Intervention At baseline (before three years) all parents in the intervention group received a standardised "knowledge package", included "Lift the lip program". Both general and local interventions were repeated at first follow-up at three years and second follow-up at five years. Risk assessment was made by the following background factors: 1) dental factors such as visible caries, visible plaque, gingivitis, erosion and DDE; 2) parental oral health related behaviours such as oral hygiene habits, dietary habits and use of fluoride; 3) social factors such as immigrant background where parents showed poor language skills; and 4) medical factors such as comorbidity and use of medication with drugs sweetened with sucrose.