Orthograde retreatment of a maxillary first molar with untreated MB2 and MB3

Diagnosis: Previously treated tooth / symptomatic apical periodontitis Treatment plan: Nonsurgical endodontic retreatment followed by an indirect cuspal coverage restoration performed by the referral clinician. Clinical steps: Removal of the existing coronal restoration and carious tissue. Pre-endodontic build-up. Removal of root canal filling material. Determination of working lengths and chemomechanical preparation using a sequence of rotary instruments.At the level of the mesial root, after the removal of the guttapercha of the MB1 canal, a ledge in the middle third blocked the access to the apex. Therefore, I decided to return to this canal after identifying the orifice of the MB2 system and establishing patency in this canal, which had not been previously identified. After removing the dentin bridge covering this…