2010 Volume 52 Issue 4 Pages 647-652
The purpose of the present study was to evaluate the effect of cooling rates after firing procedures of veneering porcelain on shear bond strength between veneering porcelain and a zirconium dioxide (zirconia; ZrO2) ceramic material. A total of 48 ZrO2 disks were divided equally into three groups. Two veneering porcelains that are recommended for ZrO2 material – Cerabien ZR (CZR), IPS e.max Ceram (EMX) – and one that is recommended for metal ceramics – Super Porcelain AAA (AAA) were assessed. Each group was then further divided into two subgroups (n = 8) according to cooling time (0 or 4 min) after porcelain firing. Specimens were fabricated by veneering the porcelain on the ZrO2 disks, after which shear bond testing was conducted. Bond strength differed significantly by cooling time in ZrO2-AAA (P < 0.001) and ZrO2-EMX (P = 0.001) specimens. There was no significant difference in shear bond strength with respect to cooling time in ZrO2-CZR specimens (P = 0.382). The duration of cooling from firing temperature to room temperature may affect the shear bond strength of veneering porcelain to a zirconia material depending on porcelain material used. (J Oral Sci 52, 647-652, 2010)
