Neural changes in ulcerative and hyperplastic pulpitis: a transmission electron microscopic study.

The purpose of this study was to examine at ultrastructural level the neural changes in human apical pulps of teeth clinically diagnosed as having ulcerative or hyperplastic pulpitis. Seventeen specimens were prepared from six teeth with ulcerative or hyperplastic pulpitis and four specimens from two sound teeth. After routine procedures the specimens were examined under an electron microscope for changes in the structure of myelinated and unmyelinated nerve fibres. Although the teeth used in this study responded positively to vitality test, the results revealed that moderate to severe degenerative changes occurred in the nerve fibres of the apical pulps of the teeth showing these two diseases.