Caries-free Controls Research Articles

Evaluation of EDARADD, LPO and ACTN2 genes polymorphisms in children with dental caries compared to caries-free controls.

Dental caries is a complex condition that results from a combination of genetic and environmental factors. Several genes have been found to play a role in teeth development and have been associated with various dental traits. In this study, our objective was to examine the potential correlation between the ectodysplasin a receptor (EDAR)-associated via death domain (EDARADD), Lactoperoxidase (LPO) and Actinin Alpha 2 (ACTN2) gene polymorphisms and susceptibility to dental caries. The study included a total of 600 participants, comprising 300 individuals with dental caries and 300 caries-free controls. The genotyping of the EDARADD (rs79233817), LPO (rs8178275) and ACTN2 (rs114880747) gene polymorphisms was performed using the tetra-primer amplification refractory mutation system Polymerase chain reaction (PCR) method. Individuals with dental caries were found to have a significantly higher frequency of the A allele (minor allele) for rs79233817 compared to controls. The specific single nucleotide polymorphism (SNP) (rs79233817) was associated with an increased risk of dental caries (DC) in both the co-dominant and dominant genetic models (p-value < 0.05). In addition, the study's findings revealed a significant association between the rs114880747 SNP and susceptibility to dental caries (p-value < 0.05). A higher frequency of the A allele (minor allele) of rs114880747 was observed in patients compared to the healthy controls. It is also worth mentioning that there was no association between rs8178275 susceptibility to dental caries (p-value > 0.05). It can be inferred that the EDARADD gene polymorphism (rs79233817) and ACTN2 gene polymorphism (rs114880747) potentially play a role in the genetic susceptibility to dental caries. To validate and delve deeper into these findings, it is necessary to conduct additional studies with larger sample sizes in diverse populations. This will help to establish the robustness of the results and further investigate the underlying mechanisms involved.

Relationship between the salivary concentrations of proteinase-3 and interleukin-8 and severe early childhood caries.

Severe early childhood caries (S-ECC) is a multifactorial transmissible infectious disease continuing to affect infants and toddlers worldwide. Saliva plays a modulatory role in the pathogenesis of dental caries. The present study aimed to assess the salivary levels of proteinase-3 (PR3) and interleukin-8 (IL-8) as pro-inflammatory cytokines related to the function of neutrophils in association with S-ECC and its treatment. Fifty children aged 36-60 months were recruited (25 caries-free controls and 25 S-ECC patients). Saliva sampling was performed in all participants. In the S-ECC group, sampling was repeated 6-8 weeks after restorative treatment. The salivary concentrations of PR3 and IL-8 were determined using the enzyme-linked immunosorbent assay (ELISA). The χ2 test, Fisher's exact test, the independent t test, and the paired t test were applied at p < 0.05. The baseline salivary concentrations of PR3 and IL-8 in the S-ECC group were significantly higher than in the caries-free group (p < 0.001). A significant reduction occurred in the levels of these cytokines following restorative treatment in the S-ECC group (p < 0.001), although they were still significantly higher than in the caries-free group (p < 0.05). The salivary levels of PR3 and IL-8 were significantly affected by the presence of dental caries in children, implying their potential efficiency as non-invasive indicators in the determination of the caries risk and treatment effectiveness.

Evaluation of Beta-Defensin 1 and Mannose-Binding Lectin 2 Polymorphisms in Children with Dental Caries Compared to Caries-Free Controls: A Systematic Review and Meta-Analysis

Background and objective: Some variants in defensin beta 1 (DEFB1) and mannose-binding lectin 2 (MBL2) genes can be associated with oral diseases. Herein, we designed a systematic review and meta-analysis to evaluate the association of DEFB1 (rs11362, rs1799946, and rs1800972) and MBL2 (rs7096206 and rs1800450) polymorphisms with the susceptibility to dental caries (DC) in children. Materials and methods: A systematic literature search was conducted in the PubMed/Medline, Web of Science, Scopus, and Cochrane Library databases until 3 December 2022, without any restrictions. The odds ratio (OR), along with a 95% confidence interval (CI) of the effect sizes, are reported. Analyses including a subgroup analysis, a sensitivity analysis, and funnel plot analyses were conducted. Results: A total of 416 records were identified among the databases, and nine articles were entered into the meta-analysis. A significant relationship was found between the T allele of DEFB1 rs11362 polymorphism and DC susceptibility, and the T allele was related to an elevated risk of DC in children (OR = 1.225; 95%CI: 1.022, 1.469; p = 0.028; I2 = 0%). No other polymorphisms were associated with DC. All articles were of moderate quality. Egger's test in homozygous and dominant models demonstrated a significant publication bias for the association of DEFB1 rs1799946 polymorphism with DC risk. Conclusions: The results demonstrated that the T allele of DEFB1 rs11362 polymorphism had an elevated risk for DC in children. However, there were only few studies that evaluated this association.

Association between Vitamin D and Dental Caries in a Sample of Canadian and American Preschool-Aged Children

Background: Inadequate vitamin D levels may increase the risk of caries during childhood. The purpose of this study was to investigate the association between 25-hydroxyvitamin D (25(OH)D) status and severe early childhood caries (S-ECC) in preschool children. Methods: Data were obtained from children <72 months of age in two case–control studies in Winnipeg, Manitoba and Richmond, Virginia. Serum analysis assessed 25(OH)D, calcium and parathyroid concentrations. Data on demographics, dental history and oral hygiene were obtained via questionnaires. Bivariate and multiple logistic regression analyses were performed to assess the relationships between demographic and biological variables and S-ECC. A p-value of ≤0.05 was significant. Results: Data were available for 200 children with S-ECC and 144 caries-free controls. Children with S-ECC had significantly lower 25(OH)D levels than those who were caries-free (p < 0.001), and children with deficient 25(OH)D levels were 10 times more likely to have S-ECC (p < 0.001). Multiple logistic regression revealed that having higher 25(OH)D and calcium concentrations (p = 0.019 and p < 0.0001, respectively), as well as being breastfed in infancy (p < 0.001), were significantly and independently associated with lower odds of S-ECC, while dental insurance (p = 0.006) was associated with higher odds of S-ECC. Conclusions: This study provides additional evidence of an association between nutritional status, specifically vitamin D and calcium levels, and S-ECC.

Salivary cystatin S levels in children with early childhood caries in comparison with caries-free children; statistical analysis and machine learning

BackgroundEarly childhood caries is the most common infectious disease in childhood, with a high prevalence in developing countries. The assessment of the variables that influence early childhood caries as well as its pathophysiology leads to improved control of this disease. Cystatin S, as one of the salivary proteins, has an essential role in pellicle formation, tooth re-mineralization, and protection. The present study aims to assess salivary cystatin S levels and demographic data in early childhood caries in comparison with caries-free ones using statistical analysis and machine learning methods.MethodsA cross-sectional, case–control study was undertaken on 20 cases of early childhood caries and 20 caries-free children as a control. Unstimulated whole saliva samples were collected by suction. Cystatin S concentrations in samples were determined using human cystatin S ELISA kit. The checklist was collected from participants about demographic characteristics, oral health status, and dietary habits by interviewing parents. Regression and receiver operating characteristic (ROC) curve analysis were done to evaluate the potential role of cystatin S salivary level and demographic using statistical analysis and machine learning.ResultsThe mean value of salivary cystatin S concentration in the early childhood caries group was 191.55 ± 81.90 (ng/ml) and in the caries-free group was 370.06 ± 128.87 (ng/ml). T-test analysis showed a statistically significant difference between early childhood caries and caries-free groups in salivary cystatin S levels (p = 0.032). Investigation of the area under the curve (AUC) and accuracy of the ROC curve revealed that the logistic regression model based on salivary cystatin S levels and birth weight had the most and acceptable potential for discriminating of early childhood caries from caries-free controls. Furthermore, using salivary cystatin S levels enhanced the capability of machine learning methods to differentiate early childhood caries from caries-free controls.ConclusionSalivary cystatin S levels in caries-free children were higher than the children with early childhood caries. Results of the present study suggest that considering clinical examination, demographic and socioeconomic factors, along with the salivary cystatin S levels, could be usefull for early diagnosis ofearly childhood caries in high-risk children; furthermore, cystatin S is a protective factor against dental caries.

Metagenomic Analysis Reveals Neisseria bacilliformis Variation in the Early Childhood Caries Plaque Microbiome.

The progression of early childhood caries (ECC) is caused by microbial colonized in dental plaque. However, the association framework both from 16s genus down to high resolution metagenomic strain level and from composition to genome function analysis on caries lacks. 16S rRNA sequence revealed the composition of 3–6 years dental caries (ECC, n = 29), and severe dental caries (SECC, n = 36) children are significantly different from caries-free controls (CF, n = 31). Especially, genus Neisseria is enriched in caries (P < 0.05). Metagenomics sequence of 3 ECCs, 3 SECCs, and 3 CFs reveals Neisseria bacilliformis ATCC BAA-1200 in genus Neisseria is also significantly enriched in caries (P < 0.05). Then, we recovered high-quality metagenomic assembly genomes (MAG), named bin 86, which have 99% identity with Neisseria bacilliformis ATCC BAA-1200 genome. Function analysis of Neisseria bacilliformis ATCC BAA-1200 genome shows its metabolism power of sugar and adhesion, colonization, acid production, and acid tolerance ability, which suggested Neisseria bacilliformis ATCC BAA-1200 may serve as a biomarker for childhood caries.

The complex microbiome of caries-active and caries-free supragingival plaques in permanent dentition.

Dental caries is one of the most common diseases seen in the oral cavity in all periods of deciduous, mixed, and permanent dentition. A comprehensive study of the oral microbiome is required to understand its polymicrobial etiology. The aim of this study was to reveal the plaque microbiome of caries-active and caries-free adults. A total of 52 samples were collected from 26 caries-active patients and 26 caries-free controls. Dental supragingival plaque samples were collected from each subject and the bacterial 16S rDNA, expanded V3-V4 region, was amplified using next generation sequencing. The core microbiome was defined with 235 shared bacteria in genus level, and among all microbiome 14.8% of all bacteria showed significant difference (P < 0.05). The bacteria responsible of caries may be listed as Anaeroglobus, Atopobium, Bifidobacterium, Centipeda, Cryptobacterium, Desulfobulbus, Filifactor, Howardella, Lactobacillus, Leptotrichiaceae (unclassified), Megasphaera, Mycoplasma, Olsenella, Phocaeicola, Propionibacterium, Pseudoramibacter, Scardovia, Schwartzia, Treponema, and Veillonellaceae (unclassified). The present study provides comprehensive knowledge of the microbiological etiology of caries in permanent dentition.

Characterization of Supragingival Plaque and Oral Swab Microbiomes in Children With Severe Early Childhood Caries.

The human oral cavity harbors one of the most diverse microbial communities with different oral microenvironments allowing the colonization of unique microbial species. This study aimed to determine which of two commonly used sampling sites (dental plaque vs. oral swab) would provide a better prediction model for caries-free vs. severe early childhood caries (S-ECC) using next generation sequencing and machine learning (ML). In this cross-sectional study, a total of 80 children (40 S-ECC and 40 caries-free) < 72 months of age were recruited. Supragingival plaque and oral swab samples were used for the amplicon sequencing of the V4-16S rRNA and ITS1 rRNA genes. The results showed significant differences in alpha and beta diversity between dental plaque and oral swab bacterial and fungal microbiomes. Differential abundance analyses showed that, among others, the cariogenic species Streptococcus mutans was enriched in the dental plaque, compared to oral swabs, of children with S-ECC. The fungal species Candida dubliniensis and C. tropicalis were more abundant in the oral swab samples of children with S-ECC compared to caries-free controls. They were also among the top 20 most important features for the classification of S-ECC vs. caries-free in oral swabs and for the classification of dental plaque vs. oral swab in the S-ECC group. ML approaches revealed the possibility of classifying samples according to both caries status and sampling sites. The tested site of sample collection did not change the predictability of the disease. However, the species considered to be important for the classification of disease in each sampling site were slightly different. Being able to determine the origin of the samples could be very useful during the design of oral microbiome studies. This study provides important insights into the differences between the dental plaque and oral swab bacteriome and mycobiome of children with S-ECC and those caries-free.

Sex-Based Diverse Plaque Microbiota in Children with Severe Caries

Severe early childhood caries (S-ECC) is a multifactorial disease that can lead to suffering and reduced oral health–related quality of life in young children. The bacterial and fungal composition of dental plaque and how children’s sex is associated with S-ECC are largely unknown. In this study, V4-16S rRNA and ITS1 rRNA gene amplicon sequencing was used to compare the plaque bacteriome and mycobiome of children <72 mo of age: 40 with S-ECC (15 males, 25 females) and 40 caries-free (19 males, 21 females). Health- and nutrition-related questionnaire data were also investigated. This study aimed to analyze potential sex-based differences in the supragingival plaque microbiota of young children with S-ECC and those caries-free. Behavioral and nutritional habit differences were observed between children with S-ECC and those caries-free and between male and female children. Overall, higher levels of Veillonella dispar, Streptococcus mutans, and other bacterial species were found in the S-ECC group as compared with caries-free controls (P < 0.05). A significant difference in the abundance of Neisseria was observed between males and females with S-ECC (P < .05). Fungal taxonomic analysis showed significantly higher levels of Candida dubliniensis in the plaque of children with S-ECC as compared with those caries-free (P < 0.05), but no differences were observed with Candida albicans (P > 0.05). Significant differences in the relative abundance of Mycosphaerella, Cyberlindnera, and Trichosporon fungal species were also observed between the caries-free and S-ECC groups (P < 0.05). Machine learning analysis revealed the most important bacterial and fungal species for classifying S-ECC versus caries-free. Different patterns of crosstalk between microbial species were observed between male and female children. Our work demonstrates that plaque microbiota and sex may be important determinants for S-ECC and could be factors to consider for inclusion in caries risk assessment tools.

Oral Health condition among Kindergarten children in Relation to Salivary soluble Cluster of Differentiation 14 and Tool Like Receptor 2 (comparative study)

Oral health of preschool children can be deteriorating by dental caries and periodontal disease. Early childhood caries is highly prevalence dental public health problem that affect the primary tooth in children below the age of 71 months. Salivary soluble cluster of differentiation 14 and salivary toll like receptor 2 are proteins that have the ability to recognize different bacterial component and play role in prevention of infection. This study was conducted to determine the salivary levels of soluble cluster of differentiation 14 and soluble toll like receptor 2 in children with active dental caries and caries-free controls and found the correlation with gingival parameter. Sixty children with an age range between (4–5) years were participated in this study; they categorized into two groups, 30 children with severe stage of early childhood caries as the study group and 30 caries free children as the control group. Oral examination done by recording decay, missing, filled surfaces, measuring dental caries severity, gingival health status was assessed by using gingival index, in addition to plaque index. Saliva samples were collected from both groups. Enzyme-linked immunosorbent assay was carried out to estimate the salivary level of soluble cluster of differentiation 14 and soluble toll like receptor 2. The present study found significant elevation in the mean level of soluble cluster of differentiation among early childhood caries group, moreover there are no differences in mean level of soluble cluster of differentiation between caries severity groups. On the other hand, a positive nonsignificant correlation was found between the concentration of soluble cluster of differentiation in both groups and each of plaque index and gingival index. Regarding the soluble tool like receptor 2 a higher level in caries active group than caries free group was revealed without significant difference between them. Significant differences in soluble tool like receptor 2 mean levels was found between caries severity group. Furthermore, positive significant correlation was observed between salivary level of soluble tool like receptor 2 and gingival index in both groups, on the other hand, positive non-significant correlation was found between the levels of soluble tool like receptor 2 and plaque index. It can be conclude that the levels of salivary soluble cluster of differnatation 14 and tool like receptor 2 increased as the oral disease progress and they may have a suspected protective role against microbial burden. Salivary soluble cluster of differnatation 14 could be an important biomarker of caries activity.

Association of Salivary Microbiota with Dental Caries Incidence with Dentine Involvement after 4 Years.

Salivary microbiota alterations can correlate with dental caries development in children, and mechanisms mediating this association need to be studied in further detail. Our study explored salivary microbiota shifts in children and their association with the incidence of dental caries with dentine involvement. Salivary samples were collected from children with caries and their subsequently matched caries-free controls before and after caries development. The microbiota was analyzed by 16S rRNA gene-based high-throughput sequencing. The salivary microbiota was more diverse in caries-free subjects than in those with dental caries with dentine involvement (DC). Although both groups exhibited similar shifts in microbiota composition, an association with caries was found by function prediction. Analysis of potential microbiome functions revealed that Granulicatella, Streptococcus, Bulleidia, and Staphylococcus in the DC group could be associated with the bacterial invasion of epithelial cells, phosphotransferase system, and D-alanine metabolism, whereas Neisseria, Lautropia, and Leptotrichia in caries-free subjects could be associated with bacterial motility protein genes, linoleic acid metabolism, and flavonoid biosynthesis, suggesting that functional differences in the salivary microbiota may be associated with caries formation. These results expand the current understanding of the functional significance of the salivary microbiome in caries development, and may facilitate the identification of novel biomarkers and treatment targets.

Ecological Effect of Arginine on Oral Microbiota

Dental caries is closely associated with the microbial dybiosis between acidogenic/aciduric pathogens and alkali-generating commensal bacteria colonized in the oral cavity. Our recent studies have shown that arginine may represent a promising anti-caries agent by modulating microbial composition in an in vitro consortium. However, the effect of arginine on the oral microbiota has yet to be comprehensively delineated in either clinical cohort or in vitro biofilm models that better represent the microbial diversity of oral cavity. Here, by employing a clinical cohort and a saliva-derived biofilm model, we demonstrated that arginine treatment could favorably modulate the oral microbiota of caries-active individuals. Specifically, treatment with arginine-containing dentifrice normalized the oral microbiota of caries-active individuals similar to that of caries-free controls in terms of microbial structure, abundance of typical species, enzymatic activities of glycolysis and alkali-generation related enzymes and their corresponding transcripts. Moreover, we found that combinatory use of arginine with fluoride could better enrich alkali-generating Streptococcus sanguinis and suppress acidogenic/aciduric Streptococcus mutans, and thus significantly retard the demineralizing capability of saliva-derived oral biofilm. Hence, we propose that fluoride and arginine have a potential synergistic effect in maintaining an eco-friendly oral microbial equilibrium in favor of better caries management.

Association of MBL2 Gene Polymorphism with Dental Caries in Saudi Children

The high prevalence of dental caries in children worldwide is a major oral health problem which requires early intervention. Dental caries is mainly caused by the action of acids produced by bacteria in addition to many other factors. Recent genetic studies have reported that a number of genes are associated with the susceptibility to dental caries. The majority of these genes are associated with inflammation, increased susceptibility to infection, and dentine matrix formation. Using the TaqMan assay and direct DNA sequencing, the prevalence of 6 single-nucleotide polymorphisms (SNPs) in MMP9, MBL2, MMP2, and TIMP2 genes was determined in 102 children with caries and in 100 age-matched caries-free controls. Out of the 6 SNPs tested in the 4 selected genes, only rs11003125 in the MBL2 gene was shown to be associated with a high prevalence of caries in our cohort. In addition, haplotype analysis of the 6 SNPs tested revealed that certain haplotypes, namely GT of rs11003125G and rs7501477T and GT of rs7096206G and rs7501477T, were found to be associated with a high prevalence of dental caries in our cohort, while haplotype AG of rs17576A and rs7501477G was found to have a protective effect against dental caries. In conclusion, the data indicate that rs11003125 in the MBL2 gene was shown to be associated with a high prevalence of caries in our cohort, and 2 haplotypes are also involved in the increased susceptibility to dental caries.

Higher body mass index associated with severe early childhood caries.

BackgroundSevere Early Childhood Caries (S-ECC) is an aggressive form of tooth decay in preschool children affecting quality of life and nutritional status. The purpose was to determine whether there is an association between Body Mass Index (BMI) and S-ECC.MethodsChildren with S-ECC were recruited on the day of their slated dental surgery under general anesthesia. Age-matched, caries-free controls were recruited from the community. All children were participating in a larger study on nutrition and S-ECC. Analysis was restricted to children ≥ 24 months of age. Parents completed a questionnaire and heights and weights were recorded. BMI scores and age and gender adjusted BMI z-scores and percentiles were calculated. A p-value ≤ 0.05 was significant.ResultsTwo hundred thirty-five children were included (141 with S-ECC and 94 caries-free). The mean age was 43.3 ± 12.8 months and 50.2 % were male. Overall, 34.4 % of participants were overweight or obese. Significantly more children with S-ECC were classified as overweight or obese when compared to caries-free children (p = 0.038) and had significantly higher mean BMI z-scores than caries-free children (0.78 ± 1.26 vs. 0.22 ± 1.36, p = 0.002). Those with S-ECC also had significantly higher BMI percentiles (69.0 % ± 29.2 vs. 56.8 % ± 31.7, p = 0.003). Multiple linear regression analyses revealed that BMI z-scores were significantly and independently associated with S-ECC and annual household income as were BMI percentiles.ConclusionsChildren with S-ECC in our sample had significantly higher BMI z-scores than caries-free peers.

Association of oral streptococci community dynamics with severe early childhood caries as assessed by PCR-denaturing gradient gel electrophoresis targeting the rnpB gene.

This study sought to investigate the possible association between the dynamics of oral streptococci community profiles and severe early childhood caries (S-ECC) development, compared with caries-free (CF) controls. Supragingival plaque samples were evaluated from 8-32-month-old children who had previously been assessed for overall profiles of their oral microbial community. Twelve children were in each group. Bacterial genomic DNA was extracted and amplified using rnpB-specific primers for streptococci; the products were then subjected to denaturing gradient gel electrophoresis (DGGE) and sequence analysis. We observed that the mean values for species richness (N) and diversity of oral streptococci (H') were significantly lower in the S-ECC group than in the CF group (N = 1.25 ± 4.14 vs 14.92 ± 2.84; H' = 1.41 ± 0.29 vs 1.64 ± 0.18) at 32 months of age (P < 0.05). Significantly higher detection rates of Streptococcus sanguinis and Streptococcus gordonii were found in the CF group compared with the S-ECC group at 32 months of age (P < 0.05). Cluster analysis of DGGE profiles showed that most of the clusters were constructed from one individual over time. These results suggested that the onset of S-ECC is accompanied by reduced diversity of oral streptococci, that the detection rates of S. sanguinis and S. gordonii have negative correlations with S-ECC; and that there are high levels of intra-individual similarity for the oral streptococci community over time.

Vitamin D status of children with severe early childhood caries: a case-control study.

BackgroundSevere Early Childhood Caries (S-ECC) affects the health and well-being of young children. There is limited research in this area, though evidence suggests that children with S-ECC are at an increased risk of malnutrition. The purpose of this study was to determine the association between vitamin D (25(OH)D) levels and S-ECC.MethodsThis case–control study was conducted from 2009 to 2011 in the city of Winnipeg, Manitoba, Canada. 144 preschool children with S-ECC were recruited from a local health centre on the day of their slated dental surgery under general anesthetic. 122 caries-free controls were recruited from the community. Children underwent a blood draw for vitamin D (25(OH)D), calcium, parathyroid hormone, and albumin levels. Parents completed an interviewed questionnaire assessing the child’s nutritional habits, oral health, and family demographics. Analyses included descriptive and bivariate statistics as well as multiple and logistic regression. A p value ≤ 0.05 was significant.ResultsThe mean age of participants was 40.8 ± 14.1 months. Children with S-ECC had significantly lower mean 25(OH)D (68.9 ± 28.0 nmol/L vs. 82.9 ± 31.1, p < 0.001), calcium (p < 0.001), and albumin (p < 0.001) levels, and significantly higher parathyroid hormone (p < 0.001) levels than those caries-free. Children with S-ECC were significantly more likely to have vitamin D levels below recognized thresholds for optimal and adequate status (i.e. <75 and <50 nmol/L, respectively). Multiple regression analysis revealed that S-ECC, infrequent milk consumption, and winter season were significantly associated with lower 25(OH)D concentrations. Low 25(OH)D levels, low household income, and poorer ratings of the child’s general health were significantly associated with S-ECC on logistic regression.ConclusionChildren with S-ECC appear to have relatively poor nutritional health compared to caries-free controls, and were significantly more likely to have low vitamin D, calcium, and albumin concentrations and elevated PTH levels.

Association between iron status, iron deficiency anaemia, and severe early childhood caries: a case–control study

BackgroundSevere tooth decay is known to affect the health and well-being of young children. However, little is known about the influence of Severe Early Childhood Caries (S-ECC) on childhood nutritional status. The purpose of this study was to contrast ferritin and haemoglobin levels between preschoolers with S-ECC and caries-free controls.MethodsChildren were recruited as part of a larger case–control study examining differences in nutritional status between those with and without S-ECC. Preschoolers with S-ECC were recruited on the day of their dental surgery, while caries-free controls were recruited from the community. Parents completed a questionnaire and the child underwent venipuncture. The study was approved by the University’s Health Research Ethics Board. Statistics included descriptive, bivariate and logistic regression analyses. A p value ≤ .05 was significant. A total of 266 children were recruited; 144 with S-ECC and 122 caries-free.ResultsThe mean age was 40.8 ± 14.1 months. The mean ferritin concentration for all children was 29.6 ± 17.9 μg/L while the mean haemoglobin level was 115.1 ± 10.1 g/L. Children with S-ECC were significantly more likely to have low ferritin (p=.033) and low haemoglobin levels (p>.001). Logistic regression analyses revealed that children with S-ECC were nearly twice as likely to have low ferritin levels and were over six times more likely to have iron deficiency anaemia than caries-free controls.ConclusionsChildren with S-ECC appear to be at significantly greater odds of having low ferritin status compared with caries-free children and also appear to have significantly lower haemoglobin levels than the caries-free control group. Children with S-ECC also appear to be at significantly greater odds for iron deficiency anaemia than cavity-free children.

Bacterial Biofilm Composition in Caries and Caries-Free Subjects

Background: Certain major pathogens such as Streptococcus mutans, Lactobacillus spp. and others have been reported to be involved in caries initiation and progression. Yet, in addition to those leading pathogens, microbial communities seem to be much more diverse and individually differing. The aim of this study, therefore, was to analyze the bacterial composition of carious dentin and the plaque of caries-free patients by using a custom-made, real-time quantitative polymerase chain reaction assay (RQ-PCR). Methods: The study included 26 patients with caries and 28 caries-free controls. Decayed tooth substance and plaque samples were harvested. Bacterial DNA was extracted and tested for the presence of 43 bacterial species or species groups using RQ-PCR. Results: Relative quantification revealed that Propionibacterium acidifaciens was significantly more abundant in caries samples than were other microorganisms (fold change 169.12, p = 0.023). In the caries-free samples, typical health-associated species were significantly more prevalent. Unsupervised hierarchical cluster analysis showed a high abundance of P. acidifaciens in caries subjects and distinct but individually differing bacterial clusters in the caries-free subjects. The distribution of 11 bacteria allowed full discrimination between caries and caries-free subjects. Conclusion: Within the investigated cohort, P. acidifaciens was the only pathogen significantly more abundant in caries subjects. Cluster analysis yielded a diverse flora in caries-free subjects, whereas it was narrowed down to a small range of a few outcompeting members in caries subjects.

Resemblance of salivary protein profiles between children with early childhood caries and caries‐free controls

Although prolonged bottle feeding with a carbohydrate-rich content is commonly agreed to be the main etiologic factor for early childhood caries (ECC), in recent years additional endogenous factors, including the composition of saliva, have been suspected as predisposing factors in children for the development of this aggressive form of dental caries. As a basis for investigating the putative involvement of salivary proteins in the etiology of ECC, a qualitative comparison of major salivary protein profiles between children with ECC and caries-free controls was performed. Saliva was collected from 30 children with ECC and, after separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, was compared with saliva from 20 caries-free controls for the general composition of proteins by means of silver staining, glycoprotein staining, and lectin blotting. Gels and blots were analysed using densitometry, and the protein-banding patterns resulting from the individuals' samples were compared by image analysis for the presence or absence of protein bands. Dendrograms obtained after comparison of all samples showed a high degree of similarity for the experimental groups. In summary, the results attest a uniform expression of the major protein components in children's saliva, regardless of the clinical manifestation of ECC, and thus pave the way for further detailed investigations of more subtle differences in the salivary proteome.

Genetic Profiling of the Oral Microbiota Associated with Severe Early-Childhood Caries

The determination of the composition of the microbial community in the oral cavity is usually based on cultivation methods; however, nearly half of the bacteria in the saliva and the dental plaque are not cultivable. In this study, we evaluated the difference in oral microbial diversity between children with severe early-childhood caries (S-ECC) and caries-free (CF) controls by means of a cultivation-independent approach called denaturing gradient gel electrophoresis (DGGE). Pooled dental plaque samples were collected from 20 children aged 2 to 8 years. Total microbial genomic DNA was isolated from those subjects, and a portion of the 16S rRNA gene locus was PCR amplified by using universal primers. We observed that the mean species richness of the bacterial population was greater in the CF children (n = 12) (42 +/- 3.7) than in the S-ECC children (n = 8) (35 +/- 4.3); the difference was statistically significant (P = 0.005). The overall diversity of plaque samples as measured by the Shannon index was 3.5 for the S-ECC group and 3.7 for the CF group (P = 0.004). Differences in DGGE profiles were distinguished on the basis of a cluster analysis. Sequence analysis of excised DGGE bands consisted of 2.7 phylotypes, on average. After adjusting for the number of observed bands, we estimated that the S-ECC group exhibited 94.5 total phylotypes and that the CF group exhibited 113.4. These results suggest that the microbial diversity and complexity of the microbial biota in dental plaque are significantly less in S-ECC children than in CF children.