Influence of bonding agents on metal-ceramic bond strengths for Co-Cr alloy

This study investigated the influence of bonding agents on metal-ceramic bond strengths before porcelain veneering for cobalt-chromium alloy. Three ceramic systems: Initial MC (IMC), Hera Ceram (HC), and ZEO CE LIGHT (ZCL) were tested on wrought substructures. The ZCL system was also tested on cast substructures. Three-point bending test was performed, and fractured surfaces were analyzed using electron-probe microanalysis and X-ray diffraction. The bond strengths of all specimens exceeded the requirements of ISO 9693:2019 (>25 MPa). The ZCL bonding agent significantly improved bond strengths for wrought and cast substructures whereas the IMC and HC bonding agents did not. Wrought-ZCL specimens exhibited significantly higher bond strengths than cast-ZCL specimens. In the specimens exhibiting higher bond strength, silicon and titanium, which originated from the bonding agent, were predominantly detected at the debonded metallic surfaces. Consequently, the bonding agent positively affected the bond strength but depended on the ceramic system and substructure type.