Microbiology of periodontal disease

Abstract

There is a perception of conflicting data and opinions among research laboratories that are studying periodontal microbiology. In response to this perception I was asked to discuss recent literature in this field at the 1986 Annual Meeting of the American Association of Dental Research. This review is based on that discussion which primarily concerned all of the relevant papers that were available to me and that had been published in the last 2 years (1984 and 1985). In order to determine what the data (rather than what our biases) may tell us, accurate comparisons of published reports in this field require an appreciation of the reasons for different results in different laboratories. Therefore, before we compare data, let's consider some of the reasons why results from different laboratories may differ. The periodontal flora is complex. We have found over 325 distinct bacterial species in the human gingival crevice (1). Many of these species have never been formally described, most of them are ignored by some laboratories, identified differently by others, or lumped together in various groups by still others. Some of the predominant species have special growth requirements and are not detected on some media that are widely used. Identification criteria differ among laboratories. Even with rigorous testing, identification of some species is questionable. With minimal testing it is even less reliable.