Effect of zirconia frame thickness on fracture toughness of veneer porcelain

Abstract

This review article focused on the influence of the zirconia thickness on the strength of the veneer porcelain, which was evaluated with a fracture toughness test according to JIS R 1607. The veneer porcelains for the zirconia all-ceramic crown were fired on two different thicknesses (0.4 mm and 0.8 mm) of zirconia frames (ZAC). As the controls, veneer porcelains fired on metal frames for porcelain fused to metal crown (PFM) were used. The fracture toughness value evaluated by measuring the extent of cracking associated with a Vickers indentation on the veneer porcelain part was significantly larger at the points of 1.5 mm in 0.4 mm thickness frame of ZAC samples compared with in the 0.8 mm frame.