A technique for the study of the internal structure of calcified tissues.

THE investigations of Williams and Trvinel showed that extraction of organic material from bone with ethylenediamine (ED) was superior to ashing with KOH-glycol. Since the anorganic skeleton prepared in the former manner appeared to be intact, the method was utilized by them in studies of trabecular stress patterns. They also noted that less alteration of crystalline structure resulted from preparation of the anorganic bone from ED than from glveolashing methods. Peckham and Losee2 compared the efficiency of ED and KOHglycol extractions of dentin and found that there was a negligible loss of mineral content with the -former method in contrast to an appreciable amount with the latter. This is believed to be due to the relatively low temperature (1180 C.) used in removing the organic fractions with ED in a modified Soxhlet extractor. Because ethylenediamine is readily soluble in water, it can easily be washed out of the anorganic matrix after extraction. Losee3 utilized ED extraction to study the microscopic pathways in enamel and demonstrated the presence of micro-lamellae in human enamel. It was the aim of the present investigation to utilize this improved method of extraction of organic components of calcified tissues in developing a method of studying the internal structure of these tissues.