IADR Abstract Archives
Radioactivity levels of some feldspathic ceramic powders used in prosthetic dentistry
Objectives: Ceramics are widely used in dentistry and considered as the most natural-looking restorative materials for esthetic purposes. Gamma radiation, on the other hand, has a great potential of biological hazard due to its high penetration and ionisation ability. The aim of this study was to determine the natural gamma radiation levels of some commercially available ceramic powders used for fixed restorations.
Methods: Forty-two feldspathic ceramic powder samples, used for opaque, dentine, enamel and transparent applications were selected from eight different manufacturers. Activity concentrations of the samples were determined in terms of uranium-238, thorium-232, radium-226 and potassium-40 activities. Measurements were performed on 30 grams of each powder samples using a gamma spectrometer with HPGe (High Purity Germanium) detector.
Results: Analyses revealed that all the activity concentrations were above the Minimum Detectable Activity values (MDA values: 0.12 Bq/kg for 238U, 0.14 Bq/kg for 226Ra, 0.19 Bq/kg for 232Th and 3.57 Bq/kg for 40K). Uranium-238 activities in the samples were between 17.63 Bq/kg and 357.10 Bq/kg with an arithmetic mean of 125.88 Bq/kg. Potassium-40 activity concentrations are also important since the potassium content is high in the ceramics. It was found out that, the average potassium-40 activity concentration of the samples was about 2855.44 Bq/kg ranging from 2251.80 Bq/kg to 3522.29 Bq/kg.
Conclusions: Within the limitations of this study, it was concluded that, uranium-238 activity concentrations of the all samples were lower than the limit value of 1000 Bq/kg defined by ISO and approved by EC (European Commission). Potassium activities of the dental ceramics were also below the official value for solid materials of European Commission Report.
Methods: Forty-two feldspathic ceramic powder samples, used for opaque, dentine, enamel and transparent applications were selected from eight different manufacturers. Activity concentrations of the samples were determined in terms of uranium-238, thorium-232, radium-226 and potassium-40 activities. Measurements were performed on 30 grams of each powder samples using a gamma spectrometer with HPGe (High Purity Germanium) detector.
Results: Analyses revealed that all the activity concentrations were above the Minimum Detectable Activity values (MDA values: 0.12 Bq/kg for 238U, 0.14 Bq/kg for 226Ra, 0.19 Bq/kg for 232Th and 3.57 Bq/kg for 40K). Uranium-238 activities in the samples were between 17.63 Bq/kg and 357.10 Bq/kg with an arithmetic mean of 125.88 Bq/kg. Potassium-40 activity concentrations are also important since the potassium content is high in the ceramics. It was found out that, the average potassium-40 activity concentration of the samples was about 2855.44 Bq/kg ranging from 2251.80 Bq/kg to 3522.29 Bq/kg.
Conclusions: Within the limitations of this study, it was concluded that, uranium-238 activity concentrations of the all samples were lower than the limit value of 1000 Bq/kg defined by ISO and approved by EC (European Commission). Potassium activities of the dental ceramics were also below the official value for solid materials of European Commission Report.