Search

The subgingival microflora in patients presenting concurrently with periodontitis and diabetes mellitus (DM) are poorly understood. While traditional putative periodontal pathogens are implicated, research involving other oral organisms; e.g., Capnocytophaga spp., is lacking. These organisms produce a range of bacterial enzymes relevant to periodontal breakdown. It is inferred that periodontal bacteria acquire systemic access through the ulcerated periodontal pocket surface; conclusive evidence supporting this notion is limited. The aims of this investigation were to: 1) quantify and identify Capnocytophaga spp. present in healthy and diseased sites in periodontitis patients with and without DM, and 2) isolate periodontal pathogens from these patients' blood.Twenty-one DM-periodontitis and 25 periodontitis patients were recruited. Subgingival plaque was collected from three healthy and three diseased sites per subject. Capnocytophaga spp. and total (facultative and obligate) anaerobic counts from each site were estimated. Capnocytophaga spp. were identified using 16S rRNA polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP). Statistical analyses were performed using multilevel modeling. Blood samples were subjected to HbA(1c) estimation and bacterial culture.A total of 848 Capnocytophaga spp. were isolated and identified. Significantly higher numbers of Capnocytophaga spp. (P0.001) and anaerobes (P0.001) were present in diseased sites in DM-periodontitis subjects compared to healthy sites in non-DM-periodontitis and DM-periodontitis subjects. C. ochracea (and variant) and C. granulosa were the most prevalent species. Blood samples were negative for Capnocytophaga spp.Total mean counts for Capnocytophaga spp. were significantly higher in DM-periodontitis subjects versus non-DM-periodontitis (P = 0.025) and at diseased sites versus healthy sites (P0.001). Analysis of individual species revealed that the outcome varied with site status and DM status.

Blood vessel features in periodontal pocket soft tissues may be significant in the pathogenesis and progression of chronic periodontitis. The aim of this study was to make a quantitative histological assessment of the vasculature in soft tissue biopsies from patients with chronic adult periodontitis and patients with healthy periodontal tissues. We have also investigated changes in tissue morphology at both the histological and ultrastructural level. Twelve interdental biopsies were obtained, 6 from chronic adult periodontitis patients and 6 from healthy volunteers. The specimens were sliced, fixed in 3% glutaraldehyde, postfixed in 1% buffered osmium tetroxide, dehydrated, and embeded in araldite. One micron semithin sections were differentially stained with a dichromatic technique. The number of blood vessels (BV) for sub-epithelial, superficial and deep connective tissue layers were then assessed. Only in the sub-epithelial connective tissue layer was there a significant increase in the number of blood vessels (95% Confidence interval [CI]) in the chronic adult periodontitis specimens when compared to healthy specimens. The results of this study seem to indicate that a dichromatic staining technique facilitates the identification and quantification of blood vessels in epoxy resin embedded specimens at light microscope level, and that there is an increase in the number of blood vessels in the chronic adult periodontitis lesions.

This study concerns the apical border (AB) plaque in relation to severe forms of periodontitis (SP), including juvenile, post-juvenile, and rapidly progressing periodontitis. Twenty-four (24) teeth from 16 patients with SP were examined by transmission electron microscopy (TEM). The AB was not discrete, with islands of bacteria in the so-called plaque-free zone (PFZ). Coronal to the AB the established plaque consisted of a layer of Gram-positive cocci and ghost cells and a superficial layer mainly of Gram-negative morphotypes, including cocci, rods, filaments, fusiforms, and spirochetes. The most apical apparently intact organisms in the PFZ were in bacterial islands or in isolation and were predominantly Gram-negative cocci and rods, with ghost cells in abundance. Ruthenium red, alcian blue-lanthanum nitrate, and safranin O were used to label matrix polyanionic macromolecules, and periodic acid (thiosemicarbazide) silver proteinate for intracellular polysaccharide (IPS). The matrix components were mainly fibrillar. Many intact bacteria exhibited extracellular polysaccharides or glycocalyces associated with their cell wall, and cytoplasmic IPS granules. The latter varied in distribution and were evident even in the most apically advanced intact microorganisms. The results indicate that IPS and some matrix features of the apical border plaque in severe periodontitis in certain aspects resemble those of sub-contact area plaque on children's teeth, in health or associated with early chronic gingivitis, and with those in chronic adult periodontitis. They also suggest the establishment of acidic regions in the microniche at the bottom of the periodontal pocket in the various forms of periodontitis differing in rate of progression. It was concluded that there was a limited range of intact bacterial morphotypes in the apical border plaque in severe periodontitis, similar to those in chronic adult periodontitis.

This study examined the dental cuticle (DC) at the interface with cementum surface, as well as its relationship to the overlying subgingival plaque (SP), the so-called plaque-free zone (PFZ), the junctional epithelium (JE), and the coronal fibers of the residual periodontal ligament (PL) by transmission electron microscopy (TEM) and histochemistry. Material comprised of 41 extracted, adult periodontitis-affected teeth (AP). Following extraction, 20 teeth were fixed in 3% glutaraldehyde in 0.1M sodium cacodylate, post-fixed in 1% osmium tetroxide, embedded in araldite, decalcified in EDTA, re-embedded in araldite, and sectioned. En bloc histochemistry was undertaken on the remaining 21 teeth, using ruthenium red, alcian blue-lanthanum nitrate, or safranin-O, and processed as above. Results show that the DC covered the cementum surface from the SP to the JE, and formed an interface with these structures. No DC was observed at the interface with PL. Morphological variations in DC surface were observed at the interface with the SP and at the so-called PFZ where bacteria were always in close contact with or surrounded by the DC. At the interface with JE, the DC appeared homogeneous, although layers varying in electron density were distinguishable. Teeth treated histochemically revealed a positive reaction of DC and bacteria to the three methods, suggesting the presence of anionic polymers including glycoproteins in the DC. It was concluded that on adult periodontitis affected teeth, the DC always covers exposed cementum and may mediate bacterial adhesion, and adsorb components from the periodontal pocket.

A "plaque-free" zone has been described on the enamel surface of healthy extracted teeth. This study examined this zone on chronic adult periodontitis-affected teeth (CAPT). Ten healthy controls and 16 CAPT were collected immediately after extraction, fixed, dehydrated, critical point dried, coated, and viewed by scanning electron microscopy (SEM). The "plaque-free" zone was observed in both groups as an area with few bacteria between the apical plaque border and the coronal limit of an epithelial layer on the root surface, extending to the residual periodontal ligament. On the healthy specimens, the apical plaque border consisted mainly of cocci and short rods, while on the CAPT specimens spirochetes predominated. Isolated or small groups of microorganisms were always present in the "plaque-free" zone and at its apical limit, close to or in contact with junctional epithelial cells. This zone is therefore not completely free of plaque, as suggested. It was concluded that a tissue complex, analogous to that in health on enamel, persists on the root surfaces of CAPT throughout the disease process. It comprises a discrete plaque border, a dental cuticle with sparse organisms, and an epithelium analogous to junctional epithelium. Its main function would appear to be to prevent bulk access of plaque to the surrounding tissues, including direct contact of bacteria with underlying ligament.

THIS STUDY CONCERNS THE APICAL BORDER (AB) plaque in relation to chronic adult periodontitis (AP). Fifty-six teeth from 24 patients with AP were examined by transmission electron microscopy (TEM). The AB was not discrete with islands of bacteria in the so-called plaque-free zone (PFZ). Coronal to the AB, the established plaque commonly consisted of three to four layers of Gram-positive and Gram-negative cocci, rods, filaments, and spirochetes and a superficial layer, mainly of spirochetes, but including filaments, "test tube brush," and "corn-cob" formations. The most apical apparently intact organisms in the PFZ were in bacterial islands or in isolation and were predominantly Gram-negative cocci and rods, with occasional other morphotypes. The most apical microorganisms were invariably ghost cells. A cuticle of varying thickness and structure was present at the plaque/tooth interface. It was concluded that there was a limited range of intact bacterial morphotypes in the apical border plaque in chronic periodontitis.

THE AIM OF THIS STUDY was to characterize the plaque matrix and relevant aspects of metabolism of the apical border plaque in relation to teeth affected by chronic adult periodontitis. The material comprised 56 teeth from 24 patients. Ruthenium red, alcian blue, lanthanum nitrate, and safranin 0 were used to label matrix polyanionic macromolecules and periodic acid-thiosemicarbazide-silver proteinate for intracellular polysaccharide (IPS). The matrix components were amorphous, fibrillar, or globular. Many intact bacteria exhibited extracellular polysaccharides or glycocalyces associated with their cell wall and cytoplasmic IPS granules. The latter varied in size and distribution and were evident even in the most apically-advanced intact microorganisms. The results indicate that the matrix and IPS features of the apical border plaque in chronic periodontitis in certain respects resemble those of subcontact area plaque on children's teeth, associated with chronic gingivitis and approximal caries. They also suggest the establishment of acidic regions in the microniches of the periodontal pocket.