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A method to obtain thin histological sections (4-5 microm thick) from teeth, using a conventional microtome, is described for incisors, molars and canines from Spanish red deer (Cervus elaphus hispanicus). Decalcifying solutions of formic acid and nitric acid at different concentrations were ineffective. This was not the case for a solution of 14% hypochloric acid and polyvinylpyrrolidone (TBD-1(R) of Shandon). However, the time needed to complete decalcification was longer than the time estimated by other authors. Incisors required between 4 and 6 days, molars between 7 and 15 days, and canines between 8 and 12 days. The preparation of histological thin-sections from teeth with a conventional microtome, required some training or prior specialization, because most of defective or lost material occurred during the preliminary stage of the study. However this technique is inexpensive enough to be implemented in any histological laboratory. The preparations obtained are suitable for growth mark observation in dentine and in cementum for dating studies. Nevertheless, they are not suitable for enamel change studies, because the enamel is completely destroyed during the decalcifying process.

Electrolytic decalcification is a very fast and effective method for removing calcium compounds from bones with minimum damage to tissues. Changes of dimension of tissues in histological sections prepared from specimens decalcified by immersion in a formic acid solution and sections prepared from specimens treated in an electrolytic decalcifier were studied. Heads of mouse foetuses were cut in half, decalcified by one of the above-mentioned methods and embedded in histowax. Dimensional changes of skin, tongue and nasal epithelia in histological sections were evaluated by t-test. Significant shrinking and other unwanted effects of decalcification, such as acidophilia of nuclei, were found in objects decalcified by both methods. No significant differences in the effects of the two methods on tissue dimensions were demonstrated. It is concluded that both decalcification methods are equivalent from the qualitative point of view.