Nihon Shishubyo Gakkai kaishi最新文献

Bruxism has been considered to be one of the most important factors in accelerating the progression of established periodontal lesions. However the objective diagnostic method has not yet been established. At present, diagnosing bruxism might mainly be dependent on interview. The purpose of this study was to compare and analyze the differences in frequency and duration of bruxism between a group of patients conscious of the problem and a group not conscious of bruxism. After interviewing, the subjects were divided into two groups; 1) group A consisted of 8 subjects who were conscious of bruxism and 2) group B of 8 subjects who were not conscious of bruxism. The frequencies and durations of muscle activity during sleep at night were compared between groups A and B using EMG with a telemetric method. In the one-night observation, muscle activity supposed to be bruxism was observed in both groups. Significant differences in frequencies of muscle activity were not found between the two groups. A similar result was obtained in the durations of muscle activity. In a seven-day observation, muscle activity was seen in all three volunteers, although marked differences were not found among them. A long duration of muscle activity was found under conditions of physical or mental stress. The results of this study showed the difficulty of diagnosing bruxism by interview and the necessity of an objective method.

The purpose of this study was to determine the prevalence of periodontal disease and the relationship between the results of questionnaire concerning periodontal disease and the actual periodontal condition in youth. The examination was carried out in three parts. In the first part, a questionnaire was conducted on 3,886 junior and senior high school students (12 to 18 years of age) living in Kawagoe, Japan. The questionnaire was composed by of items concerning habits of oral hygiene, periodontal symptoms, understanding of periodontal disease and history of diagnosis by dentist of periodontal disease. Secondary, mass intraoral examination was carried out on all objects. The examination covered gingival inflammation, periodontal probing depth, calculus, dental plaque, dental caries and malalignment. Lastly, we examined the relationship between the results of periodontal examination and questionnaire with the original periodontal classification. The following results were obtained: 1. As an example of items in questionnaire, 83.1% brushed their teeth more than two times daily. The understanding of oral hygiene concerning dental caries was improved, but concerning periodontal disease was still poor. 2. The symptom most frequently reported was gingival bleeding during tooth brushing (18.4%). 3. The percentage of persons with periodontal disease (moderate gingival inflammation and periodontal pocket 4 mm or deeper) was of the highest frequency at 13 years old. The proportion of males increased with the advanced state of periodontal disease. 4. A significant correlation was found (chi 2-test: alpha less than 0.001) between advanced state of periodontal disease and a decrease in tooth brushing time per day. 5. A significant correlation was found between the advance of periodontal disease and gingival bleeding on tooth brushing (chi 2-test: alpha less than 0.001). Similarly, a correlation was found between the advance of periodontal disease and gingival swelling (chi 2-test: alpha less than 0.001). 6. A significant correlation was found (chi 2-test: alpha less than 0.001) between the advance of periodontal disease and aggravation of condition of dental plaque, calculus, dental caries and malalignment.

A case of periodic neutropenia with specific symptoms of gingiva and alveolar bone loss in primary dentition is reported. The patient was a boy, and it was followed between the ages of 3- and 9 years-old. At the period of neutropenia he was suffered from recurrent redness, swelling and bleeding of the gingiva, and also with cold-like symptoms with fever. Although the cause of these symptoms was not definite at first, even in medical exploration, we could diagnose this disease as periodic neutropenia by the process of dental therapy. By alveolar bone resorption, pocket formation and severe tooth mobility, the patient had lost more than half of his primary teeth at the end of 2 years after the initial examination. However throughout this period we motivated and instructed the patient and his mother how to brush his teeth. His oral hygiene was improved in the mixed and permanent dentition stages. Then there was no evidence of bone resorption around the teeth of the permanent dentition stage, but recurrent gingival symptoms are continuing now. The specific feature of this case is found in the gingival findings. There was no ulceration of the oral mucosa, but a bright red jelly-like appearance was found periodically in the area of the marginal and attached gingiva. The junction between the reddened attached gingiva and the alveolar mucosa was well-defined. The serial examination of peripheral blood in this case revealed the cycle of neutropenia as 16 to 21 days. During this examination, and at the almost time of neutropenia of this patient, hyperplasia of monocytes and lymphocytes occurred. In this situation there was no clinical signs except for gingival redness. However at other times, generally marked signs were recurrent. This may have occurred due to the lack of both neutrophils and monocytes. From the above results we think that periodic neutropenia may be diagnosed first in the dental clinic by the distinctive redness in the gingival area as one specific sign of this disease. We also think that plaque control procedures may retain the teeth.

In order to investigate biocompatibility of pure metals, which are widely used, the gingival tissues were brought into contact with pure metals. Nine kinds of pure metals, such as gold, platinum, silver, palladium, copper, nickel, zinc, indium and tin were used in the analysis of biocompatibility. With a No. 1/2 round bar, a standardized small cavity was prepared in the mesiolingual cervical portion of the upper first molar. Nine kinds of pure metals powder were inserted into the small cavity of the maxillary root surface in rats. Post operative changes of the gingival tissue were studied histopathologically. The results were as follows: 1. Gold, palladium and indium powder were observed in the lamina propria of the gingiva. Infiltration of cells was not observed around these pure metal powders. Gold, palladium and indium powders showed little cytotoxicity. 2. Zinc powders were not associated with chronic inflammatory charges. Zinc powders were surrounded by an abundance of connective tissue substances. The fragments were surrounded by collagen fibers, but no inflammatory cells were present. Zinc powders showed little cytotoxicity. 3. Platinum and tin powders were not associated with chronic inflammatory changes. These pure metal powders were surrounded by macrophages, but no other mononuclear inflammatory cells were present. 4. Clumps and granules of silver powder were not associated with chronic inflammatory changes. Multinucleate giant cells were shown surrounding silver powders. Silver powders were observed to have been taken into the multinucleate giant cells. Many of these cells also contained fine dark granules in their cytoplasm, and a few contained small pieces of silver. The tissue reaction to silver showed little cytotoxicity. 5. Copper and nickel powders were associated with chronic inflammatory cells. Moderate chronic inflammation and occasional neutrophils leucocytes and lymphocytes were shown to be associated with these pure metal powders. Copper and nickel caused extensive damage to the gingival tissues.

The purpose of this study was to evaluate histological regeneration of epithelial and connective tissue attachment to the denuded dentin surface after hydroxyapatite ceramic granule (HAP) implantation. HAP (particle size 100-300 microns, burn temperature 900 degrees C) were implanted into dehiscent defects of alveolar bone which eliminated about a 1 x 1 mm area at mesial and palatal sites of the upper 1st molar in 20 male Wistar rats. Subsequently the root cementum was removed totally and dentin was denuded. Same osseous defects were formed but HAP was not implanted at any contralateral site for the purpose of control. Results of 8-week examination using light and electron microscopy were as follows: 1. In the HAP group junctional epithelium was regenerated on the denuded dentin surface 2 weeks after implantation and epithelial down growth was less than at the control site. 2. In the HAP group connective tissue reattachment with new cementum formation was observed at 2 to 4 weeks after implantation, the healing period tended to be shorter than at the control site and the connective tissue reattachment level was located more coronally. 3. In ultrastructural findings collagen fiber bundles attached to the denuded dentin surface had fibers continuing around HAP granules.

The purpose of this study was to examine the relationship between clinical findings and subgingival relationship between clinical findings and subgingival microbial flora in periodontitis at the first medical examination and after initial preparation. The results obtained were as follows: 1. Clinical findings with the exception of plaque index showed improvement after initial preparation in comparison with the first medical examination. 2. In phase contrast microscopy, both total bacteria and incidence of spirochetes and motile rods decreased after initial preparation in comparison with the first medical examination. 3. Clinical findings with the exception of plaque index were related to the total bacteria and proportional distribution of spirochetes and motile rods in periodontal pockets, observed in phase contrast microscopy. 4. Total bacteria and proportional distribution of black-pigmented Bacteroides in periodontal pockets decreased after initial preparation in comparison with the first medical examination.

The purpose of this study was to evaluate the clinical application of strips containing 10% Tetracycline (TC) in periodontal disease. In this double blind study, placebo strips, which did not contain TC, were also prepared. Ninety-two sites in 46 cases with greater than a 4 mm periodontal pocket were randomly assigned to experimental and control study groups. The following clinical parameters at each site were recorded at Weeks 0, 1, 2 and 3 after insertion of the LSD or placebo strip: plaque and calculus score, probing depth, gingival inflammation (redness, swelling, bleeding on probing, pus discharge), mobility of the tooth, pain on insertion of strip and pain after the procedure. The residual quantity of TC in the periodontal pocket was also determined at 1, 2 and 7 days after inserting the LSD. All clinical data was evaluated using 3 types of statistical test (X2 test, Mann-Whitney's U test and Wilcoxon's test). Thus, the following results were obtained: 1. The LSD group showed much improvement in clinical condition compared with the placebo group. 2. The conditions of bleeding, redness or swelling of gingival tissue were much improved in the LSD group, even after data evaluation with all 3 types of statistical test. 3. The residual quantity of TC was decreased day by day until finally it was not recognized in the 7 day samples. 4. This study suggested that the application of LSD in the periodontal pocket could be effective in periodontal treatment.

The purpose of this study (Report 5) was to investigate the effect of difference in the length of toothbrush shank and type of tip of toothbrush bristle on toothbrushing pressure and plaque removal in the scrubbing method. Four kinds of toothbrushes which were different in length of shank (30 mm, 40 mm) and type of bristle tip (round type, tapered type respectively) were used in this study. Referring to the results of our previous reports (1-4), the dimension of new toothbrushes were determined as follows, nylon bristles: 40 mm long and 0.20 mm in diameter, brushing surface: 30 mm long, bristles: 3 rows with 26 tufts, and a straight handle. Twelve subjects participated in this experiment. Plaque scores were measured before and after toothbrushing. Then plaque removal rates were calculated. Toothbrushing pressure was determined using Watanabe's method. The average toothbrushing pressure of the toothbrush with a 40 mm long shank (301.6 +/- 84.1 g/cm2) was higher than that with a 30 mm long shank (294.7 +/- 74.8 g/cm2), and that with a tapered bristle type (316.7 +/- 90.4 g/cm2) was higher than that with a round type bristle (279.6 +/- 61.7 g/cm2). However statistically significant differences were not found among the four toothbrushes in brushing pressure and in plaque removal on total teeth surfaces and on distal surfaces of the most posterior teeth (P less than 0.05; two-way ANOVA).

The purpose of this study was to make an objective diagnosis of bruxism using a new recording system by observation during sleeping at home. The system was composed of a portable recorder for monitoring bruxism at home and an analyzing device for recalling the data later in laboratory. Muscle activity as recorded by EMG, occlusal tooth contacts were monitored by microvibration pick-up, and grinding sounds were recorded by a small microphone, simultaneously. These were printed on the one recording paper by playing back the tape. Six subjects were selected and were monitored individually for five nights with this new system at home. Records were transcribed and analyzed in the laboratory. As a result, nocturnal muscle activity, occlusal tooth contacts, and grinding sounds were recorded and analyzed efficiently with system. This new system is considered in useful for the investigation and diagnosis of bruxism in periodontal disease.

The present study involved cultural and microscopic characterization of the subgingival microorganisms of pubertal children with gingivitis. Samples were obtained from eight children 12-14 years of age. Gram-positive organisms made up 56% of the isolates and included mainly Actinomyces israelii, Actinomyces naeslundii. Gram-negative anaerobic rods constituted 25% of the isolates and Bacteroides intermedius (9.7%) was most predominant species. The selective media permitted significantly lower recovery of Actinomyces spp. and Capnocytophaga spp. than nonselective blood agar medium. However, sixty-nine percents of isolates were cultured on the selective media employed in the present study. These results suggest that the subgingival microflora of gingivitis in pubertal children may be similar to those of adult gingivitis and that the use of these six selective media makes it possible to enumerate predominant cultivable microorganisms in subgingival area of pubertal children with gingivitis.