In a two-year clinical trial the surface-specific effect of a mineralizing agent on selected permanent teeth was evaluated as well as the effect of this agent on periodontal health in children. Compared with positive controls (Control group, n = 123, biweekly mouthrinsing with placebo and 0.2% NaF solutions), among children in the test group (n = 123, biweekly mouthrinsing with 2% Remodent and 0.2% NaF solutions) the mineralizing agent clearly affected periodontal health (as determined by the prevalence of subjects with gingival bleeding and occurrence of affected sextants at risk) positively, in addition to having a positive effect on the incidence of EFD lesions. The mineralizing agent tested was not found to have adverse effects (as determined by the prevalence of subjects with dental calculus and occurrence of affected sextants at risk). Use of the mineralizing agent is recommended especially during posteruptive maturation of permanent teeth.