In order to stereographically investigate the degradation of dentin caries in deciduous teeth, we used laser scanning microscopy (LSM) to observe these lesions stained with Villanueva. Fine tomographical pictures of the dentin caries were obtained even at high magnification, regardless of section thickness. Carious dentin lesions were stereographically observed by computer imaging of the tomographic pictures. Dentin caries proceeded along the dentinal tubules and their lateral branches. Destruction of intertubular dentin and compression of the tubular wall caused enlargement or the dentinal tubules. The use of LSM permitted detailed observation of carious lesions in deciduous teeth.
