Effects of radiation therapy on the morphology and composition of root dentin and cementum in primary teeth

The aim of this study was to evaluate, in vitro, the effects of radiation therapy on the morphology and chemical composition of root dentin and cementum of primary teeth. Roots of human primary teeth were exposed to varying doses of irradiation using a linear accelerator: Group 1 = irradiation dose of up to 30 Gy (n= 6); Group 2 = irradiation dose of up to 42 Gy (n= 6); and Group 3 = irradiation dose of up to 54 Gy (n= 6). Non-irradiated human deciduous teeth were used as controls (n= 3). Energy-dispersive X-ray spectroscopy (EDX) data were analyzed using the chi-square test (alpha = 5%). The morphological evaluation was performed using scanning electron microscopy (SEM). In the cementum, radiation increased inorganic composition and decreased oxygen levels. However, no morphological changes were observed. In the root dentin, obliterated dentinal tubules were observed in specimens irradiated with 54 Gy, with no changes in composition. Thus, radiation therapy significantly altered the morphology and composition of important tooth structures such as dentin and cementum, in primary teeth.