A dental health survey including an interview, a questionnaire and a clinical examination was conducted among adults aged 25, 35, 50, and 65 yr in Ostrobothnia, Finland. A total of 1275 subjects, 80% of the sample, participated in the clinical examination. 40% of the subjects with at least one dentate sextant had noticed gingival bleeding, 16% gingival inflammation, 20% "gum disease", and 70% at least one decayed tooth. When objectively assessed, a total of 98% had a maximum CPITN code 1-4, 38% a maximum CPITN code 3-4 and 76% were deemed to be in need of fillings. Dentures were objectively non-acceptable in 64% of wearers and subjectively so in 42%. A need for replacing missing teeth was expressed by 14% of the total sample, whereas according to "objective" assessment, 23% had such a need. It is concluded that people tend to underestimate their dental treatment needs, the discrepancy being most distinct in the field of periodontology. Sufficient emphasis should thus be given to improving people's awareness and knowledge of their own dental disorders.