Abstract
The periodontal tissues and the pulp-dentine complex form an intimate continuum through which pathological changes of either one may lead to infection of the other, and whose management can be fraught with diagnostic and therapeutic difficulty. The purpose of this review paper is to explain the nature of that relationship and to provide pointers which may assist in the diagnostic process and thus enable appropriate management from the outset. Traditional classifications of lesions affecting the periodontal-endodontic complex have caused confusion by attempting to form diagnoses which indicate the putative primary source of infection. We would suggest that the origin of the infection is irrelevant to the management process, and that what is important is whether either, or indeed both, of the tissues are viable or not. Successful therapy will only result from the establishment of an accurate diagnosis, and forming such a diagnosis requires a methodical multi-staged approach.