Scanning acoustic microscopy study of titanium-ceramic interface of dental restorations

Failures that occur in titanium–ceramic restorations are of concern in clinical dentistry. The purpose of this study was to nondestructively characterize the internal cracks and nonadherent defects at the titanium–porcelain interface using scanning acoustic microscopy. Titanium samples coated with porcelain without a bonding agent, with sputter coated palladium or chromium as an oxygen diffusion barrier on the titanium, and with the use of a porcelain bonding agent (control group) were compared. The scanning acoustic microscopy analyses were correlated with four‐point bending test results. The group that was initially coated with palladium had fewer interfacial defects and a higher load to failure than the control group, and the group that did not contain the bonding agent had a higher void area and a lower load to failure than the control group. The use of chromium produced no differences from the control group. Samples after a four‐point bending test were also analyzed by scanning electron microscopy. The scanning electron microscopy was not able to characterize interfacial defects at the fractured titanium–ceramic interface for some of the samples. The validity of nondestructive analysis at the Ti–ceramic interface using scanning acoustic microscopy was demonstrated in this study. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 508–516, 1998.