Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 5 2016 02 09 364 373 EN Simel Ayyıldız Associate Professor, Department of Prosthodontics, Dental Health Sciences Center, Gülhane Military Medical Academy, Ankara, Turkey Elif Soylu Engineer, Department of Physics, Karadeniz Technical University, Faculty of Science and Literature, Trabzon, Turkey Jülide Özen Associate Professor, Private Practitioner, Ankara, Turkey Semra İde Professor, Department of Physics Engineering, Faculty of Engineering, HacettepeUniversity, Ankara, Turkey Kıvanç Kamburoğlu Associate Professor, Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey 2015 10 12 2015 10 12 Objectives: This study aimed to compare a number of new nanocomposites capable of pro- tecting the jaw from ionizing radiation. Materials 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. https://fid.tums.ac.ir/index.php/fid/article/view/310 https://fid.tums.ac.ir/index.php/fid/article/download/310/292