The aim of this final work is to present radiological methods which are used in dental medicine and how to protect patients and staff from harmful effects of ionizing radiation. In dental radiology, there is a risk of developing brain tumor, thyroid gland tumor, salivary gland tumor, cataracts of the eye lens and the occurrence of genetic damage due to the action of small doses of radiation. In the prevention of the negative effects of radiation, the doctor who refers the patient for an examination and the radiological technologist are the most responsible. Professional staff are therefore obliged to reduce exposure of unnecessary radiation with good knowledge of diagnostic devices, the method of operation and the choice of means of protection. The dose of patients is reduced by using high-frequency generators, applying filters, collimating, selecting receptors, reducing the number of screenings, and using lead aprons and thyroid shields.