Mechanical properties of metal-ceramic systems from nickel-chromium and cobalt-chromium alloys

Nemanja Mirkovic
2007 Vojnosanitetski Pregled  
Vojnomedicinska akademija, Klinika za stomatologiju, Beograd Apstrakt Uvod/Cilj. Jačina metal-keramičkog međuspoja i modul elastičnosti legure jasno određuju potencijal njene primene, jer od te dve osobine zavisi očuvanje integriteta keramike u toku mastikacije. Istraživanje je sprovedeno sa ciljem da se utvrdi jačina metal-keramičkog međuspoja i modul elastičnosti legura kobalt-hrom u izradi metal-keramičkih zubnih nadoknada u odnosu na do sada najčešće korišćene legure nikl-hrom. Metode.
more » ... -hrom. Metode. Istraživanje je obavljeno po tipu eksperimentne studije. Izrađeno je po šest metal-keramičkih uzoraka legure nikl-hrom (Wiron99) i legure kobalt-hrom (Wirobond C) prema preporukama proizvođača i uputstvima datim u standardu ISO 9693: 1996. Korišćen je test savijanja sa opterećenjem u tri tačke do momenta loma keramike. Sila potrebna da dovede do loma keramike zabeležena je na univerzalnoj mašini za testiranje materijala (Zwick, tip 1464), koja se kretala brzinom od 0,05 mm/min. Rezultati. Rezultati ovog ispitivanja ukazali su na značajne razlike između jačine metal-keramičkog međuspoja (p < 0,01) i modula elastičnosti (p < 0,001) legura nikl-hrom i kobalt-hrom, pri čemu legure kobalt-hrom imaju veće vrednosti oba ispitivana parametra. Zaključak. Kobalt-hrom legure za metalkeramiku mogu uspešno zameniti nikl-hrom legure, naročito za izradu metal-keramičkih mostova velikog raspona, zbog velike otpornosti na savijanje. Ključne reči: legure, stomatološke; keramika; metali; nikl; hrom, legure; kobalt; elastičnost. Abstract Background/Aim. Metal-ceramic bond strength and alloys' elastic modulus clearly determine the potential of alloy application, because the ceramic integrity during mastication depends on these two characteristics. The aim of this study was to evaluate metal-ceramic bond strenght and elastic modulus of cobalt-chromium alloys in making porcelainfused-to-metal restorations, regarding the application of the most frequent nickel-chromium alloy. Methods. The research was performed as an experimental study. Six metalceramic samples were made from nickel-chromium alloy (Wiron 99) and cobalt-chromium alloy (Wirobond C), according to the manufactures manuals and instructions from ISO 9693: 1996. Three-point bending test was performed up to the ceramic fracture. The fracture load was measured on an universal testing machine (Zwick, type 1464), with cross-head speed of 0,05mm/min. Results. The results of this study confirmed the significant differences between the metal-ceramic bond strength (p < 0.01) and elastic modulus (p < 0.001) of nickel-chromium and cobalt-chromium alloys, where cobalt-chromium alloys showed higher values for both tested parameters. Conclusion. Cobalt-chromium metal-ceramic alloys can successfully replace nickelchromium alloys, especially for fabrication of long-span metal-ceramic bridges due to the great flexural strength.
doi:10.2298/vsp0704241m pmid:17580533 fatcat:sd24kzqdx5girljbh7yy62i56u