Calcified human permanent and primary teeth are often split to obtain pulp tissue for histochemical studies as well as unaltered dentin and surfaces for scanning electron microscopy. Various procedures have been used to cleave teeth, with different degrees of consistency. For rapid and fairly consistent splitting, a vise to the jaws of which triangular metal files have been welded has been found useful. The apices of the files were ground by an electric drill to the shape of typical teeth. Teeth to be split were grooved on their opposing external surfaces and were then cracked open between the file blades upon application of pressure by the vise. Teeth usually split lengthwise, exposing the entire pulp organ in one section and an empty pulp chamber-root canal in the other. This facilitated rapid penetration of fixative into pulp, and easier removal of pulp tissue in toto, as well as providing fresh enamel and dentin surfaces suitable for scanning electron microscopy.