Has anyone had any problems with dentures?

I know someone who has had partial dentures in the top front teeth for four years now and they have never been right. Shes had them rebuilt again and again. Sometimes the dentist hasn't made them right etc... Now its affecting her, shes becoming self conscious and thinks her teeth will never be right. You see they look fine to everyone else, but she doesnt think that. Has anyone been through this, or do you know how she can overcome this anxiety/ self consciousness? Thanks everyone.