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1
Content available remote 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.
2
Content available remote Computer aided manufacturing and design of fixed bridges restoring the lost dentition, soft tissue and the bone
Malara P., Dobrzański L. B.
Archives of Materials Science and Engineering
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2016
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Vol. 81, nr 2
68--75
EN
Purpose: The aim of the paper is to present the methodology of computer aided designing and manufacturing of an all-ceramic multi-unit bridge restoring missing teeth and the lost soft and hard tissues of the oral cavity as a result of surgical treatment of oral tumor. Design/methodology/approach: The methodology of computer aided designing and manufacturing of the multi-unit all-ceramic bridge was presented on the basis of an actual clinical case of a patient who underwent the surgical treatment of myxoma of the oral cavity. All the steps of clinical and technical production of the bridge were described and illustrated. Findings: It is possible to use the CAD/CAM technology to design and manufacture all-ceramic multi-unit bridges restoring missing teeth and the lost soft and hard tissues of the oral cavity. The design of the bridge must be clinically validated using mock-ups and only then can be implemented for the CAM software. Practical implications: Thanks to the method of designing and manufacturing of multiunit all-ceramic bridges for patients with significant lost of the soft and hard tissues of the mouth it is possible to carry out a prosthetic rehabilitation of patients after trauma and tumor surgery. Originality/value: : The execution of extensive bridges with the maximum available height of about 25 mm requires a high technological rigor at the design and manufacture stage. To ensure longevity of the reconstruction, it is necessary to plan all the work while maintaining the maximum thickness of the substructure. It is desirable to provide minimum of 2 mm thick substructure and the surface of at least 20 mm2 or more in the cross-sections. At the same time, the structure of the bridge must be supported on the alveolar ridge to provide aesthetics and endurance.
3
Content available Klasa przygotowania powierzchni prętów Ti6Al4V na jakość połączenia z ZrO2 w ocenie badań mikroskopowych
Wita K., Czakon K., Hajduga M.
Aktualne Problemy Biomechaniki
|
2015
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z. 9
123--128
PL
Celem pracy była ocena wpływu kondycjonowania piaskiem Al2O3 o gradacji: 50μm, 110μm, 250μm, powierzchni prętów Ti6Al4V na klasę połączenia z ZrO2 cementem dentystycznym RelyX 3M ESPE. Wnioski zostały formułowane na podstawie wyników badań topografii powierzchni 3D oraz oceny struktur metalograficznych.
EN
The aim of the research was the impact assessment conditioning sand Al2O3 grit: 50μm, 110μm, 250μm, area bars Ti6Al4V on the class connection with ZrO2 dental cement RelyX 3M ESPE. Proposals where formulated based on research results of 3D surface topography and evaluating the structures metallographic.
4
Własności mechaniczne dwutlenku cyrkonu jako materiału wykorzystywanego na elementy konstrukcyjne
Wirwicki M., Topoliński T.
Zeszyty Naukowe. Mechanika / Politechnika Opolska
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2014
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z. 103
197--198
EN
Ceramic roller bearings with rolling elements have been known since the 60’s of last century. The material used in the bearings have very good mechanical properties, much better than the standard material - steel. In the study the authors focus on material which is zirconium dioxide, authors will present the process of determining the stability and strength of the material.
PL
W roku 1963 zostały zaprojektowane i wykorzystane łożyska z elementami tocznymi wykonanymi z ceramiki. Ten innowacyjny element konstrukcyjny został wykorzystany przez NASA w jednym z programów kosmicznych. Od tamtego czasu można zauważyć bardzo duże zainteresowanie w zastosowaniu łożysk z elementami tocznymi wykonanymi z ceramiki.
5
Content available High Pressure Synthesis versus Calcination – Different Approaches to Crystallization of Zirconium Dioxide
Kaszewski J., Yatsunenko S., Pełech I., Mijowska E., Narkiewicz U., Godlewski M.
Polish Journal of Chemical Technology
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2014
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Vol. 16, nr 2
99--105
EN
Calcination and microwave-assisted hydrothermal processing of precipitated zirconium dioxide are compared. Characterization of synthesized products of these two technologies is presented. The infiuence of thermal treatment up to 1200oC on the structural and spectroscopic properties of the so-obtained zirconium dioxide is examined. It was found that initial crystallization of material inhibits the crystal growth up to the 800oC (by means of XRD and TEM techniques), while the material crystallized from amorphous hydroxide precursor at 400oC, exhibits 26 nm sized crystallites already. It was found using the TG technique that the temperature range 100–200oC during the calcination process is equivalent to a microwave hydrothermal process by means of water content. Mass loss is estimated to be about 18%. Based on X-ray investigations it was found that the initial hydroxide precursor is amorphous, however, its luminescence activity suggests the close range ordering in a material.
6
Content available Analysis of the weibull distribution for static 3-point bending of zirconium dioxide
Wirwicki M., Topoliński T.
Journal of Polish CIMAC
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2013
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Vol. 8, no 3
117--122
EN
The paper presents the results of studies of the strength of dental material; zirconium dioxide in terms of the needs of dentists. More and more frequently it happens that dentists require not only mean value (or scope) of strength of a given material as well as the analysis of its reliability under load. It seems that it is necessary each day while taking a decision on the material for the fully-ceramic crown or bridge if the element considering the properties assumed by the manufacturer is to meet the patient’s expectations. The aim of the paper is to evaluate the risk and to determine the parameters of distribution of the damage probability for zirconium dioxide specimens. The paper has been based on the results of studies of 3-point bending of cuboid beams. There has been presented a method of zirconium dioxide specimen treatment. It has been considered what effect on the scatter of the results is attributed to the cross-section of the specimens. There were determined characteristic stresses, for which 63% of the specimens will get destroyed.
7
Content available Zirconium dioxide as a biomaterial; the microstructure
Wirwicki M., Topoliński T.
Journal of Polish CIMAC
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2012
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Vol. 7, no 3
369-372
EN
Zirconium dioxide is a material which, over the recent years, has been attracting support among dental technicians and dentists, thanks to its chemical composition and mechanical properties, it can replace nonanaesthetic foundations or metal crowns. Additionally zirconium dioxide is a material which is easy to work in. Zirconium dioxide is a polymorphic material demonstrating three phases: monocyclic, cubic and tetragonal. Additionally during the crack propagation the material shows the reinforcing transformation; the replacement of the phase and increasing the volume of the molecules, which inhibits the microcracks in the material. Thanks to such potential, zirconium dioxide has acquired a very high recognition in stomatology and orthodontics. Interestingly, the factor which has a considerable impact on the fatigue life and strength of zirconium dioxide is an adequate treatment and tool operation temperature; the slightest undesired effect can trigger the accumulation of stresses and thus decrease the material strength. A lower mechanical strength can be also due to other conditions, e.g. varied nutrition habits in the patient and the frequency of oral cavity hygiene practises.
8
Content available remote Correlation between high-pressure electrical properties of ZrO2 and its crystallite size
Trefilova A. N., Korionov I. V., Babushkin A. N., Łojkowski W., Opalińska A.
Materials Science Poland
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2005
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Vol. 23, No. 1
247--252
EN
A relation between crystallite size and electrical properties of ZrO2 has been investigated by measurements of high-pressure electrical resistance. The resistance of nanocrystalline praseodymium-doped zirconia powders has been measured in the pressure and temperature ranges between 15 and 50 GPa, and 77 and 400 K, respectively. Around 30-37 GPa the resistances of all samples decrease by 3-4 orders of magnitude. Therefore, the anomalies in the pressure dependence of the resistance and of parameters depending on the concentration, mobility and activation energy of the charge carriers were found at ca. 40-45 GPa. The activation energy of the charge carriers depends on the crystallite size.
9
Content available remote Otrzymywanie i właściwości elektryczne roztworów stałych w układzie Y2O3 - ZrO2 - CeO2
Bućko M.M, Fuć P., Gajerski R., Wojciechowski K.
Materiały Ceramiczne
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2004
|
R. 56, nr 4
154-159
PL
Roztwory stałe na bazie dwutlenku ceru są alternatywne w stosunku do dwutlenku cyrkonu jako tworzywa na elementy przewodzące w urządzeniach elektrochemicznych pracujących w temperaturach nie wyższych niż 800 stopni C. Szereg niekorzystnych właściwości tworzyw na bazie dwutlenku ceru można poprawić poprzez wprowadzenie do jego struktury obcych kationów. Celem prezentowanej pracy jest otrzymanie roztworów stałych dwutlenku cyrkonu oraz tlenku itru w dwutlenku ceru w postaci gęstych spieków a także określenie ich właściwości elektrycznych, przede wszystkim przewodnictwa jonowego. Sporządzono trzy proszki dwutlenku ceru zawierające stałą ilość dwutlenku cyrkonu oraz zróżnicowaną ilość tlenku itru. Właściwości elektryczne gęstych spieków otrzymanych z tych proszków badano dwoma metodami: stałoprądową metodą czterosondową oraz zmiennoprądową metodą spektroskopii impedancyjnej. W obydwu przypadkach określono temperaturowe zależności przewodnictwa oraz jego energię aktywacji. Stwierdzono, że dobre właściwości przewodzące otrzymanych materiałów w stosunkowo niskich temperaturach związane są zarówno ze zdefektowaniem sieci tlenowej spowodowanej wprowadzeniem tlenku itru jak i z modyfikacją granic międzyziarnowych.
EN
Ceria based solid solutions are alternative materials against fully stabilized zirconia as a solid electrolyte in electrochemical devices applied at temperatures above 800 Celsius degrees. Some disadvantages of the ceria based electrolyte can be eliminated by introduction of other cations into the ceria structure. The aim of the present paper is to prepare dense materials in the Y2O3 - ZrO2 - CeO2 system and to examine their electrical properties. The materials with constant amount of zirconia and variable amount of yttria were prepared. Electrical properties of these solid solutions were investigated using dc four-probe and ac impedance spectroscopy methods. Temperature dependence and activation energy of the ionic conductivity were determined. It was stated that good conduction properties of prepared materials at moderate temperatures are connected to modification of their grain boundary.
10
Content available remote Relaxation processes in ZrO2 at high pressures
Korionov I. V., Trefilova A. N., Babushkin A. N., Łojkowski W., Opalińska A.
Materials Science Poland
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2004
|
Vol. 22, No. 3
241--244
EN
Relaxation processes in ZrO2 have been studied at pressures in the range of 22-50 GPa by measurements of high-pressure electrical relaxation of resistance in time. Electrical relaxation in nanocrystalline praseodymium doped zirconia powders and in a bulk material sample of zirconia has been measured in the pressure range from 35.5 to 50 GPa. The time dependence of electric resistance is most precisely described by exponential function up to the pressure of 35.5-50 GPa. The time dependence of electric resistance is most precisely described by exponential function up to the pressure 44-45.5 GPa. After treatment the pressure higher than 45.5 GPa, the character of the relaxation changes and resistance increased with time. Relaxation processes have not been observed in ZrO2 with 56 nm crystallite sizes.
11
Content available remote Synteza Ti-Y-TZP w układzie TiO2-Y2O3-ZrO2
Gasidło M., Haberko K., Bućko M.M., Piekarczyk J., Rączka M.
Materiały Ceramiczne
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2003
|
R. 55, nr 2
65-68
PL
Wspólny roztwór wodny ZrOCl2, YCI3 oraz TiCl4 roztwór wprowadzono do roztworu NH3. W wyniku otrzymano bezpostaciowy rentgenograficznie żel, z którego po ogrzaniu krystalizuje roztwór stały Y2O3 i TiO2 w ZrO2. Posługując się tą techniką otrzymano 12 próbek o zmienianym systematycznie składzie: Y2O3 w zakresie od 2,1 do 3,0% mol oraz TiO2 w zakresie od 4% mol. do 18% mol. Temperatura krystalizacji była tym wyższa im większa była zawartość dodatków. Zmierzono parametry komórki elementarnej roztworów stałych, co pozwoliło obliczyć tzw. gęstość rentgenowską tych roztworów. Spieki w całym zakresie składów były jednofazowe i wykazały obecność wyłącznie fazy o symetrii tetragonalnej. Właściwości mechaniczne spieków o najniższych zawartościach TiO2 były najlepsze.
EN
Coprecipitation technique with ammonia from water solution of relative oxides was applied to prepare X-ray amorphous gels in the TiO2-Y2O3-ZrO2 system. Calcination of the gels results in solid solutions of TiO2 concentration ranging from 4 to 18 mole % and Y2O3 concentration from 2.1 to 3 mole %. Crystallization temperature was the higher the higher was concentration of the additional oxides. Within the whole composition range only tetragonal phase occurred in the sintered materials. Mechanical properties of the materials (Young modulus, hardness and fracture toughness) were best in compositions of the lowest concentration of the additives.
12
Content available remote Wpływ sumy tlenków lantanowców na stabilizację wysokotemperaturowych faz ZrO2.
Żurek Z., Gil A., Bednarska I., Żmudzińska-Żurek B.
Szkło i Ceramika
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2001
|
R. 52, nr 5
18-22
PL
Przedmiot badań stanowiły proszki ZrO2 otrzymane metodą współstrącania, zawierające do 15% mol. stabilizującego dodatku w postaci sumy tlenków lantanowców. Przeprowadzono pomiary derywatograficzne dla czystego Zr(OH)4 oraz wszystkich pozostałych układów Zr(OH)4+mLn(OH)3 (m=3, 5, 8, 12, 15% mol.), które obejmowały termiczną analizę różnicową (DTA) i analizę termograwimetryczną (DT). Badano wpływ temperatury prażenia na skład fazowy proszku ZrO2 mającego różne ilości stabilizującego dodatku. Określono wpływ ilości sumy lantanowców na wielkość ziaren Zr(OH)4 i ZrO2. Przeprowadzono obserwacje morfologii powierzchni proszków za pomocą mikroskopu skaningowego SEM, pomiary powierzchni właściwej metodą BET oraz pomiar objętości porów metodą Langmuira.
EN
The object of the investigation were ZrO2 powders, prepared by co-precipitation method. ZrO2 powders contained up to 15% mol of the stabilizing additive, considered as a sum of rare earth oxides. The influence of roasting point on the phase content of ZrO2 powder with different amounts of stabilizing additives was tested. The influence of grain dimensions Zr(OH)4 and ZrO2 according to different amounts of stabilizing additives was tested as well. The thermogravimetry measurements of pure Zr(OH)4 and all other systems of Zr(OH)4+mLn(OH)3 (m=3, 5, 8, 12, 15% mol.) were carried out. Morphology observations of powder surfaces of Zr(OH)4 and ZrO2 were made by scanning microscope SEM. The measurements of specific surface area by BET and volume of pores by Langmuire method were carried out.
13
Content available remote Doświadczenia w stosowaniu nowoczesnych tworzyw ceramicznych w urządzeniach technologicznych hut szkła.
Poręba Z., Krauz M., Blok Z.
Szkło i Ceramika
|
2000
|
R. 51, nr 5
27-29
14
Content available remote Ceramiczne części maszyn.
Krząstek K., Pelc E., Strzępek A.
Szkło i Ceramika
|
1999
|
R. 50, nr 6
28-31
15
Content available remote Elementy maszyn z dwutlenku cyrkonu.
Krząstek K., Blok Z., Świder J.
Mechanik
|
1998
|
R.LXXI, nr 12
743-745
PL
Zastosowanie dwutlenku cyrkonu częściowo stabilizowanego itrem (ZrO2-Y2O3) do wytwarzania elementów maszyn i urządzeń pracujących w podwyższonej temperaturze, środowisku korozyjnym oraz w warunkach zużycia ściernego i kawitacyjnego. Przykład zastosowań.
EN
Application of zirconium dioxide partly stabilized with ytrium (Zr2O2-Y2O3) for manufacturing machine elements and equipment operating at elevated temperatures and in corroding medium under abrasive wear and cavitation conditions. Application examples.
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