Background The prevalence of periodontitis increases with aging. The present study aimed to assess descriptively the changes in periodontal status over an 18-year period among individuals aged 60 and 66 years at baseline who participated in the Swedish National Study on Aging and Care in Karlskrona, Sweden.

Methods This longitudinal study used quantitative methods based on data from the ongoing project, The Swedish National Study on Aging and Care (SNAC) in Karlskrona, Sweden. A total of 340 individuals aged 60 and 66 years underwent periodontal and radiographic examinations at baseline (2001-2003). Follow-up assessments were conducted after 12 years (2013-2015; n = 217) and after 18 years (2019-2021; n = 79). A paired t-test, McNemar's test, and binary logistic regression were performed for the statistical analysis. Statistical significance was determined at p < 0.05.

Results Overall, the mean value BOP (SD) increased from 19.71(17.6) % at baseline to 32.73 (21.7) % at the 18-year follow-up (Cohen's d = -0.57; 95%CI: -0.81 to -0.33; p < 0.001). The proportion of participants with at least one site exhibiting a bone level >= 5 mm increased significantly, from 49.4% at baseline to 88.6% at the 18-year follow-up, corresponding to an absolute increase of 39.2 percentage points (p < 0.001). In addition, the prevalence of periodontitis increased from 7.8% to 19.5% over the same period, an absolute increase of 11.7 percentage points (p = 0.035).

Conclusions The present study indicates that periodontal status deteriorates over 18 years among participants aged 60 and 66 years at baseline.