Treatments are provided by either dentists or dental hygienists during routine dental examinations. Caregivers of eligible children are informed about the study, the participation is voluntary and an informed written parental consent is obtained in accordance with the directions of the Regional Committee for Medical Research Ethics. In this study, a clinician selects a random treatment for the first tooth by choosing one of the two cards, while a collateral tooth receives an alternative treatment. Subsequently, treatments provided and materials used are recorded on a treatment registration form. During this study, clinicians follow their conventional clinical procedures for applying sealants or fluoride varnish. Information on patient's caries experience and quality of oral hygiene are recorded on treatment registration form. Fluoride varnish is applied three times, at baseline, 6 months and 12 months.