The Examination of Guinea Pig Dental Enamel Matrix by Celloidin Section.

Abstract

Much discussion has taken place regarding the organic matter found in dental enamel. Certain workers 1 have endeavored to show that calcification in this structure is so complete that no organic matrix remains. Williams 2 could not find any material in enamel which is stainable. Evans, 3 however, has shown that the organic matter in this tissue lies between one and two per cent in the human tooth. Bödecker and Gies 4 lately have demonstrated the presence of protein within the enamel by microchemi-cal methods. That sections may be prepared showing certain points of morphology of this small amount of organic material within enamel has been stated recently. 5

Celloidin sections of enamel matrix of the tooth of the guinea pig may be prepared. Methods have been elaborated by one of us (A. W.) whereby decalcification may be carried on through a supporting structure of celloidin placed about the tooth. This procedure will be described at a future time. It is somewhat different from that described briefly by Bödecker and Gies. 4 We have worked with that portion of the incisor lying midway between the gingival edge and the apex. This is moderately young enamel, therefore. Transverse sections may be prepared showing amelo-blasts, enamel, dentine and odontoblasts in proper relationship.

Examination of sections prepared thus contributes certain information to our conception of the structure of enamel. Nearly all our knowledge thus far has been based upon work done with ground sections. In the guinea pig, there is definite articulation of the enamel matrix with the ameloblasts through the region of Tomes process. The enamel rods are projections from the individual ameloblastic cells. Thus we find ourselves in conformity with the belief of Mummery. 6