Nihon Shishubyo Gakkai kaishi最新文献

Dental radiographs can be important for examination, evaluation and diagnosis of periodontal disease, and they have been widely used by dentists. However, discrepancies between radiographs and existing clinical periodontal tissue have been found. The purpose of this study was to investigate the relationship between the existing alveolar bone level on a Xeroradiograph and the root surface area covered with a periodontal ligament. Alveolar bone blocks from human skulls (total 34 teeth) and 60 patients (total 165 teeth) were used for this study. Each human skull bone block was taken Xeroradiograph under three types of conditions. 165 teeth from patients with severe periodontal disease were taken Xeroradiograph by a parallel method. The following equation was used for measuring the teeth on the Xeroradiograph. alpha = Root area supporting the existing alveolar bone/Root area from periapical to C-E junction x 100 The root surface area of each of the teeth extracted from bone blocks and of the extracted teeth from patients were measured by the membrane technique and calculated as follows: beta = Root surface area covered with periodontal ligament/Root surface area x 100 There was no significant difference in equation alpha calculated on three types of Xeroradiographs in the human skull. Significant positive correlations between alpha and beta were obtained, and an empirical regression line was constructed to estimate the ratio of the root surface area covered with periodontal ligament from the existing alveolar bone level on the Xeroradiograph. The results suggest that the ratio of the area of periodontal ligament to the root surface area given by these methods provides useful data for examination, diagnosis and evaluation of periodontal disease.

The aim of this study was to determine biocompatibility of glass ceramics and adhesion of cultured cells to glass ceramics. Four established cultured cell lines, human fibrosarcoma cells (HT-1080), human gingival carcinoma cells (Ca9-22), human osteosarcoma cells (NY) and mouse osteoblasts (MC3T3-E1), were used. For phase-contrast and electron microscopic observation they were cultured on substrates of glass ceramics or polystyrene coverslips as a control. The results obtained were as follows. Glass ceramics caused neither cellular degeneration nor death, as revealed by phase-contrast microscopy. By transmission electron microscopy an amorphous structure similar to the basal lamina was observed at the interface between the substrates and Ca9-22, and between glass ceramics and NY. A similar structure sometimes existed between the substrates and MC3T3-E1. On the other hand HT-1080 showed no such structure. The findings suggest that the biocompatibility of glass ceramics was satisfactory. Furthermore, from the clinical point of view it seems to be possible to close the material-tissue interface with epithelial, fibrocytic and osteocytic cells.

This study describes the distribution of fibronectin and laminin in periodontal tissue of rats after a flap operation. After full thickness flaps were raised, the roots were surgically exposed and planed. Animals were sacrificed at 12 hours, and 1, 3, 5, 7, 14, 28 and 56 days after the wounding. The block specimens were fixed in formalin, decalcified with EDTA, made into serial paraffin sections, and examined after hematoxylin and eosin staining, after Masson-trichrome staining and by indirect immunofluorescence for the presence of fibronectin and laminin. After the wounding, fibronectin was detected in the fibrin clot, and the migratory epithelial cells crossed over this fibrin clot (12 hours-5 days). Fibronectin was deposited heavily in the granulation tissue. When the gingival connective tissue had matured, fibronectin diminished (5-14 days). On the root surface, a layer of fibronectin was present in the region where connective tissue fibers were oriented parallel to the root surface, while no fibronectin was seen at the site of reattachment of the regenerated collagen bundle (14-56 days). Laminin was present in the basement membrane of normal epithelium and blood vessels, but was absent from the internal basal lamina. After the wounding, laminin was absent from the basement membrane zone of the distal site of the migrating epithelium (1-3 days). Upon completion of wound reepithelialization at 5-7 days after wounding, laminin reappeared throughout the basement membrane except the internal basal lamina. These results suggest that fibronectin may be important in the regeneration of epithelium, connective tissue and connective tissue attachment during repair by functioning as an extracellular provisional matrix for migrating cells. On the other hand laminin may be important in maintaining the normal epithelium.

The purpose of this study was to determine the oral conditions in bakery workers (473 subjects) in addition to the screening system of O'Leary and CPITN, designed for rapid recording of the level of periodontal treatment needs, and to evaluate the periodontal treatments, managed by professional cleaning (scaling) and oral hygiene instruction. The assessment of the prevalence and severity of periodontal disease and resultant treatment needs in this group showed the characteristics of chronic periodontal disease in an advanced stage in persons aged 25-29 and 50-54. 228 patients were selected for treatment for nine months and examined accurately for their periodontal condition. 137 patients continued the following group therapy three times and were reevaluated. Following the group therapy, the oral hygiene status and subjective symptoms of bleeding were improved in all groups, the effectiveness of the treatment on sextants, scoring cord three, four, showed markedly high. To achieve the treatment with few individual appointments, it is necessary to increase our knowledge of how these groups live, depending on the diversity of life style and the differences in ethnic consciousness.

The role of the polymorphonuclear leukocyte (PMNL) as a primary protective cell in periodontal diseases has been well recognized. Functional abnormalities of PMNL chemotaxis have been implicated in the pathogenesis of some types of periodontitis. However, no consistent correlation with other PMNL functions has been reported. In the present study, phagocytosis and intracellular killing (oxidative product formation) of the PMNL from the patients with various forms of periodontal disease were evaluated by flow cytometry. Moreover, interleukin 1 (IL-1) production by the PMNL was determined by means of the enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies against rIL-1 alpha and rIL-1 beta. In order to examine these functions of peripheral (p-PMNL) and/or gingival crevicular PMNL (g-PMNL), 15 patients with localized juvenile periodontitis (LJP), 13 patients with generalized juvenile periodontitis (GJP) and 52 patients with adult periodontitis (AP) served as subjects. About 50% of the patients in LJP and GJP group exhibited depressed p-PMNL phagocytosis. While only a minimal number of the AP patients and no healthy subjects showed any reduction of p-PMNL phagocytosis. The reduction of phagocytosis was not related to the clinical periodontal status, and no detectable improvement of p-PMNL phagocytosis could be observed after periodontal therapy. In addition, it was suggested that complement receptors on the p-PMNL might be closely related with the reduction. Compared to p-PMNL, g-PMNL from the same individual have a lower phagocytic capacity in all subjects. However, no significant difference in g-PMNL phagocytosis could be demonstrated among three patient groups. Incremental oxidative responses in p-PMNL were observed in LJP, GJP and AP patients without any significant difference being found among these three groups. The increased rate of oxidative product formation was related to the clinical periodontal status, and it followed that periodontal therapy had significant effect on the improvement of this p-PMNL function. In IL-1 production assay of PMNL, a significant amount of IL-1, especially IL-1 beta, was observed in g-PMNL, but not in p-PMNL. The g-PMNL of the patients was found to produce greater amounts of IL-1 alpha and IL-1 beta than did the healthy controls. In addition, IL-1 production of p-PMNL was induced by the stimulation with some pathogenic bacteria including Bacteroides gingivalis. These results suggest that impaired PMNL phagocytosis may contribute to the early onset of periodontal deterioration in some young patients.(ABSTRACT TRUNCATED AT 400 WORDS)

The objective of this study was to demonstrate the movement of type I and III collagens accompanying gingival inflammatory destruction. Experimental marginal periodontitis was induced by a calculogenic diet and a high-sucrose diet with feces in 3-week-old Wistar rats. We observed the changes in the interdental periodontium histopathologically by using the picrosirius-polarization method and an electron microscope. 1. After 5 weeks of eating the calculogenic diet, mild gingivitis was found. A small number of inflammatory cells consisting of neutrophils were seen. At the 2nd week, a variety of bone resorptions of alveolar crests began to appear. At the 10th week, an epithelial downgrowth was observed. At the 64th week, migration of epithelial attachment to half of the apex and a high degree of inflammatory cell infiltration of plasma cells could be seen. 2. Observations under the polarization microscope showed that interdantal horizontal fibers became coarse and type I collagen decreased but at the middle type III increased. However when the horizontal fasciculus were newly formed, type I was always dominant. Between interdental horizontal fibers and the alveolar crest, type III was increased. 3. Under the electron microscope microfibrils were found around adjacent degraded fibroblasts at the locations where collagen fibrils were destroyed and disappeared. In contrast, at the locations detached from inflammatory cell infiltration small bundles of microfibrils were seen. It is suggested that at the areas of destructive collagen structures the relative increase in type III and the appearance of microfibrils were caused by the reduction of type I. At the same time at the sites of detachment from the lesions, complete growth of type III and the appearance of microfibrils were found and were considered to be newly formed juvenile collagen structures. Moreover it is concluded that a balance proceeds with the qualitative changes in the types of collagen fibers involving breakdown and new formation.

If disease activity in periodontal disease can be determined, the therapeutic measures of periodontitis may become diverse and different from patient to patient. The purpose of the present study was to evaluate the usefulness of microbiological and serological examination of periodontopathic bacteria in detecting destructive periodontal disease activity. One hundred and forty-eight sites in 52 subjects with moderate to severe periodontitis were studied clinically. Clinical parameters included plaque index, gingival index, probing depth, bleeding on probing and percent bone loss as measured radiographically. Subgingival plaque of whole sites was investigated microbiologically by means of indirect fluorescent-antibody technique with rabbit antibodies against Actinomyces viscosus, Actinobacillus actinomycetemcomitans (2 serotypes), Eikenella corrodens, Fusobacterium nucleatum, Bacteroides gingivalis and Bacteroides intermedius. The levels of serum IgG antibody to these organisms were determined by enzyme-linked immunosorbent assay with whole cell preparations. Thirty-two of 52 subjects were instructed in oral hygiene and received several sessions of scaling and root planing. The clinical, bacteriological and serological assessments were also performed after periodontal therapy. Active disease site was defined as the site of which clinical status did not be improved even after periodontal treatment. B. gingivalis, B. intermedius and A. viscosus were detected in 80% of periodontal lesions, and the proportion of B. gingivalis was the highest among six bacterial species tested. A. actinomycetemcomitans, E. corrodens and F. nucleatum were found only occasionally and in low numbers. The proportion of B. gingivalis was higher in severely inflamed sites than in clinically healthy sites. B. gingivalis and B. intermedius are rarely found in treated periodontitis sites, while the proportion of A. viscosus was slightly increased after treatment. Sera of the pre-treatment patients demonstrated significantly higher antibody levels to B. gingivalis and significantly lower levels to A. viscosus than those of healthy persons. Antibody levels reactive with other four species in the patients did not significantly differ from the levels in healthy persons. After periodontal therapy, antibody levels to B. gingivalis, B. intermedius and A. actinomycetemcomitans (serotype a) significantly decreased and the levels to A. viscosus increased to a slight degree. B. gingivalis was found more frequently in disease-active sites than in disease-inactive sites. The proportions of other bacterial species in disease-active sites did not differ from those in disease-inactive sites. The results of the present investigation suggest that monitoring B. gingivalis in subgingival plaque and serum IgG antibody titer against this organism may aid in the description and adequate treatment of the periodontal disease.

The purpose of this study was to determine the longitudinal effect of demineralized treatment of root surfaces on initial attachment, growth and differentiation of human periodontal ligament fibroblast-like cells in vitro. Cementum and dentin fragments were prepared from intact extracted human teeth for orthodontic reason. The root fragments of one group were not demineralized. Those of the other groups were demineralized by either citric acid (pH = 1.0, 3 min) or EDTA (pH = 7.4, 30 min). Plastic sheets served as controls. Human periodontal ligament fibroblast-like cells were incubated on root fragments and plastic sheets. After incubation, the root fragments and plastic sheets were examined by electron microscopy. The collagen fibers were exposed to the root surface by demineralized root surface. The exposed collagen fibers showed an effect on the cell attachment and growth, and the cells produced collagen fibers in the extra-cellular space of the root surface. Demineralization of dentin fragments were more strongly affected in cell attachment, growth and differentiation than demineralization of cementum fragments. Citric acid demineralization of dentin fragments had a greater effect on cell attachment, growth and differentiation than EDTA demineralization of dentin fragments. The results suggest that citric acid demineralization of dentin fragments may provide the most effective dental surface for the establishment of connective tissue attachment after periodontal treatment.

The Chédiak-Higashi (C-H) syndrome in man and certain animals including the beige mouse in a genetic disorder (autosomal recessive disease) characterized by partial oculocutaneous albinism, photophobia, recurrent infections and defective leukocyte function manifested by the presence of abnormally large lysosome-like organelles in granule-containing cells. The oral manifestations that have been reported include severe gingivitis, ulcerations, and early, severe, periodontal break-down. The beige mouse is analogous to the C-H syndrome in man. This study was conducted determine the effects of diet (soft diet) on the periodontium and leukocyte functions of beige mice by observing the periodontium and the activity of the cells. Beige mice and their heterozygous male littermates (hetero mice) were used at the age of 4-24 weeks and the lower jaw and neutrophils, macrophages and lymphocytes were used. There was no significant difference histologically between the beige mice and hetero mice at the age of 24 weeks when that were fed a hard diet. But, when they were fed the soft diet for 4 weeks, bone resorption was seen in the beige mice, but not in the hetero mice. All tested cell activities of the beige mice were significantly lower than those of the hetero mice. The above findings, suggest that there was a correlation between the decreased activity of the inflammatory cells and bone resorption in the mice fed the soft diet.