If the X-ray shows infection below or adjacent to cap then it needs to be changed but if it’s in roots of the tooth then you can go through the cap without removing it. The cap wouldn’t be replaced in this case but in above case it would be changed.

Suggested way is the standard protocol of retreating the tooth. Good luck

Hi, It’s required to know the reason of reinfection of RCT first. If it’s because of leakage through the cap or food lodgement, then change of crown is a must. If not it’s usually the decision of the doctor attending you to decide whether RCT through the crown is feasible or not. Though ideally Re-RCT should be preferred after removing the cap.

If the cap is broken and tooth has infection then re root canal treatment should be done after that capping of tooth should be done but for treatment we need x-ray of tooth only then we can plan the treatment

Hi The ideal treatment is removing the cap and then re root canal has to be carried out and then put new cap ovr it In order to avoid breakage of cap, a proper clearance has to be given during vpcrown preparation and sufficient amount of crown structure has to be reduced

For proper retreatment it's better to remove the cap treat the teeth properly and go for a new cap to avoid issues in future

Ya we can do re rct through and through without damaging the cap. You can call me on 98702166seven4 for more queries. I am an Endodontist