Immunohistochemical localization of types I, V, and VI collagen in human permanent teeth and periodontal ligament.

Types I, V, and VI collagen were immunohistochemically localized in frozen and paraffin sections of human permanent teeth, periodontal ligament, and alveolar bone, by means of polyclonal antibodies. Hyaluronidase was effective in exposing epitopes of the various collagen types. The expression of type I collagen in predentin was strong in frozen sections, whereas the dental pulp stained relatively weakly. Staining intensity in the dentin matrix decreased toward enamel and cementum. Reactivity in the periodontal ligament was moderate, and it was weaker in the alveolar bone and also in cementum, which stained more intensely in paraffin sections. Staining for type V collagen was strong in the pulp. Weak reactivity in predentin became uniformly evident in frozen sections only, and dentin was negative. The periodontal ligament stained with moderate intensity, and a weak staining reaction was seen in cementum and bone. Staining for type VI collagen in the pulp and periodontal ligament was strong, whereas predentin and dentin were negative. The alveolar bone stained moderately, and non-uniform reactivity was present in cementum. In non-mineralized dental tissues, the use of frozen material enabled good immunohistochemical localization of the distinct collagen types to be carried out. Their distribution patterns in dental tissues not only differed, but the relative staining intensities for each collagen type in the pulp and predentin were inversely related. However, differences may exist in the exposure of the epitopes of collagen(s) between soft and mineralized tissues.