Were you sitting in front of me and I could get a good look in your mouth and do a bit of investigative work, I could give you more specific answers. On this forum, I'll just give you a few ideas to consider. Fixing the chipping without from finding out why it's happening is going to...
Re-treatment by an endodontic specialist have a much higher success rate than by general dentist. No treatment of that tooth will have a 100% guarantee success. An endodontist is well-trained to rule out all possible reasons for failure...