A total of 50 blood samples from the patients of both sexes with their milk teeth suffering from dental caries were investigated for RBC count, WBC count, 100 cell differential, Hb levels, and NLD. SRT diagram. Comparison was made of the types of pulpitis with analvses of variances and coefficients of variation from AAI values obtained with blood smears stained with Giemsa.
1) It was found the methods utilizing rapid analyses of blood to classify five types of pulpitis of deciduous teeth, were useful in cases of mild to severe physiologic activities.
2) A significant improvement in precision and accuracy in determining the types of pulpitis and its index (AAI), chosen for this study, was thereby obtained.
3) We have observed a significant sex difference in the physiological resistance power of leukocytes in the blood of each type of pulpitis.
4) When teeth are found to have suppurative pulpitis (P2) using analyses of blood samples from such patients, careful treatment becomes necessary.
5) Prophylactic filling after checking the pits and fissures of milk teeth for dental caries should therefore be of considerable value.
6) We have thus demonstrated the value of diagnostic hematology in dyscovering and treating pulpitis of deciduous teeth.

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This study was undertaken to estimate the effect of a dental health program for schoolchildren in a rural village where there was no dentist.
The dental health program consisted of annual dental inspections followed by the extractions of advanced carious teeth and the fillings of early carious lesions of permanent teeth for 5 years from 1972 to 1976. The subjects of this program were primary schoolchildren of 6 to 11 years of age in Koromogawa village, and the findings were compared with the children of a primary school in Sendai where dental care was readily available.
When base-line data between the two groups of children was compared, no marked difference was found in the prevalence of DMF but the restoration rate was significantly lower and the tooth fatality rate due to dental caries was significantly higher in the children of Koromogawa than in those of Sendai. After the 5-year program, while the restoration rate of the Koromogawa children increased markedly and became statistically higher than that of the Sendai children, the tooth fatality rate of the Koromogawa children decreased considerably and reached the same level as that of the Sendai children.
At the same time, the experience of dental pain in the subjects was surveyed 3 times be fore, during, and after the program using a questionnaire form. The prevalence rate of dental pain for Koromogawa children before the program was aparently higher than for Sendai children, but after the program the rate for Koromogawa children decreased markedly and became lower than for Sendai children.
We concluded that annual dental inspections followed by the extractions of advanced carious teeth and the fillings of early carious lesions was effective in obtaining good dental health for schoolchildren in a remote area.

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This report describes the fluctuations in the fluoride concentration of water supplies obtained from deep wells (about 200-300 meters in depth) in Kitatsugaru area, where dental fluorosis is endemic. The fluoride contents of 11 water samples obtained monthly from each source were analyzed with a fluoride ion electrode. Of 23 deep wells, great variations were found at four sources (coefficient of variation: 22-37 percent). When the fluoride concentrations of 28 water samples, obtained daily from one of these four sources, were determined to check the effect of each sampling day, it was found that the variation of the fluoride concentration was daily and irregular. When analyzing the relationship between special tissues of a body and the fluoride content of drinking water, it is necessary to determine fluoride content at regular intervals, e. g. during a month or a year, in order to estimate adequately the mean value of fluoride content as well as to prevent errors resulting from a single fluoride determination.

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The lower level of effective dextranase units in clinical tests was determined and its effect on the reduction of dental plaque was confirmed using the dentifrice containing 2000 units/g of Chaetomium gracile dextranase.
In vitro, reducing sugar was released from dental plaque by 500 units dextranse and its release incresed linearly to about 2000 units. Clinically, by rinsing for 1 min. with mouthwash containing 2000 units of dextranase, a statistically significant amount of reducing sugar was released in the mouth. However, 500 units of dextranase had no effect. These results suggest that the lower level of effective dextranase units is between 500 and 2000 units.
Moreover, 2 groups of 15 subjects each aged 20 and 50 used dextranase (2000 units/g) and placebo dentifrices for 2 weeks. The plaque index of dextranase dentifrice group was reduced 61.6 and 74.7 per cent after 1 and 2 weeks, respectively. But in the placebo dentifrice group reduction rates were less, being 38.5 and 41.5 per cent, respectively. Between 2 groups, there was a statistically significant difference (p<0.01), and the effect of dextranase (2000 units/g) dentifrice on the reduction of dental plaque was confirmed.
However, the effect of dextranase on the gingival index was slight and not statistically significant.

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It was undertaken to develop a simple but reliable diagnostic method of identifying and grouping Streptococcus mutans in many samples examined, and to determine their prevalence in Japanese people and some animals. 48 strains of Str. mutans, 1 strain of Str. salivarius and 1 strain of Str. sanguis were used, and three specific antisera against Str. mutans strains were obtained, after cell agglutination tests and absorption tests were performed on them. It was demonstrated that there were three specific antigens of Str. mutans. Two of them were designated H1 and H2, and were specific for strains isolated from humans. The other one was specific for rat strains and was designated R. These groupings were compared with seven serologic typing, using modified Ouchterlony method and immunoelectrophoresis. It could be shown that goup H1 strains include serotypes c, e and f, group H2 serotypes d and g, and goup R serotypes a and b. But the significance of dividing group H1 H2 and R into more additional types was not recognized. Slide agglutination tests were perfomed to identify and differentiate Str. mutans strains using three specific antisera. In humans, group H1 was the prevalent group (93.9% of all isolates). Rats were carriers of only group R. Only group H1 strains were observed in monkeys and hamsters, but Str. mutans could not be detected from mice and guinea pigs. Spontaneous agglutinations occurred in only 3.1% of all strains examind. Slide agglutination tests using three specific antisera seem to be valuable for identification and defferentiation of Str. mutans.

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The most fundamental and simple pattern of dental caries incidence is shown by using the cohort survey of one kind of teeth by post-eruptive tooth age under constant environmental conditions.
Takeuchi and his group have analysed various kinds of caries data from this point of view since 1960, but changing environmental factors, especially sugar consumption after eruption, (p), masked the fundamental pattern of caries incidence. Efforts were made by them to resolve the Cx pattern with aid of the probability of normal and exponential compound function suggested by Kawakami (1958), supposing that sugar consumption would not change.
Material used in this paper is the data from oral examination of school children, living in Shizuoka City, a typical urban area in Japan, with a fluoride content of 0.06ppm in the drinking water. Oral examination was done by the author himself and used the criteria of the WHO Oral Health Surveys (1971) for caries detection.
The number of teeth used for analysis is given in Table 3. All teeth investigated here were presumed to be exposed to constant annual sugar consumption after their eruption (p=about 27kg per head per year). In Fig. 2, the method of counting ΣCx (cumulative number of carious teeth up to the post-eruptive tooth age x-year per initial 100 teeth) and Cx (number of teeth newly attacked by caries during the post-eruptive tooth age x-year per initial 100 teeth) from the observed figures is illustrated. Both Cx and Mx are induced from ΣCx, applying the following fomula:
Cx=ΣCx-ΣCx_-1: Mx=Cx/ (100-C_x-1) ×100
In Table 4, the analysed indices of caries incidence are shown. In Fig. 3, the method of drawing abridged e^-kx line based on ΣCx and Cx is illustrated.
ΣCx and Cx given in Table 4 were drawn in Fig. 5 with the computed abridged e^-kx line. A fairly good fit of observed polygons and theoretical e^-kx lines of each tooth or tooth surface proves that the Cx curve is composed theoretically of two parts with both normal distribution and an exponential function of probability. Shimamura (1973) also reached the same conclusion from the data of deciduous teeth.
Caries attack has, therefore, a compound mechanism: the first mechanism consists of the distribution of susceptibility for caries per se of the individual tooth or tooth surface, and second mechanism is the probability of being newly attacked by caries, the chance to become carious, according to the level of an environmental factor, sugar consumption (p). This compound mechanism is shown as a model in Fig. 6.

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In order to control permanent tooth caries among school children in a nonfluoridated community, a dental health administration was conducted in Saku City, Nagano Prefecture, for six years, from April 1971. This health administration consisted of two parts: (1) daily mouth rinsing for one minute with 0.05% sodium fluoride solution and (2) detection and immediate filling of initial caries, extending the treatment from the children in lower grades to those in higher grades. At the beginning of the study, the subjects numbered 872 in the administration group (two primary schools and one middle school) and 1, 047 in the control group (also two and one). The latter group, however, was disqualified for the control group after 1976, because children in those schools have been administered the fluoride mouth rinsing from April 1975.
After the start of the administration, the percentage of children with DMF teeth in the administration group reduced gradually from 72.8% in 1971 to 56.2% in 1975 and 52.2% in 1977, while those in the control group were 79.1% in 1971 and 73.5% in 1975. In comparison between mean DMF teeth per child of both groups in 1975, a mean caries reduction by the dental health administration for four years was 63.4%, and it was greatly significant statistically. As a peculiarity of caries preventive effects in this work, it was observed that the lower the grade of the children was in initiating the treatment, and the longer the administration term, the greater were the effects derived from it. As to the preventive effects to the tooth surface type after four years, the effects on the smooth surface (69.8%) were a little greater than those on pits and fissures (64.1%). Among the children in the administration group, smooth surface caries were observed in one tenth of those among in the control group; especially, the effects seemed to be remarkable in the case of the children who were respectively in the 1st or 2nd grade when they got the initial administration and received the administration for more than four years. As a result of using the primary and secondary caries preventive methods over a six-year period, no subject with advanced dental caries (C₃and C₄) was observed in the administration group.
The chair time required for the treatment was about 15 minutes per tooth in initial caries, while about 1 hour in advanced caries. Assuming that a dental team consisting of one dentist and one dental hygienist spends one day a week for caries treatment to the school children from May to December after the annual dental examination in April, it is estimated that 800 carious teeth can be treated during the period. Therefore, even if we underestimate the caries preventive effects of the fluoride mouth rinsing at 50%, it is estimated that one dental team is able to control about 2, 000 school children.

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