The Dentinal Tubules and the Odontoblast Processes a Scanning Electron Microscopic Study

Abstract

Scanning electron microscopy of the dentinal tubules and the odontoblast processes was performed on young premolars that had been fractured to open the tubules in the crown dentine parallel to theiraxis. The tubules were viewed in an outward direction, starting from the attached pulp tissue at the buccal pulp horn. The odontoblast processes in the tubules were found within a distance from the pulp equelling about one quarter the total length of the tubule; in only a few tubules the process was more than 0.4 mm from the pulp and none were seen beyond 0.7 mm from the pulp. The process almost completely filled the tubule in the predentine-dentine area and up to a distance of 0.2 mm from the pulp. The processes were tube-like.

In the predentine-dentine area the processes were surrounded by a thin membrane-like structure. Further into the dentine the tubule wall seemed to have a coating of an amorphous substance containing a few circumferentially, and in places also longitudinally, arranged fibres. The tubules apparently contained no nerve fibres.

Key Words:

• Dentin
• Odontoblasts
• Nerve endings