Objective: to evaluate the caries preventive effect of a mother-child Preventive Dental Program (PDP) in a group of 9-10–year-old children who discontinuated the program when they were six years old. Methods: the permanent first molars of 37 children in the PDP group were evaluated clinically and radiographically for caries experience and compared with a control group of 42 children who had not participated in the PDP. Results: the proportion of caries-free children in the PDP group was 70% compared with 33% in the control group (p<0.01). For permanent first molars, the proportion of caries-free molars in the PDP group was 87% compared with 61% in the control group (p<0.01). The mean DFT in the PDP children was 0,51±0,93 versus 1,57±1.38 in the control children (p<0.01). Conclusions: children examined 4 years after discontinuation of a caries preventive program showed a long-term reduction in the DFT score of permanent first molars.