Four-year incidence rate and predictors of root caries among community-dwelling south Brazilian older adults

Objective: This study aimed to assess the incidence density (ID) of new root caries lesions and restorations among community-living south Brazilian older adults and to assess its association with predictor variables. Methods: We conducted a prospective cohort with a random sample of elders from the municipality of Carlos Barbosa, in south Brazil. Trained dentists performed interviews and oral examinations in 388 individuals at baseline, of which 273 were retained at follow-up 4 years later. Our outcome was root caries ID, with 100 root-years as its unit of measure. Demographic, biological and lifestyle predictors were tested with Poisson regression. Results: The mean number of roots at baseline among participants was 7.0 (SD ± 4.9) and the incidence rate per 100 root-year 4.9 (SD ± 8.9). Incidence of root caries among these older Brazilians was of 47.3%. The associated factors with the incidence of root caries were age, geographic location of residence, frequency of tooth brushing and stimulated saliva flow rate. Conclusion: Age, external environment, personal practices and oral status were predictors of the incidence of root caries. Preventive strategies including the use of fluorides and instruction to improve the attitude and behaviour towards oral hygiene are needed.