Hello. As I can see from the photos, you have internal discolorations in your teeth and this type of discolorations are the most resistant ones against bleaching. In these cases,mostly zirconia crowns are prefered due to their half translucent and half opaque nature which offers hiding the darkness of tooth inside.

Doctors' Response
What options are available to address the discoloration of my front teeth?
How can I remedy the discoloration of my front teeth?
Engage with a dedicated community of beauty, cosmetics, and self-care.