Fogorvosi szemle, 2000 (93. évfolyam, 1-12. szám)
2000-01-01 / 1. szám
Köszönetnyilvánítás Köszönetét mondok Walter professzornak (Drezda), Lenz professzornak (Jéna/Erfurt), valamint a Degussa, Heraeus és a Bego cégeknek, akik a cikkben vizsgált fémkerámia koronákat a rendelkezésemre bocsátották. A koronáknál az előállítás során történő eljárásbeli hibák teljes mértékben kizárhatók. Köszönetét mondok továbbá dr. Kaán Borbálának a fordításért. IRODALOM: 1. Eichner, K. : Über die Bindung von keramischen Massen und Edelmetall- Legierungen - Theorien und optische sowie elektronenmikroskopische Untersuchungen. Dtsch. Zahnärztl. Z. 23, 373 (1968). - 2. Eichner, K: Gegenwärtiger Stand der werkstoffkundlichen und klinischen Metallkeramik. Zahnärztl. Welt/Ref. 106, 411-485 (1997); Zahnärztl. Welt/Ref. 106, 562-567 (1997). - 3.Lenz, E.: Titan als Wekstoff für kombiniert festsitzenden und abnehmbaren Zahnersatz. Spitta Verlag 1998. - 4. Walter, M.: Zur Porenbildung in der keramischen Verblendung von Palladium-Silber- Legierungen. Dtsch. Zahnärztl. Z. 43, 145 (1988). - 5. Walter, M., Eichner K: Palladium-Legierungen für festsitzenden Zahnersatz. Dtsch. Zahnärztekal. 49, 47 (1989). — 6. Wirz, J., Bischoff, H.: Titan in der Zahnmedizin. Quintessenz, Berlin, 1997. Dr. Eichner, Karl: Methodic and systemic reasons of mistakes in metal ceramics Only by the use of scanning electron microscope in investigations concerning the metalporcelain interface of ceramic masses upon metal frames (approx. 160 crowns since 1967), essential differences in the reason of mistakes have been revealed recently. Primarily, methodic mistakes are to be declared relevant. Independent of their veneering origin, they contribute to fractures within the ceramic layer or to crack-offs of the fired ceramic masses from the metal frame. Obviously, the systemic causes for mistakes in metal ceramics revealed to be dependent on the groups of veneers. Veneering involves non-managable reasons for mistakes. These qualities in the material are the coefficient of thermal expansion or the share of palladium in the veneer. Very often, palladium is responsible for the formation of bubbles in the ceramic layer, and thus it is the reason for the development of cracks. The so-called pure titanium is quite extraordinary, when covered with ceramic mass, because the so-called alpha case layer cannot be bridged, despite 10 years of permanent research in that field. The clinical critical examination of systemic mistakes, however, proves to be mild. Clinical reasons for mistakes in metal ceramics remain disregarded in this paper. Key words: metal ceramics, methodic mistakes in metal ceramics, systemic mistakes in metal ceramics 22
