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After prophylaxis, 5 dent hygienists optimal oral hygiene under supervision for 6 months. At months 0,1,4 and 6, Plaque Index Gingival Extudate Flow Rate and Gingival Index were assessed and a buccal biopsy of their gingiva taken. Point counting procedures were performed at 2 different levels of maginification to estimate the volume densities of epithelium, infiltrated and non infiltrated connective tissue and collagen. The percentage of fibroblasts, polymorphonuclear nutropholic granulocytes, lymphocytes, plasma cells and macrophages were estimated by counting the number of profiles of these cells in the connective tissue area close to the apical end of the junctional epithelium. All the changes insides the tissue occurred slowly. During the 6-month period there was a continuos increase of the volume density of the epithelium in the gingiva. An increase in the percentage of fibroblasts were observed between months 1 and 4 with a decrease in the percentage of lymphoocytes and in the volume density of the infiltrated connective tissue. Between months 4 and 6 an increase of the volume density of the collagen was found together with a further increase in the percentage of fibroblast and a further decrease in the percentage of lymphocytes. After 6 months of perfect oral hygine no more plasma cells visible. This study has shown that even in presence of clinically healthy gingiva subclinical changes may take place. It appear realistic to accept the presence of a very mild gingivitis localized in an area adjacent to the attachment as compatible with gingival health. [ABSTRACT FROM AUTHOR]

The article presents a comparison between histological and clinical parameters during human experimental gingivitis. The purpose of this investigation was to study stereologically the histopathologic alterations occurring during a human experimental gingivitis, and to establish a relationship between clinical parameters and histologic findings. Eight dental students volunteered for the study. After a prophylaxis they performed optimaI oral hygiene For 3-4 weeks to reach mean plaque and gingival indices approaching zero.

The influence of chlorhexidine and Octapinol® on early plaque formation in humans was assessed in vivo. Three subjects with healthy gingiva were used. Plastic films were applied to the buccal surfaces of the maxillary right first premolars and plaque was allowed to form for either 4 or 24 hours. After 1 minute of plaque development, a drop of water, 1 % chlorhexidine or 1 % Octapinol was gently applied in situ; in the 24-h experiment an additional drop was added at 12 h. In total, 76 films were obtained, with a comparable number of specimens in each of the 6 groups. The samples were processed for light and transmission electron microscopy, using standardized techniques for area sampling and cell counting. All control films were covered by a surface coating of a cellular material in or on which bacteria, epithelial cells and leukocytes were observed. The controls and to a lesser extent the Octapinol samples exhibited a significant increase in bacterial count between 4 and 24 h. However, the number of bacteria in the chlorhexidine samples showed only a slight increase within this period. Some microorganisms in the chlorhexidine samples appeared to be undergoing degeneration. In the Octapinol specimens the bacterial morphology was generally intact with many extracellular areas of high electron density. Chlorhexidine and Octapinol both had a qualitative effect on early plaque formation, hut only the former had a detectable quantitative effect at this initial stage of plaque accumulation. [ABSTRACT FROM AUTHOR]

The experimental gingivitis model was used to compare the antigingivitis, antiplaque, and antimicrobial efficacies of two commercially available (a phenolic and a plant alkaloid) compounds used as mouthrinses with those of a mouthrinse containing chlorhexidine digluconate. Thirty-one male and female volunteers with healthy gingivae and clean teeth ceased all oral hygiene procedures for 21 days during which they rinsed twice daily with: a) a phenolic compound (Listerine®), b) sanguinarine (Viadent®), c) 0.12% chlorhexidine digluconate, or d) a placebo mouthrinse. After 21 days of rinsing, virtually no signs of clinical gingivitis were observed in the chlorhexidine group. Subjects rinsing with Listerine, Viadent, or placebo developed clinical signs of gingivitis as measured by gingivitis occurrence, severity, and the proportion of gingival bleeding sites. At the same time, plaque accumulation was only slightly higher than at baseline in the chlorhexidine group, while the Listerine, Viadent, and placebo groups had significantly greater plaque accumulations, particularly during the initial period of treatment between day 0 and day 7. Microbiological enumeration of supragingival plaque collected at the end of the treatment period showed that chlorhexidine digluconate reduced plaque bacteria by 62-99% compared to the placebo group. No significant reductions in plaque bacteria were found among subjects using Listerine or Viadent. This study demonstrated that 0.12% chlorhexidine digluconate was superior to Listerine and Viadent in its ability to maintain optimal gingival health during the entire three weeks of mouthrinse use. It was of particular interest to note these effects during the final 14 to 21-day period of extreme challenge in this experimental model when gingivitis severity and bleeding site occurrence are most pronounced in the placebo group. [ABSTRACT FROM AUTHOR]

Electron microscopic observations were made on naturally occurring gingivitis, on gingivitis at non-ligated sites of an experimental animal, and on ligature-induced periodontitis in a periodontal disease model using female cynomolgus monkeys. For bath types of gingivitis specimens, a plaque associated chronic inflammatory reaction was observed, comparable to that described for the human established lesion. Bacterial accumulations on tooth surfaces were separated from the epithelium by neutrophils which exhibited variations in fine structure and extent of bacterial phagocytosis related to their proximity to the plaque. In the inflamed connective tissue of the papillac, collagen was reduced to strands extending between the cellular elements. The plasma cell was the most common inflammatory cell and had three major variations in form. With ligature-induced periodontitis, similar inflammatory features were observed in the gingiva. A complex flora like that encountered in human periodontitis was observed around and within the ligature as well as more apically in the pocket. As compared to the flora in gingivitis, more spirochetes were encountered, a larger proportion of the microorganisms appeared to be in a living state, and bacteria were in contact with the epithelial surface, rather than being walled off by the neutrophils. This seemingly more aggressive plaque was associated with an advanced lesion characterized by changes that indicated sequential destruction of the collagenous attachment to cementum and concommitant apical migration or the epithelial attachment. No bacteria were observed in the soft tissues, even in the wide intercellular spaces between the epithelial cells. [ABSTRACT FROM AUTHOR]

Histologic observations were made on the primate Macaca fascicularis in order to describe the features of both naturally-occurring gingivitis and gingivitis present at non-experimental sites when selected teeth were ligated to induce periodontitis. Semi-thin sections of glutaraldehyde-paraformaldehyde fixed, EDTA-decalcified, and epon-embedded specimens were used, supplemented by routine histologic methods. The microscopic picture of the interdental areas was identical for the two types of gingivitis specimens and consisted of a chronic inflammatory reaction resembling the established lesion in humans. The highly infiltrated gingival tissue exhibited a predominance of plasma cells. Leukocytes were seen in pathways from the connective tissue, through the epithelium and to the surface of the plaque, and many neutrophils were interposed between the plaque and soft-tissue. The apical extent of the junctional epithelium was at or slightly below the cemento-enamel junction. Although perivascular inflammation was observed in the transseptal fiber region, the alveolar crest exhibited only evidence of normal bone remodelling. [ABSTRACT FROM AUTHOR]

Histological observations were made on ligature-induced periodontitis in two adult female monkeys (Macaca fascicularis). Silk ligatures were placed around posterior teeth and the shift from gingivitis to periodontitis was followed radiographically and bacteriologically for eight and nine weeks, respectively. Fifteen tissue blocks with ligatures in situ were obtained. Following decalcification with EDTA and epon embedding, sections one micron in thickness were prepared in the mesio-distal plane to study the interproximal regions. Two additional blocks were processed for routine histology. Radiographically, progressive bone loss was observed in the interproximal regions that had a ligated tooth surface. Histologically, prominent features included supragingival and subgingival plaque (with dense accumulations of bacteria around and within the ligature), apical migration of the junctional epithelium, loss of collagen and connective tissue attachment, and osteoclastic bone resorption. A chronic inflammatory reaction was evidenced by a dense infiltration of leukocytes in the connective tissue, with a high proportion of plasma cells. Numerous polymorphonuclear leukocytes were seen in pathways between epithelial cells and in a zone around the plaque-laden ligature. These morphological observations, similar to descriptions of human periodontitis, lend support for the usefulness of this model in the study of human periodontitis. [ABSTRACT FROM AUTHOR]