ/0.7g of atomized spherical Ti powders from 300 mF capacitor was applied to produce a microporous Ti implant compact by electro-discharge-sintering (EDS). A solid core in the middle of the compact surrounded by a microporous layer was found. X-ray photoelectron spectroscopy was employed to study the surface characteristics of the EDS Ti compact and it revealed that Ti, C and O were the main constituents on the surface with a smaller amount of N. The surface was lightly oxidized and was primarily in the form of TiO2 resulting from the air oxidation during EDS processing. The lightly oxidized surface of the EDS compact also exhibited Ti nitrides such as TiN and TiON, which revealed that the reaction between air constituents and the Ti powders even in times as short as 128 msec.

19

Screw-retained full arch restorations – methodology of computer aided design and manufacturing

Malara P., Dobrzański L. B

Archives of Materials Science and Engineering

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2017

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Vol. 83, nr 1

23--29

EN

Purpose: The aim of the paper is to present the designing and manufacturing process of the screw-retained superstructure of the dental arch in the maxilla based on six implants using CAD/CAM technology. Design/methodology/approach: The methodology is presented on the example of the implantoprosthetic treatment in a 55-year-old female patient with a significant deficit of the alveolar bone. 6 implants were placed to achieve a good anchorage for the ceramic suprastructure. The prosthetic reconstruction was milled out of a zirconium dioxide block and covered with veneering ceramics to obtain good aesthetics of the restoration. Special copings were designed and manufactured to achieve stabile connection between the implants and the suprastructure. Findings: To properly plan the prosthetic work rebuilding the alveolar ridge on dental implants it is necessary to plan the final prosthetic work before implant placement planning the number of implants and their location in the bones and the possibility of using a fixed or a mobile suprastructure. Practical implications: Design of the suprastructure has to take into account the following factors: 1. The number of implants, copings and openings for the abutment screws, 2. Arrangement of teeth in the prosthesis, 3. The shape of the alveolar ridge, 4. The shape of the space for the porcelain and for the individual crowns, which will be pasted on the suprastructure. Originality/value: For technological reasons it is not possible to make an extensive suprastructure in a single piece. It is necessary to execute the foundation of the reconstruction of the alveolar ridge and the teeth in one piece and separately the individual crowns. It is possible, however, to design and manufacture the complex screw-retained prosthetic suprastructures by means of CAD/CAM technology.

20

Łąkotki stawu kolanowego - metody regeneracji

Pukaluk A., Ryniewicz A. M.

Aktualne Problemy Biomechaniki

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2017

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z. 12

65--74

PL

Łąkotki stawu kolanowego są kluczowymi strukturami zapewniającymi prawidłową pracę stawu, a ich usunięcie powoduje zapoczątkowanie nieodwracalnych zmian chorobowych na powierzchniach stawowych. Opracowano wiele metod leczenia uszkodzonych łąkotek, jednak każda z nich charakteryzuje się pewnymi ograniczeniami co do zastosowania. Przezwyciężenie tych ograniczeń poprzez stworzenie implantu, który by doskonale zastępował anatomiczną łąkotkę, jest już podejmowanym, ale jeszcze niezrealizowanym wyzwaniem.

EN

The knee joint menisci are key structures of the joint. They are responsible for the correct joint performance. Their removal results in irreparable chondral damage. There are a few methods of menisci regeneration, but all of them have some limitation in application regard. Overcoming those limitation and creation an implant, which could substitute the anatomical meniscus, is still ongoing, but not yet finalised process.