 In the first group, Sensodyne Classic GlaxoSmithKline, UK and Sensodyne Fluor GlaxoSmithKline, UK were the brands of toothpaste used, while in the second Plidenta 15 Seconds Neva Ltd., Croatia and Plidenta Sensitive Neva Ltd., Croatia Table 1. Participants have used toothpaste for four months. The first two months they used non-fluoride toothpaste, after which, for the next two months, they used toothpaste containing fluoride of the same manufacturer and similar composition. The tested kinds of toothpaste were applied twice a day, in the morning and evening, for three minutes in the amount of 1 g 2 cm. Contemporary, participants did not use other agents for oral hygiene such as mouthwash or topical fluoridation. A detailed medical and dental anamnesis were taken from each participant. In a structured questionnaire, tailored to this study all participants provided answers to questions related to demographic factors age, gender, personal factors general health, a medication used, radiation exposure, lifestyle smoking, alcohol consumption eating habits and oral hygiene habits. Individuals who smoked three or more cigarettes a day for at least a year were considered as smokers. Those individuals who consumed two or more alcohol units for three or more times a week were not included in the study as well as patients with oral lesions, history of malignancy, and those with removable and fixed prosthodontics, orthodontic appliances. The criterion for selecting participants was to be completely healthy with no systemic disorders and diseases. 