Determination of radioactivity levels in feldspathic dental ceramics.

Activity concentrations of 42 different feldspathic dental ceramic powders were determined using a gamma spectrometer with an HPGe detector. The average 238U, 232Th and 226Ra activity concentrations of the specimens were 126 ± 8 Bq kg-1, 5.6 ± 0.5 Bq kg-1 and 12.7 ± 1.2 Bq kg-1, respectively. The average 40K activity was found as 2855 ± 89 Bq kg-1 ranging from 2252 ± 70 Bq kg-1 to 3522 ± 110 Bq kg-1 due to high potassium content in dental ceramics. None of the activity concentration measurements exceeded the limits by EC and ISO.