Diet and the microbial aetiology of dental caries: new paradigms

Plant-Derived Compounds: A Promising Tool for Dental Caries Prevention

There is a growing shift from the use of conventional pharmaceutical oral care products to the use of herbal extracts and traditional remedies in dental caries prevention. This is attributed to the potential environmental and health implications of contemporary oral products. This comprehensive review aims at the analysis of plant-derived compounds as preventive modalities in dental caries research. It focuses on data collected from 2019 until recently, trying to emphasize current trends in this topic. The research findings suggest that several plant-derived compounds, either aqueous or ethanolic, exhibit notable antibacterial effects against Streptococcus mutans and other bacteria related to dental caries, with some extracts demonstrating an efficacy comparable to that of chlorhexidine. Furthermore, in vivo studies using plant-derived compounds incorporated in food derivatives, such as lollipops, have shown promising results by significantly reducing Streptococcus mutans in high-risk caries children. In vitro studies on plant-derived compounds have revealed bactericidal and bacteriostatic activity against S. mutans, suggesting their potential use as dental caries preventive agents. Medicinal plants, plant-derived phytochemicals, essential oils, and other food compounds have exhibited promising antimicrobial activity against oral pathogens, either by their anti-adhesion activity, the inhibition of extracellular microbial enzymes, or their direct action on microbial species and acid production. However, further research is needed to assess their antimicrobial activity and to evaluate the cytotoxicity and safety profiles of these plant-derived compounds before their widespread clinical use can be recommended.

A Qualitative Study of Preschool Children's Perspectives on an Oral Health Promotion Program in New South Wales, Australia

In Australia, dental caries are observed in almost half of children starting school. Oral health promotion programs are being implemented in early childhood education and care (ECEC) settings to promote oral health. This study examined children's perceptions of one such program, the Bright Smiles Bright Futures (BSBF) program in ECEC settings in New South Wales, Australia. Data were collected using focus group discussions from 15 children aged 3-5 years, transcribed verbatim, and analysed through inductive thematic analysis. Three themes were identified as follows: (i) oral health knowledge of children, (ii) oral hygiene practices routine and skills development, and (iii) evaluation of the oral health promotion kit and opportunities for improvement. Children's perspectives highlight the BSBF program's success in communicating key messages to promote oral health. The integration of family-centric approaches, acknowledgement of children's preferences, and the use of interactive tools collectively enhance the overall effectiveness of the oral health promotion program.

Visual attention to food cues and dental caries-Are they associated?

BACKGROUND

The role of diet has a key role in dental caries. Attention to food cues can be an indicator for food choices.

AIM

This study investigates children's visual attention to images with healthy and unhealthy food cues and correlates it with that of their parents and with their dental caries status using eye-tracking technology.

DESIGN

A total of 30 children with and without dental caries and their 30 parents were calibrated to the eye-tracking device (Tobii Nano Pro) to ensure standardisation. Participants viewed matching images of healthy and unhealthy food cues, whereas an eye-tracking device tracked their eye movements. Children had a dental examination and were classified as children with dental caries (n = 15) and their parents (n = 15), and children without dental caries (n = 15) and their parents (n = 15).

RESULTS

In children with dental caries, visual attention duration was longer to healthy foods than to unhealthy foods. Likewise, parents of children with dental caries spent longer time looking at healthy foods than unhealthy foods.

CONCLUSION

Our preliminary findings indicate a significant association between children's visual attention to healthy and unhealthy food cues and their dental caries status. This underscores the need for further investigation into the correlation between children's and their parents' visual attention to food, particularly in the context of children with dental caries. Such exploration holds promise for informing targeted interventions in food choice education.

Dietary interventions and nutritional impact on oral health and development: a review

Food and nutrients play a pivotal role in the development of dentition and oral health. While diet includes the overall forms of consumed foods, the nutrients include specific micro- (vitamins and minerals) and macro- (carbohydrates, proteins, and lipids) nutrients. As much as the assimilation of macro and micronutrients depends on proper oral health for ingesting food, oral health, in turn, depends on the availability of nutrients in the food so ingested. Age, certain medical conditions, socioeconomic status, and overall changes in the evolution of society determine the type of diet which in turn influences oral health. This article has touched upon certain salient aspects of these nutrients and their bearing on overall oral health and development.

Association of polymicrobial interactions with dental caries development and prevention

Dental caries is a common oral disease. In many cases, disruption of the ecological balance of the oral cavity can result in the occurrence of dental caries. There are many cariogenic microbiota and factors, and their identification allows us to take corresponding prevention and control measures. With the development of microbiology, the caries-causing bacteria have evolved from the traditional single Streptococcus mutans to the discovery of oral symbiotic bacteria. Thus it is necessary to systematically organized the association of polymicrobial interactions with dental caries development. In terms of ecology, caries occurs due to an ecological imbalance of the microbiota, caused by the growth and reproduction of cariogenic microbiota due to external factors or the disruption of homeostasis by one's own factors. To reduce the occurrence of dental caries effectively, and considering the latest scientific viewpoints, caries may be viewed from the perspective of ecology, and preventive measures can be taken; hence, this article systematically summarizes the prevention and treatment of dental caries from the aspects of ecological perspectives, in particular the ecological biofilm formation, bacterial quorum sensing, the main cariogenic microbiota, and preventive measures.

Caries-inhibiting Effect of Microencapsulated Active Components in Pit and Fissure Sealants

OBJECTIVE

The aim of the present in vitro study was to examine the caries-inhibiting effect of a pit and fissure sealant (PFS) containing ion-releasing microcapsules under cariogenic conditions in a biofilm artificial mouth.

METHODS AND MATERIALS

Forty-eight human third molars were divided into four groups (n=12 per group). Fissures were extended with burs and sealed with experimental PFS. The four groups of specimens were treated as follows: 1) EPFS 1: EPFS (Premier Dental) of increasing viscosity, containing microcapsules loaded with remineralizing agents (calcium, phosphate, and fluoride ions); 2) US: fluoride-releasing PFS (UltraSeal XT plus, UltraDent Products, South Jordan, UT, USA); 3) EPFS 2: experimental PFS of constant viscosity containing microcapsules loaded with calcium, phosphate, and fluoride ions; and 4) FT: glass ionomer cement (GIC) (GC Fuji Triage CAPSULE WHITE glass ionomer cement, GC Europe NV, Leuven, Belgium). FT and US were used as control groups. EPFS 1 and EPFS 2 were the experimental groups. Specimens were stored in distilled water for 14 days at 37°C, subjected to 10,000 thermocycles (5°C and 55°C) and finally exposed to microbiological cycling in a Streptococcus mutans-based artificial mouth for 10 days. Replicas were made for scanning electron microscopic (SEM) evaluation and specimens were cut for fluorescence microscopy.

RESULTS

Overall demineralization depths at the margin of Fuji Triage were significantly shallower than in the other groups (p<0.05). Overall demineralization depths adjacent to the experimental pit and fissure sealant EPFS 2 (59±15 μm) were comparable to the values of the resin-based pit and fissure sealant UltraSeal XT plus (58±10 μm, p≥0.05). SEM revealed surface roughness of the GIC-based PFS.

CONCLUSIONS

The experimental PFS with microcapsules containing active components for remineralization did not show a caries-inhibiting effect compared to a fluoride-releasing resin-based PFS. Lower demineralization depths adjacent to GIC sealants indicate an anticariogenic effect through fluoride ion release.

Oral Microbiota, Its Equilibrium and Implications in the Pathophysiology of Human Diseases: A Systematic Review

Imbalances of the oral microbiota and dysbiosis have traditionally been linked to the occurrence of teeth and oral diseases. However, recent findings indicate that this microbiota exerts relevant influence in systemic health. Dysbiosis of the oral microbiota is implicated in the apparition and progression of cardiovascular, neurodegenerative and other major human diseases. In fact, the oral microbiota are the second most diverse and largely populated microbiota of the human body and its relationships with systemic health, although widely explored, they still lack of proper integration. The purpose of this systematic review is thus to widely examine the implications of oral microbiota in oral, cardiovascular and neurodegenerative diseases to offer integrative and up-to-date interpretations. To achieve that aim, we identified a total of 121 studies curated in PUBMED from the time interval January 2003–April 2022, which after careful screening resulted in 79 studies included. The reviewed scientific literature provides plausible vias of implication of dysbiotic oral microbiota in systemic human diseases, and encourages further research to continue elucidating the highly relevant and still poorly understood implications of this niche microbiota in systemic health. PROSPERO Registration Number: CRD42022299692. This systematic review follows relevant PRISMA guidelines.

Oral Microbiota-Host Interaction Mediated by Taste Receptors

Taste receptors, originally identified in taste buds, function as the periphery receptors for taste stimuli and play an important role in food choice. Cohort studies have revealed that single nucleotide polymorphisms of taste receptors such as T1R1, T1R2, T2R38 are associated with susceptibility to oral diseases like dental caries. Recent studies have demonstrated the wide expression of taste receptors in various tissues, including intestinal epithelia, respiratory tract, and gingiva, with an emerging role of participating in the interaction between mucosa surface and microorganisms via monitoring a wide range of metabolites. On the one hand, individuals with different oral microbiomes exhibited varied taste sensitivity, suggesting a potential impact of the oral microbiota composition on taste receptor function. On the other hand, animal studies and in vitro studies have uncovered that a variety of oral cells expressing taste receptors such as gingival solitary chemosensory cells, gingival epithelial cells (GECs), and gingival fibroblasts can detect bacterial signals through bitter taste receptors to trigger host innate immune responses, thus regulating oral microbial homeostasis. This review focuses on how taste receptors, particularly bitter and sweet taste receptors, mediate the oral microbiota-host interaction as well as impact the occurrence and development of oral diseases. Further studies delineating the role of taste receptors in mediating oral microbiota-host interaction will advance our knowledge in oral ecological homeostasis establishment, providing a novel paradigm and treatment target for the better management of dental infectious diseases.

Dependency of hydration and growth conditions on the mechanical properties of oral biofilms

Within the oral cavity, dental biofilms experience dynamic environments, in part due to changes in dietary content, frequency of intake and health conditions. This can impact bacterial diversity and morpho-mechanical properties. While phenotypic properties of oral biofilms are closely related to their composition, these can readily change according to dynamic variations in the growth environment and nutrient availability. Understanding the interlink between phenotypic properties, variable growth conditions, and community characterization is an essential requirement to develop structure–property relationships in oral-biofilms. In this study, the impact of two distinct growth media types with increasing richness on the properties of oral biofilms was assessed through a new combination of in-vitro time-lapse biophysical methods with microbiological assays. Oral biofilms grown in the enriched media composition presented a decrease in their pH, an increase in soluble EPS production, and a severe reduction in bacterial diversity. Additionally, enriched media conditions presented an increase in biofilm volumetric changes (upon hydration) as well as a reduction in elastic modulus upon indentation. With hydration time considered a major factor contributing to changes in biofilm mechanical properties, we have shown that it is less associated than media richness. Future investigations can now use this time-lapse approach, with a clearer focus on the extracellular matrix of oral biofilms dictating their morpho-mechanical properties.

Healthy Oral Lifestyle Behaviours Are Associated with Favourable Composition and Function of the Oral Microbiota

Modifiable lifestyle interventions may influence dental disease by shifting the composition of the oral microbiota. This study aimed to test whether lifestyle traits are associated with oral microbiota composition and function. Swedish volunteers, aged 16 to 79 years, completed a lifestyle traits questionnaire including lifestyle characteristics and oral health behaviours. Bacterial 16S rDNA amplicons were sequenced and classified into genera and species, using salivary DNA. Microbiota functions were predicted using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and the KO Database of Molecular Functions by ortholog annotation. Tests for association used partial least squares and linear regression analysis with correction for multiple testing. The main analysis included 401 participants and 229 common bacterial species (found in ≥10% of the participants). The overall microbiota composition was strongly associated with questions "do you think caries is a disease?" and "do you use floss or a toothpick?". Enriched relative abundance of Actinomyces, Campylobacter, Dialister, Fusobacterium, Peptidophaga and Scardovia genera (all p < 0.05 after adjustment for multiple testing), and functional profiles showing enrichment of carbohydrate related functions, were found in participants who answered "no" to these questions. Socio-demographic traits and other oral hygiene behaviours were also associated. Healthier oral microbiota composition and predicted functions are found in those with favourable oral health behaviours. Modifiable risk factors could be prioritized for possible interventions.

"Dental Cluster" Versus "Metabolic Cluster": Analyzing the Associations of Planned and Delivered Dental Procedures with Metabolic Syndrome, Utilizing Data from the Dental, Oral, Medical Epidemiological (DOME) Cross-Sectional Record-Based Nationwide Study

Simple Summary

There are conflicting results existing regarding the association between dental status and metabolic syndrome (MetS). This study aimed to analyze the association between the sum of the standard dental unit (SDU) scores of planned (SDU-P) and delivered (SDU-D) dental procedures per patient with MetS. Included were data from the Dental, Oral, Medical Epidemi-ological (DOME) study records-based research, which integrated large socio-demographic, medical, and dental databases of a nationally representative sample of young to middle-aged military personnel (N = 131,927). The present study demonstrated that SDU-P, but not SDU-D, is a better predictor of systemic morbidities related to MetS. In other words, MetS is associated with a higher dental treatment needs burden, rather than with dental treatments performed de facto. The study concludes that dental and general health authorities should collaborate and share in-formation and focus on reducing common health-related risk factors, such as smoking and sugar consumption, in particular among high-risk populations, such as immigrants and those with lower SES and rural locality.

Abstract

There are conflicting results existing regarding the association between dental status and metabolic syndrome (MetS). The present research analyzed the associations of the sum of the standard dental unit (SDU) scores of planned (SDU-P) and delivered (SDU-D) dental procedures per patient with MetS components, consequences, and related conditions. The SDU score of each dental procedure represents the time and complexity of the executed procedure. This cross-sectional study analyzed data from the Dental, Oral, Medical Epidemiological (DOME) repository, which includes comprehensive socio-demographic, medical, and dental databases of a nationally representative sample of 132,529 military personnel. Univariate analyses revealed that SDU-P had statistically significant positive associations with all systemic morbidities related to MetS, while the SDU-D exhibited positive associations with some of the systemic morbidities and with lower ORs. SDU-P and SDU-D were associated with worse scores of auxiliary examinations used in the assessment of MetS components. SDU-P retained significant positive associations in the multivariate analysis with impaired glucose tolerance (IGT) (OR = 7.40 (1.91–28.57)), deep vein thrombosis (DVT) (OR = 5.61 (1.53–20.83)), obstructive sleep apnea (OSA) (OR = 5.05 (2.40–10.63)), and fatty liver (OR = 1.82 (1.17–2.84)). In contrast, obesity was the only systemic parameter retaining a significant association with SDU-D following multivariate analysis (OR = 1.47 (1.23–1.76)). It can be concluded that SDU-P, but not SDU-D, is a better predictor of systemic morbidities related to MetS. In other words, MetS is associated with a higher dental treatment needs burden, rather than with dental treatments performed de facto. Dental and general health authorities should collaborate and share information and focus on reducing common health-related risk factors, such as smoking and sugar consumption, in particular among high-risk populations, such as immigrants and those with lower SES and rural locality.

A Log Ratio-Based Analysis of Individual Changes in the Composition of the Oral Microbiota in Different Dietary Phases

Background: Investigating the influence of nutrition on oral health has a long scientific history. Due to recent technical advances like sequencing techniques for the oral microbiota, this topic has gained scientific interest again. A basic challenge is to understand the influence of nutrition on the oral microbiota and on the interaction between the oral bacteria, which is also statistically challenging. Methods: Log-transformed ratios of two bacteria concentrations are introduced as the basic analytic tool. The framework is illustrated by application in an experimental study exposing eleven participants to different nutrition schemes in five consecutive phases. Results: The method could be sufficiently used to analyse the interrelation between the bacteria and to identify some bacterial groups with the same as well as different reactions to additional dietary components. It was found that the strongest changes in bacterial concentrations were achieved by the additional consumption of dairy products. Conclusion: A log ratio-based analysis offers insights into the relation of different bacteria while taking specific features of compositional data into account. The presented methods allow becoming independent of the behaviour of other bacteria, which is a disadvantage of common analysis methods of compositions. The results indicate that modulations of the oral biofilm microbiota due to nutrition change can be attained.

Current herbal medicine as an alternative treatment in dentistry: In vitro, in vivo and clinical studies

Since the time that human population comprehended the importance of general health maintenance and the burden of disease, there has been a search for healing properties in the natural environment. Herbal medicine is the use of plants with medical properties for prevention and treatment of conditions that can affect general health. Recently, a growing interest has been observed toward the use of traditional herbal medicine alongside synthetic modern drugs. Around 80% of the population, especially in developing countries relies on it for healthcare. Oral healthcare is considered a major part of general health. According to the world health organization (WHO), oral health is considered an important part of general health and quality of life. The utilization of natural medications for the management of pathologic oro-dental conditions can be a logical alternative to pharmaceutical methods due to their availability, low costs, and lower side effects. The current literature review aimed at exploration of the variety and extent of herbal products application in oral health maintenance including different fields of oral healthcare such as dental caries, periodontal maintenance, microbial infections, oral cancers, and inflammatory conditions.

The consumption of processed sugar- and starch-containing foods, and dental caries: a systematic review

The relationship between high dietary intakes of sugar (sucrose) and dental caries is well established. Processed sugars and starches have been associated with greater dental caries experience in retrospective studies. The aim of this systematic review was to determine the relationship between the consumption of processed sugar- and starch-containing foods, the frequency of consumption of these foods, and dental caries. Prospective studies were identified in databases searched from 1970 to July 2020, and relevant retrieved papers that examined associations between the consumption of sugar- and starch-containing foods by human participants and dental caries were eligible for inclusion. Five cohort studies were identified for inclusion, all of which evaluated caries risk in young children or pre-adolescents. The between-meal consumption of processed sugar- and starch-containing foods was consistently found to be associated with greater caries experience. There were mixed findings on total consumption of processed sugar- and starch-containing foods, owing to a range of confounding factors, including the simultaneous consumption of caries-protective foods at mealtimes. Although there is a paucity of research of the dietary effects of frequent consumption of processed sugar- and starch-containing foods on dental caries, there is some evidence of plausible associations between this dietary behaviour and dental caries. Future research should investigate the effectiveness of interventions to change the dietary behaviour of high-frequency consumption of processed sugar- and starch-containing foods to decrease the risk of dental caries.

Anti-Biofilm Effect of Egg Yolk Phosvitin by Inhibition of Biomass Production and Adherence Activity against Streptococcus mutans

The formation of biofilms on the enamel surface of teeth by Streptococcus mutans is an important step in dental plaque formation, demineralization, and early caries because the biofilm is where other bacteria involved in dental caries attach, grow, and proliferate. The objectives of this study were to determine the effect of phosvitin (PSV) on the biofilm formation, exopolysaccharides (EPS) production, adherence activity of S. mutans, and the expression of genes related to the compounds essential for biofilm formation (quorum-sensing inducers and components of biofilm matrix) by S. mutans. PSV significantly reduced the biofilm-forming activity of S. mutans and increased the degradation of preformed biofilms by S. mutans. PSV inhibited the adherence activity of S. mutans by 31.9%–33.6%, and the production of EPS by 62%–65% depending upon the strains and the amount of PSV added. The expressions of genes regulating the production of EPS and the quorum-sensing-inducers (gtfA, gtfD, ftf, relA, vicR, brpA, and comDE) in all S. mutans strains were down-regulated by PSV, but gtfB was down-regulated only in S. mutans KCTC 5316. Therefore, the anti-biofilm-forming activity of PSV was accomplished through the inhibition of biofilm formation, adherence activity, and the production of quorum-sensing inducers and EPS by S. mutans.

Long-Term Fluctuation of Oral Biofilm Microbiota following Different Dietary Phases

Caries development is associated with shifts in the oral biofilm microbiota and primarily linked to frequent simple carbohydrate consumption. Different nutritional ingredients can either promote or prevent caries development. To investigate the effects of selected ingredients on the oral biofilm microbiota in situ, 11 study participants underwent 3-month-long dietary phases with intake of a regular diet (PI), additional frequent sucrose (PII), milk and yoghurt (PIII), and a diet rich in dietary fiber (PIV) and then returned to their regular diet (PV). Oral biofilm was sampled and analyzed applying 16S rRNA Illumina MiSeq sequencing. Additionally, the effect on the enamel was analyzed by measuring enamel surface roughness with laser scanning microscopy. The beta-diversity results showed that the microbiota in all the following phases differed significantly from PI and that the microbial community in PII was significantly different from all other phases. The abundance of the genus Streptococcus fluctuated over the course of the five phases, with a significant increase in PII (P = 0.01), decreasing in PIII and PIV (PIII and PIV versus PII: P < 0.00001) and increasing again toward PV. Other taxa showed various fluctuations of their abundances, with PV returning approximately to the levels of PI. In conclusion, while elevated sucrose consumption favored caries-promoting non-mutans streptococci, frequent milk and yoghurt intake caused a significant decrease in the abundance of these microbial taxa and in addition reduced enamel surface roughness. These results indicate that modulations of the oral biofilm microbiota can be attained even in adults through dietary changes and corresponding recommendations can be made for the prevention of caries development.IMPORTANCE Caries affects a large proportion of the population worldwide, resulting in high treatment costs. Its etiology can be ascribed to shifts of the microbiota in dental biofilms primarily driven by dietary factors. It is unclear how diet affects the microbial community of plaque biofilm in situ and whether it can be modulated to help prevent caries development. To address these issues, we analyzed changes of the in situ plaque microbiota following 3-month-long dietary changes involving elevated sucrose, dairy, and dietary fiber consumption over a period of 15 months. Applying high-throughput sequencing, we found non-mutans streptococci, a taxonomic group involved in the beginning stages toward microbial dysbiosis, in decreased abundance with elevated dairy and dietary fiber intake. Through analysis of the enamel surface roughness, these effects were confirmed. Therefore, correspondent dietary measures can be recommended for children as well as adults for caries prevention.

Understanding LrgAB Regulation of Streptococcus mutans Metabolism

Lack of LrgAB renders cariogenic Streptococcus mutans more sensitive to oxidative stress, as well as limits the capacity of this organism to re-uptake pyruvate upon starvation. This study was aimed at investigating the ecological and metabolic contribution of LrgAB to competitive fitness, using S. mutans strains, that either lack or overexpress lrgAB. These experiments revealed that impaired aerobic growth of the ΔlrgAB mutant can be effectively restored by supplementation of pyruvate, and that perturbated expression of lrgAB significantly affects pyruvate flux and the conversion of pyruvate to acetyl-CoA by the Pdh pathway, verifying that LrgAB is closely linked to pyruvate catabolism. In vitro competition assays revealed that LrgAB plays an important role in S. mutans competition with H₂O₂-producing S. gordonii, an interaction which can also be modulated by external pyruvate. However, no obvious competitive disadvantage was observed against S. gordonii by either the S. mutans lrgAB mutant or lrgAB overexpression strain in vivo using a mouse caries model. Organic acid analysis of mouse dental biofilms revealed that metabolites produced by the host and/or dental plaque microbiota could complement the deficiency of a lrgAB mutant, and favored S. mutans establishment compared to S. gordonii. Collectively, these results reinforce the importance of the oral microbiota and the metabolic environment in the oral cavity battleground, and highlight that pyruvate uptake through LrgAB may be crucial for interspecies competition that drives niche occupancy.

Topic Application of the Probiotic Streptococcus dentisani Improves Clinical and Microbiological Parameters Associated With Oral Health

Streptococcus dentisani 7746, isolated from dental plaque of caries-free individuals, has been shown to have several beneficial effects in vitro which could contribute to promote oral health, including an antimicrobial activity against oral pathogens by the production of bacteriocins and a pH buffering capacity through ammonia production. Previous work has shown that S. dentisani was able to colonize the oral cavity for 2–4 weeks after application. The aim of the present work was to evaluate its clinical efficacy by a randomized, double-blind, placebo-controlled parallel group study. Fifty nine volunteers were enrolled in the study and randomly assigned to a treatment or placebo group. The treatment consisted of a bucco-adhesive gel application (2.5 10⁹ cfu/dose) with a dental splint for 5 min every 48 h, for a period of 1 month (i.e., 14 doses). Dental plaque and saliva samples were collected at baseline, 15 and 30 days after first application, and 15 days after the end of treatment. At baseline, there was a significant correlation between S. dentisani levels and frequency of toothbrushing. Salivary flow, a major factor influencing oral health, was significantly higher in the probiotic group at day 15 compared with the placebo (4.4 and 3.4 ml/5 min, respectively). In the probiotic group, there was a decrease in the amount of dental plaque and in gingival inflammation, but no differences were observed in the placebo group. The probiotic group showed a significant increase in the levels of salivary ammonia and calcium. Finally, Illumina sequencing of plaque samples showed a beneficial shift in bacterial composition at day 30 relative to baseline, with a reduction of several cariogenic organisms and the key players in plaque formation, probably as a result of bacteriocins production. Only 58% of the participants in the probiotic group showed increased plaque levels of S. dentisani at day 30 and 71% by day 45, indicating that the benefits of S. dentisani application could be augmented by improving colonization efficiency. In conclusion, the application of S. dentisani 7746 improved several clinical and microbiological parameters associated with oral health, supporting its use as a probiotic to prevent tooth decay.

Dietary patterns associated with dental caries in adults in the United States

OBJECTIVES

Dental caries experience, which affects 91% of US adults, is a consequence of a carious process influenced by diet. Although individual foods have been implicated, we hypothesized that dietary patterns might be important predictors of caries presence.

METHODS

We analysed data from 4467 people ≥18 years old participating in the 2013-2014 National Health and Nutrition Examination Survey, a nationally representative sample of the US population. Data from 24-hour dietary recalls were classified into standard food categories and reduced to three dietary patterns using principal components (PCs) analysis. We used regression to model the log-transformed decayed, missing and filled teeth (DMFT) score and the prevalence of any caries experience by quartiles of PC scores, controlling for potential confounders. Dietary patterns differed by age with respect to dental caries so 18-30-year-olds (n = 1074) and >30-year-olds (n = 3393) were analysed separately.

RESULTS

Similar dietary patterns existed among individuals aged 18-30 and >30 years, but the prevalence of DMFT score >0 and the median of DMFT was greater in those >30:78.7% (95% CI: 76.1, 81.3) vs 92.6% (95% CI: 91.4, 93.7) and 4 (95% CI: 4, 5) vs 12 DMFT (95% CI: 11, 13), respectively. In those 18-30, no dietary pattern was associated with greater prevalence or severity of dental caries experience. Among those >30, the prevalence of DMFT>0 was higher by 2% for those in each subsequent quartile of a diet high in sugar-sweetened beverages and sandwiches (adjusted PR: 1.02, 95% CI: 1.001, 1.03)-thus, the prevalence of dental caries experience was 6% higher among those in the uppermost quartile than in the lowest quartile. For every subsequent quartile in the same pattern, there was a 1.98% higher (95% CI: 0.15, 3.85) DMFT score. However, analysis using the two strongest loading food groups from any of the PCs did not identify any predictors of caries experience.

CONCLUSIONS

Dietary patterns were associated with the prevalence of dental caries experience, with differing findings by age. Although effect sizes were small, the population impact may be substantial. While food groups high in sugar were associated with caries prevalence and severity, associations were more apparent in the context of overall diet. Prospective studies are needed to confirm whether particular dietary patterns are causally related to the development of dental caries.

Oral Lactobacilli Related to Caries Status of Children with Primary Dentition

Oral lactobacilli are members of a group of bacteria implicated in caries progression, although information regarding their transmission, colonization, and caries-associated species is not well established. This study isolated oral lactobacilli from a group of children with primary dentition for determination of Lactobacillus prevalence, detection of Streptococcus mutans, a major pathogen of caries initiation, and dental caries status of the children. Species of Lactobacillus isolates were determined from examination of 16S rDNA sequences. Subsequently, the most prevalent species was evaluated for involvement in caries status, and binding ability to type I collagen of all Lactobacillus isolates was determined in association with caries status. Multilocus sequence typing (MLST) of eleven loci was carried out to study strains of the predominant Lactobacillus sp. The detection of oral lactobacilli together with S. mutans was significantly associated with the highest dental caries indices, but there was no involvement of collagen-binding properties of Lactobacillus isolates in caries status. Lactobacillus fermentum was the most prevalent, and its presence was related to high scores of caries indices. MLST analysis of L. fermentum population could not specify a particular clone associated with caries status, but revealed sharing of identical L. fermentum strains among children in the same classrooms. Taken together, the data contributed useful information on the role of oral lactobacilli, in particular L. fermentum in dental caries.

The association between beverage consumption pattern and dental problems in Iranian adolescents: a cross sectional study

BACKGROUND

With regard to the increasing consumption rates of unhealthy beverages among adolescents, the main purpose of the present study was to determine the association between beverage intake pattern and dental caries and tooth erosion in this age group.

METHODS

A total sample of 600 adolescents was recruited in this study using a multistage cluster random sampling method in the city of Kerman, in the southeast of Iran, in 2017. Then, the Decayed, Missed and Filled Teeth (DMFT) index and the Tooth Wear Index (TWI) were registered for each participant. A Beverage Frequency Questionnaire was also employed to estimate typical beverage intake frequency. Correspondingly, negative binominal regression and logistic regression were performed to determine the independent variables associated with the DMFT index and the TWI.

RESULTS

The findings revealed that the highest consumed beverage in daily living was tea in both genders, followed by sweetened soft beverages, as well as milk and kefir/yogurt drink. The results of the DMFT index were also significantly different in participants that had never consumed milk compared with those who had used milk on a daily basis. Moreover, the DMFT index in participants who had never consumed sweetened soft beverages was 39%, less than those who had had a daily intake of such beverages. Also, the chance of tooth erosion for participants who had never used sweetened soft beverages was 94%, lower than that in daily consumers.

CONCLUSIONS

The results of this study revealed that adolescents had an unhealthy beverage intake pattern. Furthermore, milk consumption was beneficial to dental caries, whereas use of soft drinks associated with more dental caries and tooth erosion.

Antimicrobial Effect of a Peptide Containing Novel Oral Spray on Streptococcus mutans

Objective

To investigate the antibacterial effect of a novel antimicrobial peptide containing oral spray GERM CLEAN on Streptococcus mutans (S. mutans) in vitro and further explore the related mechanisms at phenotypic and transcriptional levels.

Methods

The disk diffusion method was used to preliminarily appraise the antimicrobial effect of GERM CLEAN. The minimal inhibitory concentration (MIC) of GREM CLEAN towards S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method.

Results

The diameter (10.18 ± 1.744 mm) of inhibition zones formed by GERM CLEAN preliminarily indicated its inhibitory effect on the major cariogenic bacteria S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method. gtfB, gtfC, gtfD, and ldh were significantly repressed by treating with GERM CLEAN, and this was consistent with our phenotypic results.

Conclusion

The novel antimicrobial peptide containing oral spray GERM CLEAN has an anti-Streptococcus mutans effect and the inhibitory property may be due to suppression of the virulence factors of S. mutans including adhesive, acidogenicity, EPS, and biofilm formation.Streptococcus mutans effect and the inhibitory property may be due to suppression of the virulence factors of S. mutans including adhesive, acidogenicity, EPS, and biofilm formation.S. mutans was determined by the broth dilution method.

The Prevalence of Streptococcus Mutans with Different ABO Blood Groups Among Healthy College Students

Objective:

This study was conducted to determine the correlation between the occurrence ofStreptococcus mutans(S. mutans) which is considered as the main pathogen responsible for the initiation and development of dental caries with blood groups and Rhesus (Rh) factor that are considered as a genetic predictor of having dental caries among healthy students.

Methods:

Saliva and blood samples were taken from 40 healthy students whose ages were between 19-23 years old in the College of Dentistry/Al-Iraqia University in Baghdad, Iraq. Estimation of the flow rate and pH was done for all the collected saliva samples within 5 min of saliva collection. Then, 100 µL of saliva was cultured on Mitis salivarius bacitracin agar (MSBA) at 37 °C for 48 h. The colonies ofS. mutanswere identified by their morphology and biochemical tests. Later, 1 to 2 drops of blood were taken from each student’s thumb to determine the blood group.

Results:

This study showed there was a greater prevalence ofS. mutansamong students of blood group A in contrast to the blood group O. In addition, Rh+ groups were dominant than Rh- groups among the study samples.

Conclusion:

S. mutanslevels were higher in the blood group A followed by AB, B, O blood groups among the college students studied.

Dental caries, diabetes mellitus, metabolic control and diabetes duration: A systematic review and meta-analysis

OBJECTIVE

To analyze articles aimed at evaluating the association between diabetes, metabolic control, diabetes duration, and dental caries.

OVERVIEW

A systematic search in PubMed, Cochrane Library, Embase, and Web of Science was conducted to retrieve papers in English, Portuguese, and Spanish, up to April 2019. The research strategy was constructed considering the "PECO" strategy. Only quantitative observational studies were analyzed. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. The meta-analyses were performed based on random-effects models using the statistical platform R. A total of 69 articles was included in the systematic review and 40 in the meta-analysis. Type 1 diabetics have a significantly higher DMFT compared to controls. No significant differences were found between type 2 diabetics and controls and between well-controlled and poorly controlled diabetics. Concerning diabetes duration, all authors failed to find differences between groups.

CONCLUSION

Although there is still a need for longitudinal studies, the meta-analysis proved that type 1 diabetics have a high dental caries risk.

CLINICAL SIGNIFICANCE

It is necessary to be aware of all risk factors for dental caries that may be associated with these patients, making it possible to include them into an individualized prevention program.

The effect of theobromine on the in vitro de- and remineralization of enamel carious lesions

OBJECTIVES

This in vitro study investigated the effect of theobromine on the de- and remineralization of enamel carious lesions under plaque fluid-like conditions.

METHODS

Early carious lesions were created in 272 bovine enamel specimens and assigned to sixteen groups (n=17) based on Knoop surface microhardness (SMH). Lesions were demineralized again under plaque fluid-like conditions in the presence of fluoride (0.2 or 1ppm) and theobromine (0; 10; 100 or 200ppm) at different pH values (5.5 or 7.0) in a factorial design. SMH was determined again and percent SMH recovery (%SMHr) calculated. Three-way ANOVA was used for the fixed effects of fluoride, theobromine and pH levels to compare the differences between each level.

RESULTS

The three-way interaction was not significant (p=0.712). The two-way interaction between fluoride and pH was significant (p=0.030), whereas those between fluoride and theobromine as well as that for pH and theobromine were not (p=0.478 and p=0.998, respectively). Theobromine did not affect %SMHr at any of the tested concentrations. There were trends for the higher fluoride concentration and the higher pH resulting in more rehardening with the lesions exposed to 0.2ppm fluoride at pH 5.5 displaying significantly less rehardening than those exposed to 0.2ppm fluoride at pH of 7.0 and lesions exposed to 1ppm fluoride at pH of 5.5.

CONCLUSION

Theobromine, when continuously present in a plaque fluid-like medium at various concentrations and at different pH values, does not affect de- or remineralization of enamel carious lesions under the presently studied conditions.

CLINICAL SIGNIFICANCE

Based on the presently available evidence, theobromine cannot be recommended as an anticaries agent.

Oral Microbiome Alterations Associated with Early Childhood Caries Highlight the Importance of Carbohydrate Metabolic Activities

Dental caries is a highly prevalent oral disease that can lead to severe dental damage and may greatly compromise the quality of life of the affected individuals. Previous studies, including those based on 16S rRNA gene, have revealed that the oral microbiota plays a prominent role in development of the disease. But the approach of those studies was limited in analyzing several key microbiome traits, including species- or strain-level composition and functional profile. Here, we performed metagenomic analyses for a cohort of preschool children with or without caries. Our results showed that caries was associated with extensive microbiota differences at various taxonomic and functional levels. Some caries-associated species had not been previously reported, some of which may have significant clinical implications. A microbiome gene catalogue from children with caries was constructed for the first time. The results demonstrated that caries is associated with alterations of the oral microbiome, including changes in microbial composition and metabolic functional profile.

Globally, dental caries is the most prevalent chronic oral disease and affects roughly half of all children. The aim of this report was to use metagenomic analyses to investigate the relationship between the oral microbiome and caries in preschool children. A total of 25 preschoolers, aged 3 to 5 years old with severe early childhood caries (ECC), and 19 age-matched, caries-free children as controls were recruited. Saliva samples were collected from the participants and were subjected to metagenomic analyses, whereby the oral microbial communities were investigated. The metagenomic analyses revealed substantial microbiota differences between the two groups, indicating apparent shifts of the oral microbiome present in the ECC group. At the species level, the ECC-enriched microbes included Prevotella amnii, Shuttleworthia satelles, Olsenella uli, and Anaeroglobus geminatus. Interestingly, Actinomyces odontolyticus and Actinomyces graevenitzii exhibited apparent differences at the strain level but not the species level between the ECC and control groups. Functional examination showed that the ECC group displayed extensive alterations in metabolic genes/pathways/modules, including enriched functions in sugar metabolism. Finally, an SVM (support vector machine) classifier comprising seven species was developed and generated a moderately good performance in predicting caries onset (area under the receiver operating characteristic curve [AUC] = 78.33%). Together, these findings indicate that caries is associated with considerable changes in the oral microbiome, some of which can potentially be exploited as therapeutic targets or diagnostic markers. (This study has been registered at ClinicalTrials.gov under registration no. NCT02341352.)

IMPORTANCE Dental caries is a highly prevalent oral disease that can lead to severe dental damage and may greatly compromise the quality of life of the affected individuals. Previous studies, including those based on 16S rRNA gene, have revealed that the oral microbiota plays a prominent role in development of the disease. But the approach of those studies was limited in analyzing several key microbiome traits, including species- or strain-level composition and functional profile. Here, we performed metagenomic analyses for a cohort of preschool children with or without caries. Our results showed that caries was associated with extensive microbiota differences at various taxonomic and functional levels. Some caries-associated species had not been previously reported, some of which may have significant clinical implications. A microbiome gene catalogue from children with caries was constructed for the first time. The results demonstrated that caries is associated with alterations of the oral microbiome, including changes in microbial composition and metabolic functional profile.

Probiotics: Evidence of Oral Health Implications

The prevalence of common oral diseases, such as dental caries, periodontal diseases and oral candidiasis remains high in the general population. Various preventive strategies have been proposed and included in national health programs promoting oral health. Interest in probiotics in light of oral health has gradually evolved as attractive means in prevention of oral infectious diseases. The aim of the present review is to outline the current evidence on the role of probiotic species on oral health parameters and their beneficial role in contributing to healthier oral environment.

Dental Infection and Resistance-Global Health Consequences

Antibiotics are widely used in dental caries and another dental related issues, both for therapeutic and prophylactic reasons. Unfortunately, in recent years the use of antibiotics has been accompanied by the rapid emergence antimicrobial resistance. Dental caries and periodontal diseases are historically known as the top oral health burden in both developing and developed nations affecting around 20⁻50% of the population of this planet and the uppermost reason for tooth loss. Dental surgeons and family practitioners frequently prescribed antimicrobials for their patients as outpatient care. Several studies reported that antibiotics are often irrationally- and overprescribed in dental diseases which is the basis of antimicrobial resistance. The aim of this review is to evaluate the use of antibiotics in dental diseases. Almost certainly the promotion of primary oral health care (POHC) in primary health care program especially among the least and middle-income countries (LMIC) may be the answer to ensure and promote rational dental care.

Anticaries activity of egg ovalbumin in an experimental caries biofilm model on enamel and dentin

OBJECTIVES

Limited evidence suggests a putative inhibitory effect of dietary proteins on demineralization during the carious process. The aim was to explore a potential anticaries activity of the egg protein ovalbumin on a relevant in vitro approach.

MATERIALS AND METHODS

Biofilms of Streptococcus mutans UA159 were formed on saliva-coated enamel and dentin bovine slabs. Biofilms were challenged with 10% sucrose followed by either a 200 μg/mL solution of ovalbumin or 1:10, 1:100, and 1:1000 (v/v) serial dilutions of that ovalbumin solution, for the entire length of the experiment. Biofilms exposed to 10% sucrose followed only by 0.9% NaCl served as caries-positive control. Once completed the experimental phase, biofilms were analyzed for biomass, viable bacteria, and polysaccharide formation. Final surface hardness (SH) was obtained to calculate %SH loss (demineralization). Two independent experiments were conducted, in triplicate. Data were analyzed by ANOVA and a post hoc test at the 95% confidence level.

RESULTS

A reduction (p < 0.05) in biomass and extracellular polysaccharide formation, but not in the number of viable cells, was observed for both dental substrates. All ovalbumin concentrations tested showed lower demineralization than the positive control (p < 0.05), in a dose-dependent manner. The highest concentration showed a reduction in the %SH loss of about 30% for both enamel and dentin.

CONCLUSION

Egg ovalbumin presented to sucrose-challenged biofilms of Streptococcus mutans seems to reduce cariogenicity of a biofilm-caries model.

CLINICAL RELEVANCE

Ovalbumin may counteract the cariogenic effect of sugars. If these findings are clinically confirmed, novel preventive approaches for caries are warranted.

Zerumbone from Zingiber zerumbet (L.) smith: a potential prophylactic and therapeutic agent against the cariogenic bacterium Streptococcus mutans

BACKGROUND

Essential oil obtained from rhizomes of the Zingiber zerumbet (L.) Smith (popularly known in Brazil as bitter ginger) is mainly constituted by the biomolecule zerumbone, which exhibit untapped antimicrobial potential. The aim of this study was to investigate the antimicrobial activity of the zerumbone from bitter ginger rhizomes against the cariogenic agent Streptococcus mutans.

METHODS

Firstly, the essential oil from rhizomes of Zingiber zerumbet (L.) Smith extracted by hydrodistillation was submitted to purification and recrystallization process to obtain the zerumbone compound. The purity of zerumbone was determined through high-performance liquid chromatography analysis. Different concentrations of zerumbone were tested against the standard strain S. mutans (ATCC 35668) by using microdilution method. The speed of cidal activity was determined through a time kill-curve assay. The biological cytotoxicity activity of zerumbone was assessed using Vero cell line through MTT assay.

RESULTS

The zerumbone showed a minimum inhibitory concentration (MIC) of 250 μg/mL and a minimum bactericidal concentration (MBC) of 500 μg/mL against S. mutans. After six hours of bacteria-zerumbone interaction, all concentrations tested starts to kill the bacteria and all bacteria were killed between 48 and 72 h period at the concentration of 500 μg/mL (99,99% of bacteria were killed in comparison with original inoculum). In addition, zerumbone showed no cytotoxicity activity on mammalian continuous cells line.

CONCLUSIONS

These results draw attention to the potential of zerumbone as antimicrobial agent against S. mutans infection, indicating its possible use in the phyto-pharmaceutical formulations as new approach to prevent and treat tooth decay disease.

In-vivo shift of the microbiota in oral biofilm in response to frequent sucrose consumption

Caries is associated with shifts of microbiota in dental biofilms and primarily driven by frequent sucrose consumption. Data on environmentally induced in vivo microbiota shifts are scarce therefore we investigated the influence of frequent sucrose consumption on the oral biofilm. Splint systems containing enamel slabs were worn for 3 × 7 days with 7-day intervals to obtain oral biofilm samples. After a three-month dietary change of sucking 10 g of sucrose per day in addition to the regular diet, biofilm was obtained again at the end of the second phase. The microbiota was analysed using Illumina MiSeq amplicon sequencing (v1-v2 region). In addition, roughness of the enamel surface was measured with laser scanning microscopy. The sucrose phase resulted in significant differences in beta-diversity and significantly decreased species richness. It was marked by a significant increase in abundance of streptococci, specifically Streptococcus gordonii, Streptococcus parasanguinis and Streptococcus sanguinis. Enamel surface roughness began to increase, reflecting initial impairment of dental enamel surface. The results showed that frequent sucrose consumption provoked compositional changes in the microbiota, leading to an increase of non-mutans streptococci, hence supporting the extended ecological plaque hypothesis and emphasizing the synergy of multiple bacterial species in the development of caries.

Ecological Approaches to Dental Caries Prevention: Paradigm Shift or Shibboleth?

Contemporary paradigms of dental caries aetiology focus on the ecology of the dental plaque biofilm and how local environmental factors can modulate this to cause disease. The crucial role that a healthy oral microbiome plays in preventing caries and promoting oral health is also being increasingly recognized. Based on these concepts, several ecological preventive approaches have been developed that could potentially broaden the arsenal of currently available caries-preventive measures. Many of these ecological approaches aim for long-term caries control by either disrupting cariogenic virulence factors without affecting bacterial viability, or include measures that can enhance the growth of health-associated, microbially diverse communities in the oral microbiome. This paper argues for the need to develop ecological preventive measures that go beyond conventional caries-preventive methods, and discusses whether these ecological approaches can be effective in reducing the severity of caries by promoting stable, health-associated oral biofilm communities.

The oral microbiome

The human microbiome is receiving a great deal of attention as its role in health and disease becomes ever more apparent. The oral microbiome, perhaps due to the ease with which we can obtain samples, is arguably the most well-studied human microbiome to date. It is obvious, however, that we have only just begun to scratch the surface of the complex bacterial and bacterial–host interactions within this complex community. Here, we describe the factors which are known to influence the development of the seemingly globally conserved, core, oral microbiome and those which are likely to be responsible for the observed differences at the individual level. We discuss the paradoxical situation of maintaining a stable core microbiome which is at the same time incredibly resilient and adaptable to many different stresses encountered in the open environment of the oral cavity. Finally, we explore the interactions of the oral microbiome with the host and discuss the interactions underlying human health and disease.

Profiling of Oral Microbiota in Early Childhood Caries Using Single-Molecule Real-Time Sequencing

Background: Alterations of oral microbiota are the main cause of the progression of caries. The goal of this study was to characterize the oral microbiota in childhood caries based on single-molecule real-time sequencing. Methods: A total of 21 preschoolers, aged 3-5 years old with severe early childhood caries, and 20 age-matched, caries-free children as controls were recruited. Saliva samples were collected, followed by DNA extraction, Pacbio sequencing, and phylogenetic analyses of the oral microbial communities. Results: Eight hundred and seventy six species derived from 13 known bacterial phyla and 110 genera were detected from 41 children using Pacbio sequencing. At the species level, 38 species, including Veillonella spp., Streptococcus spp., Prevotella spp., and Lactobacillus spp., showed higher abundance in the caries group compared to the caries-free group (p < 0.05). The core microbiota at the genus and species levels was more stable in the caries-free micro-ecological niche. At follow-up, oral examinations 6 months after sample collection, development of new dental caries was observed in 5 children (the transitional group) among the 21 caries free children. Compared with the caries-free children, in the transitional and caries groups, 6 species, which were more abundant in the caries-free group, exhibited a relatively low abundance in both the caries group and the transitional group (p < 0.05). We conclude that Abiotrophia spp., Neisseria spp., and Veillonella spp., might be associated with healthy oral microbial ecosystem. Prevotella spp., Lactobacillus spp., Dialister spp., and Filifactor spp. may be related to the pathogenesis and progression of dental caries.

Type 2 diabetes as a risk indicator for dental caries in Korean adults: the 2011-2012 Korea national health and nutrition examination survey

OBJECTIVES

The associations between type 2 diabetes (T2D) and untreated dental caries was examined. This study hypothesized that there would be a positive association between T2D and the prevalence of decayed permanent teeth (DT) in representative Korean adults.

METHODS

The information was derived from the Korea National Health and Nutrition Examination Survey conducted in 2011-2012. Sociodemographic and lifestyle variables, anthropometric and biochemical status, metabolic health and glucose tolerance status, oral health behaviors, and dental caries index were evaluated.

RESULTS

The number of DT had a positive association with degree of fasting plasma glucose (FPG) level, and glycated hemoglobin (HbA1c) (p-value = 0.045 and 0.007, respectively). The levels of FPG and HbA1c increased with the number of DT (p for trend = 0.009 and 0.004, respectively). The prevalence of untreated caries uncontrolled T2D participants was about 26% higher than those with normal glucose tolerance levels after adjusting for potential confounders including diets and socioeconomic status (OR [95% CI] = 1.26 [1.02, 1.56]).

CONCLUSIONS

T2D is an independent risk indicator for untreated caries in Korean adults.

Quantitative analysis of S. mutans, Lactobacillus and Bifidobacterium found in initial and mature plaques in Thai children with early childhood caries

AIMS

To quantify Streptococcus mutans, lactobacillus and bifidobacterium in initial and mature plaque collected from children with severe early childhood caries (S-ECC) and caries-free (CF) groups and to analyse the association between these bacteria and caries-related factors in each group.

STUDY DESIGN

A collection of 120 initial and overnight supra-gingival plaques were collected from Thai children aged 2-5 years-old (S-ECC = 60, CF = 60). Plaque, gingival indices and decayed, missing, filled tooth (dmft) scores were recorded. A questionnaire was used to assess the parents' attitudes and behaviour regarding the child's oral hygiene care and diet.

METHODS

After DNA extraction, quantitative real-time polymerase chain reaction (PCR) using fluorescent dye (SYBR green) was performed.

RESULTS

Levels of Streptococcus mutans, lactobacillus and bifidobacterium in both initial and mature plaques of S-ECC were significantly higher than those from the caries-free group (p < 0.05). The ratio of S. mutans, lactobacillus, and bifidobacterium to the total bacteria in S-ECC was significantly higher than in the caries-free group (p < 0.05). Levels of lactobacillus and bifidobacterium in both plaques significantly correlated with dmft scores and the plaque index, while S. mutans levels only correlated with dmft scores (p < 0.05). Factors that were significantly associated with caries were parents's education, duration of bottle feeding, especially during sleeping and the frequency of consuming cariogenic food between meals (p < 0.05).

CONCLUSION

Levels of S. mutans, lactobacillus, bifidobacterium and the ratio of these bacteria to total bacteria in both initial and mature plaques were significantly higher in children with S-ECC and related to dmft scores, oral hygiene and dietary habits.

Oral Health Status Related to Social Behaviors among 6 - 11 Year Old Schoolchildren in Kosovo

Aim

The aim of the present study was to evaluate the current oral health status among schoolchildren in Kosovo aged 6-11 years.

Material and methods

A study included 5679 schoolchildren aged 6 -11 years, from different towns of Kosovo. Dental health status was evaluated using the World Health Organization (WHO) caries diagnostic criteria for decayed, missing and filled teeth (dmft/DMFT index), for deciduous and permanent dentition. The observed children have answered a number of questions about their oral hygiene, eating habits, and dental visits. The analysis included frequencies and means. The differences between means were tested using the student t-test (p<0.05). The factors associated with dental caries were tested using the Spearman’s rank.

Results

The mean dmft/DMFT of schoolchildren aged 6-11 years was 4.36 ± 3.763 and 1.20 ± 1.488, respectively. Sealant placements were found among 90 schoolchildren, amounting to 1.58%. From 8 years of age, 50% of children brush their teeth twice a day. Confectionery consumption among the observed children has increased. Forty percent of them eat sweets at least once a day, and majority of them visit their dentists only when necessary. A significant correlation between consumption of confectionery, oral hygiene, dental visits and the prevalence of caries was confirmed.

Conclusion

The results of the present study show that there is a high prevalence of caries among 6-11 year old schoolchildren, thus pointing to a need for an extensive program of primary oral health care as well as utilizing preventive measures and regular dental visits.

[Geographical distribution of fluoride in the public water supply in the province of Tucumán, Argentina]

This work studied the geographical distribution of fluoride content in the public water supply in the province of Tucumán, Argentina. A total of 1,210 samples were collected in 190 localities of the 17 departments of the province during the 2008-2012 period. The analytical determination was performed using the SPADNS method and QGis 2.16 was used for processing the information. The fluoride content requirements in the studied localities were determined according to the Argentine Food Code. The results showed that 94% of population studied consumed water with fluoride concentrations below the recommended limits, 5% were exposed to fluoride concentrations above the required maximum limit and 1% consumed water at optimal fluoride concentrations. The maps showed a heterogeneous geographical distribution of fluorides, in which areas with deficit, excess and recommended values of fluorides can be differentiated; in some departments an inverse relationship between the density of the hydrological network and fluoride concentration can be observed. In the capital of the province, the average value found was 0.32 mg/l, presenting a homogeneous geographical distribution. The information obtained is indispensable for the proper management of fluoride, so as to improve public health through policy.

The caries preventive effect of 1-year use of low-dose xylitol chewing gum. A randomized placebo-controlled clinical trial in high-caries-risk adults

Objectives

The caries preventive effect of long-term use (1 year) of low-dosage (2.5 g/die) of xylitol chewing gum in a high-caries-risk adult population was evaluated.

Materials and methods

In this randomized clinical trial, 179 high-caries-risk adults were assigned to two experimental groups, xylitol and polyols. Caries status, salivary mutans streptococci (MS), and plaque pH were re-evaluated after 2 years from baseline in 66 xylitol and 64 polyol subjects. Outcomes (the net caries increment for initial, moderate, and extensive caries lesions and for the caries experience) were evaluated using the nonparametric Mann–Whitney U test.

Results

The total caries experience increment was 1.25 ± 1.26 in the xylitol group and 1.80 ± 2.33 in the polyol group (p = 0.01). Subjects treated with xylitol chewing gums had a reduction of risk rate at tooth level of 23% with respect to those treated with polyols with a number needed to treat of 55 teeth. The area under the curve at pH 5.7 was statistically significantly lower (p = 0.02) during the experimental period in the xylitol group. A decrease of the concentration of salivary MS was noted in the xylitol group (p < 0.01).

Conclusions

Subjects using the low-dose xylitol chewing gum showed a significantly lower increment of initial and extensive caries lesions and overall a lower increment of caries experience.

Clinical relevance

One-year use of chewing gums provides an effective means for the prevention of caries disease.

Trial registration number

NCT02310308

Dental plaque microbial profiles of children from Khartoum, Sudan, with congenital heart defects

Few studies have focused on the bacterial species associated with the deterioration of the dental and gingival health of children with congenital heart defects (CHD). The aims of this study were (1) to examine the dental plaque of children with CHD in order to quantify bacterial load and altered bacterial composition compared with children without CHD; and (2) to investigate the correlation between the level of caries and gingivitis and dental biofilm bacteria among those children. In this cross-sectional study, participants were children (3-12 years) recruited in Khartoum State, Sudan. A total of 80 CHD cases from the Ahmed Gasim Cardiac Centre and 80 healthy controls from randomly selected schools and kindergartens were included. Participants underwent clinical oral examinations for caries (decayed, missing, and filled teeth indices [DMFT] for primary dentition, and DMFT for permanent dentition), and gingivitis (simplified gingival index [GI]). Pooled dental biofilm samples were obtained from four posterior teeth using paper points. Real-time quantitative polymerase chain reaction was used for the detection and quantification of Streptococcus mutans, Streptococcussanguinis, and Lactobacillus acidophilus. Checkerboard DNA-DNA hybridization was used for the detection of 40 additional bacterial species. CHD cases had a significantly higher caries experience (DMFT = 4.1 vs. 2.3, p < 0.05; DMFT = 1.4 vs. 0.7, p < 0.05) and a higher mean number of examined teeth with gingivitis (4.2 vs. 2.0; p < 0.05) compared with controls. S. mutans counts were significantly higher among the CHD cases (p < 0.05). Checkerboard results revealed that 18/40 bacterial species exhibited significantly higher mean counts among CHD cases (p < 0.01). Correlation analyses revealed that among CHD cases, the detection levels of Tannerella forsythia, Campylobacter rectus, Fusobacterium nucleatum subsp. vincentii, F. nucleatum subsp. nucleatum, and F. nucleatum subsp. polymorphum were highly positively correlated with GI. CHD cases harbor more cariogenic and periodontopathogenic bacterial species in their dental plaque, which correlated with higher levels of caries and gingivitis.

Risk factors for dental caries in children with developmental disabilities

The aim of the present study was to investigate risk factors for dental caries in children with developmental disabilities who were treated at a clinical reference service for patients with special needs in Belo Horizonte, MG, Brazil. This is a retrospective cohort study that evaluated 401 dental charts of individuals without dental caries or restorations in their first dental appointment. The dependent variable was the time of occurrence of new dental caries or restorations and was measured in months. Gender, age, International Code of Diseases (ICD), mother´s education, sugar consumption, use of fluoride toothpaste, oral hygiene, mouth breathing, reports of xerostomia, gingival status, use of psychotropic or asthma drugs, and history of asthma were covariates. The Cox proportional hazards regression model was used to estimate the raw and adjusted hazard ratios and their respective 95% confidence intervals. The average time that individuals remained free of dental caries/restoration was equal to 107.46 months (95%CI 95.41 to 119.51), with a median of caries-free children up to 94 months. For each point increase in the scale of sucrose consumption, the increase in caries risk was 1.07 (95%CI 1.01 to 1.15). Sucrose consumption was the only risk factor for dental caries found in this group of individuals with developmental disabilities.

Nitrate and the Origin of Saliva Influence Composition and Short Chain Fatty Acid Production of Oral Microcosms

Nitrate is emerging as a possible health benefactor. Especially the microbial conversion of nitrate to nitrite in the oral cavity and the subsequent conversion to nitric oxide in the stomach are of interest in this regard. Yet, how nitrate influences the composition and biochemistry of the oral ecosystem is not fully understood. To investigate the effect of nitrate on oral ecology, we performed a 4-week experiment using the multiplaque artificial mouth (MAM) biofilm model. This model was inoculated with stimulated saliva of two healthy donors. Half of the microcosms (n = 4) received a constant supply of nitrate, while the other half functioned as control (n = 4). Additionally, all microcosms received a nitrate and sucrose pulse, each week, on separate days to measure nitrate reduction and acid formation. The bacterial composition of the microcosms was determined by 16S rDNA sequencing. The origin of the saliva (i.e., donor) showed to be the strongest determinant for the development of the microcosms. The supplementation of nitrate was related to a relatively high abundance of Neisseria in the microcosms of both donors, while Veillonella was highly abundant in the nitrate-supplemented microcosms of only one of the donors. The lactate concentration after sucrose addition was similarly high in all microcosms, irrespective of treatment or donor, while the concentration of butyrate was lower after nitrate addition in the nitrate-receiving microcosms. In conclusion, nitrate influences the composition and biochemistry of oral microcosms, although the result is strongly dependent on the inoculum.

Frequency of sucrose exposure on the cariogenicity of a biofilm-caries model

OBJECTIVE

Although sucrose is considered the most cariogenic carbohydrate in the human diet, the question of how many exposures are needed to induce damage on the hard dental tissues remains unclear. To approach this question, different frequencies of daily sucrose exposure were tested on a relevant biological caries model.

MATERIALS AND METHODS

Biofilms of the Streptococcus mutans were formed on enamel slabs and exposed to cariogenic challenges with 10% sucrose for 5 min at 0, 1, 3, 5, 8, or 10 times per day. After 5 days, biofilms were retrieved to analyze biomass, protein content, viable bacteria, and polysaccharide formation. Enamel demineralization was evaluated by percentage of microhardness loss (percentage surface hardness loss [%SHL]).

RESULTS

Biomass, protein content, polysaccharide production, acidogenicity of the biofilm, and %SHL proportionally increased with the number of daily exposures to sucrose (P < 0.05). One daily sucrose exposure was enough to induce 20% more demineralization than the negative unexposed control. Higher frequencies induced greater demineralization and more virulent biofilms, but eight and ten exposures were not different between them in most of the analyzed variables (P > 0.05).

CONCLUSIONS

Higher sucrose exposure seems to increase cariogenicity, in a frequency-dependent manner, by the modification of bacterial virulent properties.

Natural Immunoreactivity of Secretory IgA to Indigenous Strains of Streptococcus mutans From Chinese Spousal Pairs

Background

Dental caries is a well-known biofilm-mediated disease initiated by Streptococcus mutans, which should infect and colonize in a milieu perfused with components of the mucosal immune system. Little is known, however, regarding the relationship between the natural secretory IgA activity and S. mutans of a variety of diverse genotypes.

Objectives

The current study aimed to use spousal pairs to investigate the natural immunoreactivity of salivary secretory IgA to different genotype strains of S. mutans.

Patients and Methods

Indigenous strains were characterized from nine spousal pairs using polymerase reaction chain (PCR) and arbitrarily primed polymerase chain reaction (AP-PCR) by genotype monitoring. Unstimulated submandibular/sublingual secretions were collected and the concentrations of secretory IgA were determined by the enzyme-linked immunosorbent assay (ELISA). Each saliva sample was examined by Western blot to analyze the immunoreactivity of naturally occurring salivary secretory IgA antibodies for his/her own indigenous strain, spouse’s strain and reference strains including S. mutans GS-5 and Ingbritt (C).

Results

The results showed that naturally induced salivary IgA antibodies against S. mutans were present in all subjects. Almost all subjects had the similar individual immunoblotting profiles to different genotype strains.

Conclusions

The current study indicated that the immunoreactivity of secretory IgA might have no direct correlation with the colonization of indigenous flora and rejection of exogenous strains in adults. The relationship of microbes, host and dental caries should be in the light of coevolved microecosystem as a whole, but not caused by one factor alone.

The Interactions of CPP-ACP with Saliva

The repair of early dental caries lesions has been demonstrated by the application of the remineralisation technology based on casein phosphopeptide-stabilised amorphous calcium phosphate complexes (CPP-ACP). These complexes consist of an amorphous calcium phosphate mineral phase stabilised and encapsulated by the self-assembly of milk-derived phosphopeptides. During topical application of CPP-ACP complexes in the oral cavity, the CPP encounters the enamel pellicle consisting of salivary proteins and peptides. However the interactions of the CPP with the enamel salivary pellicle are not known. The studies presented here reveal that the predominant peptides of CPP-ACP complexes do interact with specific salivary proteins and peptides of the enamel pellicle, and provide a mechanism by which the CPP-ACP complexes are localised at the tooth surface to promote remineralisation.

Breastfeeding, Dental Biofilm Acidogenicity, and Early Childhood Caries

Aim: This study evaluated the acidogenicity of human milk by the dental biofilms of children with and without early childhood caries (ECC). Method: Biofilms of 16 children (7 with ECC; 9 caries free) were exposed to human milk or 10% sucrose solution in the crossover design, and the biofilm pH was determined. Results: Breastfeeding did not provoke a decrease in biofilm pH, irrespective of the children's caries status, whereas sucrose decreased the pH for both groups. In addition, higher ΔpH5min (pH variation occurring at 5 min) was observed in the biofilms of ECC children (p < 0.05). The results suggest that breastfeeding may not contribute to ECC.

Cariogenicity features of Streptococcus mutans in presence of rubusoside

BACKGROUND

One promising way of reducing caries is by using sucrose substitutes in food. rubusoside is a prototype sweet substance isolated from the leaves of the plant Rubrus suavissimus S. Lee. (Rosaceae), and is rated sweeter than sucrose. The purpose of this study was to investigate the effects of rubusoside on Streptococcus mutans growth, acidogenicity, and adherence to glass in vitro.

METHODS

The effects of rubusoside on the growth and glass surface adhering of Streptococcus mutans were investigated by measuring the optical density of the culture at 540 nm with a spectrophotometer. Rubusoside influence on Streptococcus mutans acidogenicity was determined by measuring the pH of the culture. Sucrose, glucose, maltose, fructose and xylitol were designed to compare with rubusoside.

RESULTS

S. mutans growth in the rubusoside-treated group was significantly lower than that in the sucrose, glucose, maltose and fructose groups (p < 0.05) except for xylitol group (p > 0.05). Sucrose-treated S. mutans exhibited the highest adherence to glass, and rubusoside-treated S. mutans exhibited the lowest. S. mutans adherence to a glass surface and acidogenicity with sucrose were significantly reduced by rubusoside.

CONCLUSIONS

Rubusoside may have some potential as a non-cariogenic, non-caloric sweetener.

Activity of Synthetic Antimicrobial Peptide GH12 against Oral Streptococci

Controlling the growth of cariogenic microorganisms such as oral streptococci is an adjunct therapy for caries-active individuals to prevent and treat caries. Here we investigated the antimicrobial activity of the synthetic amphipathic α- helical antimicrobial peptide GH12 (GLLWHLLHHLLH-NH2) against oral streptococci in vitro. Circular dichroism studies showed that GH12 takes on an α-helical conformation in the presence of membrane-mimicking solvents, and reversed-phase high-performance liquid chromatography studies showed that GH12 remains stable in saliva. The peptide showed bactericidal activity against oral streptococci, with minimum inhibitory concentrations ranging from 6.7 to 32.0 μg/ml. GH12 concentrations 4-fold higher than the minimum bactericidal concentration completely killed oral streptococci within 20 min. Treating oral streptococci with GH12 caused noticeable changes in bacterial viability and morphology based on confocal laser scanning microscopy and scanning electron microscopy. Effects of GH12 on biofilm formation and on viability of mature biofilm were quantified by crystal violet staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. GH12 effectively inhibited biofilm formation and metabolic activity in biofilms of oral streptococci, especially S. mutans, S. sobrinus and S. salivarius. These results suggest that GH12 shows rapid and strong antimicrobial activity against oral streptococci in vitro, opening the door to preclinical and clinical studies to explore its potential for caries prevention and treatment.