Desenvolvimento de um objeto simulador virtual para dosimetria em radiografias intraorais

Abstract

Intraoral radiographs are composed of three techniques, periapical, bitewing, and occlusal, and are used to visualize the structures of the oral cavity. The techniques are differenti ated by the positioning of the x-ray equipment, photographic receptors, and equipment configurations. In some situations, patients may be submitted to many dental exams, depending on the dental treatment, where the primary beams of radiation directed to radiosensitive organs and tissues may present risks to the patients’ health. The objective of this work was to develop a head and neck phantom and to computationally calculate the Conversion Coefficients for Absorbed Dose (CC[D]) in the phantom’s radiosensitive organs and tissues for the exposure scenarios of intraoral radiographs. The CC[D] were calculated by Monte Carlo simulations with Monte Carlo N-Particle (MCNP) code (version 6.2), considering the voltages of 60, 65, and 70 kVp with filtration between 1.5 mmAl and 2.5 mmAl, recommended for intraoral radiographs, and the placements of the periapical, bitewing and occlusal techniques. The results showed the salivary glands showed the highest CC[D] values in the intraoral techniques, with the sublingual glands having the highest deposited energies, followed by the parotid and submandibular glands. In some positions of the periapical and occlusal techniques, organs such as the eyes, lens, and thyroid, presented higher CC[D] values, due to the direction of the primary radiation beams and the positioning of the techniques.