Effect of therapeutic doses of radiotherapy on the organic and inorganic contents of the deciduous enamel: an in vitro study

This study evaluated the effects of radiotherapy on the composition of deciduous teeth enamel using micro-energy-dispersive X-ray fluorescence and Fourier transform Raman spectroscopy before and after a pH cycling process. Ten deciduous molars were sectioned and divided into two groups (n = 10). The radiotherapy group (RT) was irradiated with 54 Gy at 2 Gy/day, 5 days per week for 5 weeks and 2 days, and the normal group (N) was not irradiated. The RT group was evaluated before radiotherapy (RTb), after radiotherapy (RTa), and after radiotherapy and pH cycling (RTc). The normal group was evaluated before (N) and after pH cycling (Nc). The weight percentage (wt%) of calcium (Ca), phosphorus (P), and organic content; the Ca/P ratio; and the integrated area of the Raman bands relative to the organic, carbonate, and phosphate contents were also evaluated. The exclusive use of RT reduced the organic content of the enamel (p = 0.000). The RTc group exhibited a decrease in P wt% (p = 0.016), an increase in the Ca/P ratio (p = 0.000), and a reduction in the integrated area of the phosphate band (p = 0.046). An increase in the Ca/P ratio (p = 0.000) and a reduction in the areas of the carbonate and phosphate bands were found in the RTb/RTc treatments. RT application at a therapeutic dose reduced the organic content of the deciduous enamel. Preventive measures should be included in the patient treatment protocol because of RT-induced chemical changes to the deciduous enamel.