
Background: Radiographic examination has a great value in the detection of carious lesions, especially the diagnosis of the smooth surface caries on the interproximal areas, thereby preventing extensive tooth loss. Periapical radiographs are primarily useful for detecting the extent of the wide carious lesions and changes around the teeth mainly pulp and periodontium. However, it is well known that ionizing radiation is capable of causing genetic damage to cellular systems. One of those genetic alteration is the formation of micronuclei which are not included into the main nuclei of the daughter cells and are used to evaluate the magnitude of DNA damage. Objectives: To evaluate micronucleus frequency in exfoliated buccal mucosa cells of healthy children before and after the exposure to IOPA radiography during diagnosis and treatment of proximal carious lesion, using Buccal Micronucleus Cytome assay. Methods: A total of 20 children between the age group of 4-8 years were involved in the study. Cytological smears are taken from the buccal mucosa immediately before the X-ray exposure and 10 ± 2 days after exposure. The cells were stained with fuelgen and evaluated for micronuclei by scoring 1000 cells per sample. Results: The frequency of micronuclei increases significantly post exposure to IOPAR with a ‘p’ Value of 0.001. Conclusion: The X-ray radiation emitted during IOPAR does induce some genotoxic changes in the form of increased frequency of micronuclei. So, great care to be taken only to advice radiographs if necessary and reduce these cumulated biological effects of radiation exposure.