Preventive dentistry primarily aims to promote and maintain oral health. During the last 50 years, all children and adolescents in Sweden have been exposed to preventive programs through the public dental health. The programs include education in oral health (diet, hygiene measures, and tobacco use), fluoride application, and fissure sealants for permanent molars. Repeated epidemiological studies of the population in Jönköping, Sweden, show a dramatic improvement in oral health during this time period. The number of teeth has increased and edentulousness is very rare. The incidence of caries has continuously decreased and there has also been a decrease in the prevalence of mild and moderate periodontal disease. A risk-based preventive program, with a follow-up of 30 years, took place in Karlstad, Sweden. This preventive program included detailed information regarding oral health status and instructions in oral hygiene routines. During the first 2 years, the subjects attended maintenance visits every second month and then every third month for the subsequent 4 years. After 6 years, patients were recalled based on their risk profile. Compared to the control group the participants showed a low incidence of caries lesions. The new lesions were predominantly secondary lesions. They also had stable periodontal attachment levels, except for buccal surfaces.