A Scoping Review on Arginine in Caries Prevention

Caries preventive potential of professionally deliverable fluoride-containing agents with incorporated arginine: A scoping review

The scoping review objectives were to: 1) investigate the caries preventive potential of professionally deliverable fluoride (F)-containing agents with incorporated arginine (Arg); and 2) identify the future scope of research on Arg-F interventions for caries prevention. Of 150 identified records, 7 articles (6 in vitro investigations and 1 scoping review) were included for a complete review; with no clinical studies with/without appraisal. Arginine variants (L-Arg/Arg.HCl at 1% to 10% w/v.) were examined for a potential professional application aimed at caries prevention, as reported with in vitro studies. Of the included articles, four in vitro studies explored L-Arg enriched 5% NaF varnish (Duraphat®) as a promising caries preventive agent, while only one considered incorporating L-Arg in MI varnish®/nanohydroxyapatite and one investigated glass ionomer cement for primary/secondary and tertiary caries prevention. The scoping review highlighted the scope for incorporating Arg to professionally deliverable F-containing agents. No clinical data are available to make conclusive recommendations about the caries preventive potential of professionally deliverable F-containing agents with incorporated Arg. With Arg-F varnish being investigated predominantly through in vitro studies, the data so far suggest that Arg was incorporated exclusively in Duraphat®, while the potential of Arg to prevent caries in other F-containing varnishes remains unexplored.

A Comparative Evaluation of Arginine Complex Combined With Flouride and Two Standard Non-Fluoridated Remineralizing Agents: An In Vitro Study

Background Dental caries represents a dynamic process, often reversible in its early stages. Fluoride has conventionally served as the cornerstone for remineralization and early caries arrest. However, excessive fluoride intake can lead to both local and systemic toxicity. Hence, there's a pressing need to develop adjunct therapies that enhance fluoride's efficacy while minimizing its dosage. This study aims to assess and compare the remineralization potential of a novel combination comprising arginine bicarbonate and fluoride against established technologies such as Bioactive glass (NovaMin Technology; Sensodyne Repair and Protect, GlaxoSmithKline, UK) and CPP-ACP technology (GC Tooth Mousse; Tokyo Japan). Materials and methods The experiment utilized extracted premolars designated for orthodontic extraction. The initial evaluation employed the DIAGNOdentTM fluorescence method. Subsequently, teeth underwent demineralization and were measured for values. Following this, the teeth were subjected to seven cycles of remineralization, after which moment values were reassessed. Statistical analysis was performed on the recorded values. Results Participants were divided into six groups (BR-A, AR-A, BR-B, AR-B, BR-C, AR-C). T-tests demonstrated significant reductions in moment values within each group, indicating the effectiveness of all remineralizing agents. Group C exhibited the most substantial difference (-6.900 ± 0.4), followed by Group A and Group B. ANOVA analysis revealed statistically significant differences among all three groups (p=0.016). Tables showed significant distinctions between the remineralizing values of Groups A and C and Groups B and C (p=0.02 and 0.002, respectively), with no discernible distinction between Groups A and B. Conclusion The study elucidates the superior efficacy of the arginine complex with fluoride combination compared to CPP-ACP and Bioactive Glass individually. This finding underscores the potential of the novel combination therapy in enhancing remineralization while minimizing fluoride dosage, thus presenting a promising strategy for addressing early-stage dental caries.

Fluoride release potential of arginine-incorporated fluoride varnishes

The study aimed to examine the fluoride (F) release potential of arginine (Arg)-incorporated F varnishes. Four commercially available F varnishes were included in the study: Duraphat® (5% NaF), Flúor Protector® (0.9% SiH2F2), Fluor Protector S® (NH4F), and Fluorimax™ (2.5% NaF). L-arginine (2% w/v.) was incorporated in these varnishes to estimate F release at 1 h, 4 h, 6 h, 24 h, 3 days, and 7 days using an F-ion selective electrode. The media pH of eluded varnishes was estimated and primary inorganic F extraction was performed. The main effects pH, F release, and computed integrated mean/cumulative F release for experimental groups were significantly higher than the controls (p<0.01). The primary extracted F concentrations for the Arg-containing groups were significantly lower than the control groups (p<0.001) demonstrating a chemical interplay with Arg incorporation. To conclude, irrespective of the inorganic F content, incorporating Arg in F-containing varnishes increases their F release potential.

Effect of arginine-fluoride varnish on preventing enamel erosion by paediatric liquid medicaments

BACKGROUND

The study objective was to examine the effect of arginine-sodium fluoride (Arg-NaF) varnish on preventing enamel erosion by acidic paediatric liquid medicaments (PLM).

METHODS

The treatment groups were: 1) 2% Arg-NaF; 2) 4% Arg-NaF; 3) 8% Arg-NaF; 4) NaF; 5) MI (CPP-ACFP) varnishes; and 6) no varnish. The pH of PLM (paracetamol and chlorpheniramine) was measured at baseline and after immersing the Perspex® blocks coated with varnishes at 0 min, 30 min, 1 h, and 4 h. Seventy-two enamel specimens (n = 72) were randomly divided into 2 groups by PLM and further by treatment groups. Then, the specimens were pre-treated with varnishes and subjected to erosive cycles (5 min, 2×/day for 4 days) by PLM. After each erosive challenge, the specimens were stored in artificial saliva. At baseline and after 4 days, the specimens were assessed for surface roughness (Ra) using 2D-surface profilometric analysis (SPA) and atomic force microscopy (AFM). Additionally, the Ca/P ratio was determined using scanning electron microscopy with energy-dispersive X-ray spectroscopy. Paired samples dependent t-test, 1-way ANOVA and 2-way ANOVA with Bonferroni post-hoc tests were used to analyse data with the level of significance set at p < 0.05.

RESULTS

The pH of PLM with 8% Arg-NaF was significantly higher than the other groups at 30 min and 4 h (p < 0.05). With paracetamol, no significant difference was observed between the baseline and post-erosive cycle measured enamel Ra (by SPA/AFM) and Ca/P ratio for all treatment groups (p > 0.05). The Ra determined by AFM, at the post-erosive cycle with chlorpheniramine, when treated with 4 and 8% Arg-NaF was significantly lower than the other groups (p < 0.05); except CPP-ACFP (p > 0.05). With the chlorpheniramine post-erosive cycle, the Ca/P ratio for 4, 8% Arg-NaF and CPP-ACFP treated specimens was significantly higher than the baseline Ca/P (p < 0.05).

CONCLUSION

The 4%/8% Arg-NaF and MI varnish® application exhibit an enhanced preventive effect against low pH (pH < 3.0) PLM-mediated enamel erosive challenges compared to 5% NaF varnish.

Arginine: A New Paradigm in Preventive Oral Care

Dental caries is ubiquitous and one of the most prevalent oral diseases and the foremost cause of dental pain and poor quality of life (QoL). Fluoride is an effective caries preventive agent; however, despite its use, there remain some gaps in prevention of dental caries. Arginine, an amino acid, helps to maintain a noncariogenic plaque. It shows synergistic effects with fluoride in dental caries and can help nourish the tooth by enhancing the remineralization effect of fluoride. Supplementing fluoride dentifrices with arginine can bridge the gap in caries prevention. Several clinical studies with 1.5% arginine + fluoride provide evidence for its use in prevention of dental caries. This report throws light on the benefits of arginine in dental caries and guides on its use with fluoride. Recommendations given in the report will help in effective prevention of dental caries.

How to cite this article

Goyal V, Damle S, Puranik MP, et al. Arginine: A New Paradigm in Preventive Oral Care. Int J Clin Pediatr Dent 2023;16(5):698-706.

The effect of synbiotic-fluoride therapy on multi-species biofilm

OBJECTIVES

The study objective was to examine the effect of synbiotic-fluoride (SF) therapy within a multi-species cariogenic biofilm model system comprising of S. mutans, S. sanguinis, and S. gordonii.

METHODS

The SF therapy was prepared using 2% L-arginine (Arg), 0.2% NaF and probiotic L. rhamnosus GG (LRG). The 8 treatment groups were: Group 1: No treatment, Group 2: 2% Arg, Group 3: 0.2% NaF, Group 4: LRG, Group 5: 2% Arg+0.2% NaF, Group 6: 2% Arg+LRG, Group 7: 0.2% NaF+LRG, and Group 8: SF therapy (2% Arg+0.2% NaF +LRG). Multi-species biofilm model over 96 h comprising Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii was utilized. The biofilms received cariogenic challenge and SF therapy 2 × /day. The extracellular matrix components were analyzed for carbohydrates, proteins, and extra-cellular DNA (eDNA). The live/dead cells were imaged and quantified using confocal microscopy. The viable/dead bacterial concentrations were estimated using propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR). The gene expressions for gtfB, sagP, arcA, argG, and argH were measured using real-time reverse transcriptase qPCR.

RESULTS

Carbohydrates and protein content with SF therapy were higher than non-LRG containing groups, while eDNA content was lower than other groups (p<0.05). Live bacterial proportions determined using confocal imaging with SF therapy were the lowest (p<0.05). The 2% Arg+LRG and SF therapy showed higher viable L. rhamnosus GG than 0.2% NaF+LRG (p<0.05). The dead S. mutans with SF therapy were higher than the other groups (p<0.05) with no difference from 2% Arg+0.2% NaF and 2% Arg+LRG (p>0.05). The SF therapy significantly downregulates gtfB and upregulates sagP, arcA, argG, argH gene expression (p<0.05).

CONCLUSION

Synbiotic-fluoride therapy effectuates multi-fold changes in the multi-species biofilm matrix and cellular components leading to superior ecological homeostasis than its individual contents, prebiotics (arginine), probiotic (L. rhamnosus GG), and fluorides (NaF).

CLINICAL SIGNIFICANCE

The ecological-based synbiotic-fluoride caries-preventive therapy aids in maintaining biofilm homeostasis to preempt/restore dysbiosis thereby sustaining dynamic-diverse health-associated microbial stability significant as a preventive regimen for high caries-risk patients.

Synbiotic-fluoride synergism on enamel remineralization, cytotoxicity and genotoxicity

OBJECTIVE(S)

The objectives of the present study were to examine the - a) enamel remineralization potential of synbiotic-fluoride (SF) therapy using a multi-species bacterial pH-cycling model; and b) cytotoxic and genotoxic effects of SF therapy extracts.

MATERIALS AND METHODS

The SF therapy group comprised of 2% arginine (Arg), 0.2% NaF, and a probiotic Lactobacillus rhamnosus GG (LRG). The intervention groups studied were: 1) No treatment; 2) 2% Arg; 3) 0.2% NaF; 4) LRG; 5) 2% Arg+0.2% NaF; 6) 2% Arg+LRG; 7) 0.2% NaF+LRG; and 8) 2% Arg+0.2% NaF+LRG (SF therapy). The enamel remineralization potential of SF therapy was investigated under cariogenic biofilm challenge; while the cytotoxicity and genotoxicity of SF therapy extracts were examined on HGF-1 and Chinese hamster fibroblast V79, respectively. To determine the remineralization effect, the specimens were subjected to mineral density (MD) assessment using micro-CT, Ca/P molar ratio with SEM-EDX, and enamel fluoride uptake (EFU) estimates. The HGF-1 proliferation assessment was quantified using MTT/CCK-8 assays with qualitative analysis by nuclei staining Hoechst-based fluorescence imaging. The genotoxicity was determined by micronuclei formation test.

RESULTS

Mineral gain and %remineralization derived from MD assessment for the SF therapy were significantly higher than the other groups (p<0.05). The %ΔCa/P for the SF and 2% Arg+0.2% NaF were significantly higher than the other groups (p<0.05). The SF and 2% Arg+0.2% NaF groups had the highest EFU compared to the other groups (p<0.05). No significant difference in the %viable HGF-1 cells were observed between the treatment interventions and no treatment group (p>0.05). Compared to the EMS-positive control, the micronuclei formation for all the intervention groups was significantly lower (p<0.05), with no significant difference among the treatment groups (p>0.05).

CONCLUSION

The SF therapy enhanced enamel remineralization with no biocompatibility concerns.

CLINICAL SIGNIFICANCE

With the enhanced enamel remineralization potential discerned in the present study, the SF therapy can be used as a promising caries-preventive agent targeted for high caries-risk individuals.

A Fresh Look at Mouthwashes-What Is Inside and What Is It For?

Mouthwashes are a very popular additional oral hygiene element and there are plenty of individual products, whose compositions are in a state of flux. The aim of our study was to investigate the compositions of mouthwashes and their functions, as well as to discuss their effectiveness in preventing and curing oral diseases and side effects. We searched for mouthwashes available on the market in Poland. We identified 241 individual mouthwash products. The extraction of compositions was performed and functions of the ingredients were assessed. Then, analysis was performed. The evaluation revealed that there are plenty of ingredients, but a typical mouthwash is a water–glycerine mixture and consists of additional sweetener, surfactant, preservative, and some colourant and flavouring agent, as well as usually having two oral health substances, anticaries sodium fluoride and antimicrobial essential oils. The effectiveness or side effects of several substances of mouthwashes were thoroughly discussed. We recommend not multiplying individual mouthwash products and their ingredients beyond medical or pharmaceutical necessity, especially without scientific proof.

Regulatory Effect of Irresistin-16 on Competitive Dual-Species Biofilms Composed of Streptococcus mutans and Streptococcus sanguinis

Based on the ecological plaque hypothesis, suppressing opportunistic pathogens within biofilms, rather than killing microbes indiscriminately, could be a biofilm control strategy for managing dental caries. The present study aimed to evaluate the effects of irresistin-16 (IRS-16) on competitive dual-species biofilms, which consisted of the conditional cariogenic agent Streptococcus mutans (S. mutans) and oral commensal bacteria Streptococcus sanguinis (S. sanguinis). Bacterial growth and biofilm formation were monitored using growth curve and crystal violet staining, respectively. The microbial proportion was determined using fluorescence in situ hybridization. A 2, 5-diphenyltetrazolium bromide assay was used to measure the metabolic activity of biofilms. Bacterial/extracellular polysaccharide (EPS) dyeing, together with water-insoluble EPS measurements, were used to estimate EPS synthesis. A lactic acid assay was performed to detect lactic acid generation in biofilms. The cytotoxicity of IRS-16 was evaluated in mouse fibroblast L929 cells using a live/dead cell viability assay and cell counting kit-8 assay. Our results showed that IRS-16 exhibited selective anti-biofilm activity, leading to a remarkable survival disadvantage of S. mutans within competitive dual-species biofilms. In addition, the metabolic activity, EPS synthesis, and acid generation of dual-species biofilms were significantly reduced by IRS-16. Moreover, IRS-16 showed minimal cytotoxicity against mouse fibroblast L929 cells. In conclusion, IRS-16 exhibited remarkable regulatory effects on dual-species biofilms composed of S. mutans and S. sanguinis with low cytotoxicity, suggesting that it may have potential for use in caries management through ecological biofilm control.

Concentration-Dependent Multi-Potentiality of L-Arginine: Antimicrobial Effect, Hydroxyapatite Stability, and MMPs Inhibition

This study's objective was to examine L-arginine (L-arg) supplementation's effect on mono-species biofilm (Streptococcus mutans/Streptococcus sanguinis) growth and underlying enamel substrates. The experimental groups were 1%, 2%, and 4% arg, and 0.9% NaCl was used as the vehicle control. Sterilised enamel blocks were subjected to 7-day treatment with test solutions and S. mutans/S. sanguinis inoculum in BHI. Post-treatment, the treated biofilms stained for live/dead bacterial cells were analysed using confocal microscopy. The enamel specimens were analysed using X-ray diffraction crystallography (XRD), Raman spectroscopy (RS), and transmission electron microscopy (TEM). The molecular interactions between arg and MMP-2/MMP-9 were determined by computational molecular docking and MMP assays. With increasing arg concentrations, bacterial survival significantly decreased (p < 0.05). The XRD peak intensity with 1%/2% arg was significantly higher than with 4% arg and the control (p < 0.05). The bands associated with the mineral phase by RS were significantly accentuated in the 1%/2% arg specimens compared to in other groups (p < 0.05). The TEM analysis revealed that 4% arg exhibited an ill-defined shape of enamel crystals. Docking of arg molecules to MMPs appears feasible, with arg inhibiting MMP-2/MMP-9 (p < 0.05). L-arginine supplementation has an antimicrobial effect on mono-species biofilm. L-arginine treatment at lower (1%/2%) concentrations exhibits enamel hydroxyapatite stability, while the molecule has the potential to inhibit MMP-2/MMP-9.

Nonrestorative Management of Dental Caries

The World Dental Federation (FDI) policy statement in 2016 advocated evidence-based caries-control measures for managing dental caries. The caries management philosophy has shifted from the traditional surgical manners to minimal intervention dentistry. Minimal intervention dentistry aims to extend the longevity of natural teeth. It places the nonrestorative approaches as a priority. The nonrestorative approaches for caries management aim to tackle the etiological factors of dental caries. Caries can be prevented or reversed by restricting the sugar intake and its frequency in the diet, improving oral hygiene practices, and using fluoride toothpaste. This article aims to present strategies for the nonrestorative management of dental caries, which are divided into four components to address the different etiological factors of dental caries. The first component is controlling dental plaque. Strategies for plaque control include oral hygiene instruction, motivational interviewing, mechanical plaque control, and chemical plaque control. The second component for nonrestorative management is reducing the risk of caries by identifying caries risk factors and protective factors, assessing personal caries risk, and customizing a treatment plan. Evidence-based measures for caries prevention include using fluoride, and dental sealants should be provided. The third component includes topical treatment to remineralise early carious lesions. The last component is long-term follow-up. Appropriate strategy adoption for the nonrestorative management of dental caries prolongs the life span of the teeth and sustains the good oral health of patients.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2020 professional literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to this work to cover this broad topic. Specific subject areas addressed include prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders (TMDs); sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence day-to-day dental treatment decisions with a keen eye on future trends in the profession. With the tremendous volume of dentistry and related literature being published today, this review cannot possibly be comprehensive. The purpose is to update interested readers and provide important resource material for those interested in pursuing greater detail. It remains our intent to assist colleagues in navigating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the dental patients they encounter.