Risk factors for dental caries in childhood: a five-year survival analysis.

Objectives: The purpose of this study was to examine the risk factors of dental caries at the level of an individual person with survival analysis of the prospective data for 5 years.

Methods: A total of 249 first-grade students participated in a follow-up study for 5 years. All participants responded to a questionnaire inquiring about socio-demographic variables and oral health behaviors. They also received an oral examination and were tested for Dentocult SM and LB. Over 5 years, the participants received yearly oral follow-up examinations to determine the incidence of dental caries. The incidence of one or more dental caries (DC1) and four or more dental caries (DC4) were defined as one or more and four or more decayed, missing, and filled permanent teeth increments, respectively. Socio-demographic variables, oral health behaviors, and status and caries activity tests were assessed as risk factors for DC1 and DC4. The adjusted hazard ratios (HRs) of risk factors for DC1 and DC4 were calculated using Cox proportional hazard regression models.

Results: During the 5-year follow-up period, DC1 and DC4 occurred in 87 and 25 participants, respectively. In multivariate hazard models, five or more decayed, missing, and filled primary molar teeth [HR 1.93, 95% confidence interval (CI) 1.19-3.13], and Dentocult LB of two or three (HR 2.21, 95% CI 1.37-3.56) were independent risk factors of DC1. For DC4, only Dentocult LB of two or three was an independent risk factor (HR 2.95, 95% CI 1.11-7.79).

Conclusions: Our results suggest that dental caries incidence at an individual level can be associated with the experience of dental caries in primary teeth and Dentocult LB based on the survival models for the 5-year prospective data.