HRTEM observation of bonding interface between Ce-TZP/Al2O3 nanocomposite and porcelain.

The surface of a ceria-stabilized tetragonal zirconia polycrystal (Ce-TZP/Al2O3) nanocomposite was sandblasted by alumina particles and veneered with feldspathic porcelain via a conventional condensation method. The part of each specimen containing the interface layer was sliced to ultrathin sections with an argon ion slicer, and these sliced sections were observed using high-resolution transmission electron microscopy (HRTEM). For both interfaces, Ce-TZP/porcelain and Al2O3/porcelain, no transition layers due to abrupt changes in atomic distributions were observed. Besides, the porcelain layers of both interfaces consisted of homogeneous amorphous phases. These results suggested that both Ce-TZP and Al2O3 could be directly bonded to porcelain by Van der Waals forces arising from the close contact between them.