Objective: Ishemic bone disease has multifactorial etiologies. Cronic dental infections should be eliminated to prevent osteonecrosis of the jaw. Case report: We report an unusual case of osteonecrosis due to the pulpal-peridontal syndrome and subsequent pulp necrosis. A case of 38 year old woman who presented with exposed bone, 8 mm in diameter, in the lingual area of the right lower third molar. The patient was otherwise healthy and was not taking any medications. A detailed medical history showed no previous diseases. Patient denied any type of local trauma. A complete blood count showed no abnormalities. The panoramic radiograph revealed a deep periodontal pocket between teeth 47 and 48. The CBCT revealed a deep periodontal pocket between molars and bone sequestrum of the lingual plate. Topical treatment consisted of adhesive periodontal dressing based on the cellulose and betamethasone oitnment together with orabase, without improvement. Therefore, peroral amoxycillin was prescribed for a week. Since there was no improvement, the third molar was removed as well as necrotic bone; the alveolar bone was remodelled and utures were placed. After suturing, the whole area was covered using intraoral resorbable bandage. Microbial swab of the wound aspirate did not reveal polymorphonuclears or the presence of icroorganisms. Microbial swab of the biopsy specimen of the necrotic bone particle and sequestrum showed a large amount of gram-positive coccae, however, polymorphonuclears were not found. Histopathological analysis revealed acute chronic inflammation. One week after the surgery, the area healed completely. Conclusion: This case highlights the fact that in some patients bone exposure might develop due to the pulpal-peridontal syndrome i.e. pulp necrosis.