Association between more complex special care needs and overweight status and adolescents' difficulty with dental caries.

OBJECTIVE: Little is known about dental caries experience in adolescents with overweight and complex special health care needs (SHCNs). METHODS: Adolescent data (10-17 years) from the 2016-2020 National Survey of Children's Health (n = 91,196) was analyzed. The sample was grouped into the following: more complex SHCN and overweight, more complex SHCN without overweight, less complex SHCN and overweight, less complex SHCN without overweight, no SHCN but with overweight, and neither SHCN nor overweight. A multivariable-adjusted logistic regression model was conducted. RESULTS: Adolescents with more complex SHCNs with (OR: 1.82, 95% CI: 1.44-2.30, p < 0.001) or without overweight (OR: 1.51, 95% CI: 1.30-1.76, p < 0.001) were at higher odds of experiencing dental caries compared to healthy adolescents. No significant associations were observed between adolescents with less complex or no SHCN regardless of the overweight status with healthy adolescents. CONCLUSIONS: Adolescents with more complex SHCNs, irrespective of overweight status, experienced a higher caries severity than adolescents with no SHCNs or overweight.

Tooth-Specific Streptococcus mutans Distribution and Associated Microbiome.

Dental caries is multifactorial and polymicrobial in nature and remains one of the most common oral diseases. While caries research has focused on Streptococcus mutans as the main etiological pathogen, its impact at the tooth level is not fully understood. In this cross-sectional study, the levels and distribution of S. mutans in the posterior teeth at different dentition stages were investigated along with the corresponding tooth-specific microbiome. Occlusal plaque samples of 87 individual posterior teeth were collected from thirty children in three dentition stages (primary, mixed, and permanent). The S. mutans levels in the occlusal plaque of individual posterior teeth were quantified with qPCR, and those with preferential colonization were selected for tooth-specific microbiome analysis using 16S rRNA sequencing. Results: Quantification of S. mutans levels in the occlusal plaque confirmed the preferential colonization on the first primary and permanent molars. These teeth were selected for further tooth-specific microbiome sequencing, as they also displayed high caries experience. There were significant differences in the relative abundance of the four most abundant genera: Neisseria, Streptococcus, Rothia, and Veillonella. Furthermore, the tooth-level caries experience was correlated with a reduction in the microbiome diversity. Analyzing the different tooth-associated microbial communities, distinct tooth-specific core microbiomes were identified. Conclusions: Our findings suggest that caries susceptibility at the tooth level, depending on tooth type and dentition stage, is influenced by individual species as well as plaque community.

Effect of Cigarette and E-Cigarette Smoke Condensates on Candida albicans Biofilm Formation and Gene Expression.

Smoking triggers environmental changes in the oral cavity and increases the risk of mucosal infections caused by Candida albicans such as oral candidiasis. While cigarette smoke has a significant impact on C. albicans, how e-cigarettes affect this oral pathogen is less clear. Here, we investigated the effect of cigarette and e-cigarette smoke condensates (CSC and ECSC) on C. albicans growth, biofilm formation, and gene expression. Whereas pure nicotine (N) at the minimum inhibitory concentration (MIC, 4 mg/mL) prevented C. albicans growth, enhanced biofilm formation was observed at 0.1 mg/mL. In contrast, at this nicotine sub-MIC (0.1 mg/mL) concentration, CSC and ECSC had no significant effect on C. albicans biofilm formation. Additionally, N, CSC, and ECSC increased the expression of HWP1 and SAP2 genes. The ECSC group exhibited elevated expression levels of the EAP1 and ALS3 genes, compared to the nicotine-free ECSC (-) control. Moreover, our in vitro study illustrated that the antifungal drugs, fluconazole and amphotericin B, alleviated the effect of nicotine on C. albicans gene expression. Overall, the results of the study indicated nicotine from different sources may affect the pathogenic characteristics of C. albicans, including hyphal growth, biofilm formation, and particularly the expression of virulence-related genes.

The impact of fixed orthodontic appliances and clear aligners on the oral microbiome and the association with clinical parameters: A longitudinal comparative study.

INTRODUCTION: Orthodontic treatment interferes with oral hygiene and promotes plaque retention, which leads to gingival inflammation and enamel demineralization. Although removable clear aligners (CAs) are designed to improve oral hygiene compared with fixed appliances (FAs), comprehensive studies comparing their respective effects on the oral microbiome are limited. This longitudinal study investigated the microbial changes during orthodontic treatment with FA and CA in correlation with clinical parameters. METHODS: Clinical parameters and supragingival plaque were collected from 12 study participants for the FA or CA treatment groups at baseline and at least twice at the 1, 3, 6, and 12-month follow-up appointments. The plaque was also harvested from the aligner tray for the CA group. Microbiome composition was determined via 16S rRNA gene sequencing, compared between groups, and correlated with clinical parameters. RESULTS: Plaque (PI) and gingival indexes (GI) increased significantly in the FA but not the CA group. Beta but not alpha diversities of the microbial communities were distinct between the 2 treatment groups, even though genus-level differences were not significant except for Leptotrichia. The CA tray harbors a unique plaque community. Elevated PI and GI in the FA group correlated with a higher abundance of disease-related genera. CONCLUSIONS: Orthodontic treatments trigger appliance-related plaque community shifts from baseline, and the CA tray environment attracts distinct microbial communities. In comparison with FA, the use of CA resulted in better oral health index outcomes, which is reflected by the corresponding PI and GI-associated oral microbial communities.

Oral Microbiome: Streptococcus mutans/Caries Concordant-Discordant Children.

Dental caries remains the most common chronic disease in children, and the respective etiology is not fully understood. Though Streptococcus mutans is an important factor in the initiation and progression of caries, its presence is not always associated with the disease. The existence of caries discordant populations, in which S. mutans counts do not correlate with caries experience, poses a challenging problem. This study explored the possible correlation of S. mutans and other microorganism levels on caries-associated ecology of caries-concordant and discordant populations. A total of forty-seven children were analyzed in this study and stratified into four clinical groups based on their S. mutans levels in saliva (HS/LS: High/low S. mutans) and caries experience. Streptococcus mutans levels were determined by culture-based selective plating. The salivary microbiome of caries concordant and discordant populations was investigated by 16S rRNA gene sequencing and downstream bioinformatics analysis. The salivary microbial communities significantly clustered based on S. mutans levels and independent of their caries experience. In addition to S. mutans levels, significant differences in the abundance of other species were observed between HS and LS groups. Interestingly, disease-associated species such as Veillonella dispar, Streptococcus spp., and Prevotella spp. were significantly increased in HS groups and may contribute, in combination with S. mutans, to the caries progression. Furthermore, health-associated species exhibited higher abundance in the LS groups, such as Veillonella rogosae, Haemophilus sp., and Alloprevotella spp. but their possible contribution to the caries process remains to be elucidated. This study provides evidence that S. mutans may play a role in shaping the salivary microbial community. Our results highlight that future caries research should consider additional species as health/disease microbial markers in conjunction with S. mutans to improve diagnosis and caries management of the caries-discordant population.

Omics and interspecies interaction.

Interspecies interactions are key determinants in biofilm behavior, ecology, and architecture. The cellular responses of microorganisms to each other at transcriptional, proteomic, and metabolomic levels ultimately determine the characteristics of biofilm and the corresponding implications for health and disease. Advances in omics technologies have revolutionized our understanding of microbial community composition and their activities as a whole. Large-scale analyses of the complex interaction between the many microbial species residing within a biofilm, however, are currently still hampered by technical and bioinformatics challenges. Thus, studies of interspecies interactions have largely focused on the transcriptional and proteomic changes that occur during the contact of a few prominent species, such as Porphyromonas gingivalis, Streptococcus mutans, Candida albicans, and a few others, with selected partner species. Expansion of available tools is necessary to grow the revealing, albeit limited, insight these studies have provided into a profound understanding of the nature of individual microbial responses to the presence of others. This will allow us to answer important questions including: Which intermicrobial interactions orchestrate the myriad of cooperative, synergistic, antagonistic, manipulative, and other types of relationships and activities in the complex biofilm environment, and what are the implications for oral health and disease?