The interrelationship between periodontal and endodontic disease has always aroused confusion, queries, and controversy. Differentiating between a periodontal and an endodontic problem can be difficult. A symptomatic tooth may have pain of periodontal and/or pulpal origin. The nature of that pain is often the first clue in determining the etiology of such a problem. Radiographic and clinical evaluation can help clarify the nature of the problem. In some cases, the influence of pulpal pathology may cause the periodontal involvement and vice versa. The simultaneous existence of pulpal problems and inflammatory periodontal disease can complicate diagnosis and treatment planning. An endo-perio lesion can have a varied pathogenesis which ranges from simple to relatively complex one. The differential diagnosis of endodontic and periodontal diseases can sometimes be difficult, but it is of vital importance to make a correct diagnosis for providing the appropriate treatment. This paper aims to discuss a modified clinical classification to be considered for accurately diagnosing and treating endo-perio lesion.
The periodontal-endodontic lesions have been characterized by the involvement of the pulp and periodontal disease in the same tooth. This makes it difficult to diagnose because a single lesion may present signs of both endodontic and periodontal involvement. There is a general agreement today that the vast majority of pulpal and periodontal lesions are the result of bacterial infection. This suggests that one disease may be the result or cause of the other or even originated from two different and independent processes which are associated with their advancement [
The apical foramen is the main access route between the pulp and the periodontium, with the participation of all root canal system: accessory, lateral, and secondary canals, as well as the dentinal tubules through which the bacteria and its products contaminate the medium [
Vertical root fractures and cracks may serve as a “bridge” for pulp contamination. If the periodontium had a previous inflammation, it may lead to dissemination of the inflammation which can result in pulp necrosis [
Several authors, through their studies, diverge on the contamination routes. Rubach and Mitchell [
Lindhe [
It is highlighted that the root planning and scaling may result in the rupture of the vessels and destruction of the neurovascular bundle in the lateral canals, provoking a reduction of the blood supply and consequently leading to pulp alterations.
Knowledge of these disease processes is essential in coming to the correct diagnosis. This is achieved by careful history taking, examination, and performing special tests.
This paper is an attempt to provide a rational classification to the endo-perio question in order to scientifically diagnose and treat these lesions with predictable success.
The periodontal-endodontic lesions have received several classifications, among which is the classification of Simon et al. [ primary endodontic lesions, primary endodontic lesions with secondary periodontal involvement, primary periodontal lesions, primary periodontal lesions with secondary endodontic involvement, true combined lesions.
From the point of view of treating these cases efficaciously, another clinical classification was provided by Torabinejad and Trope in 1996 [ endodontic origin, periodontal origin, combined endo-perio lesion, separate endodontic and periodontal lesions, lesions with communication, lesions with no communication.
Another classification was recommended by the world workshop for classification of periodontal diseases (1999) [ endodontic-periodontal lesion, periodontal-endodontic lesion, combined lesion.
Based on these classifications, the most widely used classification of endodontic-periodontal lesions is the one that has been classified by Simon et al. [ retrograde periodontal disease: primary endodontic lesion with drainage through the periodontal ligament, primary endodontic lesion with secondary periodontal involvement; primary periodontal lesion; primary periodontal lesion with secondary endodontic involvement; combined endodontic-periodontal lesion; iatrogenic periodontal lesions.
The integrity of the periodontium will be reestablished if root canal treatment is done properly. If a draining sinus tract through the periodontal ligament is present before root canal treatment, resolution of the probing defect is expected.
It is known that both the pulp and the periodontium are closely linked to each other, through the apical foramen, accessory canals, and dentinal tubules of the root, and one can interfere on the integrity of the other. Although there is existence of these communication routes, the mechanism of direct transmission of the periodontal infection to the pulp is still controversial. Some authors such as Rubach and Mitchell [
The differential diagnosis of endodontic and periodontal diseases can sometimes be difficult but it is of vital importance to make a correct diagnosis so that the appropriate treatment can be provided. Endodontic-periodontal lesions present challenges to the clinician as far as diagnosis and prognosis of the involved teeth are concerned. Etiologic factors such as bacteria, fungi, and viruses as well as other various contributing factors such as trauma, root resorptions, perforations, and dental malformations also play an important role in the development and progression of such lesions.
The endo-perio lesion is a condition characterized by the association of periodontal and pulpal disease in the same dental element. This highlights the importance of taking the complete clinical history and making the right diagnosis to ensure correct prognosis and treatment. Taking into consideration all these factors and the divergences regarding the origin and direction that these infections developed, the new modified classification of these lesions has been justified.
Based on the current classification, it can be concluded that it is of extreme importance that the dentist should know how to differentiate between the origins of the periodontal-endodontic lesions, including all the routes of communication between the pulp and the periodontium which act as possible “bridges” for the microorganisms, thereby enabling the dissemination of the infection from one site to another.
Through this knowledge, the dentist will achieve the correct diagnosis and adequate treatment, resulting in greater chances of obtaining success in the treatment of the periodontal-endodontic lesions.
Due to the complexity of these infections, an interdisciplinary approach with a good collaboration between endodontists, Periodontist, and microbiologists is recommended.
The authors declare that there is no conflict of interests regarding the publication of this paper.