Microbial etiology of periodontal disease

Abstract

Longitudinal studies with humans indicate that gingivitis is associated with an increased dental plaque mass. Also, prior to the onset of gingivitis, changes in the microflora towards a more complex bacterial composition frequently occur. On the other hand, recent cross sectional cultural studies generally do not reveal clear‐cut differences between the composition of the subgingival microflora associated with healthy or inflamed gingivae. Also, some studies have demonstrated an enhanced cell‐mediated immune response during the course of gingivitis to a variety of subgingival plaque bacteria. It has also been observed that plaques allowed to form on cleaned teeth for 2 or 3 days do not differ substantially in their microbial composition. However, long‐term thorough oral hygiene performed at intervals of 48 h permits maintenance of gingival health, whereas that instituted at intervals of 72 h will lead eventually to gingivitis. Collectively, this evidence supports the concept that the etiology of gingivitis is bacteriologically nonspecific. Thus a large increase in the accumulation of bacteria on the tooth surface per se may have a greater pathogenic effect on the periodontal tissues than the relatively minor and inconsistent shifts in the microbial composition. The transition from gingivitis into periodontitis may be induced by changes in the pathogenic potential of subgingival plaque. Gram‐negative rods appear to be specifically associated with periodontitis. A growing body of evidence implicates especially Bacteriodes asaccharolyticus as one of the responsible pathogens. Juvenile periodontitis (periodontosis) seems to be a distinct disease entity. Recent findings suggest abnormalities in peripheral blood polymorphonuclear leucocytes (PMNL) of patients with juvenile periodontitis. The subgingival microflora is different from that associated with periodontitis and the findings so far implicate Actinobacillus actinomycetemcomitans as an important pathogen. The bacterial etiology of acute necrotizing ulcerative gingivitis (ANUG) is still unclear. Satisfactory cultural studies have yet to be performed. The presence of spirochetes in the ulcerative lesions of the junctional epithelium does not necessarily imply that they play an important role in this disease entity. Future research on the bacteriology of periodontal disease should concentrate on longitudinal studies; particular attention should be paid to the change of gingivitis into periodontitis whereby animals as well as humans can be used. Improvements of sampling methods as well as precise and simple identification techniques of microorganisms are required.

Direct Modulation of Human Neutrophil Adherence by Coaggregating Periodontopathic Bacteria

“…Although dental plaque with its microbial constituents has been firmly impli cated as the étiologie agent in periodontitis [1][2][3][4], many features of the disease cannot be explained on the basis of microbial factors alone [5]. Existing the ories of immunopathogenesis are based on classical mechanisms such as immune complexes [6,7], com plement activation [8], lymphocytes [9,10], and var ious combinations of the above [5,11], and may ade quately account for the established and advanced le sions of periodontitis.…”

Effect of a School-Based Plaque Control Programme on the Microbiology of Dental Plaque

“…There is little in the literature to support an inverse relationship between anaerobic gram-ne gative cocci and caries experience such as that seen in the control group in the pres ent study, even though the Veillonella are known to ferment organic acids to weaker acidic products [Hare et al, 1952;Distler and Kroncke, 1980], and it has been sug gested that they might thus constitute a de terrent to the progress of the disease [Douglas, 1950;van der Hoeven et al, 1978]. However, an association between anaerobic gram-negative rods and period ontal disease has been reported by a num ber of authors [reviewed by van Palenstein Helderman, 1981], and there were indica tions of a direct relationship with gingivi tis scores in the control subjects in the present study. In the experimental group the lower mean gingivitis score and pro portion of gram-negative rods provided less opportunity for such a relationship to show itself.…”

Antibiotic Resistance in Oral/Respiratory Bacteria

“…However, there are some generalities of the microflora that have been found. For example, in people with healthy gingiva, the microflora in the area between the gingiva and the tooth will be predominantly Gram-positive bacteria, while an individual with periodontal disease will have many more Gram-negative bacteria (Slots, 1979;van Palenstein-Helderman, 1981). The result is that over the life of an individual, the variety of bacterial species living in this ecosystem is very large.…”