Case Report International Journal of Periodontology and Implantology, January-March 2017;2(1):30-33 30 Endo-perio lesion- A diagnostic quandary Shyama Haridas 1,* , Harish Kumar 2 , Santhosh VC 3 , Sameera G. Nath 4 , Arya Sreedhar 5 1,5 PG Student, 2 Professor & HOD, 3 Professor, 4 Reader, Dept. of Periodontology, KMCT Dental College, Kozhikode, Kerala *Corresponding Author: Email: haridasshyama@gmail.com Abstract The pulp and periodontium originate from ectomesenchyme. They are embryonically, anatomically and functionally inter- related. The concurrent existence of pulpal inflammation and periodontal disease are clinical dilemma as it can complicate diagnosis and treatment planning. This case report evaluates the efficacity of decalcified freeze-dried bone allograft (DFDBA) along with bio-resorbable barrier membrane in the management of right maxillary central incisor. A patient aged 33 yrs reported to our department with endo-perio lesion in right maxillary central incisor. It was treated with decalcified freeze-dried bone allograft (OSSEOGRAFT) along with bio-resorbable barrier membrane (PERIOCOL). 6 months after the procedure, there was improvement in clinical parameters. Keywords: DFDBA, GTR membrane, Endo-perio lesion Introduction Dental pulp and periodontal tissues are ectomesenchymal in origin. The pulp originates from dental papilla and periodontal ligament originates from dental follicle. They are separated by Hertwig’s epithelial root sheath (HERS). In 1964, Simring and Goldberg first described the relation between diseases of pulp and periodonium. (1) Since then, the term “endo- perio” lesion has been used to illustrate the lesions with varying degree of inflammation in both pulpal and periodontal tissues. Endo-perio lesion presents challenges to the clinician with respect to diagnosis and prognosis of the involved teeth. Although there are many factors that lead to the development and progression of endodontic and periodontal diseases, the most important cause is bacterial infections with complex microbial flora. The similarities of the microbial flora of the endodontic and periodontal lesions have been reported by many authors. (2,3) If lesion in one of these tissues is left untreated, it can lead to signs and symptoms of disease within the other tissue. (4,6) Classification Simon et al. classified endo-perio lesion based on primary source of infection. It is the most accepted and commonly used classification. (7)  Primary endodontic lesion  Primary periodontal lesion  Primary endodontic lesion with secondary periodontal involvement  Primary periodontal lesion with secondary endodontic involvement  True combined lesion Connecting paths between endodontium and periodontium: The endodontium and periodontium develop from a common ectomesnchymal origin which results in numerous communication channels, which may lead to the spread of pathological disorders. The common possible pathways for spread of bacteria and their products are: Anatomical and Non- physiological. (8) Anatomic pathways: The primary connection between the pulp and periodontium are apical foramina. In addition, there are numerous lateral and accessory canals that connect the main root canal system and the periodontium. Dentinal tubules are the third most common anatomic route for spread of infection. (8) Non-physiological pathways: Iatrogenic root canal perforations and vertical root fractures are main cause. They are produced by powered rotary instruments during access opening or tooth preparation for post placement. It can also be caused by improper manipulation of endodontic instruments. They are critical complications of dental treatment and have poor prognosis. (9) Vertical root fractures are caused by trauma to the tooth. It can occur in vital as well as non-vital teeth. In vital teeth it can be an extension of coronal fractures in the “cracked tooth syndrome” or it can occur exclusively on root surfaces. (10) Case Report A healthy female patient aged 33 years reported to the OPD, Dept. of Periodontology, KMCT Dental College, with the chief complaint of dull pain and mobility in relation to upper right front tooth from past 3 months. The pain was throbbing in nature. It was intermittent and aggrevated on mastication. Patient gave a history of trauma to her upper front tooth following which it was endodontically treated 1 year ago. There was no relevant medical history. On intra-oral examination, a sinus opening with suppuration was present in relation to discoloured 11. A probing pocket depth of 9mm and gingival recession of 3mm was present. Grade I mobility was also present. It