Surface activity of titanium alloys contacted with the simulated body fluid

The purpose of this study was to analyze surface chemical species deposited on various implant materials immersed in simulated body fluid (SBF). The investigated materials including pure titanium, two beta titanium alloys and stainless steel (316L) were formed into discs using cold pressing and sintering. The samples were examined using SEM and mid-IR microscopes. All the sample discs exhibited nucleation and growth of calcium phosphates, precipitated from the SBF solution containing calcium, phosphate and other ions. The results have shown that the nucleation and growth of phosphates depend on the alloy composition and become more intensive in the case of the titanium alloy with the niobium additio

Fatigue stress resistance of some composite materials for dental fillings

The paper investigates fatigue stress resistance of some originally made composite materials based on Bis-GMA resin with fluoridated glass and YbF3. The material was used to fill in the cavities in teeth extracted for orthodontic reasons. For laboratory tests a mastication simulator was used. The tooth samples were placed in special holders with resin and exposed to cyclic mechanical loads (100 000 cycles) in order to assess their resistance to fatigue stress. The influence of repeatable mechanical loads on the teeth and the structure of the material were investigated. Additionally, the impact of cyclic loads on fluoride release from the composite materials was estimate

Biocorrosion of dental alloys due to Desulfotomaculum nigrificans bacteria

Purpose: Degradation processes of metallic biomaterials in the oral cavity limit the stability and reliability of dental materials. The influence of environment bacteria Desulfotomaculum nigrificans sulfate reducing bacteria on the corrosion processes of Co-Cr-Mo and Ti-6Al-4V alloys was assessed. Methods: After 28 and 56 days of contact of the materials with the bacterial environment, the surfaces of the tested biomaterials were observed by means of confocal scanning laser microscopy (CSLM), and their chemical composition was studied using X-Ray Photoelectron Spectrometry (XPS). Results: Corrosive changes and the presence of sulfur (with medium atomic concentration of 0.5% for Co-Cr-Mo and 0.3% for Ti-6AL-4V) were observed on the surface of the biomaterials. Image analysis conducted using APHELION software indicated that corrosion pits took up approx. 2.3% and 1.8% (after 28 days) and 4.2% and 3.1% (after 56 days) of the total tested surfaces of cobalt and titanium alloys respectively. The greatest number of corrosion pits had a surface area within the range of 1-50 m2. They constituted from 37% until 83% of all changes, depending on the type of material. Conclusions: An evident influence of the SRB on the cobalt and titanium alloys surfaces was observed. Significant corrosive losses caused by the activity of micro-organisms were stated on the studied metallic surfaces. The results of this study have much cognitive and utilitarian significance

The characteristic of selected properties of composite materials for dental fillings

W pracy przedstawiono wyniki badań wpływu napełniaczy proszkowych na procesy uwalniania fluoru z kompozytowych materiałów na stałe wypełnienia stomatologiczne. Oceniano wpływ fluorku strontu oraz nanokrzemionki na ilość uwalnianego fluoru. Emisję jonów fluorkowych analizowano przy pomocy metody potencjometrii bezpośredniej z zastosowaniem fluorkowej elektrody jonoselektywnej. Badano także chropowatość powierzchni oraz mikrotwardość analizowanych kompozytów.This work presents results of research of the influence two filler powders on fluorine release from composite materials for dental fillings. The influence of fluoride strontium and nanosilica on fluorine release was investigated. Fluorine release was measured using direct potentiometry method with fluoride electrode. The surface roughness and microhardness were also analyzed

Tribological characteristics of the kinematics couple: tooth - composite material for permanent dental fillings

W pracy przedstawiono charakterystyki tribologiczne układu kinematycznego ząb - materiał kompozytowy na stałe wypełnienia stomatologiczne. Badaniom poddano własne kompozyty zawierające źródła fluoru, nanokrzemionkę oraz modyfikator tarcia w postaci proszku polietylenu. Badania przeprowadzono przy użyciu specjalnie skonstruowanego testera tarcia zębów typu pin-on-disc w środowisku roztworu o pH śliny. Oceniano wpływ całkowitego obciążenia na współczynnik tarcia zaprojektowanych materiałów kompozytowych oraz zużycie liniowe badanych kompozytów i zużycie objętościowetkanek zęba. Przeprowadzono obserwacje mikroskopowe struktury materiałów kompozytowych po badaniach tarciowych.The paper presents a tribological characteristics of the kinematics couple: tooth - composite material for permanent dental fillings. Two original composites containing fluorine sources, nanosilica and a friction modifier in the form of polyethylene powder were investigated. The wear tests were carried out in a special solution of saliva pH using a special pin-on-disc tribotester. The impact of total load on the friction coefficient of designed composite materials and linear wear of both the analyzed materials and volume wear of the tooth samples were evaluated. The composites' friction surface including wear particles was examined by SEM

Overlay dentures - constructional and research aspects

The paper presents selected issues relating to movable dentures with their general characteristics of fixings. Reference was made to the most importantmaterial-constructional aspects and the problems that arise with this type of solutions. In the work the method of durability and reliability evaluation and selection of materials for the kinematics connections of this type of structure was proposed

The influence of friction process on the structure of composite materials for dental fillings

W pracy przedstawiono wyniki badań wpływu procesu tarcia na strukturę materiałów kompozytowych na stałe wypełnienia stomatologiczne. Badane kompozyty zawierały fluorowane szkło oraz różne modyfikatory tarcia. Procesy tarcia przeprowadzono w specjalnie skonstruowanym symulatorze tarcia. Obserwowano wpływ wzajemnego oddziaływania pomiędzy cząstkami napełniaczy a żywicą organiczną na właściwości tribologiczne otrzymanych próbek materiałów. Powierzchnię tarcia z widocznymi cząstkami zużycia analizowano przy wykorzystaniu programu do analizy obrazu.The paper presents results of research of the influence of friction process on the structure of composite materials for dental fillings. The investigated composites contain a fluoridated filler and different powder fillers. Wear tests were carried out by means of special tribotester. The interaction between the filler particle and organic matrix and its influence on the tribological behavior of prepared specimens were observed. The friction surface with the wear particles was observed by means of SEM and the pictures were analyzed by a computer image editing software

The application of FT-IRM technique in research of mucin adsorption on selected biomaterials surface

W pracy przedstawiono wyniki badań adsorpcji mucyny zwierzęcej na powierzchni wybranych biomateriałów. Przebadano po dwie próbki każdego z materiałów, których powierzchnie różniły się chropowatością. Badania przeprowadzono za pomocą mikrospektroskopii w podczerwieni z transformacją Fouriera (FT-IRM). Wyniki badań wskazują na adsorpcję mucyny do wszystkich testowanych materiałów. Zaobserwowano wpływ rodzaju biomateriału na intensywność adsorpcji testowanej proteiny do jego powierzchni.This work presents results of research of animal mucin adsorption on the surface of selected biomaterials. Two samples of each material with different surface roughness were investigated. The tests were performed using Fourier-transform infrared microspectroscopy (FT-IRM). The results indicate that mucin adsorb to all tested materials surface. The influence of biomaterial type on protein adsorption intensity to material surface was observed

Model odporny systemu monitorowania w automatyzacji procesu etykietowania z wykorzystaniem sterowników PLC

This paper presents a method for improving the labelling process and a robust monitoring model for the labelling machine with the purpose of reducing waste of labels and bottles.The proposed monitoring method is based on a combination of Matlab®-designed and hardware-in-the-loop (HIL) simulationas well as Arena Simulation. The method solves problems with the application of labels during the labelling stage and provides a robust monitoring algorithm that recognizes defective labels before they are stuck onto bottles.The Grafcet optimal algorithm for recognizing defective labels is executed. The Matlab®Stateflow model for monitoring and recognizing defective labels is applied. The proposed algorithms are complete, and optimized solutions are ready for implementation in the existing PLC supervisory control system. Based on HIL simulations, the proposed method ensures an increase of the total production quantity. Statistical data was collected directly from the field, classified using Statfit software, and used in Arena Simulation software to present the difference and benefits before and after using the PLC-based robust monitoring model for the labelling machine automation process.W pracy przedstawiono metodę poprawy procesu etykietowania oraz model odporny monitorowania uszkodzeń etykiet w celu zmniejszenia ilości odpadów etykiet i butelek. Opracowanie proponowanej metody monitorowania i wykrywania wad etykiet opiera się na wykorzystaniu kombinacji funkcji środowiska Matlab® oraz symulacji sprzętowej (ang. hardware-in-the-loop, HIL). Nowa metoda rozwiązuje problemy związane z wykrywaniem uszkodzeń przyklejanych etykiet do butelek w przemysłowej linii produkcyjnej oraz zawiera model odporny detekcji wad etykiet. Algorytm systemu monitorowania w procesie etykietowania został przedstawiony za pomocą sieci Grafcet, a następnie zrealizowany w środowisku Matlab Stateflow®. Proponowane algorytmy monitorowania/detekcji zostały zoptymalizowane pod kątem ich realizacji w istniejącym systemie sterowania opartym o programowalne sterowniki logiczne (ang. programmable logic controllers, PLCs). Przeprowadzone symulacje sprzętowe HIL pomyślnie weryfikują opracowane rozwiązania podnoszące efektywność produkcji. Zaproponowany odporny model detekcji uszkodzeń etykiet został zaimplementowany w układzie sterowania linii produkcyjnej i zweryfikowany eksperymentalnie. Zebrane dane statystyczne bezpośrednio z obiektu sterowania zostały opracowane w programie Statfit. Oprogramowanie Arena Simulation zostało wykorzystane do porównania wyników pracy linii produkcyjnej przed i po wprowadzeniu modelu wykrywania uszkodzeń etykiet

Influence of self-made saliva substitutes on tribological characteristics of human enamel

This paper describes the results of tests on the influence of human saliva and its substitutes on tribological characteristics of friction pairs. Each pair consists of enamel and one of the following materials: ceramics, the Meridian B2 dental composite, the GK dental amalgam, and Ti-6Al-4V titanium alloy. The saliva substitutes used were prepared using pyrophosphates, xanthan gum, and mucins dissolved in a saline buffer. The results of the tribological tests show that the values of the parameters under investigation (coefficient of friction and linear wear) were different from each other. Some similarity was observed between the evaluated level of wear characteristics after the friction process in the environment of human saliva and that in the environment of one of the mucins tested. Microscopic observations of the surfaces of the enamel samples after friction revealed varied forms of tribological wear