Dens Invaginatus—Mandibular Second Molar—Case Report

<b>Background:</b> Dens invaginatus is a rare developmental tooth anomaly that can occur in permanent, primary, and supernumerary teeth, with a tendency to affect the maxillary second incisors. It develops during odontogenesis due to the invagination of the enamel organ into the dental papilla. <b>Methods:</b> This study describes the endodontic management of a 24-year-old patient with a type IIIb invaginated tooth in the mandibular second molar. Clinical examination revealed no response to thermal and electrical stimuli, no response to vertical and horizontal percussion, and no pathological mobility. The depth of the gingival pocket was 8 mm. Root canal therapy was performed over three sessions. The patient remained asymptomatic during the treatment and follow-up visits. <b>Results:</b> Radiographs at 4-, 6-, and 9-month post-treatment showed healing of the periapical lesion. <b>Conclusions:</b> Due to the complex canal anatomy of invaginated teeth, confirming the diagnosis with cone-beam computed tomography (CBCT) is essential. Treating invaginated teeth presents significant challenges for clinicians, requiring a thorough understanding of the dental anatomical variability, advanced manual skills, and the use of specialized equipment.