Electron microscopic demonstration of non-mineralized and hypomineralized areas in dentin and cementum by silver methenamine staining of collagen.

An electron microscopic study on silver methenamine staining of hard dental tissues was made on a material that comprised human permanent teeth and primary tooth germs from human and porcine fetuses. It was demonstrated that silver-stained material consisted of collagen fibrils. In predentin and precementum all collagen fibrils were stained, while collagen fibrils of dentin and cementum were unstained except for some fibrils of minor special areas such as Owen's contour lines, interglobular dentin, Tomes's granular layer, and in cementum small "interglobular-like" areas. It is concluded that silver methenamine visualizes collagen fibrils of hypo- and unmineralized areas in dental hard tissues and therefore may be used to demonstrate abnormal patterns of mineralization. Finally variations of silver methenamine stainability in relation to differences in material and methods were studied and discussed.