Relative distribution of bacteria at clinically healthy and periodontally diseased sites in humans*

Abstract

Samples of subgingival bacteria were collected with a clean curette from two relatively normal and two periodontally diseased sites in each of 12 patients with advanced periodontal disease. The samples were suspended in physiologic saline containing 1 % gelatin and examined within 1 hour by darkfield microscopy. From 100‐200 bacteria were classified on a percentage basis into one of the following categories: (1) coccoid cells, (2) straight rods, (3) filaments, (4) fusiforms, (5) curved rods, (6) small spirochetes, (7) medium‐sized spirochetes, (8) large spirochetes, and (9) motile rods. For each area sampled the following clinical criteria were also recorded: (1) Gingival Index, (2) Plaque Index, (3) probing depth and (4) gingival fluid flow. For each patient separate mean values were calculated for the normal and the diseased sites. The results indicated that significant differences existed in the microbial flora of clinically normal and diseased sites using a paired t‐test comparison (2α= 0.001), with coccoid cells more predominant at normal sites (74.3 % vs. 22.3 %), while at diseased sites motile rods were more frequent (12.7 % vs. 0.3 %), as well as curved rods (1.7 % vs. 0 %), small spirochetes (12.6 % vs. 1.1 %), medium‐sized spirochetes (18.5 % vs. 0.5 %) and large spirochetes (6.7 % vs. 0.2 %). The ratio of motile to non‐motile cells in the normal was 1:49, whereas at diseased sites the ratio was in the vicinity of 1:1. These results clearly show that a different flora is associated with healthy and periodontally diseased sites in the same patient population and that these differences can be detected by means of a technique which is simple and readily adaptable to a clinical setting. The data obtained in this fashion may be useful in monitoring the effect of various treatment modalities on the periodontal flora and possibly in determining the presence or absence of active disease.

Investigation of Subgingival Profile of Periodontopathic Bacteria Using Polymerase Chain Reaction

“…have been detected by several methods: anaerobic culture 15) , microscopy 11) , enzyme reaction 6) , immunohistology 8) , DNA probe 9) and polymerase chain reaction (PCR) 2) . The culture method is time-consuming and requires specific techniques.…”

Comparison of peptidase, glycosidase and esterase activities of oral and non-oral Treponema species

“…Spirochaetes are helical-shaped Gram-negative organisms which are prominent in subgingival plaque of inflamed periodontal tissue and in the microflora associated with the mucosa of the intestinal tract of man and animals with severe forms of diarrhoea (Harris et al, 1976;Listgarten & Hellden, 1978;Sanna et al, 1982). Oral spirochaetes have been observed in gingival lesions in and between gingival epithelial cells (Listgarten, 1965;Mikx et al, 1990).…”

Effect of Systemic Doxycyline Administration on the Subgingival Microbial Flora: A Dark-field Microscopy Study.

“…Spirochetes and motile rods are suggested to be related to the severity of periodontal disease [6,8,16]. An increased number of spirochetes and gram-negative motile bacteria in diseased sites, and a predominance of gram-positive coccoid bacteria in clinically healthy sites has been demonstrated [6,8,16,18].…”