Changing paradigms in concepts on dental caries: consequences for oral health care

Analysis of ENAM gene single-nucleotide polymorphism rs3796704 with caries susceptibility in young adult Tamil population

Background:

Dental caries is as primeval as humanity, but still, investigations are undergoing regarding the etiopathogenesis behind this multifactorial disease. Genetics is known to play a vital role in the etiology behind dental caries in addition to environmental and socioeconomic factors. Genetic variations like single-nucleotide polymorphisms (SNPs) were extensively studied in the past decade to portray the etiopathogenesis contributing to dental caries.

Aim:

This investigation was undertaken to analyze the ENAM gene SNP rs3796704 with caries susceptibility in ethnic young adult Tamil population of India.

Materials and Methods:

Out of 370 patients included, 215 patients belonged to the high caries group (Decayed, Missing and Filled Tooth [DMFT] ≥2) and 155 patients belonged to the low caries group (DMFT ≤ 1). DNA was extracted from the blood of all the individuals. SNP genotyping was performed utilizing tetra-primer amplification refractory mutation system–polymerase chain reaction with specific primers.

Results:

The genotyping results showed that there were no differences in allelic (P = 0.114) and genotypic frequencies (P = 0.159) between the high caries and low caries groups.

Conclusion:

Future studies can be conducted in larger samples and different ethnicities around the globe to analyze the role played by SNPs of enamel formation genes in cariogenesis.

Construction and properties of the antibacterial epitaxial transition layer on a zirconia ceramic surface

Secondary caries is one of the main causes of dental zirconia restoration failure in the clinic. Therefore, it is urgent to improve the antibacterial performance of zirconia ceramics to reduce the occurrence of secondary caries. In this study, a quaternary ammonium compound antibacterial polymer was innovatively synthesized by solution polymerization with a quaternary ammonium salt monomer as the antibacterial component. The antibacterial epitaxial transition layer was successfully prepared on the surface of zirconia ceramics by the hydroxyl group on HEMA reacting with the siloxane group in the KH570 hydrolysate, which makes the antibacterial polymer indirectly chemically combine with the silicate epitaxial transition layer. The antibacterial epitaxial transition layer exhibited excellent mechanical properties, satisfactory biocompatibility and significant antibacterial effects, and the maximum antibacterial rate is 99%. The antibacterial epitaxial transition layer plays an important role in preventing secondary caries and improving the success rate of clinical zirconia ceramic restorations.

Construction of an antibacterial epitaxial transition layer on a zirconia ceramic surface to improve the antibacterial properties.

The Effects of Three Remineralizing Agents on the Microhardness and Chemical Composition of Demineralized Enamel

This study aimed to determine the effects of three different varnish materials (containing casein phosphopeptide-amorphous calcium phosphate, nano-hydroxyapatite, and fluoride) on enamel. Thirty-three extracted human third molars were used for specimen preparation. These were demineralized using phosphoric acid. Three experimental groups (n = 11) were treated with 3M™ Clinpro™ White Varnish, MI Varnish^®, and Megasonex^® toothpaste, respectively, every twenty-four hours for fourteen days. Analysis of the microhardness of the specimens’ enamel surfaces was carried out via the Vickers method, and by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Analysis was performed at three stages: at baseline value, after demineralization, and after the period of remineralization. Data were subjected to Scheffe’s post hoc test. The mean microhardness values (HV0.1) obtained for the group of samples treated with MI Varnish^® were higher compared with the other two groups (p = 0.001 for both comparisons), while the first and third groups did not differ significantly from each other (p = 0.97). SEM analysis showed uneven patterns and porosities on all samples tested. EDS results showed an increase in the mineral content of the examined samples, with the highest mineral content observed in the MI Varnish^® group. It can be concluded that MI Varnish^® use has a better remineralization effect on enamel than the other two materials.

Effect of Xylitol Chewing Gum on Presence of Streptococcus mutans in Saliva

BACKGROUND: Oral disease ranks third among the most serious diseases in the world, after cancer and cardiovascular disease. Vietnamese population has suffered from various dental and oral diseases, of which the most common have been identified to be cavities and inflammation around the teeth. AIM: The aim of the study was to evaluate the effectiveness of using xylitol gum on the status of Strepptococus mutans bacteria in saliva. METHODS: The study design was an uncontrolled clinical study conducted at the Hanvinco Texture Factory (Hanoi). Two hundred and fifty-four subjects between the ages of 18 and 63 were included in the clinical trial. These subjects brushed their teeth for 2 weeks before providing a saliva sample for S. mutans. The 80 subjects with the highest number of salivary S. mutans were recruited for the further analysis (at least 104 CFU/ml). After each clinical intervention, participant chewed Lotte xylitol gum after each meal, two capsules each time and 1 time in the evening (total 4 times/day), continuously for 4 weeks. Saliva samples were quantified for S. mutans by real-time PCR method. RESULTS: Quantitative analysis of S. mutans bacteria in saliva of 254 subjects showed that 19.7% had S. mutans detected within 105 CFU/ml of saliva. These result shows that nearly 20% of the subjects examined have a high risk of tooth decay. After continuous use of xylitol chewing gum 4 times a day for 4 weeks by 80 subjects, it showed a decrease in the number of S. mutans in the saliva of participants, and the difference was statistically significant. CONCLUSIONS: The use of xylitol chewing gum taken 4 times/day is effective in reducing the number of S. mutans bacteria in saliva when combined with brushing your teeth.

Molecular mechanisms of inhibiting glucosyltransferases for biofilm formation in Streptococcus mutans

Glucosyltransferases (Gtfs) play critical roles in the etiology and pathogenesis of Streptococcus mutans (S. mutans)- mediated dental caries including early childhood caries. Gtfs enhance the biofilm formation and promotes colonization of cariogenic bacteria by generating biofilm extracellular polysaccharides (EPSs), the key virulence property in the cariogenic process. Therefore, Gtfs have become an appealing target for effective therapeutic interventions that inhibit cariogenic biofilms. Importantly, targeting Gtfs selectively impairs the S. mutans virulence without affecting S. mutans existence or the existence of other species in the oral cavity. Over the past decade, numerous Gtfs inhibitory molecules have been identified, mainly including natural and synthetic compounds and their derivatives, antibodies, and metal ions. These therapeutic agents exert their inhibitory role in inhibiting the expression gtf genes and the activities and secretion of Gtfs enzymes with a wide range of sensitivity and effectiveness. Understanding molecular mechanisms of inhibiting Gtfs will contribute to instructing drug combination strategies, which is more effective for inhibiting Gtfs than one drug or class of drugs. This review highlights our current understanding of Gtfs activities and their potential utility, and discusses challenges and opportunities for future exploration of Gtfs as a therapeutic target.

Bioadhesive Curcumin-Mediated Photodynamic Inactivation and Its Potential to Cause Undesirable Effects on Dental and Restorative Surfaces

Curcumin-mediated Photodynamic Inactivation (PDI) has shown great potential to disinfect specific sites on tooth enamel but may involve contact with restorative materials. Thus, before use in dentistry, it is necessary to investigate whether the PDI protocol causes undesirable changes in the surfaces of aesthetic restorative materials and dental enamel. This study investigated the effect of PDI mediated by curcumin (CUR) in a liquid crystal precursor system on color stability (ΔE), surface roughness (Ra), and microhardness (kgf) of three different composite resins and bovine dental enamel specimens. The microhardness and roughness readings were performed 60 days after the treatments while the color readings were performed immediately, 24, 48, and 72 h, 7, 14, 21, 30, and 60 days after the treatments. Results showed that CUR mediated-PDI does not seem to have the potential to promote any esthetic or mechanical changes to the surface of tooth enamel and can be applied safely in clinical practice. However, the results on color, roughness, and hardness obtained for composite resins show that some negative effects can be produced, depending on the type of restorative material; more experiments must be performed with different formulations and, perhaps, with lower concentrations of CUR.

Assessment of Microstructure and Release of Fluoride Ions from Selected Fissure Sealants: An In Vitro Study

The aim of this study was to compare fluoride release from four selected fissure sealants: fissure sealant manufactured by Arkona, Helioseal F, Helioseal F Plus, and Conseal. Tested parameters included emission of fluoride ions into saline (0.9% NaCl) and deionized water over a period of 2 weeks. Values were recorded after 1, 3, 24, 48, 72, and 96 h, and then after 1 and 2 weeks. All sealants were characterized by a constant fluoride release level. The highest fluoride release level was noted for Conseal (0.0169 ppm/mg), while the lowest was noted for fissure sealant manufactured by Arkona (0.063 ppm/mg). Fissure sealants, which contain fluoride, release it not only during polymerization, but also for several days after application. The use of fissure sealants whose composition includes fluoride is an effective method of preventing tooth decay.

Modelling the impact of increase in sugar prices on dental caries in India

OBJECTIVES

This study aims to assess the impact of raising the price of sugar and/or sugar-sweetened beverages (SSBs) on caries incidence in the Indian population.

METHODS

A tooth-level decision-analytic model was developed to evaluate a change in caries increment after increasing the price of Sugar and SSBs. The transition of a tooth from a caries-free state to the state of tooth loss in both scenarios was modelled with the help of a Markov model for a time horizon of 63 years, ranging from 2021 to 2083 for the 12-year-old population cohort of India. A conceptual framework was designed to implicate the possible effects of an increase in sugar prices on the reduction of caries incidence. Health effects were estimated in terms of the number of carious lesions and tooth-loss in both the scenarios and modelled as a product of the dose-response relationship between sugar intake and caries incidence. The model was thus used to establish the number of caries lesions prevented, and tooth-loss avoided. Uncertainties in the parameters were assessed using probabilistic sensitivity analysis. The Monte Carlo method was used for simulating the results 999 times.

RESULTS

A 20% rise in the price of sugar is expected to result in the prevention of an average of 1.32 teeth in a lifetime of an individual and prevent 27.96 million tooth-loss incidents among the population cohort of India that will eventually lead to a saving of INR (₹) 3116.32 billion (US$ 42.69 billion) on account of dental caries treatment. Similarly, increasing-price of SSBs by 20% will lead to a 0.86% reduction in carious teeth incidence in an individual's lifetime.

CONCLUSION

Increasing the cost of sugar and/or SSBs will reduce the daily intake of sugar, which will reduce caries incidence and subsequent progression, thereby preventing caries-attributed tooth-loss and saving treatment costs.

Follow-up of patients subjected to direct and indirect pulp capping of young permanent teeth. A retrospective study

OBJECTIVE

A retrospective study of the success rate of direct pulp capping (DPC) and indirect pulp capping (IPC) was carried out in children between 6-14 years-old, considering separately primary caries or caries affecting teeth with molar incisor hypomineralization (MIH).

MATERIAL AND METHODS

Data were collected in a dental public health service. Following the inclusion criteria, 232 treatments were analyzed. Success was defined by the presence of a functional tooth without clinical signs or symptoms of pulpal or periapical disease. The success rate was correlated to patient gender, the affected tooth and the indication of therapy using the chi-squared and Fisher exact test. The success time related to treatment type was evaluated through the Mann-Whitney test.

RESULTS

The IPC and DPC success rate was 99.4%, and 84.6%, respectively (p = .01). Success was significantly lower when caries affected teeth with MIH than when caries affected teeth without MIH (p = .01). The mean survival for DPC and IPC was 14.07 ± 1.30 and 15.98 ± 0.80 months, respectively (p = .07).

CONCLUSIONS

When caries were located in teeth that were not affected by MIH, IPC was significantly more successful than DPC, but did not differ significantly when caries were placed in teeth with MIH. Key points Minimally invasive therapy is a successful approach for decayed young permanent teeth. The success of IPC was greater than the success of DPC wen caries was placed in teeth not affected by MIH. In teeth not affected by MIH the success of DPC or IPC did not differ significantly.

Remineralization potential and caries preventive efficacy of CPP-ACP/Xylitol/Ozone/Bioactive glass and topical fluoride combined therapy versus fluoride mono-therapy - a systematic review and meta-analysis

OBJECTIVE

To compare the remineralization potential and caries preventive efficacy of CPP-ACP/bioactive glass/xylitol/ozone and topical fluoride (TF) combined therapy versus TF mono-therapy.

MATERIAL AND METHODS

Embase, PubMed, Scopus, Web of Science and Cochrane databases were searched. 4457 records were screened and 26 trials were included. Data from 16 trials was pooled using Review Manager 5.4. Level of significance was p < .05. The certainty of the evidence was evaluated using GRADE.

RESULTS

Pooled analysis of two trials for white spot lesions (WSLs) regression (SMD -0.6, 95% CI: [-1.07 to -0.14], p = .01) and three trials for post-intervention DIAGNOdent values (SMD -1.24, 95% CI: [-1.96 to -0.52], p = .0007) significantly favoured CPP-ACP-TF combined therapy over TF mono-therapy. The sub-group analysis for caries increment (SMD -0.14, 95% CI: [-0.21 to -0.07], p < .0001) and the post intervention S mutans count (SMD -0.42, 95% CI: [-0.62 to -0.23], p < .0001) significantly favours 'xylitol-TF' and 'CPP-ACP-TF' combined therapy respectively. The high/unclear risk of bias, imprecision and indirectness of the included trials presented a low certainty of evidence.

CONCLUSION

CPP-ACP-TF exhibits superiority over TF monotherapy in remineralizing existing lesions and demonstrates better antibacterial effect, whereas it is not more effective for preventing caries incidence. However, Xylitol exerts an added benefit over fluoride alone in preventing caries increment. The low-certainty evidence highlights the need for more good quality trials.

Community interventions and strategies for caries control in Latin American and Caribbean countries

Dental caries remains highly prevalent in Latin American and Caribbean countries (LACC). However, this disease can be controlled through interventions that implement evidence-based strategies in an affordable manner and that target all population groups instead of the most affluent only. Therefore, the aim of this report was to summarize the main scientifically documented community interventions and strategies based on restriction of sugars consumption, use of fluoride, and the use of occlusal sealants for caries control in LACC. A critical literature review was carried out in a systematic manner that included defined search strategies, independent review of the identified publications, and compilation of results in this report. Three systematic searches were conducted using the PubMed, LILACS, and SciELO databases to identify studies related to community interventions and strategies for caries control in LACC. Of the 37 publications identified, twenty-six focused on fluoride use, eight on occlusal sealant use, and three on the restriction of sugar consumption. Documented community interventions for sugars restriction were scarce in the region and were based on food supplementation, sugar replacement, and education. Thus, local and/or national policies should prioritize investment in upstream, coherent, and integrated population-wide policies such as taxes on sugary drinks and stronger regulation of advertising and promotion of sugary foods and drinks mainly targeting children. The main fluoride-based strategies used drinking water, refined domestic salt, cow milk, toothpaste and, to a lesser extent, mouth-rinses, acidulated phosphate fluoride (APF) gels, and varnishes to deliver fluoride to the population. Evidence of fluoride use was seen in Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay, and Venezuela. Studies reporting the use of occlusal sealants were mainly located in Brazil, Chile, Colombia, Costa Rica, Peru, Mexico, and Venezuela. Community interventions restricting sugar consumption should be implemented at the individual level and through public policies. The use of fluoride must be monitored at the local, regional, and national levels so as to achieve maximum anti-caries effect while also minimizing the risk of dental fluorosis. Moreover, fluoridated water and salt programs, used as a mutually exclusive community level strategy for caries control, should expand their benefits to reach non-covered areas of the LACC while also simultaneously providing adequate surveillance of the fluoride concentration delivered to the population. Regulating the concentration of soluble fluoride (for anti-caries effect) in dentifrice formulations is also necessary in order to provide the population with an effective strategy for disease control. Targeting culturally appropriate, economically sustainable caries control interventions to rural populations and native ethnic groups such as indigenous people, quilombolas (African-origin), and riverside Amazonian people remains a crucial challenge.

Determinants of dental caries in children in the Middle East and North Africa region: a systematic review based on literature published from 2000 to 2019

Background

Dental caries risk factors have been expanded to not only emphasize biology, dietary and oral habits but also broader social determinants such as socioeconomic factors and the utilization of health services. The aim was to review sociobehavioural/cultural and socioeconomic determinants of dental caries in children residing in the Middle East and North Africa (MENA) region.

Methods

A search was conducted in the PubMed/Medline database and Google Scholar to identify studies published from 2000 to 2019 covering children using key search terms. In the initial stages, titles, abstracts and, if needed, full articles were screened for eligibility. In the final stage, all included articles were reassessed and read, and relevant data were extracted.

Results

Out of 600 initial articles, a total of 77 were included in this review, of which 74 were cross-sectional, 2 were longitudinal and one was a case–control study. The studies included a total of 94,491 participants in 14 countries across the MENA region. A majority used the World Health Organization scoring system to assess dental caries. The caries prevalence ranged between 17.2% and 88.8%, early childhood caries between 3% and 57% and decayed missing filled teeth (dmft) varied between 0.6 and 8.5 across the various age groups. Increased age, low maternal education, low overall socioeconomic status, decreased frequency of tooth brushing, low parental involvement, poor oral habits, infant feeding practices and sugar consumption were among the most prevalent determinants for increased risk of caries in the reviewed studies.

Conclusions

Dental caries was found to be high among children in many of the studies published from MENA. The key determinants of dental caries were found to include factors related to child characteristics, family background, oral hygiene and infant feeding and eating habits. The high dental caries prevalence emphasises the need to address the prevailing modifiable sociobehavioural and socioeconomic determinants by translating them into effective oral health prevention policies and programmes.

Fluoride exposure and factors affecting dental caries in preschool children living in two areas with different natural levels of fluorides

BACKGROUND

Successful oral health interventions must be based on the specific needs of the population that they serve. Evaluation of habits related to dental caries development and estimation of fluoride exposure in a target group of young patients helps to plan effective and safe caries prevention strategies.

OBJECTIVES

The study aimed to evaluate factors affecting dental caries experience and sources of fluoride exposure in preschool children living in two areas: with optimal and low natural content of fluoride in drinking water.

MATERIALS AND METHODS

The study included a group of 73 children of both sexes aged 4-7 years attending two kindergartens in Środa Wielkopolska and Turek (Wielkopolska Voivodeship, Poland), where the content of fluoride in drinking water according to data obtained in the sanitary station ranged from 0.68 to 0.74 mg/L (optimal concentration of fluoride) and from 0.19 to 0.30 mg/L (low concentration of fluoride), respectively. Parents of patients completed a survey about diet, hygiene, and dental care, taking into account the child's fluoride exposure. The calibrated dentist assessed the oral health condition using a mirror, a CPI probe, and a headlamp. Oral hygiene was recorded using the Silness and Löe plaque index, caries experience by calculating the numbers of decayed, missing, and filled primary, and permanent teeth (dmf and DMF, respectively) while caries frequency by calculating the percentage of children with caries experience above 0. In order to assess the fluoride concentrations in urine and drinking water, parents were asked to provide a urine sample collected on fasting and a tap water sample. Fluoride concentrations were assessed using a 09-37 (MARAT) fluoride ion-selective electrode and a RAE 111 silver-chloride reference electrode. Statistical analysis was conducted using the data analysis software system Statistica (version 12, StatSoft, Inc. 2014), assuming a statistical significance level p < 0.05.

RESULTS

No statistically significant differences were found between caries indices of the examined children in each kindergarten (p > 0.05). Urinary fluoride levels were higher in children who tended to swallow toothpaste or used fluoride rinses and positively correlated with fluoride concentrations in the drinking water. Dental caries experience in the examined children depended on the effectiveness and frequency of oral hygiene procedures and dietary habits.

CONCLUSIONS

The strategy aimed at improving the oral health of the examined group of children should include accomplishing oral hygiene, promoting a non-cariogenic diet, and, finally, controlling fluoride exposure from at-home fluoride products. Caries prevention program ought to be adjusted to individual characteristics of each child, taking into consideration oral hygiene practices, dietary habits and total fluoride intake.

The Potential of a Bioactive, Pre-reacted, Glass-Ionomer Filler Resin Composite to Inhibit the Demineralization of Enamel in Vitro

CLINICAL RELEVANCE

A prereacted, glass-ionomer filler fluoride-containing resin composite had lower remineralization potential than glass-ionomer cements but was able to inhibit enamel demineralization; thus, it may be an option for restoring dental surfaces for patients at high risk of caries.

SUMMARY

Evidence is lacking on the use of surface prereacted glass-ionomer filler resin composites to inhibit demineralization and that simulate real clinical conditions. The present laboratory study evaluated the potential of such composites to prevent demineralization and quantified fluoride (F) and other ions released from restorative materials after a dynamic pH-cycling regimen applied to the tooth material interface in vitro. The pH-cycling regimen was assessed by measuring surface hardness (SH) along with energy dispersive X-ray spectroscopy (EDX).

METHODS AND MATERIALS

Ninety blocks of bovine enamel were subjected to composition analysis with EDX, and were further categorized based on SH. The blocks were randomly divided into 6 treatment groups (n=15 each): F IX (Fuji IX Extra; GC Corporation); IZ (Ion Z, FGM); F II (Fuji II LC, GC Corporation); B II (Beautifil II, Shofu); F250 (Filtek Z250 XT, 3M ESPE); and NT (control, no treatment). The blocks were subjected to a dynamic pH-cycling regimen at 37°C for 7 days concurrently with daily alternations of immersion in demineralizing/remineralizing solutions. EDX was conducted and a final SH was determined at standard distances from the restorative materials (150, 300, and 400 μm).

RESULTS

The EDX findings revealed a significant increase in F concentration and a decrease in Ca2+ in the enamel blocks of group B II after the pH-cycling regimen (p<0.05). SH values for groups F IX, IZ, and F II were greater than those for groups B II, F250, and NT at all distances from the materials.

CONCLUSIONS

The results suggest that each of 3 restorative materials, F IX, IZ, and F II, partially inhibited enamel demineralization under a dynamic pH-cycling regimen.

Is dietary pattern a mediator of the relationship between socioeconomic status and dental caries?

OBJECTIVE

To investigate whether a healthy diet and added sugar mediate the relationship between socioeconomic status and oral health status in adults.

METHODS

This is a secondary cross-sectional analysis of adult participants from the 2015-2016 National Health and Nutrition Examination Survey from the United States (n=3367). Structural equation modeling tested direct and indirect pathways from a latent variable for socioeconomic status to oral health via healthy eating (Health Eating Index) and added sugar in a multiple-mediator multiple-outcome model.

RESULTS

Added sugar was directly associated with untreated dental caries [Standardized coefficient (SC)=0.10], and healthy eating was directly associated with both untreated dental caries (SC=-0.11) and tooth loss (SC=-0.05). Higher socioeconomic status was associated with lower untreated dental caries through direct (SC =-0.246) and small indirect paths via healthy diet (SC= -0.026), lower consumption of added sugar (SC=-0.007), and dental visits (SC=-0.162). Higher socioeconomic status was associated with fewer teeth lost through direct (SC =-0.306) and very small indirect paths via healthy diet (SC=-0.016), added sugar consumption (SC=-0.001), and untreated dental caries (SC=-0.094).

CONCLUSIONS

Both socioeconomic status and dietary pattern independently contributed to tooth loss and dental caries. The contribution of dietary factors as a mediator to socioeconomic inequities in oral health was small, and statistically significant.

CLINICAL RELEVANCE

A systems approach to socioeconomic inequities in oral health takes into account the complex relationships between socioeconomics, dietary patterns, oral health and health. Socioeconomic conditions and nutrition, as common risk factors to noncommunicable disorders, should be tackled in programs to improve oral health.

Comparative Evaluation of Antibacterial Activity of Probiotics SK12 and SM18: An In Vitro Study

Aim

To assess the antimicrobial activity of probiotics SK12 and SM18 on Streptococcus mutans and also to compare the antimicrobial activity of SK12 and SM18.

Materials and methods

Synthetic strains of Streptococcus mutans were used to study the antimicrobial activity of probiotics SK12 and SM18 using various tests such as disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). In disk diffusion, the zone of inhibition was measured to assess the antimicrobial activity. Chlorhexidine was used as a control for this test. The MIC and MBC were assessed at different dilutions of the probiotic sample (100 mg/mL, 50 mg/mL, 25 mg/mL, 12.5 mg/mL, 6.25 mg/mL, 3.12 mg/mL, 1.6 mg/mL, 0.8 mg/mL, 0.4 mg/mL, and 0.2 mg/mL).

Result

SM18 demonstrated 20 mm of zone of inhibition, whereas SK12 demonstrated 15 mm showing a less antibacterial activity in comparison to SM18. SM18 was found to be bactericidal and effective at a minimum concentration of 0.8 mg/mL, whereas SK12 was bactericidal and effective at a minimum concentration of 1.6 mg/mL.

Conclusion

Probiotics demonstrate antibacterial activity against cariogenic microflora. SM is 18 having a better antibacterial activity at lower concentrations than SK12 in reducing cariogenic microorganisms. Clinical significance: BLIS K12 and M18 both demonstrated an antibacterial effect on Streptococcus mutans, wherein the use of probiotic in caries prevention is found to be limited. Hence, it is suggestive to reap the bacterial effects of BLIS K12 and M18 in caries prevention.

How to cite this article

Chandrasekhar SN, Mallikarjun SB, Salim HP. Comparative Evaluation of Antibacterial Activity of Probiotics SK12 and SM18: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(6):611–616.

Multifaceted effect of caffeic acid against Streptococcus mutans infection: microbicidal and immunomodulatory agent in macrophages

The aim of the present study was to investigate the effects of caffeic acid in the interface between the antimicrobial and anti-inflammatory function in macrophage response against S. mutans. S. mutans (10⁸ cfu/mL) were incubated with caffeic acid to determinate the half-maximal inhibitory concentration (IC₅₀) and macrophage cells were incubated with caffeic acid to determinate cell viability and toxicity. Anti-inflammatory effects were measured by nitrite accumulation, TNF-α and PGE₂ production, and NF-kB phosphorylation, and S. mutans survival following internalization by macrophages was investigated. We found that caffeic acid presented antimicrobial activity against S. mutans (IC₅₀ = 2.938 ± 0.1225 mM) without exerting cytotoxicity. Caffeic acid inhibited nitrite, TNF-α and PGE₂ production by the NF-kB dependent pathway, indicating an immunomodulatory property. Caffeic acid also contributed to macrophage bacteria clearance activity. In summary, caffeic acid presented antimicrobial activity against S. mutans and anti-inflammatory effects in macrophages.

Oral Health Related Behaviors in Relation to DMFT Indexes of Teenagers in an Urban Area of North-West Poland-Dental Caries Is Still a Common Problem

Caries has a negative influence on health and is still a public health problem among children and adolescents in Poland. The aim of this study was to analyze the association of dietary habits, oral hygiene behaviors and the frequency of usage of dental services with the dental caries index in teenagers in North-West Poland. The study enrolled 264 children (147M/117F) aged 15. Participants filled out a questionnaire regarding age, sex, frequency of visits to the dentist, dietary habits and oral hygiene behaviors, and the Decayed Missing Filled Teeth Index (DMFT) was calculated. Caries was found in 88.6% of subjects. The lower or no caries experience group (DMFT ≤ 5) comprised of 180 subjects, while higher caries experience (DMFT > 5) was found in 84 teenagers and was significantly inversely associated with tooth brushing after the last meal (OR = 0.45; 95% CI:0.21–0.97; p = 0.04) and the daily use of dental floss (OR = 0.12; 95% CI:0.01–0.92; p = 0.04). There is an emerging need for the implementation of effective caries prevention and recovery programs in Poland. Health promotion focusing on oral hygiene behaviors should be disseminated more widely because lower caries experience was demonstrated in teenagers declaring healthy oral habits. Another important need is the development of multi-sectorial actions aiming at the improvement of dietary habits.

Quantification and gene expression of Lactobacillus casei group species associated with dentinal lesions in early childhood caries

Background

Considering that the Lactobacillus casei group is strongly associated with caries progression, the use of lactobacilli as probiotics must be balanced due to their possible involvement in dental caries.

Objective

This study aimed to detect and quantify L. paracasei, L. rhamnosus, and L. casei group species in the active and arrested dentinal lesions of preschoolers. It also aimed to determine the expression profiles of lactobacilli genes related to adhesion, extracellular polymeric substance regulation, and pyruvate oxidation.

Methods

Total ribonucleic acid (RNA) was extracted from dentinal lesion samples (25 active, 13 arrested) of children between 2 and 5 years of age. The samples were converted to complementary deoxyribonucleic acid (cDNA), and quantitative polymerase chain reaction (qPCR) analyses were performed to quantify and determine the relative abundance (measured by percentage of total bacteria) of L. paracasei, L. rhamnosus, and L. casei group species. The expression profiles of L. paracasei/casei genes (spaC and spxB) and L. rhamnosus genes (spaE and wzb) were assessed. The Student t-test and the Mann-Whitney U test were used for comparisons.

Results

The L. casei group species were found to be part of the viable microbial community in dentinal caries. L. paracasei (p = 0.001), L. rhamnosus (p = 0.022), and L. casei (p = 0.004) group species were abundant in the active dentinal lesions compared to the arrested dentinal lesions. Only the wzb gene (p = 0.006) exhibited a statistically significant difference between the active and arrested lesions in terms of its expression profile; it was expressed to a higher extent in the active dentinal lesions.

Conclusions

The L. casei group species presented in large numbers in the active dentinal caries lesions, indicating that these microorganisms are related to caries activity, and the wzb gene may play an important role in caries progression.

In-vitro Evaluation of toothpaste containing enzymes and proteins on inhibiting plaque re-growth of the children with high caries experience

Background

Dental caries belong to a disease which has a complex etiology. Individual preventive measures are not adequate enough to control the disease especially in children with high caries experience The aim of the study was to evaluate the efficacy of tooth paste containing enzymes and proteins in inhibiting plaque re-growth when compared to fluoride tooth paste in children with high caries experience.

Material and Methods

A total of 15 plaque samples are collected from 15 subjects in the age group of 5-7 years with High caries experience. The participants were asked to fast overnight for 12 h. On the day of the study, the participants were asked to report without brushing. Pre brushing pooled plaque was collected from buccal and palatal/lingual surfaces of maxillary and mandibular teeth and transferred to chilled Eppendorf tubes. Samples were divided into two groups; according to the test toothpaste used; Zendium toothpaste and Colgate cavity protection along with controls. Inhibition of plaque re-growth is assessed by comparing optical density using a spectrophotometer at intervals between 0-8 hours.

Results

Results demonstrated that toothpaste containing enzymes and proteins can significantly inhibit plaque growth when compared to normal toothpaste (p<0.05) in children with high caries experience.

Conclusions

Toothpaste containing enzymes and proteins can augment natural salivary defenses and control plaque re-growth which plays a major role in dental caries formation.

Key words:Enzymes, proteins, toothpaste, children, caries, dental plaque.

The consumption of milk supplemented with probiotics decreases the occurrence of caries and the salivary concentration of hβD-3 in children

OBJECTIVES

This study evaluated the effect of milk supplemented with Lactobacillus rhamnosus SP1 on the occurrence of caries and the salivary concentration of human β-defensin-3 (hβD-3) in preschool children with high caries risk.

MATERIALS AND METHODS

A sample of 42 children was randomly assigned to two groups; children in the intervention group were given 150 mL of milk supplemented with 10⁷ CFU/mL of Lactobacillus rhamnosus SP1, while children in the control group were given standard milk, for 10 months. The occurrence of dental caries was assessed using the International Caries Detection and Assessment System (ICDAS), and the concentration of hβD-3 was measured in unstimulated saliva using an ELISA test at baseline and after the intervention.

RESULTS

There was an increase in the number of teeth with carious lesions (d_ICDAS2-6 mft) in the control group, and this increase was statistically significant (p = 0.0489). The concentration of hβD-3 in saliva from the intervention group decreased from 597.91 to 126.29 pg/mL (p = 0.0061), unlike in the control group, where no change in hβD-3 salivary concentration was found.

CONCLUSIONS

These findings showed that regular intake of probiotic-supplemented milk in preschool children with high caries risk decreased the occurrence of caries and the salivary levels of hβD-3.

CLINICAL RELEVANCE

Our results suggest the need for developing and implementing probiotic supplementation, as adjuvants to the conventional treatments for caries and allow to considerate the salivary levels of hβD-3 as markers of oral tissue homeostasis.

Relationship of levels of trace elements in saliva and dental caries in preschool children using total reflection X-ray fluorescence technique (TXRF)⋆

BACKGROUND

Considering that studies on the relationship between dental caries and trace elements present contradictory and inconclusive results, the purpose of this study was to determine the levels of salivary trace elements in saliva samples of preschool children and investigate their relationship with dental caries.

METHODS

In total, 120 samples of unstimulated saliva were collected from children aged 36-72 months, of both sexes, who participate in the preventative educational program in oral health at the State University of Londrina, Brazil. The children were divided into two groups, caries (n = 60) and non-caries (n = 60). Levels of Al, Cu, Fe, Mn, and Zn were analyzed by total reflection X-ray fluorescence (TXRF). Descriptive statistics, the Student's t-test, Mann-Whitney U test, and Pearson's Chi-squared test were performed (P < 0.05).

RESULTS

The concentrations of Mn and Fe were significantly higher in the caries group (Mn =0.015 mg/L [0.007-0.020]; Fe =0.080 mg/L [0.031-0.239] than the non-caries group (Mn =0.010 mg/L [0.001 - 0.017]; Fe =0.044 mg/L [0.023 - 0.107]).

CONCLUSION

The results suggest a relationship between trace elements and dental caries, indicating possible involvement of these elements in the metabolism of microorganisms involved in the carious process. In addition, the use of TXRF presented satisfactory results, with a simple and fast methodology for the detection of the studied elements.

Exogenous Intake of Fluorides in Caries Prevention: Benefits and Risks

Caries incidence and prevalence have decreased significantly over the last few decades due to widespread use of fluoride. However, an increase in the prevalence of dental fluorosis has been reported in both fluoridated and non-fluoridated communities. Care must be taken to ensure that a balance between the optimal fluoride preventive effect at the individual and community level and minimal risk of dental fluorosis is maintained. This review describes the main sources of fluoride intake that have been identified: fluoridated drinking water, dietary fluoride supplement, and topical forms comprising toothpastes, rinses, gels and varnishes. The cited data were taken from meta-analytic studies and reports from Cochrane database systematic reviews up to December 2019. Efficiency, but safety, of topically applied fluorides in individual home care is dependent on the degree of compliance of individuals/parents and on the level of competence of providers of preventive counselling. The broad spectrum of these resources allows individualization of fluoride prevention based on risk analysis of caries attack and taking into consideration other preventive measures.

Applying Pb2+ to probe the dissolution of carbonated hydroxylapatite by Enterobacter sp.: A new insight into the bioerosion of tooth mineral

Dental caries is one of the most common disorders in dentistry. Typically, it is caused by the dissolution of the tooth mineral due to cariogenic organisms. Bioapatite is vulnerable to acid-etching ascribed to a variety of substitutions. This study applied Pb²⁺ cations to probe the dissolution of synthetic carbonated hydroxylapatite (CHAp) in the acidic environment induced by Enterobacter sp. It indicated a decreasing tendency of crystallite size (from ∼400 nm to 10-20 nm) during gradual incorporation of carbonate (from 2.5 to 13.8 wt %). Meanwhile, the shape of CHAp crystals was transformed from elongated to plate-like. Addition of Enterobacter sp. enhanced P release from CHAp (especially for the CHAp with ∼8 wt % CO₃ ) around 10 times. Moreover, the bacterium provided a moderately acidic environment to cause more formation of stable pyromorphite over other Pb-minerals, for example, Pb₃ (PO₄ )₂ , and PbCO₃ . Then, transmission electron microscopy-energy dispersive X-Ray spectroscopy mapping successfully confirmed the Pb labeling on the newly formed phosphate mineral as Pb (with high-atomic weight) has strong signal under electron microscopy. This study therefore elucidated that Pb labeling has a bright future to explore the degradation of tooth mineral by microorganisms, as well as to evaluate the resistance of calcium phosphate dental restorative materials.

The Concept of Sustainable Development of Modern Dentistry

This paper concerns the assessment of the current state of dentistry in the world and the prospects of its sustainable development. A traditional Chinese censer was adopted as the pattern, with a strong and stable support on three legs. The dominant diseases of the oral cavity are caries and periodontal diseases, with the inevitable consequence of toothlessness. From the caries 3.5–5 billion people suffer. Moreover, each of these diseases has a wide influence on the development of systemic complications. The territorial range of these diseases and their significant differentiation in severity in different countries and their impact on disability-adjusted life years index are presented (DALY). Edentulousness has a significant impact on the oral health-related quality of life (OHRQoL). The etiology of these diseases is presented, as well as the preventive and therapeutic strategies undertaken as a result of modifying the Deming circle through the fives’ rules idea. The state of development of Dentistry 4.0 is an element of the current stage of the industrial revolution Industry 4.0 and the great achievements of modern dental engineering. Dental treatment examples from the authors’ own clinical practice are given. The systemic safety of a huge number of dentists in the world is discussed, in place of the passive strategy of using more and more advanced personal protective equipment (PPE), introducing our own strategy for the active prevention of the spread of pathogenic microorganisms, including SARS-CoV-2. The ethical aspects of dentists’ activity towards their own patients and the ethical obligations of the dentist community towards society are discussed in detail. This paper is a polemic arguing against the view presented by a group of eminent specialists in the middle of last year in The Lancet. It is impossible to disagree with these views when it comes to waiting for egalitarianism in dental care, increasing the scope of prevention and eliminating discrimination in this area on the basis of scarcity and poverty. The views on the discrimination of dentistry in relation to other branches of medicine are far more debatable. Therefore, relevant world statistics for other branches of medicine are presented. The authors of this paper do not agree with the thesis that interventional dental treatment can be replaced with properly implemented prophylaxis. The final remarks, therefore, present a discussion of the prospects for the development of dentistry based on three pillars, analogous to the traditional Chinese censer obtaining a stable balance thanks to its three legs. The Dentistry Sustainable Development (DSD) > 2020 model, consisting of Global Dental Prevention (GDP), Advanced Interventionist Dentistry 4.0 (AID 4.0), and Dentistry Safety System (DSS), is presented.

Analysis of relative bacterial activity and lactate dehydrogenase gene expression of caries-associated bacteria in a site-specific natural biofilm: an ex vivo study

Objectives

Detecting bacterial activity is considered a promising approach to monitor shifts from symbiosis to dysbiosis in oral microbiome. The present study aimed at investigating both the relative bacterial activity and the lactate dehydrogenase (ldh) gene expression of caries-associated bacteria in a site-specific natural biofilm.

Material and methods

Sixty subjects (age, mean ± SE: 30.1 ± 1.4) were allocated to two groups: caries-free subjects (CF) or caries-active subjects (CA). CF presented one sound surface (CFS, n = 30). CA presented two donor sites: a cavitated caries lesion (CAC, n = 30) and a sound reference surface (CAS, n = 30). Real-time quantitative PCR (q-PCR) on species or genus level and total bacteria was performed targeting the 16S gene, the 16S rRNA, the ldh gene, and the ldh mRNA (increasing 16S ribosomal RNA copy numbers can function as an indicator of increased energy metabolism). As the 16S rRNA abundance represents the number of ribosomes, while the 16S gene abundance represents the number of genomes, the quotient of the relative abundances functions as a measure for the relative bacterial activity (%).

Results

Both lactobacilli and S. mutans showed the highest relative bacterial activity in CAC ((mean ± SE) 218 ± 60% and 61 ± 16%, respectively) and the lowest values for both sound reference surfaces (69 ± 48%; 8 ± 3%). Significant differences were found between CAC and CAS as well as between CAC and CFS for both lactobacilli and S. mutans (p < 0.05). The ldh gene expression of lactobacilli and S. mutans only showed moderate values in CAC (1.90E+03 ± 2.11E+03; 2.08E+04 ± 4.44E+04 transcripts/μl) and CFS (2.04E+03 ± 2.74E+03; 8.16E+03 ± 6.64E+03 transcripts/μl); consequently no significant differences were detected.

Conclusion and clinical relevance

Caries-associated bacteria (lactobacilli and S. mutans) showed the highest relative bacterial activity in plaque of cavitated lesions, the lowest in sound surfaces, allowing the detection of a significant activity shift in health and disease for caries-active patients. However, no significant differences in ldh gene expression could be determined.

Characterization and effect of nanocomplexed fluoride solutions on the inhibition of enamel demineralization created by a multispecies cariogenic biofilm model

OBJECTIVES

The aim of this study was to assess the in vitro caries preventive effect of nanocomplexed solutions of hydroxypropyl-β-cyclodextrin and γ-cyclodextrin associated with titanium tetrafluoride (TiF₄) after different complexation times (12 or 72 h).

MATERIALS AND METHODS

Enamel blocks were randomly distributed in 9 groups (n = 11): negative control, hydroxypropyl-β-cyclodextrin, γ-cyclodextrin, TiF₄, hydroxypropyl-β-cyclodextrin:TiF₄ 12 h, hydroxypropyl-β-cyclodextrin:TiF₄ 72 h, γ-cyclodextrin:TiF₄ 12 h, γ-cyclodextrin:TiF₄ 72 h, and NaF (positive control). The solutions were applied for 1 min and the blocks were exposed to a biofilm model. Nanocompounds were characterized by differential scanning calorimetry and X-ray powder diffraction. The percentage of surface microhardness loss (%SML), mineral density changes (ΔZ), lesion depth, surface morphology (scanning electron microscopy-SEM), and chemical characterization (energy-dispersive spectroscopy-EDS) were assessed.

RESULTS

No oxidation was observed, and the formation of the nanocomplexes was evidenced by changes in the melting point compared to pure cyclodextrins and the loss of crystallinity of the materials. Hydroxypropyl-β-cyclodextrin:TiF₄ 72 h resulted in lower %SML than negative control, hydroxypropyl-β-cyclodextrin, γ-cyclodextrin, and TiF₄ (p < 0.05). NaF differed from all groups (p < 0.05), except for hydroxypropyl-β-cyclodextrin:TiF₄ 72 h (p = 0.83). ΔZ of hydroxypropyl-β-cyclodextrin:TiF₄ 72 h was higher than negative control, hydroxypropyl-β-cyclodextrin, γ-cyclodextrin, γ-cyclodextrin:TiF₄ 1 2 h, γ-cyclodextrin:TiF₄ 72 h, and NaF (p < 0.05) and similar to TiF₄ and hydroxypropyl-β-cyclodextrin:TiF₄ 12 h (p > 0.05). SEM/EDS detected Ti in the blocks subjected to TiF₄-products.

CONCLUSION

The hydroxypropyl-β-cyclodextrin:TiF₄ 72 h solution showed caries preventive effect on the surface and subsurface of the enamel.

CLINICAL RELEVANCE

A hydroxypropyl-β-cyclodextrin nanosystem, in association with TiF₄ after 72 h of complexation, may be a promising agent for the prevention of enamel demineralization.

Effect of xylitol tablets with and without red propolis on salivary parameters, dental biofilm and sensory acceptability of adolescents: a randomized crossover clinical trial

The effect of xylitol tablets with (XPT) and without (XT) red propolis on salivary parameters, dental biofilm and acceptability of adolescents was evaluated through a blinded randomized crossover clinical trial. Healthy volunteers were allocated in the XPT and XT groups with a 30-day washout period for consumption of two tablets/dayfor seven days. An increase in salivary parameters was only observed immediately after tablet consumption, without differences between XPT and XT. The results for total microorganisms were similar, but XT was better in controlling Streptococcus spp. Rothia dentocariosa and Streptococcus salivarius were the most frequent in the biofilm and saliva, respectively. XPT and XT showed similar acceptability, with the highest purchase intention for XT. Although propolis did not enhance the properties of XT, further studies testing different protocols and follow-up are necessary; XT controlled Streptococcus spp. in biofilms, which demonstrate its potential for clinical application.

Remineralization of enamel subsurface lesions using toothpaste containing tricalcium phosphate and fluoride: an in vitro µCT analysis

Background

This study aimed to compare the efficacies of experimental toothpastes containing functionalized tricalcium phosphate (fTCP) with and without fluoride for in vitro enamel remineralization under pH-cycling conditions.

Methods

To create artificial white spot lesions, 36 bovine enamel specimens were immersed in a demineralization solution for 10 days. During pH-cycling for 12 days, the specimens were divided into four groups based on the experimental toothpaste type used: (a) fTCP-free, fluoride-free (fTCP − F −); (b) fTCP-containing, fluoride-free (fTCP + F −); (c) fTCP-free, fluoride-containing (fTCP − F +); and (d) fTCP-containing, fluoride-containing (fTCP + F +). Micro-focus X-ray computed tomography (μCT) scans of all specimens were obtained before demineralization, after demineralization, and after pH-cycling. The mineral density and mineral loss (ΔZ) in the enamel subsurface lesions were measured and the percentage of remineralization (%R) was calculated from ΔZ after demineralization and pH-cycling. One-way ANOVA with Tukey’s test was used for statistical analysis of the %R values. The treated enamel surface was investigated via scanning electron microscopy (SEM).

Results

The fTCP − F − group presented with the lowest amount of mineral gain after pH-cycling. In contrast, the fTCP + F + group showed the highest degree of remineralization within all lesion parts. The %R was highest in the fTCP + F + group (38.2 ± 7.8, all P < 0.01). SEM revealed the presence of small crystals on the enamel rods in the fTCP + F − and fTCP + F + groups.

Conclusions

The experimental toothpaste containing fTCP and fluoride increased remineralization of the artificial enamel subsurface lesions during pH-cycling. Furthermore, fTCP and fluoride appear to act independently on the remineralization of enamel subsurface lesions, although they coexisted in one toothpaste type.

Trial registration: This is not a human subject research.

Minimum intervention dentistry in the US: an update from a cariology perspective

Despite evidence strongly supporting use of non-invasive or minimally invasive procedures in caries management, there is still a large gap between evidence-based recommendations and application of these concepts in practice, with the practice of dentistry still largely dominated by invasive procedures in the US. This paper describes efforts in education and clinical practice in the US in the last decade to promote evidence-based cariology strategies, which support a minimum intervention dentistry (MID) philosophy. These include, for example: a competency-based core cariology curriculum framework which has been developed and disseminated. National education accreditation standards supporting caries management are likely to soon be changed to support assessment of best evidence in cariology. There are several ongoing efforts by organised dentistry and other groups involving dental educators, researchers and clinical practitioners to promote cariology concepts in practice, such as the development of evidence-based clinical practice guidelines for caries management by the American Dental Association. Within each of these strategies there are challenges, but also opportunities to expand the implementation of MID in the US, which create optimism for future improvements over time.

Effects of Sodium Trimetaphosphate, Associated or Not with Fluoride, on the Composition and pH of Mixed Biofilms, before and after Exposure to Sucrose

The aim of the present study was to evaluate the influence of sodium trimetaphosphate (TMP), associated or not with fluoride (F), on the concentrations of F, calcium (Ca), and phosphorus (P) and on the pH of mixed biofilms of Streptococcus mutans and Candida albicans, before and after exposure to sucrose. The biofilms received three treatments (72, 78, and 96 h after the beginning of their formation), at three TMP concentrations (0.25, 0.5, or 1%), with or without F at 500 ppm. Solutions containing 500 and 1,100 ppm F as well as artificial saliva were also tested as controls. Biofilm pH was measured and the concentrations of F, Ca, and P were determined (solid and fluid phases). In a parallel experiment, after the third treatment (96 h), the biofilms were exposed to a 20% sucrose solution to simulate a cariogenic challenge and the pH of the medium, F, Ca, P, and TMP were determined. The data were submitted by two-way ANOVA, followed by Fisher's least significant difference test (p < 0.05). Treatment with TMP and 500 ppm F led to higher F concentration in the biofilm fluid. Although TMP did not affect Ca concentrations, biofilms treated with TMP alone presented higher P concentrations. Treatment with 1% TMP and F led to the highest pH values of the biofilm, both before and after the cariogenic challenge. It was concluded that TMP increases F and P in the biofilm and that its presence promotes an increase in the pH of the medium, even after the cariogenic challenge.

Caries Prevalence Evolution and Risk Factors among Schoolchildren and Adolescents from Valencia (Spain): Trends 1998-2018

The aim of this study was to determine the caries status and risk factors in the schoolchildren of Spain’s Valencia region in 2018 and to compare them to the 20-year evolution of caries indicators in the region. A cross-sectional survey was conducted with 1722 children and adolescents aged between 6 and 15 using cluster sampling. Caries status, using International Caries Detection and Assessment System II (ICDAS II) criteria, and sociodemographic variables were recorded. To ensure the comparison with previous studies using WHO caries criteria, the cut-off point was established at ICDAS II code 4. Caries prevalence was found to be 37.4% and the decayed and filled teeth index (dft) was 1.23 at 6 years for deciduous dentition (DD). In permanent dentition (PD) at 12 years, caries prevalence was 30.1% with a 0.66 decayed, missing and filled teeth index (DMFT), and at 15 years, prevalence was 44.6% and DMFT was 1.21. Socioeconomic status poses a major risk factor for caries prevalence in deciduous dentition; it is 1.8 times higher in the lowest socioeconomic group. Deciduous dentition status has worsened in the most recent eight-year period, whereas in permanent dentition the 12- and 15-year values are similar to those of the 2010 survey. Evolution analysis suggests that community dental care programs be enhanced, involving preventive activities staring at the first year and targeting disadvantaged groups.

Effect of bioactive compounds on the regulation of quorum sensing network-associated genes and virulence in Streptococcus mutans-A systematic review

OBJECTIVE

The aim of this study was to systematically review the literature on the effect of bioactive compounds and their regulation of quorum sensing (QS)-related and/or -regulated-virulence genes expression in Streptococcus mutans.

DESIGN

The search strategy was conducted through the electronic databases Pubmed, Scopus, and Web of Science for studies reporting the effects of natural and synthetic bioactive compounds on the regulation of QS-associated and/or -regulated genes of S. mutans.

RESULTS

After full-text reading, 19 studies met the inclusion criteria, in most of them, QS-inhibitors from synthetic origin were evaluated, 16 articles described the effect of the compounds on biofilm formation cultivated in vitro and five studies described these effects on adhesion of biofilm-producing cells. Only 2 studies analyzed the potential target-component of the QS.

CONCLUSIONS

Mostly, the bioactive compounds affected the expression of QS-associated and/or -regulated genes and virulence traits (e.g. adhesion, biofilm formation, acid stress tolerance) of S. mutans. Further studies are necessary to elucidate the target-specific QS-system constituent used by bioactive compounds to achieve QS inhibition as well as validate the use of these compounds in controlling dental caries.

Conceptualization of dental caries by dental students is related to their preventive oral care routine

OBJECTIVE

Whether the understanding of dental caries influences how future dentists manage the disease themselves has not been previously studied. Thus, this study evaluated whether the conceptualization (understanding) of dental caries by dental students is related to their own preventive oral care routine.

METHODS

Dental students at a U.S. dental school (n = 517) were invited to voluntarily respond to an anonymous electronic survey in spring 2018. Demographic characteristics, caries conceptualization (CC), dental care habits, and self-caries risk determination were asked. Discursive responses to CC were analyzed by content analysis technique, and categories [c] were created. Chi-square and Fisher's exact tests were used for analysis.

RESULTS

Overall response rate was 54.5% (n = 282, 48.2% female). Three researchers independently analyzed discursive answers and classified them into 1 of 6 caries concept categories [c]: [c1] only signs of the disease (10.3%), [c2] bacterial disease-not specifying bacterial metabolism (38.3%), [c3] bacterial byproducts-not specifying substrate (13.8%), [c4] biological or multifactorial concept (24.8%), [c5] comprehensive multifactorial disease (8.2%), or [c6] other (4.6%). Only 33% completely defined dental caries according to the modern understanding of the disease (c4-c5). Statistical differences were found between: CC and diet modification, CC and rinsing after brushing, year of school (YS) and self-determined caries-risk, YS and brushing at school, and YS and rinsing after brushing (P < 0.05).

CONCLUSION

Our data suggest that the students' understanding of the disease can influence how they will manage the disease in terms of diet modification and behavior after brushing. Moreover, self-caries risk determination influenced students' brushing behavior.

Comparative Evaluation of the Remineralizing Potential of Commercially Available Agents on Artificially Demineralized Human Enamel: An In vitro Study

Background

Caries is highly prevalent multifactorial disease, but its progression can be prevented in the initial stage of demineralization through remineralization (RML). Various materials have been proposed for the same, successful outcome can prove to be a boon in the prevention of caries.

Aim

The aim of the study is to assess the RML potential of four commercially available agents so as to restore the enamel closest to its previous microhardness levels.

Materials and Methods

Sixty permanent intact premolars were randomly divided into six groups: Four test groups - (1) bioactive glass (BAG) Novamin (SHY-NM), (2) nano-hydroxyapatite (nHAp) (Acclaim), (3) functionalized tricalcium phosphate (f-TCP) (Clinpro Tooth Crème), and (4) grape seed extract (GSE); one positive control - (5) fluoride (1000 ppm) containing dentifrice (Colgate Calci-Lock); and one negative control - (6) distilled water. The samples were initially evaluated for baseline surface microhardness (SMH); later on, these samples were placed in the demineralizing solution for 48 h in an incubator at 37°C, and postdemineralization again SMH was measured. Thereafter, the samples were subjected to the pH cycling for consecutive 21 days, and SMH was recorded. The SMH was evaluated using a Vickers microhardness tester. Statistical analysis was done using a post hoc Tukey test for each group based on the stage of treatment and one-way ANOVA for comparison among different groups.

Results

BAG Novamin showed SMH recovery at 96.75% followed by f-TCP at 95.83%, nHAp at 90.88%, and GSE at 48.71%. Statistically significant differences were observed between the first three groups and the rest of the groups after RML stage.

Conclusion

BAG Novamin, f-TCP, and nHAp showed considerable RML followed to a lesser extent by GSE.

A Comparative Study to Evaluate the Effects of Probiotic Curd on Streptococcus mutans, Bifidobacterium dentium, and pH of Saliva in Caries-free Children: An In Vivo Study

BACKGROUND

Dental caries is one of the commonest oral diseases that require early stages of prevention and intervention. The primary organisms related to dental caries are streptococcus mutans and lactobacilli. In the past decades, some of the non-pathogenic bacteria called probiotics have been added to the food products for the beneficial effect of human health. Intake of probiotic food products has been shown to have beneficial effects on the oral tissues. Hence the present study aimed to compare the levels of salivary pH, S. mutans, B. dentium counts in children consuming probiotic and non-probiotic curd.

METHODS AND MATERIAL

40 healthy caries free children were randomly allocated into two groups. First baseline salivary samples were collected from all the participants and tested for salivary pH, salivary B. dentium and S. mutans count. After collecting the baseline values test group of children were provided with probiotic curd whereas the control group were provided with non probiotic curd for 15 days. After 15 days of consumption of these dairy products, salivary samples were collected again and tested for salivary pH, salivary B. dentium and S. mutans count.

RESULTS

Probiotic curd was found to be more effective in reducing the colony counts of B.dentium and S.mutans. There was a marginal decrease in pH in both the groups but was well above the critical pH.

CONCLUSIONS

Probiotic curd showed considerable level of decrease in colony counts of B.dentium, S.mutans and salivary pH when compared to normal curd.

A Century of Change towards Prevention and Minimal Intervention in Cariology

Better understanding of dental caries and other oral conditions has guided new strategies to prevent disease and manage its consequences at individual and public health levels. This article discusses advances in prevention and minimal intervention dentistry over the last century by focusing on some milestones within scientific, clinical, and public health arenas, mainly in cariology but also beyond, highlighting current understanding and evidence with future prospects. Dentistry was initially established as a surgical specialty. Dental caries (similar to periodontitis) was considered to be an infectious disease 100 years ago. Its ubiquitous presence and rampant nature-coupled with limited diagnostic tools and therapeutic treatment options-meant that these dental diseases were managed mainly by excising affected tissue. The understanding of the diseases and a change in their prevalence, extent, and severity, with evolutions in operative techniques, technologies, and materials, have enabled a shift from surgical to preventive and minimal intervention dentistry approaches. Future challenges to embrace include continuing the dental profession's move toward a more patient-centered, evidence-based, less invasive management of these diseases, focused on promoting and maintaining oral health in partnership with patients. In parallel, public health needs to continue to, for example, tackle social inequalities in dental health, develop better preventive and management options for existing disease risk groups (e.g., the growing aging population), and the development of reimbursement and health outcome models that facilitate implementation of these evolving strategies. A century ago, almost every treatment involved injections, a drill or scalpel, or a pair of forceps. Today, dentists have more options than ever before available to them. These are supported by evidence, have a minimal intervention focus, and result in better outcomes for patients. The profession's greatest challenge is moving this evidence into practice.

Assessment of the antibacterial, antivirulence, and action mechanism of Copaifera pubiflora oleoresin and isolated compounds against oral bacteria

The microorganisms that constitute the oral microbiome can cause oral diseases, including dental caries and endodontic infections. The use of natural products could help to overcome bacterial resistance to the antimicrobials that are currently employed in clinical therapy. This study assessed the antimicrobial activity of the Copaifera pubiflora oleoresin and of the compounds isolated from this resin against oral bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays provided values ranging from 6.25 to > 400 μg/mL for the C. pubiflora oleoresin and its isolated compounds. The fractional inhibitory concentration index (FICI) assay showed that the oleoresin and chlorhexidine did not act synergistically. All the tested bacterial strains formed biofilms. MICB₅₀ determination revealed inhibitory action: values varied from 3.12-25 μg/mL for the oleoresin, and from 0.78 to 25 μg/mL for the ent-hardwickiic acid. Concerning biofilm eradication, the C. pubiflora oleoresin and hardwickiic acid eradicated 99.9 % of some bacterial biofilms. Acid resistance determination showed that S. mutans was resistant to acid in the presence of the oleoresin and ent-hardwickiic acid at pH 4.0, 4.5, and 5.0 at all the tested concentrations. Analysis of DNA/RNA and protein release by the cell membrane demonstrated that the oleoresin and hardwiickic acid damaged the bacterial membrane irreversibly, which affected membrane integrity. Therefore, the C. pubiflora oleoresin and ent-hardwickiic acid have potential antibacterial effect and can be used as new therapeutic alternatives to treat oral diseases such as dental caries and endodontic infections.

Antimicrobial effect of anacardic acid-loaded zein nanoparticles loaded on Streptococcus mutans biofilms

Bacterial biofilms play a key role in the pathogenesis of major oral diseases. Nanoparticles open new paths for drug delivery in complex structures such as biofilms. This study evaluated the antimicrobial effect of zein nanoparticles containing anacardic acid (AA) extracted from cashew shells of Anacardium occidentale on in vitro Streptococcus mutans biofilm formation and mature biofilms. The minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC), and antibiofilm assays were performed. Streptococcus mutans UA159 biofilms were formed on saliva-coated hydroxyapatite disk for 5 days. To evaluate the preventive effect on biofilm formation, before contact with the inoculum, the disks were immersed once for 2 min in (1) hydroethanolic solution; (2) blank zein nanoparticles; (3) zein nanoparticles containing AA; and (4) 0.12% chlorhexidine gluconate. To determine the effect against mature biofilms, the disks containing 5-day preformed biofilms were further treated using the same procedure. The bacterial viability and dry weight were determined for both assays and used to compare the groups using ANOVA followed by Tukey's test (p < 0.05). Both MIC and MBC for AA-loaded zein nanoparticles were 0.36 μg/mL. Groups 3 and 4 were very effective in inhibiting S. mutans biofilm formation, as no colony-forming units were detected. In contrast, for mature biofilms, no difference in bacterial viability (p = 0.28) or dry weight (p = 0.09) was found between the treatments. Therefore, the AA-based nanoformulation presented very high inhibitory and bactericidal activities against planktonic S. mutans, and the results indicate a strong antiplaque effect. However, the formulation showed no antimicrobial effect on the established biofilm.

pH-Responsive Resveratrol-Loaded Electrospun Membranes for the Prevention of Implant-Associated Infections

To date, the implant-associated infections represent a worldwide challenge for the recently reported bacterial drug resistance that can lead to the inefficacy or low efficacy of conventional antibiotic therapies. Plant polyphenolic compounds, including resveratrol (RSV), are increasingly gaining consensus as valid and effective alternatives to antibiotics limiting antibiotic resistance. In this study, electrospun polylactic acid (PLA) membranes loaded with different concentrations of RSV are synthesized and characterized in their chemical, morphological, and release features. The obtained data show that the RSV release rate from the PLA-membranes is remarkably higher in acidic conditions than at neutral pH. In addition, a change in pH from neutral to slightly acidic triggers a significant increase in the RSV release. This behavior indicates that the PLA-RSV membranes can act as drug reservoir when the environmental pH is neutral, starting to release the bioactive molecules when the pH decreases, as in presence of oral bacterial infection. Indeed, our results demonstrate that PLA-RSV2 displays a significant antibacterial and antibiofilm activity against two bacterial strains, Pseudomonas aeruginosa PAO1, and Streptococcus mutans, responsible for both acute and chronic infections in humans, thus representing a promising solution for the prevention of the implant-associated infections.

Human microbiome: an academic update on human body site specific surveillance and its possible role

Human body is inhabited by vast number of microorganisms which form a complex ecological community and influence the human physiology, in the aspect of both health and diseases. These microbes show a relationship with the human immune system based on coevolution and, therefore, have a tremendous potential to contribute to the metabolic function, protection against the pathogen and in providing nutrients and energy. However, of these microbes, many carry out some functions that play a crucial role in the host physiology and may even cause diseases. The introduction of new molecular technologies such as transcriptomics, metagenomics and metabolomics has contributed to the upliftment on the findings of the microbiome linked to the humans in the recent past. These rapidly developing technologies are boosting our capacity to understand about the human body-associated microbiome and its association with the human health. The highlights of this review are inclusion of how to derive microbiome data and the interaction between human and associated microbiome to provide an insight on the role played by the microbiome in biological processes of the human body as well as the development of major human diseases.

Biomimetic chitosan against bioinspired nanohydroxyapatite for repairing enamel surfaces

In this study, chitosan was employed as a novel biomimetic mineralization model to repair damaged enamel to compare its performance with that of bioinspired zinc-doped nanohydroxyapatite. Fifty human premolar tooth slices were prepared, and artificial caries lesions were induced to produce demineralized enamel surfaces. The etched slices were randomly divided into two groups: a chitosan-hydrogel-treated group and a zinc-doped nanohydroxyapatite-treated group. In vitro assessment using energy-dispersive X-ray analysis, X-ray diffraction analysis and scanning electron microscopy was conducted at the baseline, demineralization and remineralization stages. Baseline results were matched with those for normal enamel; a marked reduction in the calcium (Ca)/phosphorus (P) ratio to 1·12 and the lack of the characteristic hydroxyapatite diffraction peaks were detected for demineralized enamel. The remineralization stage revealed evident recovery of the mineral contents (the calcium/phosphorus ratio was 1·61 for the chitosan-treated group and 1·58 for the bioinspired-nanohydroxyapatite-treated one), with apparent distinctive X-ray diffraction patterns of hydroxyapatite in both groups. Scanning electron microscopic analysis showed the absence of etched enamel porosity, with the formation of a newly formed rod-like apatite layer, similar to natural enamel, which extended over the treated enamel surfaces of both groups. Chitosan hydrogel is recommended as a biomimetic mineralization smart system for repairing demineralized carious enamel.

A Virtual 3D Dynamic Model of Caries Lesion Progression as a Learning Object for Caries Detection Training and Teaching: Video Development Study

BACKGROUND

In the last decade, 3D virtual models have been used for educational purposes in the health sciences, specifically for teaching human anatomy and pathology. These models provide an opportunity to didactically visualize key spatial relations that can be poorly understood when taught by traditional educational approaches. Caries lesion detection is a crucial process in dentistry that has been reported to be difficult to learn. One especially difficult aspect is linking clinical characteristics of the different severity stages with their histological features, which is fundamental for treatment decision-making.

OBJECTIVE

This project was designed to develop a virtual 3D digital model of caries lesion formation and progression to aid the detection of lesions at different severity stages as a potential complement to traditional lectures.

METHODS

Pedagogical planning, including identification of objectives, exploration of the degree of difficulty of caries diagnosis-associated topics perceived by dental students and lecturers, review of the literature regarding key concepts, and consultation of experts, was performed prior to constructing the model. An educational script strategy was created based on the topics to be addressed (dental tissues, biofilm stagnation areas, the demineralization process, caries lesion progression on occlusal surfaces, clinical characteristics related to different stages of caries progression, and histological correlations). Virtual 3D models were developed using the Virtual Man Project and refined using multiple 3D software applications. In the next phase, computer graphic modelling and previsualization were executed. After that, the video was revised and edited based on suggestions. Finally, explanatory subtitles were generated, the models were textured and rendered, and voiceovers in 3 languages were implemented.

RESULTS

We developed a 6-minute virtual 3D dynamic video in 3 languages (English, Spanish, and Brazilian Portuguese) intended for dentists and dental students to support teaching and learning of caries lesion detection. The videos were made available on YouTube; to date, they have received more than 100,000 views.

CONCLUSIONS

Complementary pedagogical tools are valuable to support cariology education. This tool will be further tested in terms of utility and usability as well as user satisfaction in achieving the proposed objectives in specific contexts.

Prevalence of dental caries among 6 - 12 year old schoolchildren in social marginated zones of Valencia, Spain

Background

To estimate the prevalence of caries and to study oral health habits (oral hygiene, toothbrushing frequency, cariogenic or no cariogenic diet, visits to dentist) in children aged 6 to 12 with social exclusion risk.

Material and Methods

A cross sectional study was conducted in a sample of 160 children aged form 6 to 12 years belonging to Colegio Madre Petra in Torrent and Colegio Nuestra Señora de los Desamparados in Nazaret (Valencia). Among other variables DMFT and Greene and Vermilion simplified plaque index were analyzed.

Results

The prevalence of caries observed was 81.87% and the global DMFT was 4.481. The mean plaque index observed was 1.12. No statistically significant differences were found between global DMFT and sex, global DMFT and age, global DMFT and diet, global DMFT and visits to the dentist and global DMFT and plaque index. A significant association was seen between global DMFT and ethnicity and global DMFT and brushing frequency. Statistically significant association was found also between plaque index and visits to the dentist and plaque index and diet.

Conclusions

It was observed that children at risk of social exclusion had a very high global DMFT and a regular plaque index. So, it can be concluded that social exclusion constitute an underlying factor that increase caries prevalence and global DMFT and a marker of poor oral hygiene habits.

Key words:Dental caries, caries prevalence, oral hygiene habits, plaque index, toothbrushing frequency, social exclusion.

Risk Factors Associated with Carious Lesions in Permanent First Molars in Children: A Seven-Year Retrospective Cohort Study

The aim of this study was to evaluate the risk factors associated with the occurrence of caries in permanent teeth (PT) and in the permanent first molar (PFM) seven years after their eruption. Children born in 2005 who were enrolled in a Community Dental Program were included. A total of 278 children were enrolled. Evaluated risk factors were parental caries experience, educational level of the mother, routine medications, systemic diseases, dietary habits, toothbrushing frequency, existence of molar incisor hypomineralization (MIH) in the PT, and caries in the temporary teeth (TT). Associations between independent variables and the DMF-T (decayed, missing, and filled teeth in PT) and DMF-M (DMF in PFM) indices, only considering cavitated and non-cavitated carious lesions or cavitated carious lesions as outcomes, were evaluated by Poisson regression with robust variance analysis. A cariogenic diet (sweets and soft drinks), toothbrushing frequency of <1 a day, a presence of df-t (decayed and filled temporary teeth) score of >0, low educational level of the mother, and existence of MIH were associated with high DMF-T or DMF-M values (p < 0.05). We can conclude that the intake of sweets and soft drinks, toothbrushing frequency, the presence of caries in TT, and MIH in PT were the best predictors of the occurrence of caries in PT and PFM.

Fluoride exposure alters Ca2+ signaling and mitochondrial function in enamel cells

Fluoride ions are highly reactive, and their incorporation in forming dental enamel at low concentrations promotes mineralization. In contrast, excessive fluoride intake causes dental fluorosis, visually recognizable enamel defects that can increase the risk of caries. To investigate the molecular bases of dental fluorosis, we analyzed the effects of fluoride exposure in enamel cells to assess its impact on Ca2+ signaling. Primary enamel cells and an enamel cell line (LS8) exposed to fluoride showed decreased internal Ca2+ stores and store-operated Ca2+ entry (SOCE). RNA-sequencing analysis revealed changes in gene expression suggestive of endoplasmic reticulum (ER) stress in fluoride-treated LS8 cells. Fluoride exposure did not alter Ca2+ homeostasis or increase the expression of ER stress-associated genes in HEK-293 cells. In enamel cells, fluoride exposure affected the functioning of the ER-localized Ca2+ channel IP3R and the activity of the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) pump during Ca2+ refilling of the ER. Fluoride negatively affected mitochondrial respiration, elicited mitochondrial membrane depolarization, and disrupted mitochondrial morphology. Together, these data provide a potential mechanism underlying dental fluorosis.

Ecological study on needs and cost of treatment for dental caries in schoolchildren aged 6, 12, and 15 years: Data from a national survey in Mexico

To determine the treatment needs and the care index for dental caries in the primary dentition and permanent dentition of schoolchildren and to quantify the cost of care that would represent the treatment of dental caries in Mexico.A secondary analysis of data from the First National Caries Survey was conducted, which was a cross-sectional study conducted in the 32 states of Mexico. Based on dmft (average number of decayed, extracted, and filled teeth in the primary dentition) and DMFT (average number of decayed, extracted, and filled teeth in permanent dentition) information, a treatment needs index (TNI) and a caries care index (CI) were calculated.At age 6, the TNI for the primary dentition ranged from 81.7% to 99.5% and the CI ranged from 0.5% to 17.6%. In the permanent dentition, the TNI ranged from 58.8% to 100%, and the CI ranged from 0.0% to 41.2%. At age 12, the TNI ranged from 55.4% to 93.4%, and the CI ranged from 6.5% to 43.4%. At age 15, the TNI ranged from 50.4% to 98.4%, and the CI ranged from 1.4% to 48.3%. The total cost of treatment at 6 years of age was estimated to range from a purchasing power parity (PPP) of USD $49.1 to 287.7 million in the primary dentition, and from a PPP of USD $3.7 to 24 million in the permanent dentition. For the treatment of the permanent dentition of 12-year-olds, the PPP ranged from USD $13.3 to 85.4 million. The estimated cost of treatment of the permanent dentition of the 15-year-olds ranged from a PPP of USD $10.9 to 70.3 million. The total estimated cost of caries treatment ranged from a PPP of USD $77.1 to 499.6 million, depending on the type of treatment and provider (public or private).High percentages of TNI for dental caries and low CI values were observed. The estimated costs associated with the treatment for caries have an impact because they represent a considerable percentage of the total health expenditure in Mexico.

Assessment of diagnostic accuracy of a direct digital radiographic-CMOS image with four types of filtered images for the detection of occlusal caries

BACKGROUND

Digital imaging has the potential to improve diagnostic accuracy and make quantitative diagnoses. In the recent decades, software for radiographic analysis has been investigated and developed for the detection of lesions and the quantitative assessment of the depth of a caries lesion. In addition, the accuracy of diagnosis may also be enhanced by programs that filter the images. These programs can adjust the brightness and contrast, determine the gray level, invert the shades of gray, and apply pseudocolors. Few studies compared different types of digital images in the diagnosis of changes in the tooth crown.

AIM

The main aim of this study was to assess the the diagnostic accuracy of a direct digital radiography (DDR)-CMOS image with four types of filtered images for the detection of occlusal caries.

MATERIALS AND METHODS

Fifty randomly selected patients' teeth were clinically examined and digitally radiographed. Radiographed images are converted into four filter images with the help of software. Filtered images were then selected for inter- and intraobserver examination and the result was subjected to statistical analysis.

CONCLUSION

DDR-CMOS and negative image were found to be more useful in diagnosing occlusal caries.