Prevalence and incidence of dental caries and related risk factors in 70- to 76-year-olds

Abstract

Objective: The prevalence of caries and various risk factors was studied cross-sectionally in two cohorts of 72-year-olds over the course of 20 years. Incidence was also studied over a period of 6 years.

Material and methods: Samples of two dentate subjects from cohorts of 70 to 72-year-olds were included; cohort III (n=135), born 1911-12, and cohort VI (n=139), born 1930. Cohort III was also examined at 70 years of age and re-examined after 6 years. An interview and clinical examination, including DMFS, plaque and gingival bleeding indices, pocket depth, and secretion rate for stimulated whole saliva, were carried out.

Results: The mean numbers of teeth in cohorts III and VI were 14 and 21, respectively. On average, 2.1 tooth surfaces were decayed (DS) in cohort III compared with 1.3 in cohort VI (p<0.05). 49% of the individuals in cohort III did not develop any new DS, while 19% developed ≥3 DS during the 6-year follow-up period. The prevalence of caries was related to plaque and gingival bleeding indices, as well as a pocket depth of ≥4 mm, at ages 70 and 72. Moreover, the incidence of caries was related to the same factors.

Conclusions: The numbers of remaining teeth increased and the prevalence of caries decreased over the 20-year period. The incidence of caries over the follow-up period of 6 years was moderate. The results indicate that the prevalence of plaque, gingival bleeding, and a pocket depth of ≥4 mm are predictive factors for both prevalence and incidence of caries.