There must be 90% pain relief by 1st sitting rct and 100% pain relief after 2nd sitting. To ensure the rct done teeth will be painless after completion. Possible causes of pain
1.Tooth may have cracked vertically
2.excess chemicals used in canal
3.over instrumentation.
4.canal perforations.
Next Steps
2,3 pain will settle if approach by dentist is re organised.
4 . needs expertise in approach by dentist.
1. it's difficult to settle the pain. teeth may need extraction