Organ and effective doses from CBCT examination in dentistry

Objective: The study was carried out to determine the organ and effective dose from CB mercury CBCT scanner with TLD method for all those protocols that used in dental practice. Method: TLD-100H were used to measure the doses inside the 24 site of critical organ of Alderson Rando phantom and calibrated with an ionization chamber (Type TM 30009 with a volume of 3.14 cm³ ). Using both the 1990 and recently approved 2007 International Commission Radiological Protection on recommended tissue weighting factors, effective doses were calculated. Results: FOV in P-mode E₁₉₉₀ ranged from 0.65 to 0.96 mSv, E₂₀₀₇ ranged from 0.95 to 1.66 mSv. FOV in I-mode E₁₉₉₀ ranged from 0.78 to 1.88 mSv, E₂₀₀₇ ranged from 0.89 to 2.19 mSv. FOV in D-mode E₁₉₉₀ ranged from 0.02 to 0.97 mSv, E₂₀₀₇ ranged from 0.22 to 1.23 mSv. The E₂₀₀₇ calculations were 12% to 1081% greater than E₁₉₉₀. The maximum of organ dose is thyroid organ. Conclusions: The dose from CBCT are varies depending on the FOV and selected technique factors. The doses from CBCT are low compared with conventional CT but higher than conventional dental radiography technique.