WHO and FDI introduced in 1984 a simplified periodontal examination system for dental practitioners utilizing the CPITN. Finland was among the first countries to adopt the newly developed index nationwide. The process of introducing the CPITN was a tough and time-consuming task. Close co-operation between the administration, the educational system and the dental association was needed. The National Board of Health for Finland initiated the monitoring of periodontal diseases in 1981. The University of Helsinki was invited to provide the scientific basis for the monitoring process. The CPITN was then tested in a dozen municipal health centres. Testing of the index took one year and the results led to the adoption of the CPITN nationwide. In 1984 instructions for the use of CPITN were issued by the National Board of Health to all dentists in Finland. The role of the Finnish Dental Association was essential in launching a national training programme on the practical use of the index. The first national data on CPITN indicate that the index is suitable and useful in the monitoring of the periodontal health of the population. It is noteworthy that the national introduction of this index took several years in a fairly well developed small country. Much co-operation, testing and training were required until the first national results using CPITN were available.