The current study summarizes actual dose measurements for dental workers in Canada over a 40-year period. This study was limited by the fact that monitoring of dental work ers was not compulsory throughout the entire study period and varied from province to province. As such, an unknown number of dental workers are missing from the cohort, and some dose records may be incomplete 15 However, there is no reason to assume that the radiation dose received by moni- tored dental workers was systematically different from that for workers who were not monitored. The dose of ionizing radiation received by Canadian dentists and other dental workers has declined to very low levels. Continued adherence to established guidelines for occupational radiation exposure22 is recommended as a means of protecting dental workers from the harmful effects of ionizing radiation.