a nanocomposite shield constructed for protection against the harmful effects of dental x-rays

o bjectives: this study aimed to compare a number of new nanocomposites capable of pro- tecting the jaw from ionizing radiation. mat erials and methods: four different types of nano-powders [ti, zr (iv) oxide, ag and co] were mixed in a polymer matrix to create nano-composites with doping values of 8% in weight. small-angle x-ray scattering (saxs) analysis was performed using a hecus- saxs system with 50 kv- 50 ma. co nano-composites (co-pnm) yielded the most prom- ising values of the 4 nanocomposites tested in terms of x-ray absorption. thus, 4x2 cm co- pnm samples of different thicknesses (0.20, 0.50, 0.57 and 0.60 cm) were prepared, and saxs analysis was performed in order to assess the effects of material thickness on x-ray absorption. an experimental multi part shield was constructed from co-pnm around tooth #36 to test the effect of nanomaterial on the image quality under x-ray beam. results: logarithmic distributions of the transmitted intensity values (i) showed that 0.20 cm co-pnm had the highest transmission value (16.05) followed by 0.50 cm co-pnm (15.44), 0.57 cm co-pnm (15.07) and 0.60 cm co-pnm (15.06). the 0.2 cm co-pnm had an effective radius of the nano-aggregation value (77.44 å) lower than that of the other thick- nesses (0.50, 0.57 and 0.60 cm) of co-pnm, which had similar values ranging from 66.22-66.34 å. the 0.50 cm co-pnm had the lowest dmax value of the different thicknesses of co- pnm tested. conclusion: co nanocomposite can be used as a protection shield for the harmful effects of dental x-ray.