Irradiation effect of low-energy laser on rat submandibular salivary gland.

Histopathological studies of rat submandibular salivary glands following low-energy laser irradiation using gallium-arsenide semi-conductor laser were conducted. The mitoses of duct epithelial cells without atypia increased between 1 and 24 h after irradiation, reaching a maximum of greater than 5 times control values by 24 h. Mitoses of duct epithelial cells had a tendency to be more frequent in granular ducts, less in striated ducts, and still less in intercalated ducts. Qualitative differences in the effect of low-energy lasers on salivary gland epithelia were also noted. This is the first experimental study of the effect of low-energy laser on salivary glands.