Formulation and antibacterial properties of lollipops containing of chitosan- zinc oxide nano particles on planktonic and biofilm forms of Streptococcus mutans and Lactobacillus acidophilus.

This study aimed to formulate and characterize the experimental lollipops containing chitosan- zinc oxide nanoparticles (CH-ZnO NPs) and investigate their antimicrobial effects against some cariogenic bacteria. The CH-ZnO NPs were synthesized and characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) analysis, and Transmission electron microscope (TEM). Then, four groups were made, including lollipops coated with 2 and 4 ml of CH-ZnO NPs, 0.7 ml CH-ZnO NPs incorporated lollipops, and those with no CH-ZnO NPs. Their antibacterial effectiveness against Streptococcus mutans and Lactobacillus acidophilus was evaluated by direct contact test and tissue culture plate method in planktonic and biofilm phases, respectively. Chlorhexidine mouthrinse (CHX) was used as a positive control group. In the planktonic phase, the antibacterial properties of both groups coated with CH-ZnO NPs were comparable and significantly higher than incorporated ones. There was no significant difference between CHX and the lollipops coated with 4 ml of NPs against S. mutans and CHX and two coated groups against L. acidophilus. None of the experimental lollipops in the biofilm phase could reduce both bacteria counts. The experimental lollipops coated with 2 and 4 ml of CH-ZnO NPs could reveal favorable antimicrobial properties against two cariogenic bacteria in the planktonic phase.

Anti-adhesion and anti-biofilm activity of slightly acidic electrolyzed water combined with sodium benzoate against Streptococcus mutans: A novel ecofriendly oral sanitizer to prevent cariogenesis.

Streptococcus mutans (S. mutans) can promote the establishment of high acidic biofilms and therefore have contribution to the development of dental caries. Alleviating the acidic environment and/or disrupting the structure of S. mutans biofilm are effective approaches against dental caries, rather than killing the microorganisms. The anti-biofilm effect of slightly acidic electrolyzed water (SAEW) is entirely based on the hypochlorous acid and ROS generation. In this study, sodium benzoate (NaB) acts as a pH adjuster and enhances SAEW's anti-biofilm activity. The results showed that the SAEW combined with NaB (SAEW + NaB) is highly effective in controlling biofilm. The adhesive strength of biofilm was significantly reduced by SAEW, and NaB was found to have a synergy effect with SAEW. Biofilm treated by SAEW + NaB was entirely removed by 60 s of ultrasonic wave, whereas the untreated biofilm can only be removed to a lesser extent. Atomic force microscope (AFM) analysis revealed that SAEW and NaB reduced the height of S. mutans biofilm. The metabolites derived from biofilm positively changed during the periodic 1-min treat, the production of lactic acid was hindered by the treatment. Altogether, these findings suggested a novel therapeutic intervention against S. mutans biofilm by targeting the cariogenic action.

Advances of Anti-Caries Nanomaterials.

Caries is the most common and extensive oral chronic disease. Due to the lack of anti-caries properties, traditional caries filling materials can easily cause secondary caries and lead to treatment failure. Nanomaterials can interfere with the bacteria metabolism, inhibit the formation of biofilm, reduce demineralization, and promote remineralization, which is expected to be an effective strategy for caries management. The nanotechnology in anti-caries materials, especially nano-adhesive and nano-composite resin, has developed fast in recent years. In this review, the antibacterial nanomaterials, remineralization nanomaterials, and nano-drug delivery systems are reviewed. We are aimed to provide a theoretical basis for the future development of anti-caries nanomaterials.

Anti-carious Effects of Galla chinensis: A Systematic Review.

As a natural traditional Chinese medicine, Galla chinensis has been widely used since ancient times for its astringency, stypticity, detoxification, and antibacterial activity. Our group has concentrated on the research about its potential of being an applicable anti-caries agent. The crude extract and some other components purified from it show remarkable efficacy on anticaries, and the most likely mechanism is proposed through specific research. For the fact that crude drugs consist of numerous compounds, and their bioactivity is a result of synergistic effects and/or antagonistic effects of several compounds, it is difficult to clarify the exact mechanism and evaluate the safety and effectiveness of G. chinensis. This review article systematically summarizes previous findings from the following aspects: (1) inhibitory effect on oral bacteria; (2) the demineralization inhibition property; (3) the remineralization-enhancing property; and (4) stability and toxicity evaluation, and thus indicates the further research direction.

Nanoparticles in orthodontics, a review of antimicrobial and anti-caries applications.

Nanoparticles (NPs) are insoluble particles smaller than 100 nm in size. In order to prevent microbial adhesion or enamel demineralization in orthodontic therapy, two broad strategies have been used. These are incorporating certain NPs into orthodontic adhesives/cements or acrylic resins (nanofillers, silver, TiO2, SiO2, hydroxyapatite, fluorapatite, fluorohydroxyapatite) and coating surfaces of orthodontic appliances with NPs (i.e. coating bracket surfaces with a thin film of nitrogen-doped TiO2). Although the use of NPs in orthodontics can offer new possibilities, previous studies investigated the antimicrobial or physical characteristic over a short time span, i.e. 24 hours to a few weeks, and the limitations of in vitro studies should be recognized. Information on the long-term performance of orthodontic material using nanotechnology is lacking and necessitates further investigation and so do possible safety issues (toxicity), which can be related to the NP sizes.

A Comprehensive Narrative Review of Nanomaterial Applications in Restorative Dentistry: Demineralization Inhibition and Remineralization Applications (Part I).

Nanotechnology is extensively employed in various aspects of dentistry, including restorative dentistry, because of its substantial improvement and promising potential in the clinical efficacy of restorative materials and procedures. The main purpose of this review is to explore the different uses of nanomaterials in restorative dentistry. The review is divided into two parts: the current review (Part 1) focuses on the prevention of demineralization and promotion of remineralization, while the upcoming review (Part 2) will discuss the reinforcement of restorative materials and their therapeutic applications. Nanofillers are added to dental materials to boost their antibacterial, anticaries, and demineralization inhibitory capabilities. Additionally, they improve remineralization and enhance both mechanical properties and therapeutic features. The nanoparticles (NPs) used to increase antibacterial and remineralization inhibitions can be classified into two main groups: inorganic and organic NPs. Examples of inorganic NPs include silver, zinc oxide, titanium oxide, and gold. Examples of organic NPs include silica, quaternary ammonium salt monomers, and chitosan NPs. Furthermore, the nanofillers utilized to enhance the process of remineralization include various types such as metals, nano-hydroxyapatite, nano-amorphous calcium phosphate (ACP), dicalcium phosphate NPs, casein phosphopeptide-ACP (CPP-ACP), and calcium fluoride NPs. These uses underscore the potential applications of NPs in restorative dentistry, although there are still some limitations to address.

Assessing the Effects and Acceptance of Silver Diamine Fluoride Treatment in Early Childhood Caries.

BACKGROUND:  Early childhood caries (ECC) is a widespread dental problem that impacts children below the age of six years. Traditional restorative treatments like fillings are often challenging and invasive for young children. Silver diamine fluoride (SDF) offers a minimally invasive and cost-effective alternative for managing ECC. However, the effects, acceptance, and understanding of this treatment by parents remain crucial for its successful implementation. AIM: To evaluate the impact and level of acceptance of SDF treatment in ECC. MATERIALS AND METHODS: Thirty-two children from an Anganwadi center aged between two to five years suffering from ECC were selected. A 38% SDF was applied for 3 minutes on the identified carious lesion, and the arrest percentage was checked after a recall period of three weeks and three months. The Likert scale was used for the questionnaire regarding parental feedback about the ease of application procedure, tooth discoloration, possible pain associated with the procedure, and the taste of SDF. RESULTS: In the present study, a total of 75 surfaces were subjected to the application of SDF. After a period of three weeks, it was observed that 64 of these surfaces had successfully undergone the process of caries arrest. This finding was deemed to be statistically significant, with a P value of 0.021. Furthermore, the remaining surfaces that had not achieved caries arrest were subsequently treated at three months. The results of this subsequent treatment were also found to be statistically significant, with a P value of 0.027. These findings highlight the efficacy of both caries treatment and caries arrest in relation to the utilization of SDF. CONCLUSION: SDF was found to be minimally invasive, easy to administer, inexpensive, highly efficient, and effective treatment in arresting caries in the primary dentition of young children, particularly in patients lacking cooperation.

Evaluating the Effectiveness of Phellodendron Amurense Ruprecht Extract as a Natural Anti-Caries Material.

BACKGROUND: This study aimed to investigate the antibacterial and cytotoxic potential of Phellodendron amurense Ruprecht (PAR) extract against Streptococcus mutans (S. mutans) and explore the possibility of using PAR extract as an anticariogenic agent. METHODS: Mixed extracts were prepared at 0, 1.25, 2.5, and 5 mg/mL concentrations, and an S. mutans-containing solution of 100 µL was inoculated into the medium. The survival rate of human keratinocyte (HaCaT) cells was assessed to confirm stability. One-way ANOVA was performed to evaluate the antibacterial activity against S. mutans and the proliferation of HaCaT cells. RESULTS: Higher concentrations of the PAR extract showed more growth inhibition of S. mutans over time, with the complete inactivation of S. mutans at 5 mg/mL. HaCaT cell density was reduced at a PAR extract concentration of 1.25 mg/mL, but IC50 was not observed, confirming that the concentration used did not affect the cytotoxicity and proliferation. CONCLUSIONS: Results showed that the PAR extract was excellent as a natural substance with anticariogenic effects that inhibited the growth of S. mutans and did not affect the cell viability, thus indicating the potential for clinical application.

Urchin-like multiscale structured fluorinated hydroxyapatite as versatile filler for caries restoration dental resin composites.

Caries is one of the most prevalent human diseases, resulting from demineralization of tooth hard tissue caused by acids produced from bacteria, and can progress to pulpal inflammation. Filling restoration with dental resin composites (DRCs) is currently the most common treatment for caries. However, existing DRCs suffer from low fracture strength and lack comprehensive anti-caries bioactivity including remineralization, pulp protection, and anti-cariogenic bacteria effects. In this study, inspired by plant roots' ability to stabilize and improve soil, fluorinated urchin-like hydroxyapatite (FUHA) with a three-dimensional whisker structure and bioactive components of calcium, phosphorus, and fluorine was designed and synthesized by a dynamic self-assembly method. Furthermore, versatile FUHA particles with different loading fractions were used as functional fillers to fabricate methacrylate-based DRCs, where the urchin-like hydroxyapatite (UHA) filled DRCs and commercial DRCs (Z350XT and BEAUTIFIL II) served as the control groups. The results demonstrated that FUHA with 50 wt% loading in resin matrix endowed DRC (F5) with excellent physicochemical properties, dentin remineralization property, cell viability, promotion of dental pulp stem cells mineralization, and antibacterial properties. Meanwhile, F5 also presented good clinical handling and aesthetic characteristics. Therefore, structure/functional-integrated FUHA filled DRCs have potential as a promising strategy for tooth restoration and anti-caries bioactivity.

Recent advances in the use of inorganic nanomaterials as anti caries agents.

Caries is the most prevalent and widespread chronic oral disease. Traditional caries filling materials, due to their lack of anti-caries capabilities, can readily develop secondary caries. Nanomaterials proposed as an effective approach for caries treatment can inhibit biofilm formation. It also can not only reduce demineralization but also promote remineralization. In recent years, nanotechnology in anti-caries materials, particularly nano-adhesive and nano-composite resin, has advanced rapidly. Because inorganic nanoparticles (NPs) interfere with bacterial metabolism and inhibit biofilm development, inorganic NPs have emerged as a new trend in dental applications. Metal and metal oxide NPs by releasing metal ions, oxidative stress induction, and non-oxidative mechanisms showed significant antimicrobial activity. For applying metal and metal oxide NPs as anti caries agents, silver, zinc, titanium, copper, and calcium ions have been shown significant attention. Moreover, fluoride functionalized inorganic NPs were also employed to improve their efficacy of them. The fluoride-functionalized NPs can promote remineralization, and inhibit demineralization by enhancing apatite formation. In this review, we have provided an overview and recent advances in the use of inorganic NPs as anti caries agents. Furthermore, their antimicrobial, remineralizing, and mechanical impacts on dental materials were discussed.

Fluoride exchange by glass-ionomer dental cements and its clinical effects: a review.

The topic of fluoride release and uptake by glass-ionomer (glass polyalkenoate) dental cements is reviewed. The study was based on a literature search carried out using PubMed. The main key words used were glass-ionomer and fluoride, and further refinements were made by adding the keywords anti-microbial, anti-caries and remineralization. Papers were selected from the initial search, which concentrated on fundamental aspects of fluoride release, including kinetics and the influence of the cement composition, and resulting clinical performance against caries. Other relevant papers were cited where they added useful and relevant data. From these published papers, it was possible to explain the detailed mechanism of fluoride release by glass-ionomer cements and also its uptake. Fluoride release has been shown to be a two-step process. In neutral solutions, the steps can be divided into early wash-out and long-term diffusion. In acid conditions, the early wash-out remains, though with greater amounts of fluoride released, and the long-term release becomes one of slow dissolution. The effect of fluoride on the viability of oral micro-organisms has been described, and glass-ionomers have been shown to release sufficient fluoride to reduce the size and viability of adjacent populations of oral bacteria. The effect of low levels of fluoride on the remineralization of tooth tissue has been considered. Levels needed to increase remineralization are much lower than those needed to adversely affect oral bacteria, from which we conclude that glass-ionomers release sufficient fluoride to promote remineralization. Despite this, there remains uncertainty about their overall contribution to sound oral health, given the widespread use of other sources of fluoride, such as toothpastes.

Antimicrobial peptide temporin derivatives inhibit biofilm formation and virulence factor expression of Streptococcus mutans.

Introduction: Temporin-GHa obtained from the frog Hylarana guentheri showed bactericidal efficacy against Streptococcus mutans. To enhance its antibacterial activity, the derived peptides GHaR and GHa11R were designed, and their antibacterial performance, antibiofilm efficacy and potential in the inhibition of dental caries were evaluated. Methods: Bacterial survival assay, fluorescent staining assay and transmission electron microscopy observation were applied to explore how the peptides inhibited and killed S. mutans. The antibiofilm efficacy was assayed by examining exopolysaccharide (EPS) and lactic acid production, bacterial adhesion and cell surface hydrophobicity. The gene expression level of virulence factors of S. mutans was detected by qRT-PCR. Finally, the impact of the peptides on the caries induced ability of S. mutans was measured using a rat caries model. Results: It has been shown that the peptides inhibited biofilm rapid accumulation by weakening the initial adhesion of S. mutans and reducing the production of EPS. Meanwhile, they also decreased bacterial acidogenicity and aciduricity, and ultimately prevented caries development in vivo. Conclusion: GHaR and GHa11R might be promising candidates for controlling S. mutans infections.

Antibacterial Effects of Ramulus mori Oligosaccharides against Streptococcus mutans.

Ramulus mori has been widely used in traditional Chinese medicine because of its physiological activities, including antibacterial, anti-inflammatory, and antioxidant activities. Antimicrobial properties of Ramulus mori extract have been well described. However, no information is available regarding on Ramulus mori oligosaccharides (RMOS). The aim of this study was to investigate the effects of RMOS on the growth and virulence properties of the cariogenic bacterium Streptococcus mutans. The effects of RMOS on the biofilm structure and virulence gene expression of S. mutans were also evaluated, and the results were compared with the effects of commercial prebiotic galactooligosaccharides. RMOS were found to have an antibacterial effect against S. mutans, resulting in significant reductions in acid production, lactate dehydrogenase activity, adhesion, insoluble extracellular polysaccharide production, glucosyltransferase activity, and biofilm formation in a dose-dependent manner. Moreover, the biofilm structure was visibly damaged. A quantitative real-time PCR assay revealed downregulation of virulence gene-regulated acid production, polysaccharide production, adhesion, biofilm formation, and quorum sensing. These findings suggest that RMOS may be a promising natural product for the prevention of dental caries.

Corrigendum: Association of polymicrobial interactions with dental caries development and prevention.

[This corrects the article DOI: 10.3389/fmicb.2023.1162380.].

Association of polymicrobial interactions with dental caries development and prevention.

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

Streptococcus mutans glutamate binding protein (GlnH) as antigen target for a mucosal anti-caries vaccine.

BACKGROUND: In recent years, several studies have demonstrated that bacterial ABC transporters present relevant antigen targets for the development of vaccines against bacteria such as Streptococcus pneumoniae and Enterococcus faecalis. In Streptococcus mutans, the glutamate transporter operon (glnH), encoding an ABC transporter, is associated with acid tolerance and represents an important virulence-associated factor for the development of dental caries. RESULTS: In this study, we generated a recombinant form of the S. mutans GlnH protein (rGlnH) in Bacillus subtilis. Mice immunized with this protein antigen elicited strong antigen-specific antibody responses after sublingual administration of a vaccine formulation containing a mucosal adjuvant, a non-toxic derivative of the heat-labile toxin (LTK63) originally produced by enterotoxigenic Escherichia coli (ETEC) strains. Serum anti-rGlnH antibodies reduced adhesion of S. mutans to the oral cavity of naïve mice. Moreover, mice actively immunized with rGlnH were partially protected from oral colonization after exposure to the S. mutans NG8 strain. CONCLUSIONS: Our results indicate that S. mutans rGlnH is a potential target antigen capable of inducing specific and protective antibody responses after immunization. Overall, these observations raise the prospect of the development of mucosal anti-caries vaccines.

Anti-Caries Effect of a Mouthwash Containing Sambucus williamsii var. coreana Extract: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

This study was performed to verify the clinical effect of a mouthwash containing Sambucus williamsii var. coreana extract on the acid production of oral bacteria and bacteria involved in dental caries. A randomized, double-blind, and placebo-controlled trial was conducted on 66 patients of the following groups: a Sambucus williamsii var. coreana extract gargle group (n = 34) and a saline solution gargle group (n = 32). According to the application time of a mouthwash (before gargle application, immediately after gargle application, and five days after gargle application), we examined the emergence of dental caries-causing bacteria by PCR analysis and changes in the amount of acid production in dental plaque through a Cariview test. As a result of verifying the effect of inhibiting and preventing dental caries in the oral environment, the dental caries-causing bacteria decreased in the Sambucus williamsii var. coreana extract gargle group compared to the saline gargle group. In particular, Streptococcus mutans showed a marked decrease from immediately after application of gargle to 5 days after application. In addition, the mouthwash containing Sambucus williamsii var. coreana extract did not cause acid production and had low dental caries activity. A mouthwash containing Sambucus williamsii var. coreana extract, a natural substance, can be used as an anti-dental caries agent and be commercialized as an effective dental caries prevention agent that is safe for teeth and has an excellent antibacterial effect.

The findings of glucosyltransferase enzymes derived from oral streptococci.

Glucosyltransferase enzymes (Gtfs) distribute among some streptococcal species in oral cavity and are known as key enzymes contributing to the development of oral biofilm such as dental plaque. In 18 streptococcal species, 45 glucosyltransferase genes (gtf) are detected from genome database. Gtfs catalyze the synthesis of the glucans, which are polymers of glucose, from sucrose and they are main component of oral biofilm. Especially, the Gtfs from Streptococcus mutans are recognized as one of dental caries pathogens since they contribute to the formation of dental plaque and the establishment of S. mutans in the tooth surface. Therefore, Gtfs has been studied particularly by many researchers in the dentistry field to develop the anti- caries vaccine. However, it is not still accomplished. In these days, the phylogenetic and crystal structure analyses of Gtfs were performed and the study of Gtfs will enter new situation from the technique in the past old viewpoint. The findings from those analyses will affect the development of the anti-caries vaccine very much after this.　In this review, we summarize the findings of oral streptococcal Gtfs and consider the perspectives of the dental caries prevention which targeted Gtf.

Fabrication of oral nanovesicle in-situ gel based on Epigallocatechin gallate phospholipid complex: Application in dental anti-caries.

The conventional anti-caries agents exhibit many shortcomings such as poor stability, low efficacy or short residence time in the oral environment, it is urgent to develop efficacy treatments to prevent dental caries. As the most active polyphenols from tea, Epigallocatechin gallate (EGCG) shows remarkable anti-cariogenic bioactivity. However, the poor stability and low bioavailability of EGCG limit its potential application. This study aimed to fabricate nanovesicles in-situ gel based on EGCG phospholipid complex in order to increase its stability and efficacy. The formation of EGCG phospholipid complex was characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The ethanol injection method was used to prepare the EGCG-loaded nanovesicles, an optimal ratio of Poloxamer407 (P407) and Poloxamer188 (P188) as in-situ gel matrix was selected to fabricate oral nanovesicles in-situ gel. EGCG-loaded nanovesicle in-situ gel based on the phospholipid complex had uniform spherical shape without any agglomeration. The discrete nanoparticle with a size (131.44 ± 4.24 nm) and a negative zeta potential value at -30.7 ± 0.5 mV possessed good physical stability and high entrapment efficiency (83.66 ± 3.2%). The formulation exhibited a strong antibacterial activity on S. mutans, which could reduce acid production and tooth surface adhesion. In addition, EGCG formulation could inhibit the formation of glucan and biofilm from S. mutans by suppressing the activity of glycosyltransferase enzymes (GTF). In conclusion, the EGCG-loaded nanovesicle in-situ gel holds great promise as an efficient anti-cariogenic formulation for topical oral delivery.

Pu'er tea rich in strictinin and catechins prevents biofilm formation of two cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus.

Cariogenic bacteria, such as Streptococcus mutans and Streptococcus sobrinus, are main pathogens responsible for human dental caries. Pu'er tea is empirically observed to prevent tooth decay. Besides caffeine and catechins commonly found in oolong tea, strictinin is also found as an abundant phenolic compound in Pu'er tea. Infusion of Pu'er tea as well as single compound, strictinin, caffeine or (-)-epigallocatechin gallate (EGCG) was examined for its inhibitory effects on S. mutans and S. sobrinus. Relatively weak inhibition of bacterial growth was observed for these Pu'er tea constituents. However, biofilm formation of S. mutans or S. sobrinus was strongly prevented by the infusion of Pu'er tea as well as by strictinin or EGCG, but not caffeine. Relatively, strictinin showed a higher potency than EGCG to prevent biofilm formation. Anti-caries effect of Pu'er tea seems to be resulted from the prevention of biofilm formation of cariogenic bacteria mainly by strictinin and catechins.