Svrha: Ispitati utjecaj protokola starenja na kemijski i fazni sastav te na kvalitetu površine monolitne translucentne cirkonij-oksidne keramike. Materijali i postupci: Translucentna cirkonij-oksidna ...keramika KATANA-Zirconia STML s različitom završnom obradom površine (bez obrade, K1, K2; glazirana, G1 – G8; polirana, P1 – P8) podvrgnuta je eksperimentalnim protokolima starenja (hidrotermalna degradacija u autoklavu na 134 °C, pri tlaku od 2 bara tijekom 3 sata: G1 – G4, P1 – P4 te kemijskoj degradaciji u 4-postotnoj octenoj kiselini na 80 °C tijekom 16 sati (ISO 6872): G5 – G8, P5 – P8) kako bi se utvrdio njihov utjecaj na kemijski sastav, osobito udio stabilizatora itrijeva oksida (energetsko disperzivna flourescencija X-zraka – EDXRF), fazni sastav (rendgenska difraktometrija – XRD) te stanje površine izraženo hrapavošću i sjajem. Rezultati: Protokoli starenja nisu utjecali na stabilnost kemijskog sastava testiranih uzoraka i visok udio stabilizatora itrijeva oksida (≥ 10 % ukupnog udjela) koji je u korelaciji s odsutnošću monoklinske faze. Statistički je značajno smanjenje sjaja površine svih uzoraka. Kemijska degradacija u korozivnom mediju značajno je povećala površinsku hrapavost testiranih uzoraka. Zaključak: Monolitna translucentna cirkonij-oksidna keramika pokazala je stabilnost kemijskog sastava i otpornost na tetragonsko-monoklinsku transformaciju. Sjaj površine značajno je smanjen, osobito na poliranim uzorcima. Suprotno testiranim glaziranim uzorcima, na testiranim poliranim uzorcima uočeno je povećanje hrapavosti površine. Glaziranje površine translucentne monolitne cirkonijeve keramike osigurava bolji estetski, tribološki i higijenski učinak u usporedbi s poliranjem.
Staklokeramika je polikristalni materijal koji nastaje kontroliranom kristalizacijom stakla. Tijekom kontrolirane, upravljane kristalizacije stakla nastaje dvofazni materijal; kristali i amorfna ...staklena matrica. Nastanak kristala, veličine nekoliko mikrometara, događa se kod postupka temperiranja sveukupnoga volumena stakla, stvaranjem klica i rastom kristala. Klice su ili latentno postojeće u staklu ili se dodaju kao netopljiv materijal u fino dispergiranoj podjeli mješavine (staklenoj amorfnoj masi). Postoje sustavi staklokeramike za laboratorijsku izvedbu i za strojno glodanje gotovih keramičkih blokića. Iskorištavanjem postupka lijevanja i vrućega tlačenja staklokeramike dobili su sematerijali s izvrsnim mehaničkim i estetskim svojstvima za izradbu nesamo pojedinačnih krunica, inlaya, onlaya već i tročlanih mostova.
Purpose: Commercially pure titanium (CP Ti) has been recognized in dentistry for its biocompatibility, good mechanical properties and corrosion resistance. Conventional manufacturing processes can ...affect surface quality and result in poor bonding of dental ceramics to CP Ti. This is why powder metallurgy (P/M) and wire electro-discharge machining (WEDM) are being introduced in the manufacturing process. The aim of this study was to evaluate the effect of WEDM on the surface composition and microstructure of P/M CP Ti samples produced for bond strength testing according to ISO 9693. Materials and methods: Eight samples of P/M CP Ti, dimensions according to ISO 9693, were made using WEDM and divided in two groups (untreated and grinded). Microanalyses of chemical composition and microstructure of both groups were made using SEM, EDS and XDR. Results: SEM and EDS analysis of untreated samples showed a thin layer on surfaces with fractures in it. Grinded samples showed homogenous structure with no layer and no fractures. XDR analysis showed high level of oxides on the surface of untreated samples, while after grinding only pure a-phase was found. Conclusion: WEDM is a suitable method of sample production for ISO 9693 if accompanied by grinding with silicon carbide papers P320-P4000. Key words Titanium, WEDM, bond strength, powder metallurgy, Surface Properties Komercijalno cisti titanij (CP Ti) se koristi u dentalnoj medicini zbog biokompatibilnosti, dobrih mehanickih svojstava i otpornosti na koroziju. Konvencionalni proizvodni procesi izrade takvog titanija mogu utjecati na kvalitetu povrsine uzoraka i rezultirati slabim vezanjem CP Ti s dentalnom keramikom. Zato se uvode nove tehnologije proizvodnje titanija, primjerice metalurgija praha i oblikovanje na erozimatu s zicom (WEDM). Svrha ovog istrazivanja jest odrediti utjecaj WEDM-a na povrsinu uzoraka P/M CP Ti proizvedenih za ispitivanje vezne cvrstoce prema normi ISO 9693. Materijali i metode: Osam uzoraka P/M CP Ti dimenzija prema normi ISO 9693 proizvedeno je koristenjem WEDM-a i podijeljeno u dvije grupe--u neobradene i brusene. Povrsine obje grupe uzoraka analizirane su metodama SEM, EDS i XDR. Rezultati: Analize neobradenih uzoraka metodama SEM i EDS pokazuju tanki sloj razlicitog sastava i frakture. Bruseni uzorci imaju homogenu strukturu bez fraktura. Analiza metodom XDR pokazuje visoku koncentraciju titanijevih oksida na povrsini neobradenih uzoraka, a nakon brusenja dobivena je samo cista a-faza. Zakljucak: WEDM je metoda prikladna za proizvodnju uzoraka prema normi ISO 9693, ako se uzorci naknadno bruse. Kljucne rijeci titanij; erozimati sa zicom; vezna cvrstoca; metalurgija praha; svojstva povrsina
Introduction: Among dental applications, the zirconia based ceramics are widespread because of their general properties. The changes in superficial surface roughness correspond to the structural ...changes in the material caused by the influence of corrosion. The aim of this study was to determine chemical stability of glazed Y-TZP using surface roughness measurements. Materials and methods: Five samples of Y-TZP material BruxZir (Glidewell Laboratories S 2012.) with the addition of pigment A3 were sintered, polished and glazed to imitate the finishing process in producing monolithic crowns. After determining the mass of the sample, each sample was immersed in 10 ml of 4 wt. % CH.sub.3COOH aqueous solution. The roughness was measured five times before and after immersion. Results: All measured roughness parameters have significantly increased, showing higher penetration depth in all surface areas after immersion in 4 wt. % CH.sub.3 COOH aqueous solution compared to the initial values. Weight loss of investigated dental ceramics samples was 2.45 mg/cm.sup.2 ± 0.026. Conclusion: Highly acidic conditions augment surface roughness of Y-TZP glazed dental ceramics. Key words Dental Porcelain; Surface Properties; Corrosion Uvod: Cirkonij-oksidna (Y-TZP) keramika zbog specificnih svojstava cesto se primjenjuje u stomatologiji. Gradivni materijal moze korodirati ako na njegovoj povrsini postoji razlika u koncentraciji elektrolita. Nekvalitetna obrada povrsine nadomjeska pridonosi korozivnim procesima koji i sami dodatno narusavaju povrsinsku morfologiju. Svrha ovog istrazivanja bila je ustanoviti kemijsku stabilnost glaziranog Y-TZP-a mjerenjem parametara hrapavosti povrsine. Materijali i metode: Pripremljeno je pet uzoraka keramike Y-TZP (BruxZir, Glidewell Laboratories S 2012) s dodatkom pigmenta A 3. Svi su bili sinterirani, polirani i glazirani--tako su simulirani zavrsni postupci u izradi monolitickih nadomjestaka. Nakon odrecivanja mase uzorka svaki je uronjen u 10 mL 4-postotne otopine octene kiseline. Svi parametri hrapavosti izmjereni su pet puta i to prije izlaganja korozivnom mediju i poslije toga postupka. Rezultati: Znacajan porast izmjerenih parametara hrapavosti, u odnosu na pocetne vrijednosti, upucuje na prodiranje 4-postotne vodene otopine octene kiseline. Zabiljezen je i gubitak tezine uzoraka i to u iznosu od 2,45 mg/cm.sup.2 ± 0,026. Zakljucak: Vrlo kiseli uvjeti povecavaju povrsinsku hrapavost glazirane zubne keramike Y-TZP. Kljucne rijeci keramika; svojstva povrsina; korozija
The aim of this study was to evaluate the behavior of high-noble gold-platinum alloy samples (18 + 8 Rafinerija plemenitih kovina, Zagreb, Hrvatska), in a phosphate buffer pH 6.0. The aim of the ...study was to determine the type and amount of released metal ions from the alloy, and to evaluate how the time of exposure to the phosphate buffer pH 6.0 influences the release of metal ions from the alloy. Manufacturer samples 8.0 x 6.5 x 1.0 mm in size, with a surface area of 133 mm2 were used. The release of metal ions from the tested alloy was measured in ten time periods (after 1, 2, 3, 4, 5, 6, 7, 14, 21 and 30 days). Six samples were used (n = 6) for each time period that the alloy was in the solution, which means that a total of 60 samples was analyzed. Solutions, in which the samples were placed, were analyzed with the inductively coupled plasma atomic emission spectrometer (ICP-AES, JY 50P, Jobin-Ywon, France). It was found that four metal ions were released; zinc ions (Zn), chromium ions (Cr), copper ions (Cu) and iron ions (Fe). The most released ions from the gold-platinum alloy were those of zinc (Zn), and the least released were those of iron (Fe) (p < 0.01). The results of the study show that the time the tested alloy spent in the phosphate buffer pH 6.0 solution has an effect on the release of ions (p < 0.01).
Fractures of polymer material are one of the most frequent reasons for the repair of removable dental prostheses. Therefore, there is a constant endeavor to strengthen them, and polymer materials ...with high resistance to fracture are being developed. The aim of this study was to determine the flexural strength of polymer materials and their reinforcements and thus give preference to their clinical use. Specimens with dimensions 18 x 10 x 3 mm were tested after polymerization, immersion in water at a temperature 37 degrees C for 28 days, and thermocycling by using the "short-beam" method to determine the flexural strength. Microscopic examination was performed to determine the quality of bonding between the glass fibers and matrix. Common polymer materials (control group) demonstrated the lowest flexural strength, although, when reinforced with fibers they showed higher flexural strength, matching that of the tested high-impact strength resin. Thermocycled specimens had the highest flexural strength, whereas there was no difference (p > 0.05) between specimens tested after polymerization and immersion in water.
Endodontsko liječenje zuba smatra se dovršenim i uspješnim onda kada je zub opskrbljen adekvatnom koronarnom restauracijom. Dugi niz godina postoje nedoumice kako postići najoptimalniju ...postendodontsku opskrbu zuba. Jedan od načina koji se najduže i najčešće koristi u praksi postavljanje je intrakanalne nadogradnje koja omogućava retenciju konačnog fiksnoprotetskog rada. No, iako se takvim načinom opskrbe zuba postižu dobri rezultati, postoje i negativne strane takve tehnike rada kao što je dodatno uklanjanje tvrdog zubnog tkiva, mogućnost nastanka lomova korijena ili nadogradnje, perforacije korijena itd. S druge strane pojavom adhezivnih tehnika cementiranja sve češće se javljaju minimalno invazivne tehnike brušenja zuba kojima se nastoji maksimalno sačuvati tvrda zubna struktura te tako pospješiti prognoza fiksnoprotetskog rada. Endokrunice su oblik postendodontske opskrbe koji prati načela suvremene minimalno invazivne stomatologije. Pokazale su se kao dobra alternativa intrakanalnim nadogradnjama posebice u posteriornoj regiji te onda kada zbog složene morfologije endodontskog prostora postavljanje intrakanalne nadogradnje nije sigurno ili moguće. Također se navode kao dobar način opskrbe u smanjenom interokluzijskom odnosu i nepostojanju ferulle učinka. No za uspješnost ovakve tehnike rada moraju biti zadovoljeni svi principi adhezivne tehnike cementiranja.
This case report describes the management of a crown-root fractured maxillary right central incisor and a crown fractured maxillary left central incisor using two different techniques. A complex ...procedure was designed to manage this case including orthodontic extrusion to move the fracture line above the alveolar bone and surgical recontouring of the altered gingival margin. Finally, the right incisor was restored prosthodontically. Prosthetic treatment was based on performing a post and core, and all-ceramic crown on the extruded tooth. The left, less-damaged incisor was restored directly using composite resin. The treatment resulted in good esthetics and secured periodontal health. This case report demonstrates that a multidisciplinary treatment approach is a reliable and predictable option to save a tooth. How to cite this article: Ortolan SM, Strujic M, Aurer A, Viskic J, Bergman L, Mehulic K. Esthetic Rehabilitation of Complicated Crown Fractures Utilizing Rapid Orthodontic Extrusion and Two Different Restoration Modalities. Int J Clin Pediatr Dent 2012;5(1):64-67.
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