Asymmetry in the weight of the mandible and teeth was studied in 60 rabbits consisting of 40 young rabbits (males 20, females 20, weighing around 1.9kg) and 20 adult rabbits (females 20, weighing around 2.7kg).
And the authors examined whether the one sided dominance would exist or not, and the relation of the dominant side between the mandible and the teeth. The following conclusions were obtained.
1. The mean weights of the mandible and the teeth are greater on the dominant side (p<0.001).
2. The degree of difference between the dominant and non-dominant side in the mandible and the teeth by the method of von VERSCHUER'S average percentile deviation is greater on adult rabbits than on young ones.
3. There do not exist one-sided dominance in the mandible and the teeth of both young and adult rabbits.
4. The relation of the dominant side between the mandible and the teeth is not clear in young rabbits but adult ones show the same side dominance between them.

View full abstract

The result of the comparative examinations on the physical properties and adhesive properties of fluid resin, respectively with MMA-CHPMA comonomer and MMA-EDMA comonomer used as liquid part is as follows :
1) Hardness, tensile strength and transverse-bending strength of MMA-CHPMA system resin rise in accordance with the increase of the mixed amount of CHPMA, and transverse-deflection contrarily shows a tendency to decrease, but no remarkable difference can be seen as compared with the MMA-EDMA system.
2) The amount of water absorption of MMA-CHPMA system resin shows a tendency to increase in accordance with the increase of the mixed amount of CHPMA, but no remarkable difference can be seen as compared with the MMA-EDMA system.
3) MMA-CHPMA system resin shows preferable adhesion to glass plate and copper plate, but the MMA-EDMA system has little adhesion. Again, its adhesive strength shows a tendency to rise in accordance with the increase of the mixed amount of CHPMA. The adhesive strength differs according to the kinds of substrates; It is large, about 1.5 times, in the case of copper plate, compared with the case of glass plate.

View full abstract

The authors measure the bonding strength between thermo-setting resin and palladium alloy and gold alloy, and obtain the following results.
1) In case the substrate surface is cast surface or #600, preferable adhesive properties can be seen, each showing approximately the same bonding strength. But in the Lapping case, the bonding strength is small by some 20%, as compared with the former two.
2) The bonding strength shows a tendency to decrease as time goes on in case the test pieces are stored in 37°C water, but cast surface and #600 show 40 kg/cm² even after 90 days.

View full abstract

The color reaction of α-cholestanol with acyloxysulfonium salt solutions prepared by several sulfoxides and acetyl chloride is reported. Optimal conditions for the reaction which could be employed were 1.25 mmoles acyloxysulfonium salt solution prepared by dimethyl sulfoxide and acetyl ckloride per mmole of α-cholestanol reacted at 70°C. The solution prepared by methyl methylthiomethyl sulfoxide and acetyl chloride can be used in place of dimethyl sulfoxide for the method of detection of α-cholestanol. The other sulfoxides, tetramethylene sulfoxide and diphenyl sulfoxide, were of no use for the method the authors employed.

View full abstract