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Dental caries is a widespread bacterial infectious disease that imposes a significant public health burden globally. The primary culprits in caries development are cariogenic bacteria, notably Streptococcus mutans ( S. mutans ), due to their robust biofilm-forming capabilities. To address this issue, a series of cationic pyridinium-substituted photosensitizers with aggregation-induced emission have been designed. All of these aggregation-induced emission luminogens (AIEgens) exhibit outstanding microbial visualization and photodynamic killing of S. mutans , thanks to their luminous fluorescence and efficient singlet oxygen generation ability. Notably, one of the membrane-anchored AIEgens (TDTPY) can inactivate planktic S. mutans and its biofilm without causing significant cytotoxicity. Importantly, application of TDTPY-mediated photodynamic treatment on in vivo rodent models has yielded commendable imaging results and effectively slowed down caries progression with assured biosafety. Unlike traditional single-mode anticaries materials, AIEgens integrate the dual functions of detecting and removing S. mutans and are expected to build a new caries management diagnosis and treatment platform. To the best of our knowledge, this is also the first report on the use of AIEgens for anticaries studies both in vitro and in vivo.

Objectives: To compare the effectiveness of caries arrest by micro-operative treatment (sealing) to operative treatment (flowable resin composite restoration) through a 2-year randomized controlled clinical trial., Materials and Methods: A prospective randomized controlled trial was conducted among 7-9-year-old children. At baseline, 630 subjects were screened and 92 children who had at least one carious lesion classified as ICDAS 3 on the pit and fissure of first permanent molar were included. Then they were randomly assigned to the sealant group (73 lesions) and the flowable resin composite group (76 lesions) to receive the corresponding intervention. Lesions status in each group was evaluated every 6 months up to 24 months. Clinical progression of dental caries and materials retention were the outcomes used for group comparisons at p-value < 0.05., Results: After 24 months, three lesions (4.1%) in the sealant group clinically progressed to dentin caries. No lesion in the flowable composite group was observed a progression. The results of Life-table survival analysis show that the cumulative caries arrest rate had no statistically significant difference between the two groups (p = 0.075). However, the cumulative retention rate was 57.5% in the sealant group and 92.1% in the flowable composite group, with significant differences (p < 0.001). The multilevel mixed model showed the sealant had higher risk of retention failure than the flowable composite (OR = 8.66, p < 0.001), while tooth position did not influence material retention (p = 0.083). In addition, the results of Fisher Exact test show that dentin lesions had more retention failure than enamel lesions in the sealant group (p = 0.026)., Conclusion: Although sealing microcavitated carious lesions of the first permanent molar achieved lower retention rate than resin composite restoration, both sealing and restoration effectively arrested caries progression for two years., Clinical Relevance: To preserving dental structure and delaying or eliminating the need for operative procedures, microcavitated carious lesion can be arrested by sealing., Trial Registration: Registered at http://www.chictr.org.cn ; Feb 15th, 2020; No. ChiCTR2000029862., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: We aimed to investigate the composition and functions discrepancy of supragingival plaque associated with active deciduous teeth caries in mixed dentitions., Design: Thirty-three subjects with mixed dentition participated in this study. Children with deciduous teeth caries (dt ≥ 3) were recruited to the caries group, whereas children without deciduous teeth caries (dt = 0) were recruited to the caries-free group. Plaque were collected from deciduous teeth surface and permanent teeth surface respectively. A total of 66 samples of dental plaque were collected and conserved. Illumina 16S rRNA sequencing and diversity analysis were performed for microbiome. Untargeted liquid chromatograph-mass (LC-MS) and partial least squares discriminant analysis were performed for metabolome., Results: A dominant microbiome of 8 phyla and 22 genera were detected. The alpha diversity indices did not detect differences between the caries and caries-free groups (p > 0.05). Beta diversity analysis showed that the microbiota composition was similar between subgroups. Comparative analysis at genus level did not detect difference between caries and caries-free subgroups. The metabolomics analysis yielded 419 biochemical metabolites, 56 of which were related to caries status. Metabolites in glucose metabolism and byproducts of oxidative stress were identified as related to dental caries in mixed dentition. Dominant bacteria are positively correlated with metabolites, such as Streptococcus and organic acids., Conclusions: The upgrade of glucose metabolism and oxidative stress was observed in caries status. Functions discrepancy of oral microbiome may be more pronounced than the composition of oral microbiome with active dental caries in mixed dentitions., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Biofilm formation under cariogenic conditions contributes to dental caries development, in which Streptococcus mutans (S. mutans) is regarded as the major cariogenic bacteria. Here, we synthesized a series of imidazolium salts. Their properties of antimicrobial and anti-biofilm were investigated. The microdilution method crystal violet staining, and cell counting Kit-8 assay were used to screen imidazolium salts. Then, the bacterial composition in multi-species biofilm composed of S. mutans, Actinomyces naeslundii, and Streptococcus gordonii was quantified by quantitative PCR. The exopolysaccharide and morphology of the structure of multi-species biofilm were further observed by confocal laser scanning microscopy and scanning electron microscope, respectively. Imidazolium salts exhibited highly antimicrobial activity against oral pathogens, especially for S. mutans. Compounds with ortho-diisopropyl and para-methoxyl on N-moieties as well as bearing ancenaphthyl skeleton (C5) showed the lowest cytotoxicity and most efficient anti-biofilm activity. C5 inhibited approximately 50% of multi-species biofilm at 0.98 μg/mL. Notably, C5 resulted in 98.97% live S. mutans and 77.65% A. naeslundii decreased. Furthermore, the exopolysaccharide was reduced by 88%, along with a sparse and scattered microstructure. The imidazolium salts present low cytotoxicity and remarkable antimicrobial activity against S. mutans in multi-species biofilm, suggesting that they may have a great potential in anti-biofilm clinical applications. [ABSTRACT FROM AUTHOR]

A series of well-defined copper-NHCs have been synthesized and characterized. Relationship between the structure of the copper-NHCs and the inhibition effects was investigated, and Copper-NHCs of Cu1 was demonstrated as a broad-spectrum inhibitor to oral bacteria. With the goal of developing high-efficiency oral antimicrobial agents to prevent S. mutans biofilm formation, a collection of copper(I)- N -heterocyclic carbenes (NHCs) complexes with different substitutions was synthesized and characterized. Their inhibitory activities of Cu1–Cu7 were screened. It was found that Cu1 provided significant excellent performance, which suggested that the less lipophilic and less sterically hindered copper complexes would be effective towards the bacteria. This study demonstrates the great potential of copper(I)-containing small molecule complexes as broad-spectrum inhibitors to treat oral bacteria, especially for diminishing S. mutans biofilm formation, which opens promising perspectives for the development of new metal-NHCs for controlling the biofilm formation associated with pathogens. [ABSTRACT FROM AUTHOR]