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 titan ium-porcelain interface using scanning acoustic microscopy. Titanium s amples coated with porcelain without a bonding agent, with sputter coa ted palladium or chromium as an oxygen diffusion barrier on the titani um, and with the use of a porcelain bonding agent (control group) were compared. The scanning acoustic microscopy analyses were correlated w ith four-point bending test results. The group that was initially coat ed with palladium had fewer interfacial defects and a higher load to f ailure 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 th e control group. Samples after a four-point bending test were also ana lyzed by scanning electron microscopy. The scanning electron microscop y was not able to characterize interfacial defects at the fractured ti tanium-ceramic interface for some of the samples. The validity of nond estructive analysis at the Ti-ceramic interface using scanning acousti c microscopy was demonstrated in this study. (C) 1998 John Wiley & Son s, Inc.