Formic Acid-Sodium Citrate Decalcification and Butyl Alcohol Dehydration of Teeth and Bones for Sectioning in Paraffin

Abstract

Oral calcified tissue, which includes extracted teeth, teeth in situ, and alveolar bone, is usually prepared for histological examination by the general method of nitric acid decalcification, ethyl alcohol dehydration, and celloidin embedding. This paper describes a different method of tissue preparation which consists of formic acid-sodium citrate decalcification, butyl alcohol dehydration, and paraffin or celloidin embedding. The technic, described here in detail, was arrived at after 10 years of experimentation. During the last 3 years of this period, approximately 500 pieces of tissue were prepared and from these some 30,000 slides. An analysis of the various problems involved in the preparation of oral calcified tissue are presented in an effort to demonstrate the advantages of the proposed technic of preparation. For purposes of clarity, the outline of the technic is followed by an analysis of each step of the method in sequence.