The non‐fibrous nature of the von Korff fibres in developing dentine. A light and electron microscope study

Abstract

AbstractFirst molar tooth germs were dissected from one‐ and seven‐day‐old mice, fixed in gluteraldehyde and impregnated in bulk using silver nitrate for the demonstration of reticulin. After impregnation the tooth germs were embdded in Epon, and thin sections cut for examination with both the light and electron microscope. Control tooth germs were prepared similarly, but were not impregnated with silver. Light microscopic examination showed the classical picture of von Korff fibres. These were associated with the formation of mantle dentine. von Korff fibres were not found associated with forming circumpulpal dentine. Examination of successive sections with the electron microscope showed silver particles between the widely separated, newly differentiated, odontoblasts. In forming circumpulpal dentine, the odontoblasts were closely aligned and no silver particles were found in the now narrowed extracellular spaces. Examination of control sections revealed that the extracellular compartment between the newly differentiated odontoblasts consisted of ground substance and a few sparse collagen fibrils which were too small to be resolved with the light microscope. It is considered that the “von Korff fibres” seen with the light microscope represent silver impregnation of the extracellular material, which is mainly ground substance, in the continuum between the widely separated odontoblasts.