RESUMO
This case report describes the management of a mandibular first molar with an additional distolingual root (radix entomolaris) and grade III cervical enamel projection through a multidisciplinary approach. Diagnosis for the case was endodontic-periodontal lesion due to non-vitality and associated advanced periodontal destruction. The patient was treated with drainage of the periodontal abscess with adjunct antibiotics, phase I periodontal therapy, endodontic therapy, radiculoplasty, regenerative periodontal therapy, replacement of the missing right mandibular second molar, and long-term maintenance. Follow-up of the patient up to 9 months has been uneventful. Cases of advanced periodontal destruction typically show some degree of tooth mobility, which was absent in this case. The article discusses the tripod effect as well as the increased surface area for periodontal attachment provided by the additional root contributing to the non-mobility of the involved tooth.