diplomsko delo
Abstract
Uvod: Dentalna keramika že dolgo opravičuje svojo uporabo v dentalni medicini. Da se
lahko uporablja na področju laboratorijske zobne protetike, mora poleg varnega in
neinvazivnega posega v gostiteljevo telo zagotavljati tudi dobre mehanske lastnosti in
visok estetski videz. Takšno keramiko imenujemo biokeramika in v to skupino sodi tudi
steklokeramika, ki je danes v dentalni medicini najpogosteje uporabljen keramični
material. Tako kot je značilno za vse keramične materiale, velja tudi za biokeramiko, da je
krhka, saj se že v elastičnem področju obremenitve na površini pojavijo razpoke. Ta
problem se na področju dentalne medicine najpogosteje rešuje z dodatkom kovinskih
materialov, oziroma z izdelavo kovinsko-keramičnih konstrukcij, kar pa žal zmanjša
željeno estetiko. V moderni fiksni protetiki so se kot odgovor na ta izziv pojavile polne
keramične konstrukcije iz aluminijevega (Al2O3) in cirkonijevega (ZrO2) oksida. V
primerjavi s kovinsko-keramičnimi strukturami se lahko ta materiala pohvalita z visoko
trdnostjo in trdoto, temperaturno stabilnostjo, visoko odpornostjo na agresivno okolje,
korozijsko in obrabno odpornostjo, ter boljšo prosojnostjo kot steklo infiltrirana keramika.
Tako lahko pacientu zagotovimo material, ki ima dobre mehanske lastnosti in hkrati nudi
visok estetski videz. Doseganje optimalnih lastnosti je odvisno od čistosti keramičnega
prahu, porazdelitve velikosti prašnih delcev ter od pogojev stiskanja in sintranja. Namen:
Namen diplomskega dela je bil analizirati zgradbo in lastnosti ZrO2 in Al2O3 keramike in
ugotoviti katera od obeh že predpisanih tehnologij (tehnologija izdelave ZrO2, oziroma
tehnologija izdelave Al2O3) zagotavlja konstantnejšo kvaliteto izdelka z manjšim
odstopanjem mehanskih lastnosti od predpisanih vrednosti. S tem smo razkrili, kateri
material je zanesljivejši in posledično primernejši za izdelavo zobnih nadomestkov.
Dodatno je bil namen diplomskega dela izdelati dva nadomestka iz cirkonijeve oksidne
keramike. Metode dela: Diplomsko delo je sestavljeno iz teoretičnega in
eksperimentalnega dela. V teoretičnem delu je bila z uporabo strokovne literature, ki je bila
na voljo na spletnem mestu Google Učenjak ter Medicinski knjižnici Ljubljana, izvedena
analiza strukture in lastnosti izbranih materialov. V eksperimentalnem delu smo na osnovi
predpisanih tehnologij izdelali preizkušance Al2O3 in ZrO2, ki smo jih nato uporabili za
izvedbo mehanskih preizkusov. Vsi preizkušanci so bili testirani pod enakimi pogoji.
Rezultati: Preizkušanci so bili pripravljeni v zobnem laboratoriju Dentom v Ljubljani in
zobnem laboratoriju Franca Rojka na Ptuju. Izvedba preizkusov pa na Inštitutu za
tehnologijo materialov na Fakulteti za strojništvo Univerze v Mariboru. Razprava in
zaključek: Na podlagi upogibnih testov s katerimi je bil določen prelomni modul za
cirkonijevo in aluminijevo oksidno keramiko, lahko povzamemo, da ima cirkonijeva
oksidna keramika višji prelomni modul in višjo lomno žilavost, ter da je posledično ta
keramika primernejša za izdelavo večjih protetičnih konstrukcij. Iz dobljenih rezultatov je
tudi razvidno, da zagotavlja predpisana tehnologija izdelave cirkonijeve oksidne keramike
manjša odstopanja in večjo konstantnost lastnosti. Aluminijev oksid je občutljivejši na
laboratorijsko izdelavo in bolj primerjen za manjše protetične nadomestke.
Keywords
diplomska dela;laboratorijska zobna protetika;cirkonijev oksid;aluminijev oksid;trdota;trdnost;mehanske lastnosti;biokompatibilnost;biokeramika;estetika;
Data
Language: |
Slovenian |
Year of publishing: |
2022 |
Typology: |
2.11 - Undergraduate Thesis |
Organization: |
UL ZF - University College of Health Studies |
Publisher: |
[N. Kotnik] |
UDC: |
616.31 |
COBISS: |
115247107
|
Views: |
78 |
Downloads: |
42 |
Average score: |
0 (0 votes) |
Metadata: |
|
Other data
Secondary language: |
English |
Secondary title: |
Comparison of structure and properties of Al2O3 and ZrO2 ceramics |
Secondary abstract: |
Introduction: Dental ceramics have long justified their use in dentistry. In order to be used
in the field of dental technology, it must not only be safe and non-invasive for the host’s
body, but also provide good mechanical properties and a high aesthetic appearance. Such
ceramics are called bioceramics and include glass-ceramics, which is still the most
commonly used material in dentistry today. As is typical for all ceramic materials,
bioceramics are brittle, with cracks appearing on the surface of the material already in the
elastic range of the load. In the field of dentistry, this problem is most often solved by the
addition of metal materials or by the construction of metal-ceramic crowns or bridges,
which unfortunately reduces the desired aesthetics. In modern fixed prosthodontics full
ceramic frameworks made of aluminium (Al2O3) and zirconium oxide (ZrO2) have
emerged as a response to this challenge. Compared to metal-ceramic structures, these
materials boast high strength and hardness, temperature stability, high resistance to
aggressive environments, corrosion and abrasion resistance, and better translucency than
glass-infiltrated ceramics. This allows us to provide the patient with a material that has
good mechanical properties and at the same time offers a high aesthetic appearance. For
optimum properties to be achieved depends on the purity of the powder, the particle size
distribution, and the compression and sintering conditions. Purpose: The aim of this study
is to analyse the structure and properties of ZrO2 and Al2O3 ceramics and to determine
which of the two already prescribed technologies (ZrO2 and Al2O3) provides a more
consistent product quality with a smaller deviation of mechanical properties from the
prescribed values. This has revealed which material is more reliable and therefore more
suitable for dental crowns. Additionally, the aim of my thesis was to produce two zirconia
ceramic substitutes. Methods: The thesis consists of a theoretical and an experimental part.
In the theoretical part, an analysis of the structure and properties of the selected materials
was performed using the literature available on the Google Scholar website and the
Ljubljana Medical Library. In the experimental part, Al2O3 and ZrO2 test specimens were
made based on the prescribed technologies and used for mechanical tests. All subjects were
tested under the same conditions. Results: The test specimens were prepared in the
Dentom dental laboratory in Ljubljana and the Franc Rojko dental laboratory in Ptuj. The
tests were made at the Institute of Materials Technology at the Faculty of Mechanical
Engineering University of Maribor. Discussion and conclusion: Based on the bending
tests, which were used to determine the fracture modulus of zirconia and alumina ceramics,
it can be summarised that zirconia ceramics have a higher fracture modulus and higher
fracture toughness and as a consequence these ceramics are more suitable for the
fabrication of larger dental prosthetics constructions. The results also show that the
prescribed zirconia ceramics manufacturing technology ensures lower variation and higher
constancy of properties. |
Secondary keywords: |
diploma theses;laboratory dental prosthetics;zirconium oxide;alumina;hardness;strength;mechanical properties;biocompatibility;bioceramics;aesthetics; |
Type (COBISS): |
Bachelor thesis/paper |
Study programme: |
0 |
Thesis comment: |
Univ. v Ljubljani, Zdravstvena fak., Oddelek za protetiko |
Pages: |
35 str., [18] str. pril. |
ID: |
15899356 |