Aim: To assess trends over 40 years regarding prevalence and severity of periodontitis in a Swedish adult population.

Materials and methods: Cross-sectional examinations using the same clinical protocol have been repeated every 10years (1973-2013) in a Swedish city with focus on periodontal disease in adults. Periodontal recordings included all teeth, excluding 3rd molars. Periodontal disease experience was classified (no/minor, moderate and severe).

Results: The no/minor group increased from 43% in 1983 to 60% in 2013. There was a non-significant trend for a decrease of the severe group. Over the 40-year period, the number of teeth increased significantly and at the examination 2013, the severe group accounted for this increase. More than 60% of the study population in 2013 had no periodontal pockets (PD) 6mm. The number of PD 4mm and 6mm were unaltered between 2003 and 2013 in all age groups, except for the 20-year old individuals. This group showed a statistically significant increase of 4mm PD.

Conclusions: The periodontal health has improved in the population over the 40 years. The number of teeth increased significantly in the population, and in 2013, this increase occurred entirely in the severe group. Finally, there was a trend toward diminished prevalence of severe periodontitis.