Oral health status and associated factors among 12 to 15-year-old Chinese adolescents in Southeast China: A cross-sectional study.

This study assessed oral health conditions and associated factors (including sociodemographic characteristics and self-reported oral health-related behaviors) among Chinese adolescents. This cross-sectional study enrolled 3840 adolescents aged 12 to 15 years from 12 middle schools in Foshan, Southeast China, in 2016, using multistage, stratified cluster sampling. Participants underwent a clinical oral examination and completed a questionnaire. The prevalence of dental caries, probe bleeding, and calculus was 37.6%, 46.2%, and 39.7%, respectively; the mean decayed/missed/filled teeth index was 0.86 ±â€…1.58. A mean of 2.09 ±â€…3.65 and 1.85 ±â€…3.52 teeth showed probe bleeding and calculus, respectively. Only 0.3% and 0.1% of adolescents aged 15 years had periodontal pockets (depth ≥ 4 mm) and attachment loss, respectively, which were most common in tooth positions 46 and 36 (Federation Dentaire International 2-digit system). Regarding oral health-related behavior, 49.1% of the participants failed to brush their teeth at least twice daily, 98.5% never or rarely used dental floss, and 58.7% reported middle-high frequency sugar consumption. Older age, female, administrative region, maternal education lower than university, brushing teeth less than twice daily, flossing less than once daily, and frequent sugar consumption were significant risk factors of caries. Older age, female, administrative region, brushing less than twice daily, and flossing less than once daily significantly increased periodontal risk. Despite the overall low prevalence of adverse dental conditions among adolescents in Foshan, their oral hygiene habits were undeveloped. Thus, their identified risk factors need close monitoring, and families, schools, communities, and the government should jointly promote adolescents' oral health.

Pre-Endcapping of Hyperbranched Polymers toward Intrinsically Stretchable Semiconductors with Good Ductility and Carrier Mobility.

The advancement of semiconducting polymers stands as a pivotal milestone in the quest to realize wearable electronics. Nonetheless, endowing semiconductor polymers with stretchability without compromising their carrier mobility remains a formidable challenge. This study proposes a "pre-endcapping" strategy for synthesizing hyperbranched semiconducting polymers (HBSPs), aiming to achieve the balance between carrier mobility and stretchability for organic electronics. The findings unveil that the aggregates formed by the endcapped hyperbranched network structure not only ensure efficient charge transport but also demonstrate superior tensile resistance. In comparison to linear conjugated polymers, HBSPs exhibit substantially larger crack onset strains and notably diminished tensile moduli. It is evident that the HBSPs surpass their linear counterparts in terms of both their semiconducting and mechanical properties. Among HBSPs, HBSP-72h-2.5 stands out as the preeminent candidate within the field of inherently stretchable semiconducting polymers, maintaining 93% of its initial mobility even when subjected to 100% strain (1.41 ± 0.206 cm2 V-1 s-1). Furthermore, thin film devices of HBSP-72h-2.5 remain stable after undergoing repeated stretching and releasing cycles. Notably, the mobilities are independent of the stretching directions, showing isotropic charge transport behavior. The preliminary study makes this "pre-endcapping" strategy a potential candidate for the future design of organic materials for flexible electronic devices.