A powdering technique for veneering zirconia and its effect on the flexural strength of ceramic bilayers

The aim of this study was to assess the powdering technique and its effects on the flexural strength of bilayered zirconia. Bars made of zirconia partially stabilized by yttrium (Y-TZP) received porcelain by the following techniques (n = 10 per group): (1) L: VM9 application; (2) P: powdering technique + VM9 application; (3) C: Y-TZP coloring before sintering + Y-TZP sintering + VM9 application; or (4) CP: Y-TZP coloring before sintering + Y-TZP sintering + powdering technique + VM9 application. The powdering technique consisted of the application of VM9 margin powder followed by sintering. The samples were subjected to a 4-point flexural strength test and contact angle. Data were analyzed by one-way ANOVA and Tukey test (a = 5%). Surface treatments did not affect the flexural strength of bilayered specimens (P = .1264), but contact angle was affected by surface treatments (P < .0001), wherein the association of coloring and powdering (CP) reached higher values of wettability. Powdering did not affect the flexural strength of bilayered specimens, but did increase the Y-TZP wettability.