Concern and anxiety over medical radiation exposure have increased in Japan following the Tokyo Electric Power Company nuclear plant accident in Fukushima triggered by the Great East Japan Earthquake in March 2011. In June 2015, based on domestic fact-finding surveys by various academic societies and organizations connected with the Japan Network for Research and Information on Medical Exposure, a diagnosis reference level (DRL) “Diagnostic Reference Levels Based on Latest Surveys in Japan—Japan DRLs 2015—” was made public for the first time in Japan. Although X-ray photography is routinely used in the dental field for diagnosis and treatment, inspection and review of devices are insufficient because dentistsʼ awareness of radiation protection is low. This low awareness may be because the effective dose per unit exposure in dental devices is very small compared with that in medical devices, thus dentists do not perceive a high risk of radiation exposure. However, it is important for dentists to understand the contents of DRLs and pay careful attention to radiation protection from a public health standpoint. The objective of this paper is to overview the radiation protection in the dental field.