The survey of the surface doses of the dental x-ray machines / 대한구강악안면방사선학회지

ABSTRACT

PURPOSE: The purpose of this study was to investigate variability of doses with same exposure parameters and evaluate radiographic density according to the variability of doses. MATERIALS AND METHODS: Twenty-eight MAX-GLS (Shinhung Co, Seoul, Korea), twenty-one D-60-S (DongSeo Med, Seoul, Korea), and eleven REX-601 (Yoshida Dental MFG, Tokyo, Japan) dental x-ray machines were selected for this study. Surface doses were measured under selected combinations of tube voltage, tube current, exposure time, and constant distance 42 cm from the focal spot to the surface of the Multi-O-meter (Unfors Instruments, Billdal, Sweden). Radiographic densities were measured on the films at maximum, minimum and mean surface doses of each brand of x-ray units. RESULTS: With MAX-GLS, the maximum surface doses were thirteen to fourteen times as much as the minimum surface doses. With D-60-S, the maximum surface doses were three to eight times as much as the minimum surface doses. With REX-601, the maximum surface doses were six to ten times as much as the minimum surface doses. The differences in radiographic densities among maximum, mean, and minimum doses were significant (p< 0.01). CONCLUSION: The surface exposure doses of each x-ray machine at the same exposure parameters were different within the same manufacturer's machines.