Salivary proteins and microbiota as biomarkers for early childhood caries risk assessment

Early childhood caries （ECC） is a term used to describe dental caries in children aged 6 years or younger. Oral streptococci, such as Streptococcus mutans and Streptococcus sorbrinus, are considered to be the main etiological agents of tooth decay in children. Other bacteria, such as Prevotella spp. and Lactobacillus spp., and fungus, that is, Candida albicans, are related to the development and progression of ECC. Biomolecules in saliva, mainly proteins, affect the survival of oral microorganisms by multiple innate defensive mechanisms, thus modulating the oral microflora. Therefore, the protein composition of saliva can be a sensitive indicator for dental health. Resistance or susceptibility to caries may be significantly correlated with alterations in salivary protein components. Some oral microorganisms and saliva proteins may serve as useful biomarkers in predicting the risk and prognosis of caries. Current research has generated abundant information that contributes to a better understanding of the roles of microorganisms and salivary proteins in ECC occurrence and prevention. This review summarizes the microorganisms that cause caries and tooth-protective salivary proteins with their potential as functional biomarkers for ECC risk assessment. The identification of biomarkers for children at high risk of ECC is not only critical for early diagnosis but also important for preventing and treating the disease.

Expert consensus on early childhood caries management

Early childhood caries(ECC)is a significant chronic disease of childhood and a rising public health burden worldwide.ECC may cause a higher risk of new caries lesions in both primary and permanent dentition,affecting lifelong oral health.The occurrence of ECC has been closely related to the core microbiome change in the oral cavity,which may be influenced by diet habits,oral health management,fluoride use,and dental manipulations.So,it is essential to improve parental oral health and awareness of health care,to establish a dental home at the early stage of childhood,and make an individualized caries management plan.Dental interventions according to the minimally invasive concept should be carried out to treat dental caries.This expert consensus mainly discusses the etiology of ECC,caries-risk assessment of children,prevention and treatment plan of ECC,aiming to achieve lifelong oral health.

Differences in carbon source usage by dental plaque in children with and without early childhood caries

Early childhood caries （ECC） is a considerable pediatric and public health problem worldwide. Preceding studies have focused primarily on bacterial diversity at the taxonomic level. Although these studies have provided significant information regarding the connection between dental caries and oral micmbiomes, further comprehension of this microbial community＇s ecological relevance is limited. This study identified the carbon source metabolic differences in dental plaque between children with and without ECC. We compared the microbial community functional diversity in 18 caries-free subjects with 18 severe ECC patients based on sole carbon source usage using a Biolog assay. The anaerobic microbial community in the ECC patients displayed greater metabolic activity than that of the control group. Specific carbon source metabolism differed significantly between the two groups. Subjects from the two groups were well distinguished by cluster and principal component analyses based on discriminative carbon sources. Our results implied that the microbial functional diversity between the ECC patients and healthy subjects differed significantly. In addition, the Biolog assay furthered our understanding of oral microbiomes as a composite of functional abilities, thus enabling us to identify the ecologically relevant functional differences among oral microbial communities.

Characterizing Diversity of Lactobacilli Associated with Severe Early Childhood Caries: A Study Protocol

Lactobacilli have been consistently associated with dental caries for decades;however, knowledge of this group of bacteria in the etiology of the disease is limited to quantitative elucidation. Nowadays, explicit identification of oral Lactobacillus species is possible, despite their taxonomic complexity. Here we describe a combined approach involving both cultivation and genetic methods to ascertain and characterize the diversity and abundance of the Lactobacillus population in the oral cavities of children with severe early childhood caries (S-ECC). Eighty 3- to 6-year-old children (40 S-ECC and 40 caries free) who were seeking dental care at the Pediatric Dental Clinic of Bellevue Hospital in New York City were invited to participate in this study. Clinical data on sociodemographic information and oral health behavior were obtained from the primary caregiver. The data included a detailed dental examination, children’s medical history, and a questionnaire survey. Combined non-stimulated saliva and supragingival plaque samples were collected from each child and cultivated on selective media for quantitative measures of lactobacilli levels. The procedure for Lactobacillus species screening will include the random selection of 50 colonies per plate, ex- traction of DNA from each colony, and genotyping by arbitrarily primed polymerase chain reaction (AP-PCR). Each unique Lactobacillus AP-PCR genotype will be selected for taxonomic assessment by 16S rRNA gene sequencing analysis. Lactobacillus species will be identified by comparing the 16S rRNA sequences with the Ribosomal Database and the Human Oral Microbiome Database. Meanwhile, the same set of clinical samples will be independently subjected to genomic DNA isolation, 16S rRNA amplification with Lactobacillus genus-specific primers, sequencing, and taxonomic identification, both at genus and species levels with a customized pipeline. The distribution and phylogenetic differences of these Lactobacillus species will be compared between children with or without S-ECC. One of the main objectives of this study is to establish a study protocol for the identification and characterization of lactobacilli in the oral cavity. Future caries risk assessments can include lactobacilli counts (quantitative) and the presence/absence of specific cario- genic genetic signatures of a Lactobacillus species (qualitative) associated with S-ECC.

Iron deficiency and early childhood caries:a systematic review and meta-analysis

Backgrounds:Previous surveys have found that children with iron deficiency(ID)were likely to suffer from early childhood caries(ECC).We aimed to assess the scientific evidence about whether ID is intrinsically related to ECC.Methods:The medical subject headings(MeSH)terms and free words were searched on PubMed,Web of Science,Cochrane,China National Knowledge Infrastructure,Wanfang,and the Database for Chinese Technical Periodicals from March 2020 to September 2020.Two researchers independently screened the articles.Data extraction and cross-checking were performed for the studies that met the inclusion criteria.Meta-analysis was performed using the Cochrane Collaboration’s Review Manager 5.3 software.Results:After excluding duplication and irrelevant literature,12 case-control studies were included in the study.The meta-analysis demonstrated that children with ECC were more likely to have ID(odds ratio[OR]=2.63,95%confidence interval[CI]:[1.85,3.73],P<0.001).There was no statistically significant association found between the level of serum ferritin and ECC(weighted mean difference(WMD)=5.80,95%CI:[11.97,0.37],P=0.07).Children with ECC were more likely to have iron-deficiency anemia(OR=2.74,95%CI:[2.41,3.11],P<0.001).The hemoglobin(HGB)levels in the ECC group were significantly lower compared with that in the ECC-free group(WMD=9.96,95%CI:[15.45,4.46],P=0.0004).The mean corpuscular volume(MCV)levels in the ECC group were significantly lower compared with that in the ECC-free group(WMD=3.72,95%CI:[6.65,0.79],P=0.01).Conclusions:ID was more prevalent in children with ECC,and the markers of iron status in the ECC group,such as serum ferritin,HGB,and MCV,were relatively lower than the ECC-free group.

Caries Patterns in the Primary Dentition: Cluster Analysis of a Sample of 5,169 Arizona Children 5-59 Months of Age

Aim Cluster analysis was conducted on data from 5,169 United States （U.S.） Arizona children, age＇s 5-59-months with the goal of delineating patterns of caries in the primary dentition of pre-school children without a priori pattern definitions. Methodology Cluster analyses were conducted using all data for children ages 0-4 years in aggregate： 1） for all subjects, and 2） for subjects without crowned restored teeth. Each of these two sets of analyses consisted of 8 differently specified cluster analyses as a validation procedure. Results The caries patterns identified from the clustering analysis are： 1） smooth surfaces （other than the maxillary incisor）, 2） maxillary incisor, 3） occlusal surfaces of first molars, and 4） pit and fissure surfaces of second molars. Conclusion The cluster analysis findings were consistent with results produced by multidimensional scaling. These cross-validated patterns may represent resulting disease conditions from different risks or the timing of various risk factor exposures. As such, the patterns may be useful case definitions for caries risk factor investigations in children under 60 months of age.

Bioresponsive nanotherapy for preventing dental caries by inhibiting multispecies cariogenic biofilms

Early childhood caries(ECC)is a public healthcare concern that greatly reduces the quality of life of young children.As a leading factor of ECC,cariogenic biofilms are composed of acidogenic/aciduric pathogens and extracellular polysaccharides(EPSs),creating an acidic and protected microenvironment.Antimicrobial photodynamic therapy(aPDT)is a noninvasive,painless,and efficient therapeutic approach that is suitable for treating ECC.However,due to the hyperfine structure of cariogenic biofilms,most photosensitizers(PSs)could not access and penetrate deeply in biofilms,which dramatically hamper their efficiency in the clinic.Herein,bioresponsive nanoparticle loaded with chlorin e6(MPP-Ce6)is developed,which largely increases the penetration depth(by over 75%)and retention(by over 100%)of PS in the biofilm compared with free Ce6.Furthermore,MPP-Ce6-mediated aPDT not only kills the bacteria in preformed biofilms but also inhibits multispecies biofilm formation.A rampant caries model is established to mimic ECC in vivo,where the population of cariogenic bacteria is decreased to 10%after MPP-Ce6-mediated aPDT.Importantly,the number and severity of carious lesions are efficiently reduced via Keyes’scoring and micro-CT analysis.This simple but effective strategy can serve as a promising approach for daily oral hygiene in preventing ECC.