Tooth-surface progression and reversal changes in fluoridated and no-longer-fluoridated communities over a 3-year period

Objective: To com pa re permanent tooth surface-specific progression/revers al changes between fluoridation-ended (F-E) and still-fluoridated (S-F) com munities in British Columbia, Canada, over a 3-year period. Methods: D1D2MF S examinations were contrasted for 2,964 schoolchildren in 1993/94 (grades 2, 3, 8 and 9) and 1996/97 (grades 5, 6, 11 and 12). Generalized Estimating Equation (GEE) models explored the relation between progression/reversal c hanges and fluoridation status, age, gender, socioeconomic status, and diet ary/fluoride histories. Results: Within a scenario of low levels of caries overall, few children had multiple surfaces progressing. At least one smoot h surface progressed in 31.4% of subjects; at least one pit-and-fissure (PF ) surface progressed in 43.1% of subjects. At least one smooth surface reve rted in 89% of subjectswho had reversible stages; at least one PF reverted in 23.8% of subjects who had reversible stages. GEE (smooth) indicated that odds ratios of progression were twice as large large in the F-E site compa red to the S-F site, and slightly increased in older participants and in pa rticipants exposed to more fluoride technologies. GEE (PF) also indicated t hat progression was slightly more common in the F-E site; more frequent sna cking and lower parental educational attainment had modest associations wit h increased progression in PF surfaces. For the two types of surfaces, GEE models demonstrated that unerupted surfaces were less likely to progress th an sound surfaces. No associations were found between reversals and indepen dent variables. Conclusion: Progressions were found to be weakly linked to socio-demographic factors; baseline surface statuses were better predictors of progression. Using the current definitions for disease transitions, F-E communities had more frequent progressions than a S-F community. Copyright (C) 2001 S. Karger AG, Basel.