[in Japanese]

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Advances in research on the relationship between Helicobacter Pylori and gastric mucosa disease and H. pylon infection from oral cavities is promising, but raises the problem of H. pylon presence in the oral cavities and its influence on periodontitis. We studied the existence of H. pylori in the oral cavity of Mongolian gerbils infected with H. pylon in the stomach using the polymerase chain reaction.
H. Pylori was not detected in the oral cavities just after the administration of H. pylon in the stomach, and although H. pylori was detected from the tongue on day 60 after infection in the stomach, it was not detected from the mandibula on day 120. H. Pylori was not detected from the maxilla until day 120. The number of H. pylon in the stomach was decreased by oral administration of Chinese medicine, dai-shi-koto. In drug treatment, H. pylon was not found from the tongue sample, but was found in the sample of mandibula after drug treatment.
Although H. pylon was not colonized directly in the oral cavity, it was assumed that H. pylori existed in the counterflow from the stomach. Because H. pylon was detected from mandibula after decrease in the number in the stomach, the possibility of H. pylon in the counterflow and its fixation in the oral cavity was suggested. J. Jpn. Soc. Periodontol., 43 : 353-360, 2001.

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We assessed the effectiveness of site-specific curettes on subgingival scaling and root planing using a teaching model.
The teaching model in which the roots of the teeth were uniformly coated with a layer of manicure paint was attached to a mannequin and instrumented. Three types of Gracy curettes were used Original®, After Five®, and Mini Five® Hu-Friedy Company. Instrumented areas were individually analyzed to assess the range reached by curettes and the percentage of manicure removed, using computerized imaging. The 12 operators were divided into amateurs (≤ 2 years in periodontal practice) and professionals (≥ 6 years in periodontal practice).
Based on the type of curette, the Mini Five® showed the greatest effect, followed by After Five® and the Original® in the amateur group in the range reached and the percentage of manicure removed in lower anterior teeth. The percentage of manicure removed on mesial and distal aspects of the upper first premolar was smaller than that of the upper second premolar. The range reached by the Mini Five® on the distal aspect of the lower second molar was significantly deeper than for After Five® and Original® in the professional group, indicaling, the Mini Five® was highly effective.
Based on years of practice, the range reached by curettes and the percentage of manicure removed in lower anterior teeth by the Original® in the professional group was significantly superior than that in the amateur group.
The percentage of manicure removed in lower molars using the After Five® and Mini Five® by the professional group was occasionally greater than that of the amateur group.
In conclusion, the effectiveness of the After Five® and Mini Five® was superior if used on specific teeth. The number years of dental practice spreared to influence the effectiveness of instrumentation in all areas. J. Jpn. Soc. Periodontol., 43: 361-373, 2001.

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We evaluated periodontal regenerative potential of soft tissue cells grown around roots under e-PTFE membranes using 24 teeth from 12 mongrel dogs. premolars of both sides in the mandible were extracted except for the distal roots of second premolars (P 2 D). The crowns of the teeth were resected and root canals filled. Three months after extraction, soft tissue flaps were elevated, about 5 mm of circumferential alveolar bone was removed, and exposed P 2 D root surfaces were carefully planed to remove cementum. Prior to flap repositioning and suturing, e-PTFE membranes were placed over the bony defects in experimental groups. No membrane was used in control groups. Experithental groups (tissue with membrane) were divided into 3 subgroups based on the duration of membrane application. group A, in which e-PTFE membranes were removed after 2 postapplication weeks; group B, in which membranes were eliminated after 4 weeks; and group C, in which membranes were removed after 8 postapplication weeks. Concomitant with membrane removal, roots and circumferential tissues were extracted in a lump and implanted into prepared bony defects in the mandibular edentulous area of the same animals. P 2 Ds and tissues without membrane application were extracted at 4 posttreatment weeks and implanted using the same procedures as in experimental groups. Four weeks after implantation, all animals were sacrificed and examined. Newly produced bone and cementum and ankylosis appearance were analyzed in histologic sections. Cell proliferation in regenerated tissues was examined using proliferationg cell nuclear antigen (PCNA) immunohistochemistry. The largest amount of cementum was produced in group B, whereas prominent ankylosis was observed in group C. Little new cementum formed on the root surface of the control group. Amounts of regenerated bone increased with time in experimental groups. Immunoreactivity to PCNA was seen in group B, although activity was lower in groups A and C than in the as control group. These results suggest that tissues created by e-PTFE membranes for 4 weeks have the greatest potential for periodontal regeneration, particularly in cementum formation. J. Jpn. Soc. Periodontol., 43: 374-387, 2001

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Gingival overgrowth is a frequent side effect of nifedipine therapy in patients suffering from cardiovascular diseases such as hypertension and angina pectoris. Nifedipine is a calcium channel blocker, and other drugs having the similar action, e. g., verapamil and diltiazem, are also reported to induce gingival overgrowth. We report a clinical case of gingival overgrowth in a 69-year-old man receiving manidipine hydrochloride, a calcium channel blocker. The overgrown gingiva was observed in most of the teeth and was marked in the lower anterior and lower right posterior teeth. As chronic periodontitis was complicated by overgrowth, initial therapy was thorough. Medication was changed from manidipine chloride to angiotensin converting enzyme inhibitor. After initial therapy and subsequent periodontal surgery, overgrown gingiva disappeared and the probing depth improved in all teeth (< 3mm). No recurrence was observed in maintenance therapy. From this case, we confirmed the importance of initial therapy and the necessity of periodontal surgery when gingival overgrowth appears in chronic periodontitis. It was also suggested that the number of patient with gingival overgrowth induced by calcium channel blockers other than nifedipine will increase. J. Jpn. Soc. Periodontol., 43: 388-395, 2001.

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The present study was designed to examine the effects of enamel matrix proteins (EMP) on the proliferation of the junctional epithelial cells during wound healing in periodontal tissues. Proliferative cell nuclear antigen (PCNA) was immunohistochemically used to detect proliferative activity of epithelial cells, and immunolocalization of laminin was also demonstrated to evaluate the distribution of basement membrane during periodontal tissue healing. Forty Wistar Rats were used in this study. The palatal bone of the first molar was removed, and the exposed root surface was carefully planed to remove the cementum. The exposed root was conditioned for 15 s by means of cotton pellets soaked in a saturated solution of citric acid (pH 1) and then carefully rinsed with sterile physiologic saline. EMP was applied to the treated root surface and left first molar (experimental group), but no EMP was applied to the right first molar (control group). The flap was repositioned. On 1, 2, 3, 4 and 8 weeks after the treatment, the animals were sacrificed and block sections taken from the jaws. Tissue sections were stained with hematoxylin-eosin (H-E), and immunohistochemical. reactivities for PCNA and laminin were examined. Epithelial downgrowth was decreased in the experimental group, which was statistically significant (p<0.05) from posttreated week 1 to 8. PCNA positive cells in epithelial cells was higher in the control group than those in the experimental group from postoperative week 1 to 4, with a highly significant difference observed in weeks 3 and 4. From week 1 to 4, immuno-reactivity for laminin in the epithelium was not observed in the experimental group, while the activity was obvious in earlier stages in the control group. The results of this study suggest that EMP may act as epithelial cytostatic agent, and inhibit the growth of epithelial cells. J. Jpn. Soc. Periodontol., 43: 396-408, 2001.

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We evaluated the effectiveness of a high-power diode laser in surgical palatal pocket therapy. Subjects were 16 patients (20 sites, 34 teeth) diagnosed with adult periodontitis and deep palatal pockets after initial therapy. Each patient was treated with Osada Light Surge 3000 ® for periodontal pocket reduction. The amount of 2% Xylocaine ® was 0.36±0.19ml/tooth, laser irradiation time was 170.5±90.4sec/tooth, and operation time was 12.3±6.6min/tooth. Sites with no postoperative pain were 13 and 5 sites were slight. One site was severe. Pocket depth, gingival recession and plaque index were examined at 1, 3, 6, and 12 months after therapy. The pocket depth was 4.9±1.6mm before therapy, 1.8±0.9mm after 1 month (minimum), and 2.3±1.2mm after 12 months, maintaining a good level. No relationship was seen betw een pocket depth and plaque index. About the site of pocket depth after therapy, the center of the tooth at the palatal side remained at the same level even after 12 months. There was a tendency that the pocket depth at interproximal area became deeper. It appears that high-power diode laser use in surgical pocket therapy was effective in reducing the palatal pocket. J. Jpn. Soc. Periodontol., 43: 409-415, 2001.

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An improved test paper strip coated with anti-human hemoglobin monoclonal antibodytogether with an oral rinse sample for immunological detection of salivary occult blood (improved immunological method: TIM) was used in a trial screening test for periodontal disease, and clinically evaluated in comparison with a commercially available conventional test paper using the peroxidase method (PM). The subjects were 103 healthy adults (76 men and 27 women ranging in age between 35 and 55 years ; average 43.2 years). Prior to periodontal examination for probing depth (PD) and bleeding on probing (BOP), oral rinse samples (3 ml of water, 10-s rinse) and non-stimulated saliva were collected to detect the presence of blood by the IIM test and the PM test, respectively. According to the IIM test, 47 samples were positive, 9 were weakly positive, and 47 were negative. In the PM test, 57 were positive, 28 were weakly positive, and 18 were negative. Subjects having over 20% BOP and/or having exceeding 6 mm PD at oneor more sites were defined as having periodontal disease. The results of the IIM and PM test findingswere analyzed with clinical parameters using gold standard analysis. In the IIM test, sensitivity was 90.9%, specificity was 87.5%, positive predictive value was 89.3%, and negative predictive value was 89.4%. In the PM test, on the other hand, the corresponding values were 94.5%, 31.3%, 61.2%, and 83.3%, respectively. Therefore, the IIM test was considered to be useful as a novel screening method for periodontal disease. J. Jpn. Soc. Periodontol., 43: 416-423, 2001.

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Enamel matrix derivative (EMD), a tissue-regeneration product, was recently added to regenerative periodontal treatment tools. EMD is used to promote new attachment around treated periodontitis lesions, but, little is known about the regenerative mechanisms in vitro. We studied the effects of EMD on the proliferation of human primary gingival epithelial cell (HGK) and epithelial cell lines human oral squamous cell carcinoma cell line ; HSC-2, human submandibular gland epithelial cell line ; HSG. The expression of cyclin-dependent kinases (Cdks) and cyclin-dependent kinase inhibitors (CKIs), and their mRNA were also studied. We found that EMD inhibited the proliferation of epithelial cells dose-dependently and kinetically. The mechanism of EMD-induced inhibition involved arresting the cell cycle at the G 1 phase. Cell arrest induced by EMD differed for HGK and HSC-2. In HGK, EMD enhanced p 27 expression. In HSC-2, EMD enhanced p 21 expression. These results suggest that EMD inhibits epithelial cell growth at the G 1 phase, but that inhibitory signal entrance differs by epithelial cell type. J. Jpn. Soc. Periodontol., 43: 424-432, 2001.

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My working hypothesis was periodontal disease spread due to a lack of knowledge and technique among dentists treating the disease. A survey was conducted among general dental practitioners to determine the validity of this hypothesis. Questionnaires were distributed at 6 lectures in Shizuoka Prefecture and at training courses in Hamamatsu. Valid reponses were received from 158 dentists whose mean age was 45. 0years. Of these. 51.9% read the guideline for periodontal disease diagnosis and treatment published in 1996 by the Japanese Dental Association. Some. 34.8% measured periodontal pockets by 6-point measurement at exact periodontal examinations, . 24.1% by 4-point measurement, . 17.7% by less than 4-point measurement, and. 21.5% did not answer. Some. 31.. 0% could use Gracy curettes properly based on the number of the curettes.
Five training courses to improve periodontal practice were held to promote periodontal practice in the community, and attended by 39 dentists instructed by a dentist from the Hamamatsu-City Oral Health and Care Center. Bimonthly courses completed in 2 2-hour sessions consisted of lectures and practice about periodontal examination, periodontal disease diagnosis, toothbrushing, and scaling. Periodontal examination, toothbrushing, and scaling improved through this training.
In conclusion, the lack of periodontal disease knowledge and techniques among general dentists was clear, and training to correct this was effective and indispensable. J. Jpn. Soc. Periodontol., 43 : 433-439, 2001.

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