Fig. 2

a Pre-operative periapical radiograph showing perforation on MB of 2.6 and a 2.7 periapical lesion of MB and DB. Classified: 2.6: R2-L3 and 2.7: R3-L4. Tooth 2.7 was treated 21 months ago and subsequently retreated 12 months ago. It is evident that it is difficult to distinguish exactly which roots are affected by tooth pathology 2.7 using a 2D image. b Pre-operative CBCT showing a different classification. 2.6 Classified R3-L4 and 2.7 classified R4 and L4. c Periapical radiograph at 6 months follow-up. After Microsurgical Endodontics on MB1 e MB2 and DB root of 2.7 showing an incomplete healing. Tooth 2.6 was extracted. d Periapical radiograph at 12 months follow-up. After Microsurgical Endodontics on MB1 e MB2 and DB root of 2.7 showing a complete healing. Tooth 2.6 was extracted