Effect of NbN on the Bonding Strength of Titanium Porcelain

Objectives: The purpose of this study is to investigate the effect of niobium nitride(NbN)by magnetron sputtering on the bonding strength between a low-fusing porcelain(Ti / Vita titankeramik system) and commercially pure cast titanium(Ti). Methods: X-ray diffraction(XRD), scanning electron microscopy(SEM)and energy depressive spectrum (EDS) were employed to investigate the phases of the deposits, surface morphology and elements content. Three-point bending test was used to evaluate the bonding strength of Ti and porcelain according to ISO9693 1999. Results: The XRD results reveal that the NbN deposits are cubic crystalline phases. No apparent oxidization of Ti or NbN is observed on the surface of samples after simulated porcelain sintering thermocycles. NbN film shows high stability under the condition of porcelain sintering. The SEM micrographs of cross-sectioned Ti porcelain samples reveal that Ti and porcelain have better adhesion with NbN intermediate layer. The results of three-point bending test show that the bonding strength of the control group is(27.242±0.752)MPa, the NbN group is (43.112±0.586)MPa. Conclusions: NbN deposited by magnetron sputtering significantly improves the bonding strength of titanium porcelain.