A root canal filling material paste, mainly made of calcium hydroxide and iodoform with the addition of silicone oil, was experimentally introduced into the mandibular canals of dogs. The tissue reactions to the paste were examined by radiography, histopathology, and electron microscopy. The examination results showed that the paste was phagocytosed by macrophages and, in general, was gradually resorbed by the passage of time. The paste was also found to cause heterotopic calcification and/or bone formation within the limited area of original penetration. The histopathological tissue changes of the alveolar nerve tissue were also examined. No injury-related histopathological change was observed as long as the injected paste did not contact alveolar nerve tissue, but tissue damage was observed at sites of direct contact. After removal of degenerated nerved debris by macrophages and Schwann cells, the persisting external membrane or “Schwann tubes” appeared to provide a scaffold for axonal regeneration and Schwann cell proliferation.
Editor, Toshiyuki Kawakami
Language Editor, David M Carlson
viii, 232 p. ill. (some col.)
Chapter 4 : Injury and the Recovery Reaction due to the Penetration of Material into the Mandibular Canal
