Calcium hydroxide root canal filing paste (vitapex) is widely used as canal filling paste for infected canal. However, chemical burn is possible because of the high alkali base of calcium hydroxide. A 57-year old woman was admitted to our clinic for consistent dull pain and paresthesia in the left upper lip, zygoma and buccal cheek area, which developed during an endodontic treatment of the left lateral incisor. Radiographic finding showed radiopaque material, which exits from the left incisor root apex, and was within the left canine and first premolar buccal soft tissue. The overfilled Vitapex extended to the soft tissue was surgically curetted. The result of the surgical curettage was favorable. Though slight hypoesthesia on the upper lip was still remained, paresthesia on zygomatic and buccal cheek area was completely recovered. As far as we know, this is the first case report of infraorbital nerve damage from overfilled Vitapex material.