The purpose of this study was to investigate oxytalan fiber changes in experimental periodontitis. Eleven adult pomeranian dogs were divided into 1 control and 2 experimental groups. One experimental group was produced by placing silk ligature below the gingival margin for 1, 3 or 6 months (the ligatured group). The other experimental group was fed for 1, 3 or 6 months after removing the silk ligature after 6 months (the removed group).
Periodontal tissues were examined by histopathological observation and morphological analysis. The results were as follows. 1. Histopathologically, experimental groups showed the progressive and regressive patterns of chronic periodontitis. Morphological analysis showed that, 1) in the cervical region, epithelium and connective tissue areas increased in the ligatured group and decreased in the removed group; 2) in the bottom region of pocket, the number and total area of vessels increased in the ligatured group and decreased in the removed group; and 3) in the cervical region, the bone area decreased in the experimental group. 2. Histopathologically, oxytalan fiber distribution showed a distinct regional pattern in the gingiva and periodontium. In the ligatured group, oxytalan fibers were larger and more numerous than in the control group. In the removed group, oxytalan fibers were shorter and less numerous than in the ligatured group. Morphological analysis showed the mean and total length of oxytalan fibers increased in the ligatured group and decreased in the removed group.

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Lymphocyte subsets of gingival crevicular fluid (GCF), inflamed gingival tissue (GT) and peripheral blood (PB) sampled from 42 patients with periodontitis were examined by two-color flow cytometric analysis. GCF was sampled by the crevicular washing method. GT samples were digested with collagenase. PB was used as a control. The T cell/B cell ratio (T/B) was determined by FITC conjugated Leu 4 and PE conjugated Leu 12 monoclonal antibodies (mAbs). The helper. Einducer T cell/suppressor. Ecytotoxic T cell ratio (Th/Ts) was determined by FITC conjugated Leu 3 a and PE conjugated Leu 2 a mAbs. Significant differences were found among these three samples in T/B (PB 4.61± 1.13, GT 3.45± 2.03, GCF 2.39± 1.56). GCF (1.38± 0.76) and GT (1.26± 0.44) in Th/Ts were significantly lower than PB (1.93± 0.67), but not in GCF and GT. The lymphocyte subset ratio of GCF is similar to that of GT with some differences, so GCF lymphocyte subsets may reflect the inflammatory condition in the periodontal pocket.

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The purpose of this study was to examine the change of microbial flora under periodontal dressings, between prior and after periodontal surgery, by darkfield microscopy, culture technique and scanning electron microscopy. Bacterial samples were preoperatively taken from gingival surfaces and periodontal pockets of 33 patients who had completed the initial preparation. At 3, 7 days and 1 month after periodontal surgical procedures, samples were taken from the wound surfaces and gingival crevices. The relative proportion of bacterial forms were classified into seven groups: spirochetes, motile rods, curved rods, coccoid cells, fusiforms, filaments and straight rods. Mean value of pocket depth of prior and after surgery was 5.8mm and 2.8mm, respectively. The microscopic results indicated a significant increase in the mean percentage of straight rods, motile rods, curved rods, fusiforms and filaments and a significant decrease in the proportion of coccoid cells from baseline to postsurgery on wound surfaces under periodontal dressings. In contrast to this, a significant increase in the proportion of coccoid cells and a significant decrease in the proportion of spirochetes, motile rods, curved rods and fusiforms were observed in gingival crevices. Culture technique revealed the mean percentage of Bacteroides intermedius was increased significantly from baseline (0. 7%) to postsurgery (3.8%) on wound surfaces, and the proportion of Streptococcus sanguis I was decreased significantly. In gingival crevices, the proportions of Capnocytophaga sp., Fusobacterium sp. and Peptostreptococcus sp. were decreased significantly and those genera were maintained low levels 1 month after periodontal surgery. On wound surfaces under dressings of poorly responsive patients to periodontal surgery, whose probing pocket depth were over 3 mm at 1 month after surgery, the proportion of B. intermedius was increased significantly and the proportion of S. sanguis I was decreased significantly. While no significant changes were observed in other patients, the changes of the proportion of those species might be the indicator of the response to periodontal surgery. It was concluded that significant change in the microbial flora under periodontal dressings from baseline levels were cornfirmed, but the dressing did not produce any delay in healing process after periodontal surgery.

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The object of this study was to assess how new attachment may form by guided tissue regeneration (GTR) when a membrane is placed over the denuded root surface.
Mucoperiosteal flaps were reflected around the three premolar regions in 3 mongrel dogs. The buccal bone was reduced to approximately 5 mm from its original level. The root was thoroughly planed, and grooves were marked at the level of the crest of the remaining alveolar bone. Gore-Tex filters were adapted circumferentially to the roots and sealed to the teeth before suturing the flaps. No membranes were placed over the root surface, which served as the control. Histological examination of the experimental and control teeth was done at 5, 6, and 7 weeks after surgery. Histological findings showed extensive amounts of root resorption in the initial phase of healing in experimental teeth. New cementum with inserting fibers had formed on the previous root surface. No new connective tissue attachment could be seen in control teeth. These findings suggest that placement of the membrane was important in repopulation of the wound areaadjacent to the root by cells originating from the periodontal ligament.

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We devised a new semiconductor laser (maximum power 4 W) and studied its functions and applicability to the oral region, especially to periodontal treatment, using the following criteria : (1) color selection, reflection, absorption, and transmission; (2) transmission against water and blood; (3) blood coagulation; (4) protein coagulation; (5) correlation between power and coagulation/incision abilities; (6) correlation between color and coagulation/incision abilities.
The luser provided increased absorption, reflection, and transmission against black, white, and red sheets, respectively.
Regarding the relationship between water and blood, the laser showed transmittance against water, and absorption and coagulation/carbonization against blood.
In an experiment using egg whites and a piece of meat, we found that non-contact equipment was influenced by colors, whereas contact equipment with non-coating chips did not bring about protein coagulation. Contact equipment with ceramic coation chips gave good results for coagulation and surgical incision without any change in color.
The above suggests that this semiconductor laser may be applicable for periodontal treatment, aiming at hyperthermia, styptic effect, and coagulation/incision.

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Previous works in our laboratory have shown that morphological change hardly occurs in cementum corresponding to the periodontal pocket. The present study was carried out to statistically analyze the morphological changes in diseased cementum.
Fifty human periodontally involved teeth were used. Following the longitudinal splitting of extracted teeth, root fragments were processed for examination by SEM. Subsequently, all the specimens were divided into three groups according to the following criteria: Group A, attachment loss of less than 4mm; Group B, attchment loss of 4.7mm; and Group C, attachment loss of more than 8mm. A total of 50 fractured surfaces were evaluated for statistical analysis of morphological changes. The results showed that no morphological changes were detected at any site on the diseased cementum in Group A. Furthermore, there were no significant differences (P<0.05) between diseased and healthy cementum in terms of the structure of the inner layer, while superficial cementum showed some changes in Groups B and C. This statistical study demonstrated that the inner layer in periodontally diseased cementum was healthy.

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The purpose of this study (Report 6) was to investigate the effects of nylon bristle toothbrushes differing in hardness and the number of bristles on toothbrushing pressure and plaque removal in the scrubbing method.
Nine toothbrushes which differed in the hardness of total bristles (7kg, 10kg, 12kg) and the number of bristles were used in this study.
The toothbrushes were designed as follows: nylon bristles (0.20mm, 0.25mm, 0.30mm in diameter), rounded ends, 10mm in length, 3 rows, 26 tufts, straight handle, brushing surface 25mm long. Nine subjects participated in this experiment. Plaque scores were measured before and after toothbrushing, and the plaque removal rates were calculated. The toothbrushing pressures were determined by Watanabe's method.
The results were as follows:
There was a tendency for toothbrushes with harder bristles to show higher toothbrushing pressure. Statistically significant differences were found among the three different hardnesses (P<0.01).
Statistically significant differences in toothbrushing pressure were not found among the three different numbers of bristles or in plaque removal among the three different hardnesses and numbers of bristles. But toothbrushes with harder bristles and with bristles of larger diameter tended to show higher plaque removal.

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The effects of ultrasonic scaling in combination with povidone-iodine solution two times at one-week intervals were examined bacteriologically.
The results obtained were as follows:
1. In phase contrast microscopy, both total bacterial count and spirochetal and motile rod incidence decreased rapidly one week after instrumentation, thereafter remaining at about the same level in each group. At all observation periods, both total bacterial count and spirochetal and motile rod incidence decreased after ultrasonic scaling in combination with povidone-iodine solution (Group A) in com parison with ultrasonic scaling alone (Group B) and root planing (Group C).
2. Total bacterial count and proportional distribution of black-pigmented Bacteroides in periodontal pockets decreased weekly after instrumentation in Group A. But in Groups B and C, total bacterial count and proportional distribution of black-pigmented Bacteroides in periodontal pockets were unchanged after instrumentation.

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Periodontal status of young female students were examined using CPITN proposed by WHO for 6 years. Index teeth were the first upper right and left molars, the right first incisor, the lower first right and left molars and the first left incisor. Frequecy of detecting healthy periodontal condition was limited to approximately 10% of the first grade students of junior high school. Total CPITN value increased with year during the 6 years. Prevalence rates of periodontal disease did not show any significant difference between right and left sides. Prevalence rates of periodontal disease of the mandibule were larger than that of maxilla. Frequency of the healthy state of upper molar was smaller and frequency of the calculus state was larger than anterior molars. Mandibular molar sites had more pockets than mandibular anterior sites. The number of individuals recieving a series of examinations for 6 years were 95. They were divided into 3 groups by the chronological pattern of the total CPITN value, i. e., “increasing ” (66.3%), “constant ” (10.5 %) and “decreasing ” (23.2%) groups. Although the CPITN value of “ increasing ”group was small at the first examination, they grew into 3 types of degree, i. e., “slight ” (26.3%), “ moderate” (34.7 %) and “severe ” (5.3%) groups at the last examination. Some of the “ severe and increasig ” group may be classified as juvenile periodontitis.

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Clinical examination of phenytoin-induced gingival hyperplasia in hospitalized severely handicapped patients (19 individuals) was carried out to investigate the relationship between severity of hyperplasia and duration of phenytoin therapy, cumulative dose, daily dose, concentration of phenytoin in plasma. Special care was taken in examing severity of hyperplasia. Furthermore, the effects of oral hygiene procedures on gingival hyperplasia was evaluated for five months. Oral hygiene procedures was performed using the electric toothbrush for cleaning the teeth and using the hand toothbrush for gingival massage. Ten patients were divided into two groups. One group consisted of 7 individuals receiving phenytoin (phenytoin group), and another group consisted of 3 individuals not receiving phenytoin (non-phenytoin group).
There was no correlation between severity of hyperplasia and duration of phenytoin therapy, cumulative dose, daily dose, concentration of phenytoin in plasma. Gingival hyperplasia was clinically more marked in the posterior regions than in the anteriors of the jaws. And the hyperplasia on the labial (buccal) aspect was less marked than on the lingual (palatal). These results were not in agreement with those of predecessors.
After carefully performed oral hygiene procesures for 5 months, GI (LÖe & Silness) decreased from 1.4 to 0.3 in the phenytoin group (p<0.01), but probing depth did not significantly decrease.
Although gingival inflammation was suppressed by oral hygiene procedures applied for 5 months, the clinical condition of fibrous gingival hyperplasia was not improved.

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This paper reports oral manifestations including periodontal status and craniofacial morphology, which have not been satisfactorily investigated in past cases, in a case of primary immunodeficiency syndrome. A 17-year-old man, who was diagnosed with unclassified common variable immunodeficiency at Toranomon Hospital, was referred to the Department of Internal Medicine, Ohu University Hospital, for maintenance therapy, and to the Department of Clinical Periodontology, Ohu University Hospital, for periodontal consultation. The patient, who had typical hypogammaglobulinemia, was given γ-globulin intravenously and antibiotics orally, which resulted in good control of infection.
Positive oral findings included gingivitis with supragingival calculus deposits, aphta on oral mucous membrane and erosion on tongue. Periodontitis with severe bone loss was not observed. Bacteriological examination showed a number of black-pigmented Bacteroides and Fusobacterium from gingival sulcus and saliva.
As a result of periodontal procedures such as tooth brushing, scaling and rinsing with Risterine®, the gingivitis disappeared, but erosion of the tongue was persistent. Cephalometry showed no particular abnormalities in physiological growth or craniofacial morphology.

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