It is already known that in the case of dental caries or periodontal diseases (alveolar pyorrhea, in particular), the two most popular dental diseases, a change is brought about in the environmental factors in the oral cavity, or reversely, in case of a change taking place in the environmental factors in the oral cavity, these diseases are very apt to be contracted.
Many studies are now being conducted concerning the acti vity of these diseases. Several methods of testing the activity of dental caries have been devised and they are now being widely employed clinically. However, no similar progress has so far been witnessed in the field of alveolar pyorrhea.
Thus, for the purpose of investigating clinically the difference in the immunochemical factors in the whole saliva (hereinafter referred to merely as the saliva), in connection with the above-mentioned dental diseases, the present writer has undertaken an investigative experiment by means of the method of plate agar diffusion.
Namely, the supernatants and deposits of the centrifuged salivas from pyorrhea, caries-free (DMF above 5) and normal subjects, respectively, were injected into rabbits as antigen to immunise the animals, and their serum and their reaction to each collected saliva were examined by the method of plate agar diffusion.
The conclusions obtained were as follows:
1. The serum vaccinated with each supernatant of saliva as antigen collected from subjects reacted against each saliva. The reaction indicated a precipitated zone and was positive. In no case, the supernatant or the deposit alone was seen to be positive.
2. The behaviors of the saliva from subjects in case of a positive precipitation and the serum obtained from the deposits as antigen were as shown in the table below.
As indicated by the table, the rate of positive precipitation with the saliva of the same kind with the antigen from which the vaccinated serum was obtained was seen to be higher as compared with others. Especially, in the case of alveolar pyorrhea, this feature was strongly indicated.
3. In particular, the factors of precipitated reaction of saliva collected from alveolar pyorrhea were sought. As a result, it was found that these factors were in the supernatant of saliva but not in the deposit. Besides, these factors were not dialyzable.
4. The precipitated reaction between the condensed synthetic medium, in which the micro-organisms having the gelatin liquefaction ability isolated from the saliva of alveolar pyorrhea were cultured, and each of the serum obtained from the supernatant and deposit of the saliva of alveolar pyorrhea, as antigen, was examined, and, as a result, the following was known:
No positive precipitation was indicated with every strain only. However, a slight precipitation was seen to be indicated with the mixed several strains. From the groups of positive precipitation, rodform bacteria of genus pseudomonas and coccus-form bacteria of genus micrococcus were invariably found.
In view of the above results achieved, the present writer is strongly confident that the method of plate agar diffusion is highly effective in diagnosing alveolar pyorrhea and also that the saliva may effectively be used for the examination of its prognosis.

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Calcium amount in the deposit on clinical crown of 1|1 during one month will be considered to express the individual activity of supragingival calculus formation (ACF). It will be more reasonable that geometric mean is adopted in the case of statistical treatment of the results, when the test for some preventive measure against calculus formation will conduct with some population group.
Application of a dentogingival splint has been proved to be a new effective measure to prevent supragingival calculus formation. Eventhough the tightness of the splint depends upon the material and method to prepare it, it is the most important requirement to insure its effectiveness. Veillonella count was measured when it was withdrawn from the mouth, but the splint has no influence of their population at the time of sampling.

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Unpedigreed white virgin mice from a 20 year-old mouse colony were used in the present work. One group of copulated mice was given a single intravenous injection of 60 mg per kg body weight of alloxan on the first day of gestation (the first day group), and other 5 groups of these mice were injected with alloxan of 80 mg per kg body weight on the 4th, 5th, 6th, 7th and 8th clays of pregnancy each (the 4th, 5th, 6th, 7th and 8th day groups). Pregnant mice were sucrificed on the 19th clay of gestation, and fetuses were examined for externally visible and skeletal deformities.
The number of mothers with one or more malformed fetuses was 15 (30%) out of 50 successful pregnancies in the first day group, and those were 14 (28%), 7 (28%), 10 (38.5%), 9 (34.6%), and 7 (28%) in the 4th to 8th day groups, respectively. There were 38 (8.27%) malformed fetuses in the first day group, and 22 (5.30%), 9 (4.43%), 13 (6.81%), 13 (5.68%) and 7 (3.30%) in the 4th to 8th day groups. The frequency of fetuses having defects of the central nervous system fell progressively with later treatments of alloxan during pregnancy except for the first day group, whereas any noticeable relationship was not seen between the frequency of over all deformities and the date of alloxan injection. No appreciable difference in blood sugar levels was observed between mice with and without malformed fetuses. On the other hand, however, fetal defects were found more frequently in mothers with subnormal increase of body weight as compared with mothers showing an well increase during the period of pregnancy.

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After weaning of 44 rats obtained from in combination of one male and two females of commercial pure Wister strain rats and marked Pb-line in their dentin, 20 rats of them were fed on cariogenic diet (Table 1), containing casein at 10%, and the rest was gaved a high casein diet, containing casein at 15%, for 90 days. Average cavities produced for the experimental period were 9.00 in the low casein group, while 0.972 in the high casein group (Table 3). The difference between both average cavities was statistically significant. Interesting fact was that a rat gained the more body weight during 90 days produced the less cavities, regardless of casein content in the diet ( Fig. 1 and 2). Eventhough the determination of essential amino acids responsible for the present results (Table 5) was impossible so far in this study, important role of essential amino acids should he studied. Histological examination did not disclose any difference between two groups. However, three pictures appearing on the histological sections of Pb-marked rat dentin, written in the 1st report of this series, were also recognized. Statistical treatment of the relation between these pictures and cavities which have recorded before sectioning revealed that cavities accompanied with bacterial invasion and intact Pb-mark, and apparently healthy fissures were classified into two histological findings, dissolution of Pb-mark without any bacterial involvement and histological sound dentin (Table 4). Thus dissolution of Pb-mark is regarded as a sort of dentinal lesion but it does not mean precarious change of dentin.

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Authors observed DMF transition of second molars for 10 years on the particular 119 female package wrappers from their ages 15 to 25. These subjects were born during 1932 and 1938, entered a firm at the age 15 after finishing their compulsory education and served in the firm for more than 16 years.
The comparison of the results of the recent observation with that of DMF transition of first malars observed some years is as follows.
1. Percentage of DMF
At the time when the subjects just entered to the firm, the percentage of DMF was 67% for those who were born in 1932, 30% to 40% for those who were born in 1933 to 1937 and 9% for those who were born in 1938. Nearly all groups, however, showed remarkable changes during the two year period when the subjects grew up from 16 to 18 years of age, the percentage ranging between 35% to 87%.
2. Percentage of D teeth
Each group, without exception, showed conspicuous fluctuations. On an average, the rate rose in a steady curve, showing 12.5% at 15 years of age, 30%, as a peak, at 22 years of age, and thereafter the rate fell down.
3. Percentage of M teeth
The percentage of M teeth naught in 1933, 1934, 1935 and 1937 groups, but it was 1% at 23 years of age and 3% at 24 years of: age 1932 group, 2% at 17 years of age and 3.5% at 22 years of age in 1936 group and 2% at 22 years of age in 1938 group, which showed a general fall in percentage.
4. Percentage of F teeth
With slight fluctuations among the groups, all assumed an upward curve, especially in 1936 group the rate of M teeth rose from 4% to 46.5%.
5. Percentage of DMF teeth
A remarkable upward trend was seen in each group. The average rate of DMF teeth rose from 16% to 58%. The percentage of D teeth rose in a gentle curve: 12.5% at 15 years of age and 30%, as a peak, at 22 years of age, then a low rate followed. While the percentage of F teeth increased gradually for some years, the rate of M teeth was low.
6. Comparison of first molar and second molar with average DMF
In the percentage of D teeth, first and second molars showed the same or nearly the same rate. But in the percentage of M teeth first molar showed a higher rate than second molar, the former showing a lower rate than the latter in F teeth. In these graphs both the rates of DMF and DMF teeth of second molar were higher than those of first molar.
From above mentioned reasons authors concluded that dental health management in this firm is higher than the average level. And if a more positive work of this health management is made, the rates of D and M teeth may be lowered and thereby the rate of F teeth may be raised.

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