The effect of a bonding agent and thermo-mechanical cycling on the bond strength of a glass-ceramic to gold and cobalt-chromium alloys

Abstract

To evaluate the effects of bonding agent and thermo-mechanical cycling on the flexural bond strength of a gold and cobalt-chromium alloy to a feldspathic ceramic. Sixty-four metal bars were fused (3 × 25 × 0.5 mm 3 ): 32 with a gold alloy and 32 with a cobalt-chromium (Co-Cr) alloy. Over the bars' central area (8 × 3 mm 2 ), a bonding agent and two glass-ceramic layers were fired, totaling 1 mm in ceramic thickness. Eight specimens of each alloy were randomly divided according to the bonding agent (application or the absence thereof) and the thermo-mechanical cycle (3,000 thermo-cycles and 20,000 mechanical-cycles; or no cycling). The flexural bond strength between the metal alloy and the ceramic was evaluated by a three-point bending test and data were subjected to three-way ANOVA and Tukey's test (α = 0.05). The failure mode was classified. No significant interactions were observed among the three factors evaluated (alloy, bonding agent, and thermo-mechanical cycling; p = 0.5734). There was no statistically significant difference between the alloys (p = 0.8559). The interaction between alloy/bonding agent (p = 0.0001) showed that, for the gold alloy, the group with the bonding agent showed mean values of flexural bond strength significantly higher than those of the group without the bonding agent, while, for the Co-Cr alloy, the groups with or without bonding agent had similar mean values of flexural bond strength. The interaction between alloy/thermo-mechanical cycling (p = 0.0001) showed that, for the gold alloy, the non-cycled group had flexural bond strength mean values significantly greater than those of the cycled group, while for the Co-Cr alloy, both non-cycled and cycled groups had similar mean values. The bonding agent significantly improved the flexural bond strength between the ceramic and the gold alloy, but had no influence on the Co-Cr alloy. Thermo-mechanical cycling decreased the flexural bond strength of the gold alloy specimens, but did not affect the Co-Cr specimens.

Effects of brass addition on the flexural strength and microstructure of porous clay/brass composites

“…Addition of brass more than 20 wt.% was already able to change the natural properties of ceramic (brittle) in this study. This is supported by some previous research [23][24][25].…”

Effect of thermo-mechanical cycling on the shear bond strength of porcelain to milled and cast cobalt-chromium alloys

“…The results obtained by Lombardo et al (2010) [20] , Oliveira de Vasconcellos et al (2011) [40] , Oyafuso et al (2008) [41] and Fischer et al (2009) [49] were also similar to that reported in this research regarding reduction in the SBS values after thermomechanical cycling with significant differences. On the contrary, Antanasova et al (2018) [51] and Trindade et al (2014) [52] concluded that thermomechanical cycling decreased the bond strength for the ceramic to Co-Cr specimens but without statistically significant differences. This might be due to the difference in the thermodynamic protocols used in these two studies in comparison to the thermodynamic protocol used in this present study.…”

Farklı Ağız İçi Tamir Sistemlerinin Ni-Cr Alt Yapılara Bağlanma Dayanımının İncelenmesi

“…Araştırmacılar klinik olarak gerekli, kabul edilebilir ve uzun dönem başarılı kullanılabilecek makaslama dayanim değerinin 10 Mpa olması gerektiğini belirtmişlerdir. [21][22][23][24] Çalışmamızın sonuçlarına bakıldığında; Ultradent tamir sistemi grubu hariç tüm grupların dayanım değerleri klinik kabul edilebilir değer olan 10 MPa değerinden daha yüksektir. Literatür incelendiğinde; tamir sistemlerinin makaslama bağlanma dayanımlarını değerlendiren çalışmaların sonuçları 3 ile 37.4 MPa arasında değişmektedir.…”