Inoue Hiroshi, Izumi Toshio, Ishikawa Hironobu, Watanabe Keiji
Department of Operative Dentistry and Endodontology, Fukuoka Dental College, Fukuoka, Japan.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004 Feb;97(2):246-50. doi: 10.1016/s1079-2104(03)00474-8.
The objective of the study was to examine the morphological changes of neural elements in dentin-pulp complex ultrastructurally after Er:YAG laser irradiation and elucidate the mechanism of pain reduction in cavity ablation.
The Er:YAG laser was applied at occlusal surfaces of upper and lower first molar cusps of 6 rats, and shallow cavities were ablated. The dentin and pulps were examined with light and electron microscopes at 6 hours after the irradiation. Teeth, without laser irradiation, from three rats were used as controls.
Disruption of nerve terminals in the dentinal tubules, degeneration of nerve terminals between odontoblasts, and disruption of the myelin sheath in the pulp core were demonstrated with electron microscope.
Some Er:YAG laser beams could penetrate to deeper areas than ablated area, and damage of nerve fibers and terminals might be a mechanism of pain reduction in cavity ablation with Er:YAG laser.
