Vergleichende Untersuchungen zur Verbundfestigkeit von verschiedenen Metall- Keramik-Kombinationen auf der Basis von EM- und NEM-Legierungen in Verbindung mit herkömmlicher und niedrigschmelzender Keramik

Abstract

Das Ziel dieser Untersuchung war es, mögliche vorhandene Unterschiede in den Verbundfestigkeiten von Metallkeramikkombinationen auf der Basis von edelmetallhaltigen (goldreduziert und hochgoldhaltig) und nichtedelmetallhaltigen Legierungen im Verbund mit herkömmlicher und niedrigschmelzender Keramik aufzuzeigen. Als herkömmliche Keramik wurde Vita Omega 900 und als niedrigschmelzende Keramik Duceragold ausgewählt. Es wurde mit den hochgoldhaltigen Legierungen Ponto Lloyd G, Bio Ponto Star (verblendet mit Vita Omega 900) und Bio Platin Lloyd sowie Platin Lloyd KF (verblendet mit Duceragold) gearbeitet. Als goldreduzierte Legierung wurde Auro Lloyd KF mit Duceragold verblendet. Wirobond C, eine Kobalt-Chrom-Legierung und Wiron NT, eine Nickel-Chrom-Legierung wurden als Nichtedelmetalllegierungen mit Vita Omega 900 verblendet. Von jeder Metallkeramikkombination wurden 42 Prüfkörper gefertigt. Davon wurden jeweils 7 Prüflinge unterschiedlichen Lagerungsbedingungen ausgesetzt. Nach vier Wochen Trockenlagerung bei 35 °C, einwöchiger, vierwöchiger und sechsmonatiger Lagerung in Korrosionslösung und nach Belastung im Temperaturwechselbad mit 5000 sowie 10000 Zyklen wurden von jeder Reihe 6 Prüfkörper der Drei-Punkt-Biegeprüfung nach SCHWICKERATH unterzogen. Anhand der unversehrte Probe und der Probe mit der geringsten Scherverbundfestigkeit wurden anschließend licht- und rasterelektronenmikroskopische Untersuchungen der Bruchverläufe und eine EDX- Analyse durchgeführt. Innerhalb der Verbundkombinationen auf der Basis von edelmetallhaltigen Legierungen konnte festgestellt werden, dass tendenziell höhere Verbundfestigkeiten mit der niedrigschmelzenden Keramik erreicht werden konnten. Zwischen den hochgoldhaltigen und goldreduzierten Legierungen treten keine signifikanten Unterschiede auf. Im Vergleich zwischen der Kobalt-Chrom- Legierung und der Nickel-Chrom-Legierung erreicht die Kobalt-Chrom-Legierung höhere Verbundfestigkeitswerte, wobei beide Verbundkombinationen deutliche Einbußen der Festigkeiten nach der Lagerung in Korrosionslösung aufweisen. Zwischen den Verbundkombinationen auf der Basis von edelmetallhaltigen und nichtedelmetallhaltigen Legierungen treten signifikante Unterschiede nach der Lagerung in Korrosionslösung auf. Die edelmetallhaltigen Legierungen erreichen dabei deutlich höhere Festigkeitswerte. Statistisch nicht signifikant, aber tendenziell zu erkennen ist das Vorliegen höherer Scherverbundfestigkeiten bei den Kombinationen auf der Basis edelmetallhaltiger Legierungen. Bei den licht- und rasterelektronenmikroskopischen Untersuchungen wurden sowohl kohäsive als auch adhäsive Brüche im Metallkeramikverbund bei allen Kombinationen gefunden. Die EDX-Analyse ergab, dass bei allen Versuchskombinationen Haftoxidschichten ausgebildet wurden.

The goal of this study was to show the differences of the bond strength of metal-ceramic-systems based on precious metal alloys (gold-reduced and high- gold-bearing) and non-precious alloys veneered with conventional and low- fusing dental ceramic. Vita Omega 900 was selected as representative of conventional dental ceramics and Duceragold was selected as representative of low-fusing dental ceramics. It was worked with Ponto Lloyd G, Bio Ponto Star (high-gold-bearing alloys veneered with Vita Omega 900) and Bio Platin Lloyd and Platin Lloyd KF (veneered with Duceragold). Auro Lloyd KF (veneered with Duceragold) was chosen as a representative of gold-reduced alloys. Wirobond C, a cobalt-chromium alloy and Wiron NT, a nickel-chromium alloy (no-precious alloys) were surfaced with Vita Omega 900. Forty-two test specimens of every metal-ceramic system were examined. In each test series, 7 specimens were exposed to different conditions. After four weeks of dry storage (35°C), and one week, four weeks and six month storage in corrosive solution, and after a treatment of 5000 and 10000 thermocycles in different water baths, 6 specimens of every series were tested in the three-point-bending test according to SCHWICKERATH. The intact specimen and the specimen with lowest bonding strength value were studied by light- and scanning electron microscopes, and they underwent a electron-dispersive X-ray analysis. The findings reveal that metal-ceramic compounds based on precious metal surfaced with low-fusing ceramic achieve the tendentious highest bond-strength values. There are no significant differences between precious metal alloys and non-precious metal alloys. The cobalt-chromium alloy achieved higher bond-strength values in comparison to the nickel-chromium alloy. A reduction in bond strength was seen after storage in corrosive solution. Between the metal-ceramic compounds based on precious metal alloys and the non-precious metal alloys, significant differences were achieved after the storage in corrosive solution. Precious metal alloys showed higher values. Tendentious to realize, but not significant, were higher values found with metal-ceramic compounds based on precious metal alloys. Cohesive and adhesive separating lines were found in all metal-to-ceramic compounds. The electron-dispersive X-ray analysis showed the formation of adhesive oxide layers by all metal-to-ceramic compounds. The goal of this study was to show the differences of the bond strength of metal- ceramic-systems based on precious metal alloys (gold-reduced and high-gold- bearing) and non-precious alloys veneered with conventional and low-fusing dental ceramic. Vita Omega 900 was selected as representative of conventional dental ceramics and Duceragold was selected as representative of low-fusing dental ceramics. It was worked with Ponto Lloyd G, Bio Ponto Star (high-gold- bearing alloys veneered with Vita Omega 900) and Bio Platin Lloyd and Platin Lloyd KF (veneered with Duceragold). Auro Lloyd KF (veneered with Duceragold) was chosen as a representative of gold-reduced alloys. Wirobond C, a cobalt- chromium alloy and Wiron NT, a nickel-chromium alloy (no-precious alloys) were surfaced with Vita Omega 900. Forty-two test specimens of every metal-ceramic system were examined. In each test series, 7 specimens were exposed to different conditions. After four weeks of dry storage (35°C), and one week, four weeks and six month storage in corrosive solution, and after a treatment of 5000 and 10000 thermocycles in different water baths, 6 specimens of every series were tested in the three-point-bending test according to SCHWICKERATH. The intact specimen and the specimen with lowest bonding strength value were studied by light- and scanning electron microscopes, and they underwent a electron-dispersive X-ray analysis. The findings reveal that metal-ceramic compounds based on precious metal surfaced with low-fusing ceramic achieve the tendentious highest bond-strength values. There are no significant differences between precious metal alloys and non-precious metal alloys. The cobalt- chromium alloy achieved higher bond-strength values in comparison to the nickel-chromium alloy. A reduction in bond strength was seen after storage in corrosive solution. Between the metal-ceramic compounds based on precious metal alloys and the non-precious metal alloys, significant differences were achieved after the storage in corrosive solution. Precious metal alloys showed higher values. Tendentious to realize, but not significant, were higher values found with metal-ceramic compounds based on precious metal alloys. Cohesive and adhesive separating lines were found in all metal-to-ceramic compounds. The electron-dispersive X-ray analysis showed the formation of adhesive oxide layers by all metal-to-ceramic compounds. The goal of this study was to show the differences of the bond strength of metal-ceramic-systems based on precious metal alloys (gold-reduced and high-gold-bearing) and non-precious alloys veneered with conventional and low-fusing dental ceramic. Vita Omega 900 was selected as representative of conventional dental ceramics and Duceragold was selected as representative of low-fusing dental ceramics. It was worked with Ponto Lloyd G, Bio Ponto Star (high-gold-bearing alloys veneered with Vita Omega 900) and Bio Platin Lloyd and Platin Lloyd KF (veneered with Duceragold). Auro Lloyd KF (veneered with Duceragold) was chosen as a representative of gold-reduced alloys. Wirobond C, a cobalt- chromium alloy and Wiron NT, a nickel-chromium alloy (no-precious alloys) were surfaced with Vita Omega 900. Forty-two test specimens of every metal-ceramic system were examined. In each test series, 7 specimens were exposed to different conditions. After four weeks of dry storage (35°C), and one week, four weeks and six month storage in corrosive solution, and after a treatment of 5000 and 10000 thermocycles in different water baths, 6 specimens of every series were tested in the three-point-bending test according to SCHWICKERATH. The intact specimen and the specimen with lowest bonding strength value were studied by light- and scanning electron microscopes, and they underwent a electron-dispersive X-ray analysis. The findings reveal that metal-ceramic compounds based on precious metal surfaced with low-fusing ceramic achieve the tendentious highest bond-strength values. There are no significant differences between precious metal alloys and non-precious metal alloys. The cobalt- chromium alloy achieved higher bond-strength values in comparison to the nickel-chromium alloy. A reduction in bond strength was seen after storage in corrosive solution. Between the metal-ceramic compounds based on precious metal alloys and the non-precious metal alloys, significant differences were achieved after the storage in corrosive solution. Precious metal alloys showed higher values. Tendentious to realize, but not significant, were higher values found with metal-ceramic compounds based on precious metal alloys. Cohesive and adhesive separating lines were found in all metal-to-ceramic compounds. The electron-dispersive X-ray analysis showed the formation of adhesive oxide layers by all metal-to-ceramic compounds. The goal of this study was to show the differences of the bond strength of metal-ceramic-systems based on precious metal alloys (gold-reduced and high-gold-bearing) and non-precious alloys veneered with conventional and low-fusing dental ceramic. Vita Omega 900 was selected as representative of conventional dental ceramics and Duceragold was selected as representative of low-fusing dental ceramics. It was worked with Ponto Lloyd G, Bio Ponto Star (high-gold-bearing alloys veneered with Vita Omega 900) and Bio Platin Lloyd and Platin Lloyd KF (veneered with Duceragold). Auro Lloyd KF (veneered with Duceragold) was chosen as a representative of gold-reduced alloys. Wirobond C, a cobalt- chromium alloy and Wiron NT, a nickel-chromium alloy (no-precious alloys) were surfaced with Vita Omega 900. Forty-two test specimens of every metal-ceramic system were examined. In each test series, 7 specimens were exposed to different conditions. After four weeks of dry storage (35°C), and one week, four weeks and six month storage in corrosive solution, and after a treatment of 5000 and 10000 thermocycles in different water baths, 6 specimens of every series were tested in the three-point-bending test according to SCHWICKERATH. The intact specimen and the specimen with lowest bonding strength value were studied by light- and scanning electron microscopes, and they underwent a electron-dispersive X-ray analysis. The findings reveal that metal-ceramic compounds based on precious metal surfaced with low-fusing ceramic achieve the tendentious highest bond-strength values. There are no significant differences between precious metal alloys and non-precious metal alloys. The cobalt- chromium alloy achieved higher bond-strength values in comparison to the nickel-chromium alloy. A reduction in bond strength was seen after storage in corrosive solution. Between the metal-ceramic compounds based on precious metal alloys and the non-precious metal alloys, significant differences were achieved after the storage in corrosive solution. Precious metal alloys showed higher values. Tendentious to realize, but not significant, were higher values found with metal-ceramic compounds based on precious metal alloys. Cohesive and adhesive separating lines were found in all metal-to-ceramic compounds. The electron-dispersive X-ray analysis showed the formation of adhesive oxide layers by all metal-to-ceramic compounds.