Introduction: In contrast to the well-established caries epidemiology, data on dentin hypersensitivity seems to be contradictory. This study evaluates and assesses the prevalence, distribution and potential changes in case of dentin hypersensitivity. Dentin hypersensitivity is described as a short, sharp pain, arising from exposed dentin in response to stimuli -thermal, evaporative, tactile, osmotic or chemical. The pain generally disappears when the stimulus is removed. Sensitivity may be associated with tooth bleaching procedures, exposed dentinal tubules as a result of gingival recession, erosion, subsequent loss of cementum on root surface, abfraction in combination with vigorous tooth brushing. In spite of various treatment approaches such as careful brushing instructions, desensitizing toothpaste, fluoride application, or dentin bonding agents, there is no appropriate scientific information about prevention and treatment. Purpose: Investigation of the epidemiology of dentin hypersensitivity. Materials and methods: Dental students in Medical university of Varna and their patients, and patients from a Private dental practice in Dobrich fill two questionnaires concerning symptoms of dentin hypersensitivity and assessing the incidence of this problem. Conclusion: Dentin hypersensitivity is a clinically relevant problem. It affects the quality of life of patients and therefore it should be properly addressed in research, dental education, prevention and treatment.