Limitations
caries arrest, COVID-19 infection, caries, infection, tooth, tooth failure, arrest
INFECTION, COVID-19 INFECTION, ARREST, CARIES
This study has some limitations. Our analysis classified each study participant as positive or negative for caries prevention or arrest and thus did not distinguish between single tooth failure and multiple tooth failures. This classification was done to ensure that the comparison for study outcomes was conservative, wherein any instance of failure at the tooth level would be considered failure at the individual level, regardless of how many failures were actually observed, and is in accordance with prior studies of school-based caries prevention.The approximate 2-year gap between initial treatment and follow-up coincided with municipal policies stemming from COVID-19 infection rates in New York City, with baseline observations being conducted over a 6-month period from September 2019 to March 2020. On March 16, 2020, schools were closed citywide, and dental offices suspended care except for emergency procedures. Schools remained closed to all school-based health programs throughout the 2020-2021 academic year. The original study protocol stipulated that children would be followed up biannually, but the resulting gap in observation from baseline to first follow-up was 2 years. Although our analysis of primary outcomes for caries arrest and prevention at 2 years was not disrupted, the gap in observation meant that treated teeth could be exfoliated prior to follow-up and thus could not be included in analysis. In addition, only 47 of the originally proposed 60 schools were enrolled. This resulted in slight differences in total treatment group enrollment and baseline attributes; however, as the study analyzed caries arrest and prevention in isolation, these concerns are attenuated. Furthermore, preliminary power calculations for CariedAway estimated a necessary sample size of 396 that we artificially inflated by an a priori assumption of an intraclass correlation coefficient of 0.10, reflecting a moderate expectation of cluster correlation.Due to the continued effect of COVID-19, our follow-up rates among viable enrolled children was 46.6% (1398 of 2998). To partially address this limitation, we supplemented our original analysis with multiple imputation, and the results in the imputed sample were not different from those of the sample with completed follow-up observations. Despite this finding, our results should be interpreted with caution. Future longitudinal analysis of the CariedAway data will use all available observations of enrolled children to further expand on the presented analysis.New York City dental offices were authorized to reopen in June 2020 after the adoption of interim infection control and prevention guidelines, specifically the reduction of aerosol-generating procedures. Due to these restrictions on preventive care, combined with the CariedAway population being specifically chosen because of their traditional lack of access to or use of routine dental care, it is unlikely that confounding dental treatments were received in the time between observations.