Risk factors associated with occlusal caries in first permanent molars in a school program: longitudinal study

Aim: Evaluate the longitudinal status of dental caries in the occlusal surface of first permanent molars (FPM) and to identify risk factors for the progression to cavitated caries lesions in a school oral health program. Methods: Children who were enrolled in the program between September 2017 and October 2019, 5 to 10 years-old, presenting the four FPM were included. Four calibrated examiners assessed dental caries according to Nyvad criteria. Descriptive analysis included frequency, mean, and standard deviation calculations. Chi-square test was used in the bivariate analysis and, logistic regression adjusted for cluster effect was used to identify significant risk factors for cavity among the following independent variables: gender, age in the baseline, deft, upper/lower molar, initial caries score, Molar Incisor Hypomineralization (MIH), fluorosis, occlusal sealing. Odds ratio (OR) and respective confidence intervals (CI) are presented. Results: From 174 children enrolled in the program between 2017/2019, 120 were reevaluated in 2022. Eleven (2.6%) FPM in 11 children (9.2%) presented cavitated caries in the follow up examination. Significant risk factors for cavity were caries experience in the primary teeth (OR = 5.59; CI: 1.4 ­ 22.3) and the presence of MIH (OR = 5.33; CI: 1.6 ­ 18.1). Most of the active lesions in the follow up were considered active in the baseline examination. Conclusions: The progression to cavity was relatively low, significantly influenced by past caries experience and MIH

A framework to validate fluorescently labeled DNA-binding proteins for single-molecule experiments.

Due to the enhanced labeling capability of maleimide-based fluorescent probes, lysine-cysteine-lysine (KCK) tags are frequently added to proteins for visualization. In this study, we employed an in vitro single-molecule DNA flow-stretching assay as a sensitive way to assess the impact of the KCK tag on the property of DNA-binding proteins. Using Bacillus subtilis ParB as an example, we show that, although no noticeable changes were detected by in vivo fluorescence imaging and chromatin immunoprecipitation (ChIP) assays, the KCK tag substantially altered ParB's DNA compaction rates and its response to nucleotide binding and to the presence of the specific sequence (parS) on the DNA. While it is typically assumed that short peptide tags minimally perturb protein function, our results urge researchers to carefully validate the use of tags for protein labeling. Our comprehensive analysis can be expanded and used as a guide to assess the impacts of other tags on DNA-binding proteins in single-molecule assays.