Abstract
Histological changes of oral mucosa were detected after experimental exposure to ultraviolet light of the light cure gun. Four groups of clinically healthy rabbits were used. The first group was the control group. The region around the lower mandibular molar tooth of the other three groups was exposed to equal dose of the light for forty seconds. Animals of the three treated groups were sacrified after two days, four days and after two weeks successively. Histological sections from the irradiated areas were examined and the histological changes were cited.