Root Canal Retreatment Of Mandibular First Molar With Middle Mesial

Introduction: In this case, root canal retreatment followed by crown restoration was performed on the mandibular right first molar with middle mesial canal, resulting in a favorable prognosis. Case description: 1.Patient Information: Female,19 years old 2.History of Present Complaint: Seven years ago, the patient received right lower posterior teeth root canal treatment in another hospital.The patient complained of gingival bulge in the lower right posterior teeth for 3 years. 3.Intra-oral examination: Tooth 46:There were dental filling materials on the occlusal and mesial surfaces.Sinus can be seen in buccal mucosa. 4.Radiographic examination: CBCT revealed a high-density filling material in tooth 46, with unfilled MM canaland a periapical radiolucent lesion. 5.Diagnosis:Chronic apical periodontitis 6.Treatment plan:Root canal retreatment+ Crown restoration 7.Treatment schedule: Under rubber dam isolation, access was prepared under microscope, MM canal negotiated. Existing filling material removed, canals prepared. Three weeks later, the patient was asymptomatic with healed sinus tract. Root canal obturation and resin restoration were performed. At the three-month follow-up, apical radiolucency reduced, and crown restoration was completed. Discussion: 1.Technology-Based Methods to identify MMCs: Radiographic method; Cone-Beam Computed Tomography (CBCT); Dental operating microscope (DOM). 2.Clinical Methods to detect MMCs: Adequate access cavity preparation ; Guided troughing technique; Champagne bubble Test; Methylene blue dye Test. Conclusion/clinical significance: During clinical practice, careful identification of MM canals is essential to prevent oversight and enhance therapeutic outcomes