EFFECT OF GAMMA-RADIATION ON DE- AND RE-MINERALIZATION OF ENAMEL AND DENTIN (An IN-VITRO STUDY)

Introduction: Gamma radiation is usually used, as a primary or supplementarytreatment, for oral cancer patients. Aim: The present work was undertaken to investigate,in vitro, the effect gamma irradiation of a cumulative dose of 60 Gy (20 Gy/day overthree days) on enamel and dentin microhardness before and after demineralizationand remineralization. Materials and methods: Ten healthy freshly extracted humanthird molars were used in this study. The teeth specimens were cut perpendicular totheir occlusal surface into two halves. Half of the specimens were gamma-irradiatedto a dose of 60 Gy (20 Gy/day). The data involved the measurement of VHN Vickersmicrohardness on both radiated and non-irradiated. Results: The results indicated thatthe mean microhardness values of the non-irradiated enamel samples were decreasedafter gamma irradiation, and were significantly decreased after demineralization;meanwhile, the microhardness values of the demineralized non-irradiated enamelsamples were significantly increased after remineralization. The results showed thatthe microhardness of the demineralized non-irradiated dentin samples was increased,and that the microhardness of the gamma-irradiated dentin samples was slightlydecreased. Conclusions: gamma-irradiation had significant effect on enamel and dentinmicrohardness values and had significant decrease effect on demineralization of enamelwhile had significant increase by remineralization.