The effect of roentgen irradiation on the formation of enamel and dentin in maxillary rat incisors

Abstract

abstract – An investigation of roentgen‐ray induced enamel and dentin changes in the maxillary incisor in the rat was undertaken to assess the relative radiosensitivity of amelogenesis and dentinogenesis. Seventy Sprague‐Dawley rats received whole body irradiation with exposures between 500 and 950 rad. Five animals served as controls. During the experimental period all the animals were given an injection of oxytetracycline. The animals were killed 5–21 d after irradiation. Ground sagittal sections of the incisors were examined microradiographically and with fluorescence microscopy. The irradiation produced elongated external hypoplastic lesions in the enamel and niches in the dentin. The extent of the lesions varied with the radiation dose. The variation in the extent and appearance of the lesions was much greater in the dentin than in the enamel. Even the smallest dose regularly produced changes in the enamel but seldom in the dentin. Amelogenesis thus proved to be more radiosensitive than dentinogenesis.