The effect of the national scaling program on tooth loss: a claim-based matched large cohort study in Korea.

Objective: Tooth loss affects quality of life. Scaling is a measure to prevent periodontal disease and tooth loss. This study aimed to determine the effect of scaling on tooth loss.

Basic research design: Secondary analysis of the Korean National Health Insurance Services database, comprising 514,866 Koreans as an initial cohort, followed for 14 years up to 2015. The study population comprised people who had received an oral check-up in 2002-2003. Using propensity score matching, we matched the intervention group (receipt of scaling) and controls (no scaling) 1:1. The outcome, tooth loss was defined as including all teeth except for third molars until 2015. The final sample included 94,738 people. Analysis used a Cox proportional hazard regression model.

Results: Scaling showed conflicting results in univariate and multivariable analyses. In univariate analysis, people who received scaling were more likely to lose teeth (HR, 1.04; 95% CI, 1.02-1.05). After adjusting for confounders in the multivariable analysis, those who didn't receive scaling were more likely to lose teeth (HR, 0.97; 95% CI, 0.95, 0.99). The effects of scaling were identified in people without diabetes (HR, 0.97; 95% CI, 0.95, 0.99) but not in people with diabetes (HR, 0.97; 95% CI, 0.89-1.06).

Conclusions: Scaling was associated with less tooth loss. Regular scaling might be encouraged for vulnerable groups, such as males, older adults, lower income, handicapped, chronic diseases, and smokers.