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Standardized intra-oral photographic device is very useful for longitudinally evaluating plaque accumulation or degree of inflammation. Many devices are developed for this purpose, but most of them seem to have some short-comings for simple clinical use. A simple device for taking intra-oral standardized photographs with high reproducibility was developed. The device is composed of a camera (Medical Nikkor, Auto 1: 5.6, f=200mm), a circular attachment to the lens of the camera made of acrylic resin, and a distance-adjustable tripod connected to the attachment. Using this device, intra-oral photographs of labial aspects of upper central incisors were taken. The subjects were ten dental students and two faculties. Two examiners (K. I., M. F.) took photographs once a day for one subject. Reproducibility of this device was studied calculating repeatedly the area of the same tooth surface on slides which were projected on a section paper (5mm square). The distance between two special points on a tooth was also calculated for studying the reproducibilty of the device. The average coefficient of variation for the area of a tooth was 3.2%, and 1.6% in the case of the distance between two special points of a tooth. From these results, this device seemed to be a very simple method for taking standardized intra-oral photographs with high reproducibility.

The double blind test was performed to know the inhibitory effect for dental plaque and the clinical side effects of Plak-Out. Eighteen adults with healthy natural dentition, aged 22 to 27, were served as the subjects of this study.Scoring of plaque was restricted to six teeth (6/41|14/6). On each tooth, dental plaque was stained with 0.5% basic fuchsin and the height of plaque for gingival margin was measured. At the beginning of the study, these teeth were polished, and the use of oral hygiene device was stopped for 3 days. Plak-Out or Placebo was administered once a day for 3 days. Just before the administration, the accmulation of dental plaque was measured, and the clinical condition of whole mouth was observed. After four days, subjects were rediveded into two groups, and same procedures were performed. The subjects were applied Plak-Out or Placebe twice a day after ordinary tooth brushing and then the clinical side effects were observed every for three weeks.The results of this study were as follows:1) Plak-Out-liquid inhibited plaque accumulation than placebo statistically.2) Plak-Out-gel resulted in lower mean plaque scores than did the placebo-gel, but statistical differences (P

Maintenance phase is the most important stage in terms of the patient's continued oral health. Whether periodontal therapy succeeds or not depends on his plaque control.O'Leary et al. (1972) has devised “Plaque Control Record” and noted that goal in teaching oral hygiene procedures was to reduce plaque accumulations until they were found on 10 percent or less of the available tooth surfaces.The purpose of this study was to investigate appropriate level of plaque control in order to maintain periodontal health at the maintenance phase using the plaque control record.36 patients who had been recieved periodontal therapy at our department and visited hospital for periodic recall were investigated. Oral hygiene status and periodontal tissue condition of these patients were evaluated by the plaque control record, oral hygiene index, gingival index and pocket depth. In addition, oral photographs of the patients were taken.The results obtained were as follows:1. It seemed to be very difficult that patients maintained at the level of 10 percent or less of plaque control record at the maintenance phase.2. The patients, who showed the level of teen to twenty percent of plaque control records, exhibited clinically no inflammation at their gingiva and did not recur the deepening of periodontal pockets.3. At the thirty percent of plaque control record, edematous gingiva was observed. When the level of plaque control reached to forty clinically inflammatory change was evident.4. It was found that the plaque was retained more at the mandibule than the maxilla, on the left than the right, at the mesiodistal surfaces than the buccolingual and at the mesial aspects than the distal.

Changes in alveolar bone following various periodontal surgeries were studied. The 55 surgical treatments were performed on 16 patients with periodontal disease. Radiographs were taken at the surgical regions by using the standardized X-ray technique. The interdental bone areas were measured on the X-ray films. The measurements were followed up to a period of three to four years. At the same time, various periodontal indices were also recorded. In addition, when a flap operation was performed, the type of bone defect was evaluated and recorded.The results were as follows:(1) Loss of alveolar bone was observed until 2 months after surgery and then new bone formation was observed, (2) Among various periodontal surgeries, flap procedure demonstrated most bone loss post-operatively, gingivectomy showed moderate bone loss but following gingival curettage, apposition of new bone was observed 1 month after operation.(3) Among various pattern of bone defects, the areas with horizontal bone loss showed an increase in bone apposition after 3 months post-operatively but in contrast the defect with one wall showed resorption of alveolar bone.(4) The changes in alveolar bone were not correlated to the plaque index 10 months after operation, however 3 or 4 years postoperatively, the correlation between these two factors was significant statistically.(5) The changes in the alveolar bone observed at an interval of 6 months and 3-4 years were found to be independent of the changes in the depth of periodontal pockets.(6) The lamina dura re-appeared rapidly between 3-6 months post-operatively and then the rate of appearance levelled off at about 50%.

Prevalence of grinding habit was studied on 539 students of a womens college, aged 18 to 21 years, and 85 dental students, aged 23 to 27 years. On the womens college students, examination of gingiva, eye, ear, nose and throat were also performed to know the relation with grinding habit. The results of this study were as follows: 54 womens college students (9.85%) and 19 dental students (22.35%) had grinding habit, and 71 womens college students (13.20%) and 7 dental students (8.20%) were suspected to have the habit. Any changes of gingiva, eye, ear, nose and throat were not significantly related to the existence of grinding habit.

Free gingival grafts have been used to repair periodontal deformities resulting from gingival recession. The review of the literature has, however, revealed only a few report of successful root coverage by this technique. The cases of successful root coverage by free gingival grafts technique were presented. In this study, 6 areas of localized gingival recession with root exposure were treated. Following surgical treatment (free gingival grafts) the patients mere examined at intervals of 3, 5 and 8 years and creeping attachment was found in all cases. The creeping attachment ranged from 1 to 3.1mm, an average of 2mm. It is concluded that creeping attachment dose occure following free gingival grafts and the root coverage has been observed during 8 years.

This investigation was designed to study whether mutanolysin and chlorhexidine gluconate using a water pressure irrigating device was effective in removing or preventing formation of dental plaque. The nine subjects were devided into three groups of three subjects each according to a Latin Square design. Each subject took part in three cycles of oral prophylaxis, mouthwash assignments and accumulated plaque evaluation for a three week period.The results of an analysis of variance showed statistically significant difference at 1 percent level between the chlorhexidine gluconate group and placebo group and at 5 percent level between the mutanolysin group and placebo group. The difference between chlorhexidine gluconate group and mutanolysin group was also significant (p

This study was carried out to compare the effects in open interproximal areas on the plaque-removing ability of 1) toothbrushing plus the use of the interdental brush (Denticator Co.), and 2) toothbrushing plus the unwaxed dental floss (Gudebrod Bros. Silk Co.). Ten adults, without prosthetic restorations within or adjacent to the test areas and abnormal arrangement of the teeth, were devided into two groups.The participants performed either interdental cleaning procedure alternately at one week interval. The test teeth were consisting of first molars, lateral incisors and were in contact normally with neighbouring teeth and had open interdental spaces. The bucco-menial surfaces of the test teeth were estimated.The toothbrushing alone by modified Stillman's method removed 58% of interproximal plaque deposited at test areas, however notciable reduction of dental plaque were achieved by additional use of interdental cleaning devices (interdental brush 95%, dental floss 86%). There was no statistically significant difference between two.It has been concluded that it is difficult to clean the interproximal areas only using the toothbrush, and that the use of interdental brusn is effective for the interdental cleaning in open interproximal areas.

In spite of the well-known facts that trauma from occlusion is one of the most important factor to destroy periodontal tissue, only a few studies regarding the force itself which was added to the tooth surface of individual tooth have been carried out. It seems very important to know the occlusal tooth contact area and the degree of occlusal force.A new method was designed to measure the occlusal contact area on each tooth and the degree of pressure which was added to each contact area on one tooth. Both occlusal areas and the pressure on any one of occlusal contact areas were measured by using occlusal paper, 200μthickness, called “Prescale” by Fuji Photo Film Corporation.Prescale consists of two paper-seats and numerous microcapsules containing a red dye between the paper-seats. When the teeth are brought into occlusion, these microcapsules rapture and discharge the dye staining one of the papers red. The density of the color is in proportion to the degree of pressure added.Tooth contact areas in occlusion recorded on “Prescale” were enlarged by a projector and measured by dental area analyzer.The density of the color was measured with a densitometer after enlarging the colored area under a microscope. This densitometer was improved to measure the density of color limited to an area of diameter less than 1mm. As a sensor of this densitometer, CdS photo cell was used.To study the reproducibility of this method, a study model which teeth are made of metal was used. This study model was fixed on a articulator. Standarized force was added to the articulator ten times.Both occlusal contact area and the pressure added to the same contact area showed almost the same value. From the results obtained, this method basically seems to be a simple and feasible technique for measuring occlusal contact area and the pressure of small contact areas in occlusal surface. Then clinical appliance using few patients was performed. But the reproducibility could not be obtained. It is thought that this result was caused by the thickness of Prescale and that the paper must be improved.

Our previous report comparing the efficacy of various interdental cleaning means revealed the use of dental floss or Interdental-Brush (Denticator Co.) was more preferable than others such as rubber tip and wooden stimulator.However, the limitation of the use of Interdental-Brush was noticed in cases where the narrow interdental space were present.The present work was perfomed to investigate the inter-cervical distance of approximating tooth. Thirty-five human dry skulls with normal dentition and twenty periodontal patients comprised the material.The mean interdental distance (measured from 666 inter-dental spaces) was found as 1.4mm for human dry skulls and the same value was obtained for the periodontal patients (measured from 243 interdental spaces).The mean intercervical distance which allowed the passage of Interdental-Brush was found as 1.6mm, while the mean intercervical distance which did not allow the passage was found as 1.0mm.

Purpose of this study was to know the effect of natural and synthetic bristle toothbrushes on plaque removal.Two kinds of natural toothbrushes (animal bristle and pig bristle) and two kinds of synthetic toothbrushes (nylon bristle and rubber) were evaluated using Scrub brushing method. Twelve adults, 6 patients and 6 dentists, 6 males and 6 females, aged 19 to 42, volunteered for this study.Plaque score was calculated with the modified Volpe's method which Suzuki et al. reported before. Facial and lingual tooth surfaces of the six representative teeth (6/41|14/6) were scored, after disclosing the plaque with a 0.5% basic fuchsin.The average percentage of plaque removal on facial and lingual tooth surfaces were as follows.(1) 59.6±16.1% (nylon bristle) (2) 42.3±13.2% (pig bristle)(3) 39.8±14.7% (rubber) (4) 39.5±13.3% (animal bristle)There was a statistically significance at the 5 percent level of confidence between nylon bristle brush and the other three brushes.A similar trend was recognized on labial, lingual, medial and papillary tooth surfaces independently.The scores after brushing were evaluated, also.(The materials of animal bristles are of horse and badger hair.)

The purpose of this study was to determine the prevalence of periodontal disease in 690 15-year-old school children, living in Tokyo, Japan. This clinical survey was performed prior to the roentogenografic examination which was intended to study the prevalence of marginal bone loss.Plaque Index (by Silness and Loe) and Gingival Index (by Loe and Silness) were recorded on maxillary right first molar, left incisor, first premolar, mandibular left first molar, right premolar and right incisor. Pocket depth was measured in mm at the six teeth, maxillary and mandibular first molars, and incisors on the mesial sides. Bleeding Index during probing (by Ainamo) was also recorded.The means of the Plaque Index were 1.00 and 1.30 in girl and boy students respectively. The girl students were statistically superior (p

This study was performed to examine the effect of modern dentifrices on the abrasion of acrylic resin and human teeth.Those specimens were brushed with a tooth brushing machine for two hours, corresponding to 3000 back and forth strokes. The surface irregularities of the specimen were analyzed by a surface analyzer, and observed by scanning electron microscopy before and after the brushing procedure. The weight loss of the test specimens of acrylic resin materials was determinded, weighing them before and after brushing by a microbalance.The effect of hardness of toothbrush on the abrasion was tested, using three different toothbrushes.The abrasiveness by the dentifrices showed a wide range.All dentifrices except one dentifrice which did not contained abrasive materials had considerable abrasive effects on both acrylic resin and human teeth. There was a high correlation (r=0.96) between the weight loss and the surface irregularities in the case of acrylic resin.Without using dentifrices, abrasion was not observed on both acrylic resin and human teeth.

Six toothbrushing methods were evaluated using several kinds of toothbrushes. Two kinds of electric toothbrushes were tested also. Forty-two adults who had normal dentition and clinically healthy periodontal tissue, aged 20 to 34, 36 males and 6 females, voluntered for this study. The plaque score was calculated by the modified Volpe s method on which Suzuki et al. reported before. The scoring of the plaque was restricted to the six teeth (6/41|14/6). The average percentage of plaque removal from the total (labial and lingual) tooth surface by different toothbrushing methods was as follows: (1) 75.2± 9.9% by the Fones method with a hard brush, (2) 71.7 ± 11.1% by the Scrub method with a hard brush, (3) 67.4 ±12.5% by the modified Stillman’s method with a hard brush, (4) 64.7 ± 13.7% by the National electric toothbrush with a soft brush, (5) 62.9 ± 13.6% by the Roll method with a hard brush (6) 58.l ± 16.3% by the Charters method with a brush of a medium hardness, (7) 55.2 ± 10.2% by the Bass method with a brush of a medium hardness. A similar tendency was obtained independently on the labial, lingual and papillary tooth surface. The hard brush was the most effective for the plaque removal by all kinds of brushing methods.

The velocity of gas flow in the combustion chambers of two engines was measured, and the turbulence characteristics were investigated. It is shown that the auto-correlation coefficient of the fluctuating component of velocity and the normalized one-dimensional energy spectral density of turbulence are nearly determined by the integral time scale of turbulence and the turbulence Reynolds number, and the approximate expressions for the auto-correlation coefficient and energy spectral density are presented. Moreover, the relationship between the turbulence Reynolds number and the mean flow Reynolds number is examined, and the structure of the turbulent flow in engine combustion chambers is discussed.

1. Proteolytic activity of gingival fluid, dental plaque, saliva and serum was investigated, according to the gelatin-silver film method. The highest activity was found in gingival fluid.2. Proteolytic activity in the periodontal pocket was also investigated by inserting the film into the pocket. At the bottom of the pocket, the highest activity was observed.3. The origin of the proteolytic activity in the periodontal pocket was discussed.

The treatment process of a female periodontal patient, 33 of age, with open bite caused by tongue thrusting habit was reported. By tight cooperation between periodontists and orthodontists and with enough care, the treatment was proceeded for 2 years and 4 months, and completed with success. One year and 4 months follow up showed no clinical sign of relapsing. The significancy of ortho-periodontal relationship were discussed.

On 870 teeth, the width of attached gingiva was measured, Using Bower's method. Average width of each maxillaly tooth in normal gingival group (gingival sulcus was within 1.5mm), was ranging from 0.8 to 4.8mm. Average width of maxillaly both central incisors, premolars, and second molars, was 2.9mm, 2.4mm, and 4.6mm respectively.Average width of mandibular both central incisors, premolars, and second molars was 3.0mm, 1.1mm, and 2.0mm respectively.Average width of each maxillaly tooth with periodontal disease was measured 3.2mm in central incisors, 1.8mm in first premolars and 3.5mm in second molars.Average width of mandibular central both incisors, premolars and second molars, was 2.9mm, 0.7mm, and 0.9mm respectively.

Four cases of Acute Necrotizing Ulcerative Gingivitis (ANUG) were reported in this paper. These cases were diagnosed as ANUG clinically, histopathologically and bacteriologically. The patients with ANUG were treated systemically and locally. Local treatments were very effective. From these findings, it was suggested that the local factors were responsible for ANUG rather than systemic factors, and that the clinical features were modified and accelerated by systemic backgrounds.

When gingival recession has been observed, it is diffecult to clean the approximate surfaces only using toothbrush. The purpose of this study is to observe which interdental cleaner is effective on the approximate surface. Three types of interdental cleaner have been studied. They were “Interdental brush (Denticator co.)”, “Rubber tip (Denticator co.)” and “Wooden stimulator (Navec International pty co.)”. Between the cleaning effect of interdental brush and that of rubber tip, significant difference (p

This study was performed to know the cleaning effect of different types of toothbrushes. The head of toothbrush was designed to have same length of nylon bristles and same tufted space. Nine different types of toothbrushes were prepared as follows:A. Trimmed shape1. Straight trimmed to irregular height.2. Straight trimmed to uniform height.3. Convexly trimmed.B. Diameter of bristles1. 0.23 mm.2. 0.33 mm.3. 0.40 mm.Eighteen patients who had no denture and were normal dentition were instructed to clean with modified Stillman's method for 5 minutes. Quantity of eliminated debris was calculated by specially prepared measure.From the observation, the toothbrush that was tufted the widest bristles showed high effectiveness and it was significant at the 5% level by wholly-significant-difference method. Concerning the shape, the shape with straight trimmed to unifrom height showed high effectiveness, but it was statistically insignificant. During observation period, injuried gingiva by toothbrush was not observed.