The issue of retreatment in endodontics, necessitated by complications arising over the long term, is a pressing concern with significant medical and social implications. Materials and Methods: Radiographic assessment was performed on 86 teeth using an intraoral dental X-ray unit (model 5D2) and a SOPIX 2 radiovisiography system (Acteon Group, France), supplemented by cone-beam computed tomography (CBCT). To examine the morphology, microstructure, and elemental composition of dental specimens (extracted teeth) and root-filling materials, scanning electron microscopy (SEM) and micro-X-ray spectral analysis (MRSA) were employed on 35 tooth roots. Results and Discussion: Radiographic evidence of resorption was observed in 24.22% of cases. Extrusion of the sealers Foredent and Sealapex beyond the apical foramen occurred in 100% of cases where the apical constriction had been compromised. When Trioxident was used, extrusion was observed in 40% of cases. In all instances, the filling materials failed to achieve a tight seal against the root canal walls. Trace elements from the endodontic sealers were found to affect the root dentin. Conclusions: Using SEM, the presence of a biofilm was detected in some cases within the endodontic sealer and the root canals of teeth that had undergone endodontic treatment.