エナメル質齲蝕の研究

抄録

Of the variaus methods of section-making devised by many people to study enamel caries histo-pathologically, the Imagawa's direct paraffin embedding has been turned aut to be an effective method for studying enamel caries. This method is the one contrary to the standard section-making-first, by embedding the part necessary for the study of surface layer with paraffin and after taking off the unneclssary part by decalcification, observing the section of the necessary part remaining.
I have examined this method and, adopted the method of using the crawn part of the teeth only, or using a lower pressure in paraffin embedding and decalcification, or using stained paraffin in the last paraffin addition. I have improved the method.
Consequently I have faund out that this method is simple and easy to operate, the time taken to make a section is much shortened and a thin section is made. Moreover, in the paraffin negative model got after decalcification, we have an advantage of abserving cubically the form of normal grooves and fissures and the pracess of the early enamel caries. So I have been able to make the use of the Imagawa's direct paraffin embedding more valuable.
By using this method improved by me I have studied the birth and origin of the early enamel caries histo-pathologicalyl about human and animal teeth and got these uew results.
1) By using a stereoscopic microscope I haue abserved the paraffin negative model of human teeth grooves and fissuses and got results as follows-
a) The form of grooves and fissures is not a simple one, but a complex cupola one.
b) The individual characteristics can be seen in the height, form, color of the grooves and fissuses, in the same individual, the symmetrical form in the grooves and fissures of the teeth which are in the same jaws and have the same names.
c) The caries of fissures is not always begun at its bottom. And the early caries of fissures sometimes a completely indefinite enlargement.
2) By using the direct paraffin embedding I have observed microscopically the grooves and fissures of human teeth and their proximal surface and got results as follows-
a) In the normal fissures and on the proximal surface can be found filaments grawing always on the enamel cuticle.
b) These filaments are dyed into Gram positivity and iodine dying appears positively in some of them.
c) Filamentous organisms, on which other bacteria, food remnants and cells fix themselves, form “bacterial plague”.
d) The first and second enamel cuticles are always demonstred in the normal fissures and on the proximal surface.
e) The early enamel cariee always begins directly below “baetereial plaque” the enamel cuticles break up, and the net-warks (zone of decalcification) grow and bacteria intrude.
3) By using the direct paraffin embedding I have observed microscopically the graoves and fissures of gnimal teeth got results follows-
a) In the normal grooves and fissures and on the proximal surface of animals-such as, rat, hamster, guinea pig, cow, horse, pig, goat, dog, cat, nutria-can always be found filamentous organisms grawing.
b) Every animal has different forms of filaments grawing on the surface of its teeth.
c) In the animal filaments, the Gram positive ones are mixed up with the Gram negative ones. The iodine dying, in every case, is negative.
d) In the experimental dental caries with rats and hamsters, the microscopic findings of the early enamel caries accord with those of human dental caries.