Exploring the genomic basis of early childhood caries: a pilot study.

OBJECTIVE: A genetic component in early childhood caries (ECC) is theorized, but no genome-wide investigations of ECC have been conducted. This pilot study is part of a long-term research program aimed to: (1) determine the proportion of ECC variance attributable to the human genome and (2) identify ECC-associated genetic loci. METHODS: The study's community-based sample comprised 212 children (mean age=39 months; range = 30-52 months; males = 55%; Hispanic/Latino = 35%, African-American = 32%; American Academy of Pediatric Dentistry definition of ECC prevalence = 38%). Approximately 2.4 million single nucleotide polymorphisms (SNPs) were genotyped using DNA purified from saliva. A P < 5 × 10-8 criterion was used for genome-wide significance. SNPs with P < 5 × 10-5 were followed-up in three independent cohorts of 921 preschool-age children with similar ECC prevalence. RESULTS: SNPs with minor allele frequency ≥5% explained 52% (standard error = 54%) of ECC variance (one-sided P = 0.03). Unsurprisingly, given the pilot's small sample size, no genome-wide significant associations were found. An intergenic locus on 4q32 (rs4690994) displayed the strongest association with ECC [P = 2.3 × 10-6 ; odds ratio (OR) = 3.5; 95% confidence interval (CI) = 2.1-5.9]. Thirteen loci with suggestive associations were followed-up - none showed evidence of association in the replication samples. CONCLUSION: This study's findings support a heritable component of ECC and demonstrate the feasibility of conducting genomics studies among preschool-age children.

Photo Inactivation of Streptococcus mutans Biofilm by Violet-Blue light.

Among various preventive approaches, non-invasive phototherapy/photodynamic therapy is one of the methods used to control oral biofilm. Studies indicate that light at specific wavelengths has a potent antibacterial effect. The objective of this study was to determine the effectiveness of violet-blue light at 380-440 nm to inhibit biofilm formation of Streptococcus mutans or kill S. mutans. S. mutans UA159 biofilm cells were grown for 12-16 h in 96-well flat-bottom microtiter plates using tryptic soy broth (TSB) or TSB with 1 % sucrose (TSBS). Biofilm was irradiated with violet-blue light for 5 min. After exposure, plates were re-incubated at 37 °C for either 2 or 6 h to allow the bacteria to recover. A crystal violet biofilm assay was used to determine relative densities of the biofilm cells grown in TSB, but not in TSBS, exposed to violet-blue light. The results indicated a statistically significant (P < 0.05) decrease compared to the non-treated groups after the 2 or 6 h recovery period. Growth rates of planktonic and biofilm cells indicated a significant reduction in the growth rate of the violet-blue light-treated groups grown in TSB and TSBS. Biofilm viability assays confirmed a statistically significant difference between violet-blue light-treated and non-treated groups in TSB and TSBS. Visible violet-blue light of the electromagnetic spectrum has the ability to inhibit S. mutans growth and reduce the formation of S. mutans biofilm. This in vitro study demonstrated that violet-blue light has the capacity to inhibit S. mutans biofilm formation. Potential clinical applications of light therapy in the future remain bright in preventing the development and progression of dental caries.

Children's oral health-related behaviours and early childhood caries: A latent class analysis.

OBJECTIVE: In this cross-sectional study in a large community-based sample of preschool-age children, we sought to identify distinct clusters of modifiable early childhood oral health-related behaviours (OHBs) and quantify their association with clinical and parent-reported measures of early childhood oral health. METHODS: We relied upon a questionnaire (n = 8033; 11% in Spanish) and clinical oral health data (n = 6404; early childhood caries [ECC] prevalence = 54%] collected in the context of an epidemiologic study of early childhood oral health among 3- to 5-year-old children in North Carolina. Latent class analysis was used to identify clusters of modifiable OHBs based on parents' responses to 6 questionnaire items pertaining to their children's oral hygiene, diet and dental home. The optimal number of clusters was determined based on measures of model fit and interpretability. We examined associations of OHB clusters with clinical and parent-reported child oral health status (ie, ECC prevalence, severity and proportion with untreated disease) using bivariate association tests and multivariable regression modelling with marginal effects estimation accounting for clustered data. We used Mplus v.8.6 (Muthén & Muthén, Los Angeles, CA, USA) and Stata v.16.1 (StataCorp, College Station, TX, USA) for data analyses. RESULTS: We identified 2 OHB clusters, a favourable (74%) and an unfavourable (26%) one. Children in the favourable OHB cluster had better oral hygiene practices (ie, tooth brushing frequency and fluoridated toothpaste use), lower consumption frequency of sugar-containing snacks and beverages, less frequent reports of night-time bottle-feeding history and a higher likelihood of a dental home. Children in the unfavourable cluster had significantly higher ECC prevalence (57% vs 53%), caries burden (mean dmfs = 9.3 vs 7.6), untreated disease (43% vs 33%) and worse parent-reported oral health status than the favourable cluster. CONCLUSIONS: Our findings demonstrate the importance and utility of clustering common, modifiable ECC risk factors in population studies - health promotion efforts may centre on groups of people rather than individual behavioural risk factors.

Child Nutrition Patterns Are Associated with Primary Dentition Dental Caries.

Purpose: Diet is a well-established, modifiable factor influencing dental caries risk. However, evidence regarding its association with distinct clinical patterns of dental caries is lacking. The purpose of this study was to identify the association of child nutrition patterns with two distinct clinical presentations (subtypes) of childhood dental caries. Methods: The study sample comprised 120 children who were patients of a private pediatric dental practice: 30 ages one to three years (mean equals 2.2 years) with anterior carious lesions; 30 ages four to 12 years (mean equals six years) with posterior-only carious lesions; and 60 age-, gender-, and payment method-matched caries-free controls. Participants underwent dental examinations, and their guardians completed a 17-item nutrition frequency questionnaire. A latent profile analysis was used to define distinct dietary patterns and, subsequently, test their association with dental caries subtypes. Results: Dietary patterns were differentiated by consumption frequencies of water and cariogenic solid, soft, and liquid food items; a diet cluster characterized by frequent consumption of fruit juice, cereal bars, and daily vitamins was more common (P<0.05) among one- to three-year-old patients with anterior carious lesions compared to matched caries-free controls. Conclusions: These results affirm the key role of dietary patterns in childhood oral health and demonstrate the influence of fermentable carbohydrates on specific clinical subtypes of caries.

A Web-Based Rendering Application for Communicating Dental Conditions.

The importance of visual aids in communicating clinical examination findings or proposed treatments in dentistry cannot be overstated. Similarly, communicating dental research results with tooth surface-level precision is impractical without visual representations. Here, we present the development, deployment, and two real-life applications of a web-based data visualization informatics pipeline that converts tooth surface-level information to colorized, three-dimensional renderings. The core of the informatics pipeline focuses on texture (UV) mapping of a pre-existing model of the human primary dentition. The 88 individually segmented tooth surfaces receive independent inputs that are represented in colors and textures according to customizable user specifications. The web implementation SculptorHD, deployed on the Google Cloud Platform, can accommodate manually entered or spreadsheet-formatted tooth surface data and allows the customization of color palettes and thresholds, as well as surface textures (e.g., condition-free, caries lesions, stainless steel, or ceramic crowns). Its current implementation enabled the visualization and interpretation of clinical early childhood caries (ECC) subtypes using latent class analysis-derived caries experience summary data. As a demonstration of its potential clinical utility, the tool was also used to simulate the restorative treatment presentation of a severe ECC case, including the use of stainless steel and ceramic crowns. We expect that this publicly available web-based tool can aid clinicians and investigators deliver precise, visual presentations of dental conditions and proposed treatments. The creation of rapidly adjustable lifelike dental models, integrated to existing electronic health records and responsive to new clinical findings or planned for future work, is likely to boost two-way communication between clinicians and their patients.

Clinical Instructions for Using Silver Diamine Fluoride (SDF) in Dental Caries Management.

Manufacturer instructions for 38% silver diamine fluoride (SDF) are limited to current FDA clearance for tooth desensitization. There is a need for instructions to provide best-practice recommendations for off-label use of SDF for caries prevention and arrest. METHODS: The authors considered existing clinical approaches to the use of 38% SDF at pH 10 for the prevention and arrest of active dental caries, in light of the best current evidence. Application of SDF, with or without subsequent direct restoration, is included. The content was reviewed by stakeholders including but not limited to those listed on the consensus statement (Appendix A, below). RESULTS: 38% SDF for the prevention and arrest of active caries lesions, as well as compatibility with common direct restorative materials, such as glass-ionomer cement and resin composite, has a foundation in the scientific literature. A practical decision-flow diagram and accompanying best practices for treatment of caries lesions, based on clinical access and intention to restore, were developed based on available evidence and expert clinical observation when no evidence was available. CONCLUSIONS: Based on the best available evidence, a logical approach can be adopted regarding the practical use of 38% SDF for caries prevention and arrest. PRACTICAL IMPLICATIONS: SDF used as per these instructions for prevention on high-risk tooth surfaces and arrest of active caries lesions has a place in the practitioner's dental caries management armamentarium. When SDF is applied to active lesions, it can be used with or without subsequent restoration, depending on clinical context, expert judgment, and patient input.

Cohort Profile: ZOE 2.0-A Community-Based Genetic Epidemiologic Study of Early Childhood Oral Health.

Early childhood caries (ECC) is an aggressive form of dental caries occurring in the first five years of life. Despite its prevalence and consequences, little progress has been made in its prevention and even less is known about individuals' susceptibility or genomic risk factors. The genome-wide association study (GWAS) of ECC ("ZOE 2.0") is a community-based, multi-ethnic, cross-sectional, genetic epidemiologic study seeking to address this knowledge gap. This paper describes the study's design, the cohort's demographic profile, data domains, and key oral health outcomes. Between 2016 and 2019, the study enrolled 8059 3-5-year-old children attending public preschools in North Carolina, United States. Participants resided in 86 of the state's 100 counties and racial/ethnic minorities predominated-for example, 48% (n = 3872) were African American, 22% white, and 20% (n = 1611) were Hispanic/Latino. Seventy-nine percent (n = 6404) of participants underwent clinical dental examinations yielding ECC outcome measures-ECC (defined at the established caries lesion threshold) prevalence was 54% and the mean number of decayed, missing, filled surfaces due to caries was eight. Nearly all (98%) examined children provided sufficient DNA from saliva for genotyping. The cohort's community-based nature and rich data offer excellent opportunities for addressing important clinical, epidemiologic, and biological questions in early childhood.

Surgical Management of Caries Lesions: Selective Removal of Carious Tissues.

Traditionally, before placing a restoration, excavation of tissues affected by caries was recommended. The goal was to have all walls of the cavity on sound, hard dentin, even when at risk of pulpal exposure. Current understanding of the caries process indicates that preserving tooth structure can lead to better long-term outcomes. Selective caries excavation refers to preserving tooth structure by delineating excavation in the pulpal and axial wall according to lesion severity and depth as well as pulpal health while keeping all cavity margins on sound tooth structure. Compounding evidence indicates that when a good marginal seal is present, the lesion will arrest.

Measurement of Early Childhood Oral Health for Research Purposes: Dental Caries Experience and Developmental Defects of the Enamel in the Primary Dentition.

Epidemiological investigations of early childhood oral health rely upon the collection of high-quality clinical measures of health and disease. However, ascertainment of valid and accurate clinical measures presents unique challenges among young, preschool-age children. The paper presents a clinical research protocol for the conduct of oral epidemiological examinations among children, implemented in ZOE 2.0, a large-scale population-based genetic epidemiologic study of early childhood caries (ECC). The protocol has been developed for the collection of information on tooth surface-level dental caries experience and tooth-level developmental defects of the enamel in the primary dentition. Dental caries experience is recorded using visual criteria modified from the International Caries Detection and Assessment System (ICDAS), and measurement of developmental defects is based upon the modified Clarkson and O'Mullane Developmental Defects of the Enamel Index. After a dental prophylaxis (toothbrushing among all children and flossing as needed), children's teeth are examined by trained and calibrated examiners in community locations, using portable dental equipment, compressed air, and uniform artificial light and magnification conditions. Data are entered directly onto a computer using a custom Microsoft Access-based data entry application. The ZOE 2.0 clinical protocol has been implemented successfully for the conduct of over 6000 research examinations to date, contributing phenotype data to downstream genomics and other "omics" studies of ECC and DDE, as well as traditional clinical and epidemiologic dental research.

Protocols, Methods, and Tools for Genome-Wide Association Studies (GWAS) of Dental Traits.

Oral health and disease are known to be influenced by complex interactions between environmental (e.g., social and behavioral) factors and innate susceptibility. Although the exact contribution of genomics and other layers of "omics" to oral health is an area of active research, it is well established that the susceptibility to dental caries, periodontal disease, and other oral and craniofacial traits is substantially influenced by the human genome. A comprehensive understanding of these genomic factors is necessary for the realization of precision medicine in the oral health domain. To aid in this direction, the advent and increasing affordability of high-throughput genotyping has enabled the simultaneous interrogation of millions of genetic polymorphisms for association with oral and craniofacial traits. Specifically, genome-wide association studies (GWAS) of dental caries and periodontal disease have provided initial insights into novel loci and biological processes plausibly implicated in these two common, complex, biofilm-mediated diseases. This paper presents a summary of protocols, methods, tools, and pipelines for the conduct of GWAS of dental caries, periodontal disease, and related traits. The protocol begins with the consideration of different traits for both diseases and outlines procedures for genotyping, quality control, adjustment for population stratification, heritability and association analyses, annotation, reporting, and interpretation. Methods and tools available for GWAS are being constantly updated and improved; with this in mind, the presented approaches have been successfully applied in numerous GWAS and meta-analyses among tens of thousands of individuals, including dental traits such as dental caries and periodontal disease. As such, they can serve as a guide or template for future genomic investigations of these and other traits.

The Supragingival Biofilm in Early Childhood Caries: Clinical and Laboratory Protocols and Bioinformatics Pipelines Supporting Metagenomics, Metatranscriptomics, and Metabolomics Studies of the Oral Microbiome.

Early childhood caries (ECC) is a biofilm-mediated disease. Social, environmental, and behavioral determinants as well as innate susceptibility are major influences on its incidence; however, from a pathogenetic standpoint, the disease is defined and driven by oral dysbiosis. In other words, the disease occurs when the natural equilibrium between the host and its oral microbiome shifts toward states that promote demineralization at the biofilm-tooth surface interface. Thus, a comprehensive understanding of dental caries as a disease requires the characterization of both the composition and the function or metabolic activity of the supragingival biofilm according to well-defined clinical statuses. However, taxonomic and functional information of the supragingival biofilm is rarely available in clinical cohorts, and its collection presents unique challenges among very young children. This paper presents a protocol and pipelines available for the conduct of supragingival biofilm microbiome studies among children in the primary dentition, that has been designed in the context of a large-scale population-based genetic epidemiologic study of ECC. The protocol is being developed for the collection of two supragingival biofilm samples from the maxillary primary dentition, enabling downstream taxonomic (e.g., metagenomics) and functional (e.g., transcriptomics and metabolomics) analyses. The protocol is being implemented in the assembly of a pediatric precision medicine cohort comprising over 6000 participants to date, contributing social, environmental, behavioral, clinical, and biological data informing ECC and other oral health outcomes.

Teaching Silver Diamine Fluoride in U.S. Dental Schools' Predoctoral Curricula.

Silver diamine fluoride (SDF), a low-cost topical agent used in many countries to arrest dental caries, was cleared as a desensitizing agent by the Food & Drug Administration for the U.S. market in 2014. The aim of this study was to survey U.S. dental schools regarding their teaching of SDF. Email invitations were sent to all accredited U.S. predoctoral dental education programs (n=66) in September 2016. Deans, chairs, and selected faculty members were asked to respond or forward the survey-link provided to the appropriate person in their school. Under the assumption that some respondents from the same school were unaware of SDF implementation across departments, multiple responses from the same school were collapsed for analysis. A total of 62 schools (94% response rate) responded to the survey, and 67.7% of them reported that SDF was part of their curricula. There was a wide variation across dental schools' teaching about SDF indications and protocols of application. All but one school consistently agreed on using SDF for arresting caries on primary teeth. Only 18 respondents were able to confirm if there was an existing protocol at their school for the use of SDF. When re-application after initially arresting caries with SDF was taught, 50% of respondents advocated 2×/year re-application. Schools not teaching SDF (n=20) planned on including it in their curricula in the future. These findings suggest that, with the use of SDF increasing rapidly in the U.S. and its adoption in most dental schools, there is a need for the development of standardized evidence-based protocols.

Pilot clinical study to assess caries lesion activity using quantitative light-induced fluorescence during dehydration.

This study aimed to evaluate the ability of quantitative light-induced fluorescence (QLF) to assess caries lesion activity using visual examination (VE) as the gold standard. Twenty-four visible white spot lesions on buccal surfaces were examined from 23 children, ages 9 to 14 years. At baseline, the surface was hydrated with water, and thereafter, it was dehydrated with continuous compressed air during image acquisition. QLF images were acquired at 0 (baseline), 5, and 15 s. QLF variables [ QLF V : fluorescence loss ( ? F ), lesion size (S), ? Q : ? F × S ] was recorded. Changes-in- QLF V per second ( ? QLF V ) were determined: ? QLF V = ( QLF VN ? QLF V Baseline ) / N , where N indicates dehydration time. One experienced dentist conducted VE independently using a dental unit's light, compressed air, and explorer.