Delayed Effects of Multiple Sublethal Doses of Total Body X-Irradiation on the Periodontium and Teeth of Mice

Abstract

Studies were made of the effects of multiple sublethal doses of total body x-irradiation (6 weekly exposures of 200 r each, beginning at 9 weeks of age) on the subsequent appearance of the periodontal and dental tissues of male mice fed either a highly purified diet complete in all known nutrients or a natural food stock ration. Periodontal lesions were observed in x-irradiated animals on the purified diet at 100 days following the first irradiation exposure, but not prior to this time. The subsequent development of the lesions generally paralleled that of primate periodontitis and was characterized by plaque formation, gingival recession, periodontal destruction, dental necrosis, and exfoliation. In contrast to findings on the purified diet, no periodontal pathology was observed in x-irradiated mice on the stock diet. The multiple sublethal mode of exposure to total body x-irradiation appears to be a primary etiologic factor in the formation of periodontal lesions in mice fed the purified diet. Secondary factors, such as age, diet, trauma, oral bacterial flora, heredity, etc., may also be implicated.