Effect of different pH environments on the durability of bonds between zirconia and Ti-6Al-4V

This study investigated the role played by different pH environments in the deterioration of bonds between Y-TZP and Ti-6Al-4V. One hundred and thirty-five specimens were randomly assigned to one of the following storage media at 37°C: (1) distilled water, pH 6.9, DW; (2) acidic solution, pH 1-2, CS; and (3) alkaline solution, pH 10-11, KS. Shear bond strength (SBS) tests were carried out at the 4-, 14-, and 30-day storage time intervals. The morphology characteristics and elements distribution of the fracture surfaces were analyzed. CS-30 showed the lowest mean SBS and the least amount of residual cement on the Ti-6Al-4V surface after the SBS tests. Bond strength tended to decrease with increasing storage time for the acidic group. Alkaline and neutral media showed little influence on the SBS of Y-TZP to Ti-6Al-4V in 30 days. Acidic environments should be properly avoided to obtain reliable long-term bonding strength between Ti-6Al-4V and Y-TZP.