A Radiographic Method for Measuring Radiation Dose Based on Beam Quality

Objectives: To develop a radiographic method for measuring radiation dose based on beam quality for inexpensive postal surveys of general dental practitioners.

Methods: Different beam qualities were simulated to expose a commercially available film (X-Omat MA 18 x 22.4 cm, Ready Pack, Kodak Pathe, Paris, France). Density and contrast curves were fitted by means of 4th-degree polynomial functions. The curves were used to estimate beam quality (as the first HVL) and radiation dose in air for 22 different dental X-ray machines by means of linear interpolation. These estimations were compared with the measurements obtained with the NERO system and an ionization chamber (paired t-test).

Results: No significant differences were found between the radiographic and the conventional methods in determining beam quality and radiation dose.

Conclusions: The radiographic method can be used to determine beam quality and radiation dose of dental X-ray machines from a single exposure. The radiographic method is simple and inexpensive and causes a minimum of disruption to the dental practice.