Isolation of Secondary Metabolites From Marine Actinobacterium of Microbispora sp.T3S11 and Their Antibacterial Activities

Introduction Marine actinobacteria are promising sources of novel bioactive compounds due to their distinct ecological niches and diverse secondary metabolite production capabilities. Among these, Microbispora sp. T3S11 is notable for its unique spore chain structure, which allows for both morphological and genetic identification. Despite its potential, little is understood about the secondary metabolites produced by this strain. In this study, we hope to fill this gap by extracting and analyzing the antibacterial activities of secondary metabolites from Microbispora sp. T3S11, which will be the first time its bioactive compound profile is investigated. Aim To evaluate the antibacterial activity of secondary metabolites isolated from the marine actinobacterium Microbispora sp. T3S11. Materials and methods The antibacterial assays were carried out on agar plates containing the appropriate media for each pathogen. Sterile filter paper disks were impregnated with secondary metabolites extracted from Microbispora sp. T3S11 and placed on the surface of agar plates inoculated with the appropriate pathogens. Similarly, disks containing tetracycline were used as a positive control. The plates were then incubated at the appropriate temperature for each pathogen, and the zones of inhibition around the disks were measured to determine the extracted metabolites' antibacterial activity. Result Secondary metabolites had antimicrobial activity against Streptococcus mutans, Klebsiella pneumonia, and methicillin-resistant Staphylococcus aureus (MRSA). The inhibition of S. mutans was 7.5 mm and 8.5 mm at 75 μg/mL and 100 μg/mL, respectively. Klebsiella pneumonia zones measured 7 mm and 7.5 mm, while MRSA zones measured 7.6 mm and 8.5 mm at the same concentrations. Tetracycline, the standard antibiotic, had larger inhibition zones: 22 mm for S. mutans and Klebsiella pneumonia and 16 mm for MRSA, indicating variable susceptibility. Conclusion We conclude that the secondary metabolites extracted from Microbispora sp. T3S11 exhibits high antibacterial activity. This could be attributed to the presence of various active compounds.

In Silico Molecular Docking of Phytochemicals of Murraya koenigii Against Streptococcus mutans

Background The curry leaf tree, Murraya koenigii, is a tropical to subtropical tree in the family Rutaceae that is native to Asia. The plant parts are shown to have potential antimicrobial, antioxidant, antifungal, antidiarrheal, antidiabetic, anticancer, and anti-inflammatory properties. Streptococcus mutans is a facultative anaerobic, Gram-positive cocci, a common inhabitant of the human oral cavity that forms biofilms, contributing to dental caries. Aim The study aimed to analyze the inhibitory potential of phytocompounds in M. koenigii against the oral pathogen S. mutans. Materials and methods The protein and ligand were prepared, and molecular docking was carried out using the Hex protein docking server. The PyMOL program was used to view, analyze, and annotate the docked complex. The interaction of the drug, including the mechanism of action, and predicted adverse effects were predicted using the Way2Drug PASS Online server. The absorption, distribution, metabolism, excretion, and toxicity properties of the drug candidates were analyzed using the SwissADME online server. Results The study identified O-methyl murrayamine, koenigine, koenigicine, and murrayone as having inhibitory potential against the glycosyltransferase protein of S. mutans. Among the four compounds analyzed for docking, koenigicine had the lowest E-score, indicating a strong interaction with the receptor. Among the four compounds analyzed, murrayone had a high topological polar surface area score, while all four compounds had similar bioavailability scores. Conclusion This study concluded that O-methyl murrayamine, koenigine, koenigicine, and murrayone exhibit potent inhibitory potential against S. mutans. M. koenigiileaf extract can be used in toothpaste as an antibacterial agent to protect teeth against dental caries. These findings are important for the potential use of the above compound to act as an anticariogenic agent in oral health applications.

Antibacterial Activity and Shear Bond Strength of Orthodontic Adhesive Containing Various Sizes of Chitosan Nanoparticles: An In Vitro Study

INTRODUCTION

White spot lesions are common after orthodontic treatment. Chitosan nanoparticles (CS-NPs) have emerged as promising antibacterial agents that inhibit the growth of Streptococcus mutans. The aim of the study was to investigate the nano-effect of adhesives containing CS-NPs on S. mutans and their effects on shear bond strength.

MATERIALS AND METHODS

The inhibitory effects of two sizes of CS-NPs were assessed using the disc agar diffusion method. Four wells were created in the petri dishes, and each was inoculated with broth (negative control), chlorhexidine (positive control), CS-NPs (20 nm), or CS-NPs (131 nm). An Instron machine was used to evaluate shear bond strength by allocating 24 teeth into three groups, and all measurements were recorded in megapascals. Caries progression was assessed using the International Caries Detection and Assessment System and surface profilometry. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 27.0 (Released 2020; IBM Corp., Armonk, New York, United States) for a one-way ANOVA followed by Tukey's multiple comparison test.

RESULTS

Disc agar diffusion showed a reduction in S. mutans in the CS-NP group compared to the control (p < 0.001), with no statistical significance between the sizes of 20 and 131 nm (p = 0.95). Regarding shear bond strength, no differences were recorded when adhesive-containing CS-NPs and the control were compared (p = 0.44). Additionally, no differences were found within the CS-NP groups (p = 0.91). Caries assessments showed excellent agreement, as indicated by a weighted kappa. Profilometry readings showed higher surface roughness in the control than in the CS-NP groups (p < 0.001), with no statistically significant difference between the CS-NP groups (p = 0.72).

CONCLUSION

CS-NPs of both sizes tested had similar antibacterial effects. In addition, the incorporation of CS-NPs did not affect shear bond strength.

Comparison of the Antibacterial Efficacy of Bamboo Shoot Ethanol Extract With Chlorhexidine Mouth Rinse Against Salivary Streptococcus mutans and Lactobacillus acidophilus: An Ex Vivo Study

Background Dental caries is the most prevalent polymicrobial oral infectious disease tormenting individuals' healthy lifestyles and presents a significant public health problem. The objective of this study was to evaluate and compare the antibacterial properties of different concentrations of bamboo shoot ethanol extract with chlorhexidine mouth rinse on isolates of salivary Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus). Materials and methods Non-stimulated salivary samples from 30 young adults were treated ex vivo with bamboo shoot ethanolic extract at concentrations of 30 µg/ml, 40 µg/ml, 50 µg/ml, and 60 µg/ml. The colony-forming units were quantified by measuring the number of viable bacterial cells. Inhibition zones were evaluated using the agar diffusion method. One-way ANOVA and post-hoc test were used to analyze the significant difference between variables using SPSS version 22.0 (IBM Corp., Armonk, NY). Results The mean zone of inhibition with bamboo shoot ethanolic extract against salivary S. mutans (23.00 ± 0.816) and L. acidophilus (22.00 ± 0.816) total counts was closest to the control chlorhexidine (S. mutans = 22.00 ± 0.876 and L. acidophilus = 21.10 ± 0.876). A greater activity against S. mutans and L. acidophilus is seen in the zone of inhibition of the 60 µg/ml experimental concentration of bamboo shoot ethanolic extract, with a significant difference in the disc diffusion assay. Conclusion The treatment with bamboo shoot extract was equivalent effective in the mentioned bacterial species. Clinical relevance It can be assured that preventive measures like mouth rinse and dentifrices compromising bamboo shoots, a potential dental biomaterial, would be optimistic agents for caries control, including the cariostatic effect.

Increased fecal ethanol and enriched ethanol-producing gut bacteria Limosilactobacillus fermentum, Enterocloster bolteae, Mediterraneibacter gnavus and Streptococcus mutans in nonalcoholic steatohepatitis

Background

Non-alcoholic steatohepatitis (NASH) has become a major public health issue as one of the leading causes of liver disease and transplantation worldwide. The instrumental role of the gut microbiota is emerging but still under investigation. Endogenous ethanol (EtOH) production by gut bacteria and yeasts is an emerging putative mechanism. Microbial metagenomics and culture studies targeting enterobacteria or yeasts have been reported, but no culturomics studies have been conducted so far.

Aim

To assess fecal EtOH and other biochemical parameters, characterize NASH-associated dysbiosis and identify EtOH-producing gut microbes associated with the disease, fecal samples from 41 NASH patients and 24 controls were analyzed. High-performance liquid chromatography (HPLC) was used for EtOH, glucose, total proteins, triglyceride and total cholesterol. Viable bacteria were assessed with microbial culturomics. Microbial genetic material was assessed using 16S metagenomics targeting the hypervariable V3V4 region.

Results

Fecal EtOH and glucose was elevated in the stools of NASH patients (p < 0.05) but not triglyceride, total cholesterol or proteins. In culturomics, EtOH-producing Enterocloster bolteae and Limosilactobacillus fermentum were enriched in NASH. V3V4 16S rRNA amplicon sequencing confirmed the enrichment in EtOH-producing bacteria including L. fermentum, Mediterraneibacter gnavus and Streptococcus mutans, species previously associated with NASH and other dysbiosis-associated diseases. Strikingly, E. bolteae was identified only by culturomics. The well-known Lacticaseibacillus casei was identified in controls but never isolated in patients with NASH (p < 0.05).

Conclusion

Elevated fecal EtOH and glucose is a feature of NASH. Several different EtOH-producing gut bacteria may play an instrumental role in the disease. Culturomics and metagenomics, two complementary methods, will be critical to identify EtOH-producing bacteria for future diagnostic markers and therapeutic targets for NASH. Suppression of EtOH-producing gut microbes and L. casei administration are options to be tested in NASH treatment.

The Antibacterial Effectiveness of Citrullus lanatus-Mediated Stannous Nanoparticles on Streptococcus mutans

Introduction Dental caries is a prevalent oral health issue caused by the colonization of Streptococcus mutans in the oral cavity. Citrullus lanatus, commonly known as watermelon, is rich in bioactive compounds that possess antibacterial potential. In this study, we aimed to synthesize stannous chloride (SnCl2) nanoparticles (NPs) mediated by Citrullus lanatus extract and investigate their antibacterial effectiveness against Streptococcus mutans. Materials and method Stannous nanoparticles (SnNPs) synthesized by the green method were achieved by using the watermelon extract. Dilute stannous chloride solution was obtained by adding 0.45 g of stannous (Sn) chloride (Cl) powder to 60 mL of water, which was subjected to an orbital shaker with the watermelon extract. The nanoparticles obtained were subjected to characterization using antimicrobial testing, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray (EDAX) analysis, and scanning electron microscopy (SEM). Agar well diffusion method was used against specific strains of S. aureus, S. mutans, and Escherichia coli. Results The novel nanoparticles demonstrated promising antibacterial activity against S. mutans providing 10 mm of inhibitory action. Conclusion Due to its abundance of naturally occurring bioactive chemicals and improved efficacy against S. mutans, watermelon extract can be utilized to create stannous nanoparticles as opposed to the use of toxic chemicals. They can also be employed as oral administration systems.

Comparative Evaluation of the Physical and Antimicrobial Properties of Mineral Trioxide Aggregate, Biodentine, and a Modified Fast-Setting Mineral Trioxide Aggregate Without Tricalcium Aluminate: An In Vitro Study

Background Tricalcium aluminate, one of the major constituents of mineral trioxide aggregate (MTA), has been shown to have cytotoxic properties. Mineral trioxide aggregate has moderate to low antimicrobial activity against the most common endodontic pathogen, Enterococcus faecalis. Aim To assess the physical and antimicrobial properties of a newly modified formulation of mineral trioxide aggregate. Materials & methods The final setting time, compressive strength, and antimicrobial properties were tested for three groups of materials. The material used for Group 1 was mineral trioxide aggregate (white MTA, Angelus, Londrina, Brazil); the material for Group 2 was Biodentine (Septodont, Saint Maur des Fossés, France); and for Group 3, a modified MTA formulation was used. Results Group 1 had the longest setting time, and Group 2 had the shortest setting time. Group 3's material was set at 83.65 ± 0.28 minutes. This difference among the groups was statistically significant (p < 0.05). The highest mean compressive strength during all the time periods was seen in Group 2, followed by Group 3, and the least in Group 1. This difference in compressive strength was statistically significant (p=0.001). The largest zone of inhibition against Enterococcus faecalis, Candida albicans, and Streptococcus mutans was seen in Group 3, followed by Group 2 and Group 1. Conclusion Under the limitations of the present study, the newly modified MTA could serve as an alternative to the conventional MTA in terms of faster setting, higher strength, and better antimicrobial properties.

Anticariogenic potential of tabernaemontana divaricata

Context

Many parts of Tabernaemontana divaricata (T. divaricata) including its leaf is used for the analgesic and antibacterial purpose by Adivasis of Kerala.

Aims

To evaluate the antibacterial potential of T. divaricata against common caries pathogens like S. mutans and L. acidophilus.

Settings and Design

Research is done in Biogenix Research Lab, Thiruvananthapuram.

Methods and Material

Ethyl alcoholic extract of T. divaricata leaves is tested for its antibacterial action against common caries pathogens at various levels. It includes assessing the leaves' antibacterial activity, acid production of bacteria in the presence of the study sample, Minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC) and colony forming units (CFU) levels in the presence of the leaf extract.

Statistical Analysis Used

In descriptive statistics, mean and standard deviation is used. Mann-Whitney U test, Independent Students T-test, Student Paired T-test, and One-way ANOVA followed by Turkeys Post hoc analysis are the tests used in inferential statistics.

Results

It is found that T. divaricata has substantial antibacterial action against S. mutans and L. acidophilus.

Conclusions

Our indigenous plants have a lot of medicinal properties. T. divaricata is no exception to this, though it is commonly considered as a garden plant. In the current study, it has been proven that its leaves have antibacterial action against oral pathogens. So, the research has to be taken to a further level for its medicinal application.

Regulatory mechanisms of exopolysaccharide synthesis and biofilm formation in Streptococcus mutans

Background

Dental caries is a chronic, multifactorial and biofilm-mediated oral bacterial infection affecting almost every age group and every geographical region. Streptococcus mutans is considered an important pathogen responsible for the initiation and development of dental caries. It produces exopolysaccharides in situ to promote the colonization of cariogenic bacteria and coordinate dental biofilm development.

Objective

The understanding of the regulatory mechanism of S. mutans biofilm formation can provide a theoretical basis for the prevention and treatment of caries.

Design

At present, an increasing number of studies have identified many regulatory systems in S. mutans that regulate biofilm formation, including second messengers (e.g. c-di-AMP, Ap4A), transcription factors (e.g. EpsR, RcrR, StsR, AhrC, FruR), two-component systems (e.g. CovR, VicR), small RNA (including sRNA0426, srn92532, and srn133489), acetylation modifications (e.g. ActG), CRISPR-associated proteins (e.g. Cas3), PTS systems (e.g. EIIAB), quorum-sensing signaling system (e.g. LuxS), enzymes (including Dex, YidC, CopZ, EzrA, lmrB, SprV, RecA, PdxR, MurI) and small-molecule metabolites.

Results

This review summarizes the recent progress in the molecular regulatory mechanisms of exopolysaccharides synthesis and biofilm formation in S. mutans.

Evaluation of the Behavioral Determinants of Infant Oral Hygiene Practices in a Rural Area

Background Dental caries is one of the most common oral health diseases in children. Early childhood caries (ECC) in children can lead to delayed overall growth in the future. This can be prevented by early initiation of infant oral hygiene practices (IOHP). As mothers are the primary caregivers, assessing their behavioral factors that play a significant role in IOHP can help design a customized health prevention plan for appropriate infant oral hygiene practices. Methodology A questionnaire based-study was carried out in an Anganwadi (rural child care center in India) of Nagpur region, Central India, for two months. Parents of young children were interviewed about the oral health care of children. The study was planned to evaluate the various methods used by parents to perform IOHP and to identify various behavioral determinants that affect IOHP. An integrative model of behavior change was used to evaluate factors determining the behavioral determinants in performing oral hygiene. Results Out of 144 parents, 105 (72.92%) initiated IOHP immediately after birth. Most of them (76, 52.78%) used a moist cloth to clean the oral cavity. The other methods used were the parent's finger, water, etc. Most of the parents were unaware of commercially available oral wipes. Out of the various factors of behavioral determinants of integrative theory, oral health beliefs, emotional reactions, self-standard, and skills played a significant role in modifying parents' intention to maintain the oral hygiene of young children. There was a direct correlation between the educational qualification of the mother and oral hygiene practices. Conclusion The results of this study reveal an integrative structure that includes factors like oral health beliefs, emotional reactions, self-standard, external support, social norms, and skills that are responsible for the behavior of parents towards oral health care. These factors vary from individual to individual. Modifying these specific behavioral determinants in parents could improve the oral hygiene practices of infants and toddlers. Community-based oral health care programs should be tailormade to target these specific barriers.

Experimental Composite Resin with Myristyltrimethylammonium Bromide (MYTAB) and Alpha-Tricalcium Phosphate (α-TCP): Antibacterial and Remineralizing Effect

The aim of this study was to develop an experimental composite resin with the addition of myristyltrimethylammonium bromide (MYTAB) and α -tricalcium phosphate (α-TCP) as an antibacterial and remineralizing material. Experimental composite resins composed of 75 wt% Bisphenol A-Glycidyl Methacrylate (BisGMA) and 25 wt% Triethylene Glycol Dimethacrylate (TEGDMA) were produced. Some 1 mol% Trimethyl benzoyl-diphenylphosphine oxide (TPO) was used as a photoinitiator, and butylated hydroxytoluene (BTH) was added as a polymerization inhibitor. Silica (1.5 wt%) and barium glass (65 wt%) particles were added as inorganic fillers. For remineralizing and antibacterial effect, α-TCP (10 wt%) and MYTAB (5 wt%) were incorporated into the resin matrix (α-TCP/MYTAB group). A group without the addition of α-TCP/MYTAB was used as a control. Resins were evaluated for their degree of conversion (n = 3) by Fourier Transform Infrared Spectroscopy (FTIR). The flexural strength (n = 5) was assessed based on ISO 4049:2019 requirements. Microhardness was assessed to calculate softening in solvent (n = 3) after ethanol immersion. The mineral deposition (n = 3) was evaluated after immersion in SBF, while cytotoxicity was tested with HaCaT cells (n = 5). Antimicrobial activity (n = 3) was analyzed against S. mutans. The degree of conversion was not influenced by the antibacterial and remineralizing compounds, and all groups reached values > 60%. The α-TCP/MYTAB addition promoted increased softening of polymers after immersion in ethanol and reduced their flexural strength and the viability of cells in vitro. A reduction in S. mutans viability was observed for the α-TCP/MYTAB group in biofilm formation and planktonic bacteria, with an antibacterial effect > 3log₁₀ for the developed materials. Higher intensity of phosphate compounds on the sample's surface was detected in the α-TCP/MYTAB group. The addition of α-TCP and MYTAB promoted remineralizing and antibacterial effects on the developed resins and may be a strategy for bioactive composites.

Study of Streptococcus mutans in Early Biofilms at the Surfaces of Various Dental Composite Resins

BACKGROUND

Biofilm deposit on the composite restoration is a common phenomenon and bacterial growth follows the deposition. The study aims to evaluate Streptococcus mutans (S. mutans) early biofilm formation on the surfaces of various dental composite resins by using the real-time quantitative polymerase chain reaction (qPCR) technique.

MATERIALS AND METHODS

Thirty-two discs, where eight discs were in each group of Filtek Supreme Ultra (FSU; 3M, St. Paul, MN), Clearfil AP-X (APX; Kuraray Noritake Dental Inc., Tokyo, Japan), Beautifil II (BE2; Shofu, Inc., Kyoto, Japan), and Estelite Sigma Quick (ESQ; Tokuyama Dental, Tokyo, Japan), were fabricated and subjected to S. mutans biofilm formation in an oral biofilm reactor for 12 hours. Contact angles (CA) were measured on the freshly fabricated specimen. The attached biofilms underwent fluorescent microscopy (FM). S. mutans from biofilms were analyzed using a qPCR technique. Surface roughness (Sa) measurements were taken before and after biofilm formation. Scanning electron microscopy (SEM), including energy dispersive X-ray spectrometer (EDS) analysis, was also performed for detecting relative elements on biofilms.

RESULTS

The study showed that FSU demonstrated the lowest CA while APX presented the highest values. FM revealed that condensed biofilm clusters were most on FSU. The qPCR results indicated the highest S. mutans DNA copies in the biofilm were on FSU while BE2 was the lowest (p < 0.05). Sa test signified that APX was significantly the lowest among all materials while FSU was the highest (p < 0.05). SEM displayed areas with apparently glucan-free S. mutans more on BE2 compared to APX and ESQ, while FSU had the least. Small white particles detected predominantly on the biofilms of BE2 appeared to be Si, Al, and F extruded from the resin.

CONCLUSION

Differences in early biofilm formation onto various composite resins are dependent on the differences in material compositions and their surface properties. BE2 showed the lowest quantity of biofilm accumulation compared to other resin composites (APX, ESQ, and FSU). This could be attributed to BE2 proprieties as a giomer and fluoride content.

Evaluation of the clinical impact and In Vitro antibacterial activities of two bioactive restoratives against S. mutans ATCC 25175 in class II carious restorations

Background

Streptococcus mutans is a Gram-positive opportunistic bacterial pathogen and that causes dental caries and then restorative treatment remains the best clinical practice approach to repair and prevent dental caries.

Aims

This study compared the antimicrobial performance of resin modified glass ionomer cement (RM-GIC) and ACTIVA restoratives by evaluating the S. mutans count, pH levels, and plaque index (PI) scores before and on the 7^th day of restoration, and then determined the antimicrobial activities against S. mutans ATCC 25175 in both restoratives in vitro.

Materials and Methods

Seventy-eight eligible Saudi female participants, with class II carious lesions, were randomly distributed into RM-GIC and ACTIVA restorative groups. We evaluated the S. mutans count by the serial dilution technique and salivary pH by using a portable pH meter. The PI scores were determined by Silness-Löe method and the antibacterial activity by the agar well diffusion method. Statistical analysis of normality distribution was performed with the Kolmogorov-Smirnov and the difference between groups was an analysis by paired t-test. In addition, the independent sample was compared with the independent samples t-test.

Results

Both groups reduced the S. mutans count, pH acidity, and PI scores, and this reduction was statistically significant on the 7^th day of restoration (P < 0.05), preference for ACTIVA. The in vitro antibacterial activity against S. mutans ATCC 25175 showed a non-significant difference between both bioactive restorative materials (P < 0.05).

Conclusion

The novel application of ACTIVA restorative material is a promising option for patients at risk of caries.

Gas Chromatography-Mass Spectrometry (GC-MS) Metabolite Profiling of Citrus limon (L.) Osbeck Juice Extract Evaluated for its Antimicrobial Activity Against Streptococcus mutans

Purpose The present study aimed to determine the antimicrobial nature of Citrus limon juice extract against Streptococcus mutans and to identify its metabolic profile by gas chromatography-mass spectrometry (GC-MS) technique. Materials and methods The cariogenic bacteria S. mutans were procured from Microbial Type Culture Collection and Gene Bank (MTCC), Chandigarh, India, and revived on brain heart infusion (BHI) agar. The C. limon (L.) Osbeck fruits were authenticated from the University of Trans-Disciplinary Health Sciences and Technology (TDU), Bengaluru, India. The antibacterial property of lyophilized lemon juice extract (LJE) dissolved in methanol was evaluated against S. mutans (MTCC 497) by the agar well diffusion assay. GC-MS technique was employed to identify the volatile metabolite profile of the methanolic LJE sample. The metabolite masses of the respective compounds were identified using the National Institute of Standards and Technology (NIST) library. Results The methanolic LJE sample concentration from 5 to 25 mg/ml did not demonstrate antimicrobial activity, while 30 to 100 mg/ml displayed antibacterial activity against S. mutans. Chlorohexidine (100 µg/ml) was used as the positive control, while methanol was used as the negative control. Significant antimicrobial metabolites were detected in the methanolic LJE sample by GC-MS analysis. Maleic anhydride, succinic anhydride, 6-Oxa-bicyclo[3.1.0] hexan-3-one, and 3-methyl-2,5-Furandione were the key metabolites identified in the methanolic LJE sample.  Conclusion The present study reports that C. limon is a potential candidate for the pharmaceutical industry as it possesses bioactive compounds demonstrating therapeutic properties. Further investigations are warranted to determine the individual and synergetic effects of identified metabolites in the methanolic LJE sample for its antimicrobial property. Special attention needs to be focussed on translational research for the development of anti-caries products from C. limon.

Salivary Streptococcus mutans colony-forming unit count in patients with and without orthodontic appliances

Orthodontic appliances promote the accumulation of biofilm in the oral cavity and increase counts of Streptococcus mutans (S. mutans). However, there are few comparative studies of the effects generated by the interaction of saliva and microorganisms in absence and presence of orthodontic appliances.

AIM

The aim of this study was to determine the S. mutans colony-forming unit count (CFU/mL) in participants with and without fixed orthodontic appliances.

MATERIALS AND METHOD

It was an observational cross-sectional study on 21 participants, all over 18 years of age, non-smokers, without removable oral appliances, who had not been under antibiotic treatment within the previous three months. Sociodemographic variables, oral hygiene habits, S. mutans CFU/mL count, and salivary pH were assessed. Saliva samples were collected, and the data was analyzed using Fisher's exact and Kruskal Wallis tests. A p-value <0.05 was considered statistically significant.

RESULTS

Fourteen (66.7%) of the participants were female; average age was 20.4 ± 2.2 years. The group without fixed orthodontic appliances had the highest salivary S. mutans CFU/mL count (Me: 56.0×103, IQR: 9.2×103 - 75.5×103), but there was no statistically significant difference between groups (p=0.7459). There was a statistically significant difference in salivary pH, with the metal orthodontic appliance group having the lowest pH (p=0.0478). No statistically significant difference in salivary S. mutans CFU/mL count was found between groups. Salivary pH was lower in the group with metal appliances than in the groups with non-metal appliances and without appliances.

Potential oral probiotic Lactobacillus pentosus MJM60383 inhibits Streptococcus mutans biofilm formation by inhibiting sucrose decomposition

Streptococcus mutans is known as a contributor to dental caries. In this work, Lactobacillus pentosus MJM60383 was selected for its strong antagonistic activity against S. mutans and was characterized by good oral probiotic properties including lysozyme tolerance, adhesive ability to oral cells, good aggregation (auto-aggregation, co-aggregation) ability, hydrogen peroxide production and inhibition of biofilm formation of S. mutans. L. pentosus MJM60383 also exhibited safety as a probiotic characterized by no hemolytic activity, no D-lactate production, no biogenic amine production, and susceptibility to antibiotics. Furthermore, the biofilm formation of S. mutans was also significantly inhibited by the supernatant of L. pentosus MJM60383. An anti-biofilm mechanism study revealed that sucrose decomposition and the production of water-insoluble exopolysaccharides by S. mutans were inhibited by the treatment with L. pentosus MJM60383 supernatant. Real-time PCR analysis indicated that the supernatant of L. pentosus MJM60383 significantly inhibited the mRNA expression of S. mutans glycosyltransferases, which synthesize glucan to construct biofilm architecture and mediate bacterial adherence. Our study demonstrated L. pentosus MJM60383 as a potential oral probiotic and revealed its anti-biofilm mechanism.

Targeting cariogenic pathogens and promoting competitiveness of commensal bacteria with a novel pH-responsive antimicrobial peptide

Novel ecological antimicrobial approaches to dental caries focus on inhibiting cariogenic pathogens while enhancing the growth of health-associated commensal communities or suppressing cariogenic virulence without affecting the diversity of oral microbiota, which emphasize the crucial role of establishing a healthy microbiome in caries prevention. Considering that the acidified cariogenic microenvironment leads to the dysbiosis of microecology and demineralization of enamel, exploiting the acidic pH as a bioresponsive trigger to help materials and medications target cariogenic pathogens is a promising strategy to develop novel anticaries approaches. In this study, a pH-responsive antimicrobial peptide, LH12, was designed utilizing the pH-sensitivity of histidine, which showed higher cationicity and stronger interactions with bacterial cytomembranes at acidic pH. Streptococcus mutans was used as the in vitro caries model to evaluate the inhibitory effects of LH12 on the cariogenic properties, such as biofilm formation, biofilm morphology, acidurance, acidogenicity, and exopolysaccharides synthesis. The dual-species model of Streptococcus mutans and Streptococcus gordonii was established in vitro to evaluate the regulation effects of LH12 on the mixed species microbial community containing both cariogenic bacteria and commensal bacteria. LH12 suppressed the cariogenic properties and regulated the bacterial composition to a healthier condition through a dual-functional mechanism. Firstly, LH12-targeted cariogenic pathogens in response to the acidified microenvironment and suppressed the cariogenic virulence by inhibiting the expression of multiple virulence genes and two-component signal transduction systems. Additionally, LH12 elevated H₂O₂ production of the commensal bacteria and subsequently improved the ecological competitiveness of the commensals. The dual-functional mechanism made LH12 a potential bioresponsive approach to caries management.

Assessment of Salivary Mutans Streptococci Counts to Atraumatic Restorative Treatment Among Children: A Randomised Controlled Trial

Introduction Besides the survival rate of restorations, the effect of atraumatic restorative treatment (ART) on bacterial count is also important. After ART restoration, the bacterial count drops due to the fluoride's antibacterial activity and hence it can decrease the chances of further decay. The present study assessed salivary mutans streptococci counts for six months of evaluations subsequent to ART among 12-15-year-old children attending schools in Piparia village, Vadodara district. Methods ART was performed on 32 children and followed up after six months to evaluate the success rate of ART. Saliva collection and microbial analysis were performed five times from every participant, before ART restoration placement, seven days, 30 days (one month), 90 days (three months) and 180 days (six months) post-restoration. Results At baseline, the mean colony forming units (CFU) was 48.30 ± 46.58, which reduced to 32.64 ± 30.40 at one week, which showed a 32% reduction in colony counts. This further reduced to 18.60 ± 20.81 at one month, marking a further 43% reduction in colony counts. This again reduced to 13.63 ± 18.04 at three months, which showed a 27% reduction in colony counts. CFU came to 16.23 ± 23.34 at six months, which showed a 19% increase in colony counts. Comparison of baseline mean CFU (48.30 ± 46.58) to six months mean CFU of streptococcus mutans (SM) (16.23 ± 23.34) showed a 66% reduction in colony counts. A statistically significant difference was found between numerous intervals of time of CFU of streptococcus mutans. Conclusion The findings reveal that ART is a clinical treatment that can be used to treat caries in young children, and it helped significantly reduce Streptococcus Mutans levels in saliva.

Molecular Detection of Streptococcus mutans and Streptococcus sobrinus in Dental Plaque Samples in Children Aged Six to Nine Years

Context Dental caries is a widespread threat, usually in children, although it has been observed at other stages of life. Various pieces of literature have confirmed the prevalence of S treptococcus mutans and S treptococcus sobrinus in the progression of the disease. However, establishing procedures to detect these species remains a challenge, posing a barrier to treatment plans. Aim The aim of this study is to detect the species in dental plaque samples from children aged six to nine years by polymerase chain reaction (PCR) and correlate their prevalence in various dentitions. Material and Methods This is an observational analytical cross-sectional study conducted in a tertiary care dental hospital. After sample isolation, microbiological processing was performed, genomic DNA was isolated, and PCR run was performed using specific primers to detect the species. SPSS for Windows Version 17 (IBM Corp., Armonk, NY) and Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) were used to perform statistical analysis. A p-value of <0.05 was considered statistically significant. Results The technique could identify S. Mutans and S. Sobrinus in a short turnaround time. The frequency of S. mutans and S. sobrinus infections was higher in individuals with dental caries. Conclusions Molecular detection via PCR is a reliable, economical, and less time-consuming method for detecting S. mutans and S. sobrinus in dental plaque samples.

Copper-containing nanoparticles: Mechanism of antimicrobial effect and application in dentistry-a narrative review

Copper has been used as an antimicrobial agent long time ago. Nowadays, copper-containing nanoparticles (NPs) with antimicrobial properties have been widely used in all aspects of our daily life. Copper-containing NPs may also be incorporated or coated on the surface of dental materials to inhibit oral pathogenic microorganisms. This review aims to detail copper-containing NPs' antimicrobial mechanism, cytotoxic effect and their application in dentistry.

Metal versus Fiberglass Post-Orthodontic Retainers Short-Term Effects on Plaque Index and Microbial Colonization: An Observational Study

In orthodontics, post-treatment retention phase is crucial for maintaining the obtained clinical results. In cases of crowding, a bonded fixed retainer is often chosen to maintain teeth alignment in the anterior sector of the lower dental arch. A fixed retainer can remain in the mouth for years. Therefore, it is important that it is applied with harmless materials for the level of plaque control. The present study aimed to investigate the salivary concentrations of Streptococcus mutans (S. mutans) and Lactobacilli, and the Sillness and Loe plaque index, in patients wearing metal wire versus fiberglass orthodontic retainers. Forty post-orthodontic patients were included in the sample: in 20 subjects a metal wire retainer was applied (MR), while in the others a fiberglass retainer was applied (FR). The variables were recorded at baseline (T0), after 1 month (T1), and after 2 months (T2) of follow-up. The percentage of patients with a level of S. mutans and Lactobacilli colonization > 105 increased over time in the FR group (T0 = 0%, T1 = 5%, T2 = 35%), compared with the MR group. PI increased in the FR group (T0 = 0, T1 = 14, T2 = 27), and remained almost the same in the MR group (T0 = 3, T1 = 0, T2 = 2). From the present results it appears that the metal wire retainer is better than the fiberglass retainer for the level of plaque control performed by the patients.

Effect of antimicrobial agents on the oral microflora in patients undergoing fixed orthodontic therapy-An ex vivo comparative analysis

Aim:

To evaluate and compare the efficacy of Ozonated Olive Oil Gel, Chlorhexidine gel, and Amflor (Fluoridated) mouthwash on reducing the count of Streptococcus mutans and Lactobacillus in patients undergoing fixed orthodontic therapy evaluated at different time intervals.

Methods:

Sixty patients undergoing orthodontic treatment were randomly divided into three groups (n = 20) based on antimicrobial agents used (Group 1: Ozonated olive oil gel; Group 2: Chlorhexidine gel; Group 3: Fluoridated mouthwash). Elastomeric modules from brackets were collected at T₀ (Fresh samples) and T₁ (2^nd week) and T₂ (4^th week) for assessment of the microbial growth. These collected modules were cultured and evaluated for the presence of Streptococcus Mutans and Lactobacilli and numbers of colonies were counted at each interval. Data obtained was subjected to statistical analysis using SPSS software (Version 20.0). Level of significance was kept at 5%. Intra-group and inter-group comparison between pretreatment, 2^nd week and 4^th week was done for each group using Wilcoxon signed rank test and Mann–Whitney U test.

Results:

There was presence of Streptococcus Mutans and Lactobacilli during orthodontic treatment which progressively increased from T_o to T₁ and then declined from T₁ to T_2. The colony counts were maximum for Fluoridated mouthwash and least for Chlorhexidine and the results were statistically significant (P < 0.05).

Conclusion:

All three antimicrobial agents used were effective against Streptococcus mutans and Lactobacillus. Chlorhexidine proved to be more efficacious whereas Fluoridated mouthwash proved to be least effective against both Streptococcus mutans and Lactobacillus bacteria.

Effect of the addition of Chitosan and TiO2nanoparticles on antibacterial properties of an orthodontic composite in fixed orthodontic treatment: a randomized clinical trial study

Due to the existing demands for methods independent of patient co-operation in preventing and overcoming the incidence of white spot lesions (WSLs) and caries in fixed orthodontic treatments, several studies have considered the modification of orthodontic composites using antimicrobial nanomaterials. In this regard, the aim of this study is to investigate the effect of the addition of chitosan nanoparticles (NPs) and TiO₂NPs onStreptococcus mutans(S. mutans) counts and the enamel mineral content in fixed orthodontic patients. A double-blind randomized clinical trial study was carried out in 24 patients (i.e., 48 upper second premolars and 48 maxillary lateral incisors) who were candidates for fixed orthodontic treatment. In the case of the control group, the bracket was bonded to the tooth with an orthodontic adhesive (Transbond XT, 3M Unitek, USA) while, in the experimental group, the bracket was bonded to the tooth with Transbond XT containing 1% chitosan NPs and 1% TiO₂NPs. For the maxillary lateral incisor and upper second premolar teeth, theS. mutanscounts around the brackets were measured, through the usage of real-time PCR, at the time points of 1 day, 2 months, and 6 months after bonding the brackets to the tooth. Furthermore, the enamel mineral content measurement was also performed around the brackets at 1 day, 2 months, and 6 months after bonding the brackets to the tooth. TheS. mutanscounts were analyzed using Friedman and Mann-Whitney U tests. The Repeated measures ANOVA test and Independent samples T-test were also applied, in order to evaluate the mineral content. According to the results, there was a significant reduction in theS. mutanscounts of experimental group at the time points of 1 day, 2 months, and 6 months in both maxillary lateral incisor and upper second premolar teeth. However, we did not observe any significant differences in the control group between the reports at 1 day, 2 months, and 6 months in both maxillary lateral incisor and upper second premolar teeth. The outcomes of this study indicate that, with regard to maxillary lateral incisor teeth, there were no significant differences between the results of the experimental group and control group at the time points of 1 day, 2 months, and 6 months. Furthermore, with respect to the upper second premolar teeth, no significant differences were observed between the two groups at 1 day and 2 months; however,S. mutanscounts were significantly lower in the experimental group than in the control group at the time point of 6 months. Moreover, our gathered data confirmed the absence of any significant differences between the experimental group and control group, in terms of enamel mineral content, at the time intervals of 1 day, 2 months, and 6 months. In conclusion, the incorporation of chitosan NPs and TiO₂NPs in orthodontic composites induces an antibacterial property in the resultant adhesive to be used for fixed orthodontic treatment.

Antimicrobial activities of a small molecule compound II-6s against oral streptococci

Background: The side effects of present antimicrobials like chlorhexidine (CHX) and the emergence of drug resistance necessitate the development of alternative agents to control dental caries. Aim: This study developed a novel small molecule, namely II-6s, and investigated its antimicrobial activities against common oral streptococci associated with dental caries. Methods: The susceptibility of streptococci to II-6s was evaluated by the microdilution method, time-kill assay and scanning electron microscopy. The exopolysaccharides, dead/live bacteria and bacterial composition of the II-6s-treated Streptococcus mutans/Streptococcus gordonii/Streptococcus sanguinis 3-species biofilms were analyzed by confocal laser scanning microscopy, fluorescent in situ hybridization and quantitative PCR. The anti-demineralization effect and cytotoxicity of II-6s were evaluated by transverse microradiography and CCK-8 assay, respectively. Repeated exposure of S. mutans to II-6s was performed to assess if II-6s could induce drug resistance. Results: II-6s exhibited antimicrobial activity similar to CHX against S. mutans, S. gordonii and S. sanguinis and significantly inhibited exopolysaccharides production, live bacteria and the demineralizing capability of the 3-species streptococcal biofilms. Besides, II-6s showed reduced cytotoxicity relative to CHX and did not induce drug resistance in S. mutans after 15 passages. Conclusion: - II-6s may serve as a promising part of a successful caries management plan.

Exploring the anti-caries properties of baicalin against Streptococcus mutans: an in vitro study

Plant-derived molecules are excellent alternatives to antibiotics as anti-infective agents owing to their minimal cytotoxicity. Herein, the anti-infective property of the hydroxyflavone baicalin, was investigated against biofilms of the key dental caries pathogen Streptococcus mutans. Baicalin inhibited sucrose-dependent biofilm formation at a concentration of 500 µg ml^-1 without affecting bacterial growth. It significantly inhibited acid production for an extended period of 8 h. Microscopic analysis revealed a 6-fold reduction in the number of adhered cells with baicalin treatment. Transcriptomic analysis of the mid-log phase and biofilm cells showed marked downregulation of the virulence genes required for biofilm formation and acid production. This study sheds significant new light on the potential for baicalin to be developed into an anti-caries agent.

Comparative Assessment of Antibacterial Efficacy of Commercially Available Different Dental Gels: An In-vitro Study

BACKGROUND

The topical routes of administering drugs have certain visible advantages, such as the direct application of a drug to the site of action and persistence of action for a prolonged duration. More stability and better application property of gel allow its use for topical application.

OBJECTIVES

To determine and compare antibacterial efficacy of commercially available different dental gels.

METHODS

For the evaluation of the antibacterial efficacy of commercially available different antiseptic gels on Streptococcus mutans and Lactobacillus acidophilus, well-diffusion method was used. To assess the antibacterial efficacy after incubation in an appropriate culture medium, diameter of zone of inhibition was measured.

RESULTS

Maximum zone of inhibition was found with Cure next gel (40 mm,40mm) followed by Hexigel (30 mm, 21mm), Mucopain (17 mm, 17mm), and Dologel (7 mm, 16mm) against S. mutans and L. acidophilus, respectively. Analysis of variance (ANOVA) and Post Hoc Test were used to analyze results statistically. The difference between commercially available different dental gels was statistically significant (P < 0.001) at a 5%.

CONCLUSION

In the present study, it was observed that Curenext gel was more effective, followed by Hexigel, Mucopain gel, and Dologel on S. Mutans and L. Acidophilus.

Caries among adult patients with controlled celiac disease: A cross-sectional study

INTRODUCTION

Celiac disease (CD) is one of the most common chronic gastrointestinal disorders in the world. Currently, the literature about the dental profiles of patients with celiac disease is sparse and no studies have reported on the oral conditions and caries status of CD patients in Kuwait.

OBJECTIVE

This study investigated the association between CD and caries experience.

METHODS

Two groups were examined; study and control. The study group consisted of controlled celiac disease patients. The control group consisted of subjects who were matched for age and gender to the study group participants. Both groups received clinical and radiographic examinations of their oral cavity. Parameters recorded for the study purposes were-dental caries index (decayed, missing, and filled teeth), salivary flow rates (stimulated and unstimulated), salivary buffering capacity and Lactobacilli and mutans Streptococci bacterial counts.

RESULTS

Patients with CD had statistically significant fewer missing teeth than the controls. There were no other significant differences. Measured stimulated and unstimulated salivary flow rates and salivary buffering capacity showed no statistical differences. Bacterial counts revealed no significant differences.

CONCLUSION

Adult patients with controlled CD showed fewer missing teeth than their counterparts. Other caries and salivary parameters showed no statistical differences between the two groups.

An in vitro and in vivo study of plasma treatment effects on oral biofilms

Management of dental plaque/biofilms is critical to maintain oral health. The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on oral biofilm formation and recovery under in vitro and in vivo conditions. Streptococcus mutans biofilms, a significant contributor to tooth decay, were cultured and treated by plasma. It was found that plasma treatment not only significantly reduced the in vitro biofilms, but also increased the metabolic activity of the bacteria in the biofilms. As compared with untreated control group, the cell metabolic activity, as measured by MTT assay, increased by 273%, and the aconitase activity increased by 446% for the plasma-treated group. The increased metabolic activity of the plasma-treated biofilm bacteria enhanced their susceptibility to antibiotic and host defense. An in vivo animal model using a total of 60 female rats (19 days old) were used to evaluate the anti-caries effects on the molars by 2 min of plasma treatment. It was found that, 6 months after the plasma treatment, the decayed surfaces were reduced by 62.5% on the upper molars and by 31.6% on the lower molars as compared with the untreated upper and lower molars, respectively. These in vitro and in vivo data demonstrate that the physiological state change of the biofilm due to plasma treatment provided benefit to caries control and prevention.

Sugars and beyond. The role of sugars and the other nutrients and their potential impact on caries

The traditional concept of caries as a multifactorial transmittable and infectious disease has been challenged. Novel conceptual ideas have come to add to the complexity of this highly prevalent disease worldwide. Current etiological understanding of the disease has emphasized the pivotal role of sugars in caries. In fact, current definition points toward an ecological disease caused by the commensal microbiota that under ecological imbalances, mainly due to high and or frequent sugars consumption, creates a state of dysbiosis in the dental biofilm. This modern conceptual idea, however, tends to underrate a key issue. As humans are omnivore and consume a mix diet composed by a multitude of substances, the role of the diet in caries must not be restricted only to the presence of fermentable sugars. This review explores the contribution of other food components, ubiquitous to the diet, mostly as potentially protective factors. Anticaries nutrients might determine an environmental change, affecting the ecology of the oral microbiome and partially mitigating the effect of sugars. Understanding the function of the food usually consumed by the people will contribute new knowledge on the mechanisms associated with the onset of caries, on new caries risk variables and on potential novel strategies for the prevention and treatment of the disease.

Streptococcus Mutans: A Potential Risk Factor in Recurrent Hemorrhagic Stroke

Stroke is the fifth leading cause of death and is responsible for approximately nine percent of all deaths worldwide. Cases of Streptococcus mutans (S. mutans)-induced intracerebral hemorrhage as a result of bloodstream infections have seldom been reported. New reports show that bacteria with specific collagen binding proteins (CBPs), such as the Cnm type produced by S. mutans, may inhibit platelet aggregation and cause bleeding. In this article, we report on a 62-year-old man with a recent history of left frontal intracerebral hemorrhage (ICH) who presented to the emergency department after a fall due to suspected seizure while in rehabilitation. Computed tomography (CT) scan of the brain showed a right cerebellar hemorrhage with surrounding edema and mass effect on the fourth ventricle. A suboccipital craniotomy to evacuate the cerebellar ICH was completed without complication. Radiologic and angiographic assessments regarding the etiology of this patient's stroke did not reveal any evidence of vascular pathology or mycotic aneurysms to explain his recurrent intracranial hemorrhages. Through persistent patient and family interviews, it came to light that a few weeks prior to the patient's first ICH, he was diagnosed with a bloodstream infection by S. mutans. Bacteremia is known to be associated with embolic stroke, but only recently has it been shown that bacteremia can also be implicated in hemorrhagic stroke. S. mutans of the k serotype have specific CBPs that are attracted to exposed collagen in previously damaged small vessel walls. These bacterial proteins can interrupt the blood clotting cascade through the prevention of platelet aggregation, increasing the risk of intracerebral hemorrhage.

Zinc Oxide Nanorods-Decorated Graphene Nanoplatelets: A Promising Antimicrobial Agent against the Cariogenic Bacterium Streptococcus mutans

Nanomaterials are revolutionizing the field of medicine to improve the quality of life due to the myriad of applications stemming from their unique properties, including the antimicrobial activity against pathogens. In this study, the antimicrobial and antibiofilm properties of a novel nanomaterial composed by zinc oxide nanorods-decorated graphene nanoplatelets (ZNGs) are investigated. ZNGs were produced by hydrothermal method and characterized through field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) techniques. The antimicrobial activity of ZNGs was evaluated against Streptococcus mutans, the main bacteriological agent in the etiology of dental caries. Cell viability assay demonstrated that ZNGs exerted a strikingly high killing effect on S. mutans cells in a dose-dependent manner. Moreover, FE-SEM analysis revealed relevant mechanical damages exerted by ZNGs at the cell surface of this dental pathogen rather than reactive oxygen species (ROS) generation. In addition, inductively coupled plasma mass spectrometry (ICP-MS) measurements showed negligible zinc dissolution, demonstrating that zinc ion release in the suspension is not associated with the high cell mortality rate. Finally, our data indicated that also S. mutans biofilm formation was affected by the presence of graphene-zinc oxide (ZnO) based material, as witnessed by the safranin staining and growth curve analysis. Therefore, ZNGs can be a remarkable nanobactericide against one of the main dental pathogens. The potential applications in dental care and therapy are very promising.

Evaluation of changes in Streptococcus mutans colonies in microflora of the Indian population with fixed orthodontics appliances

BACKGROUND

Orthodontic therapy has oral ecological changes causing increased numbers of mutans streptococci in saliva and plaque. The purpose of this study was to estimate counts and colonization pattern of Streptococcus mutans after application of fixed orthodontic appliances.

MATERIALS AND METHODS

Plaque samples of randomly selected sixty patients were collected before placement of orthodontic appliances from buccal and labial aspects of the anterior teeth and four first molars and readings were recorded as T0. After placement of appliances (0.22 MBT preadjusted Gemini), i.e., 2(nd) and 3(rd) month, the plaque samples were collected again from same site and readings were recorded as T1 and T2, respectively. Counts of S. mutans in these patients were determined by using DM Strips (Orion Diagnostic, Espoo, Finland). Kruskal-Wallis test and Mann-Whitney U-test were used to find out significant differences between different time interval for Dentocult score for S. mutans in orthodontic patients (P < 0.001).

RESULTS

Prior to the treatment, 46 patients (76%) showed mild and 14 patients (24%) showed moderate colonization of S. mutans. After treatment, the severity of colonization increased showing fifty patients (84%) moderate and six patients (10%) showing severe colonization of S. mutans at T1, which further increased in severity at T2 with 54 patients (90%) showing severe colonization with S. mutans.

CONCLUSION

Results showed that fixed orthodontic appliance increases colonization of S. mutans during orthodontic treatment.

Early Colonization of Lactobacillus reuteri after Exposure to Probiotics

The aim of the present in vivo animal study is to investigate the ability of L. reuteri to colonize the oral flora during infancy.

STUDY DESIGN

Twenty four rats, aged 1 month, which were pre-analyzed for mutans streptococci and L. reuteri absence in their saliva, were randomly divided into 3 groups. The control group was infected with S. mutans ATCC 25175 at the 2nd month, three times a day for 14 days. S. mutans counts were determined with microbiological saliva analyzes obtained by standard methods of oral swabbing at 3rd, 4th and 5th months. The second group, Probiotic I group, was also infected with S. mutans at the 2nd month, and further infected with L. reuteri ATCC 55730 (1×10(8)),5 drops per day for 25 days, at the 3rd month. S. mutans and L. reuteri counts were determined at the 3rd, 4th and 5th months. Plates were incubated anaerobically at 37°C for 48 h, after which colonies were confirmed as L. Reuteri.

RESULTS

Regarding intragroup analysis, S. mutans counts of the Control group increased steadily during the 3rd. and 4th. months, and a statistically significant (p<0.05) reduction was registered at the 5. month. S. mutans counts of the Probiotic I group increased steadily during the 3rd. and 4th. months, and again a statistically significant (p<0.05) reduction, parallel with the Control group, was registered at the 5th. month. In the Probiotic II group, S. mutans counts started at a higher level than the Control group and there was a statistically significant (p<0.05) reduction of S. mutans at the 5th. month.

CONCLUSION

It may be concluded that, L. reuteri promised a better colonization as a 'first colonisation strain'.

Is Your Drinking Water Acidic? A Comparison of the Varied pH of Popular Bottled Waters

PURPOSE

Dental professionals continually educate patients on the dangers of consuming acidic foods and beverages due to their potential to contribute to dental erosion and tooth decay. Excess acid in the diet can also lead to acidosis, which causes negative systemic side effects. However, water is not typically categorized as acidic. The purpose of this in-vitro study was to investigate the pH levels of several popular brands of bottled water and compare them to various other acidic beverages. Two different brands of marketed alkaline water (with a pH of 8.8 or higher) were also studied, tested for acidity and described.

METHODS

A pilot in-vitro study was conducted to determine the pH levels of a convenience sample of popular brands of bottled water, tap water and other known acidic beverages in comparison with the pH values reported on the respective manufacturers' website. Each beverage was tested in a laboratory using a calibrated Corning pH meter model 240, and waters were compared to the corresponding company's testified pH value. Waters were also compared and contrasted based on their process of purification. The data was then compiled and analyzed descriptively.

RESULTS

The pH values for the tested beverages and bottled waters were found to be predominantly acidic. Ten out of the 14 beverages tested were acidic (pH<7), 2 municipal (or "tap") waters were neutral (pH=7) and 2 bottled waters were alkaline (pH>7). The majority of waters tested had a more acidic pH when tested in the lab than the value listed in their water quality reports.

CONCLUSION

It is beneficial for the health care provider to be aware of the potential acidity of popular bottled drinking waters and educate patients accordingly.

Lactoferrin: A Roadmap to the Borderland between Caries and Periodontal Disease

Lactoferrin is one of a number of multifunctional proteins that are present in or on all mucosal surfaces throughout the body. Levels of lactoferrin are consistently elevated in inflammatory diseases such as arthritis, inflammatory bowel diseases, corneal disease, and periodontitis. Single-nucleotide polymorphisms (SNPs) in lactoferrin have been shown to be present in individuals susceptible to Escherichia coli-induced travelers' diarrhea and in tear fluid derived from virally associated corneal disease. Here, we review data showing a lactoferrin SNP in amino acid position 29 in the antimicrobial region of lactoferrin that acts against caries associated bacteria. This SNP was initially discovered in African American subjects with localized aggressive periodontitis (LAP) who had proximal bone loss but minimal proximal caries. Results were confirmed in a genetic association study of children from Brazil with this same SNP who showed a reduced level of caries. In vitro data indicate that lactoferrin from whole saliva derived from subjects with this SNP, recombinant human lactoferrin containing this SNP, or an 11-mer peptide designed for this SNP kills mutans streptococci associated with caries by >1 log. In contrast, the SNP has minimal effect on Gram-negative species associated with periodontitis. Moreover, periodontally healthy subjects homozygous for this lysine (K) SNP have lactoferrin in their saliva that kills mutans streptococci and have reduced proximal decay. The review summarizes data supporting the ecologic plaque hypothesis and suggests that a genetic variant in lactoferrin with K in position 29 when found in saliva and crevice fluid can influence community biofilm composition. We propose that, for caries, this SNP is ethnicity independent and protective by directly killing caries-provoking bacteria (reducing proximal decay). However, the clinical effect of this SNP in LAP is ethnicity dependent, destructive (increases LAP incidence), and complex with mechanisms still to be determined.

Effect of epigallocatechin-3-gallate application for remaining carious dentin disinfection

CONTEXT

Epigallocatechin-3-gallate (EGCG) is a flavonoid extracted from green tea that demonstrated antimicrobial activity.

AIMS

To evaluate the efficacy of EGCG 0.5%, 1%, and 2% concentrations as an antimicrobial solution in dentin caries-like lesions induced in a bacterial-based in vitro model.

MATERIALS AND METHODS

Twenty-five human dentin specimens were submitted to a microbial-based caries model by immersion in brain heart infusion (BHI) broth inoculated with Streptococcus mutans UA159, for 5 days. After the demineralization period, the specimens were randomly divided into groups: Group I: 0.9% saline solution; Group II: 2% chlorhexidine digluconate; Group III: 0.5% EGCG; Group IV: 1% EGCG; and Group V: 2% EGCG. After the treatments, carious dentin samples were harvested from dentin specimens and analyzed by colony-forming unit (CFU) counts. Data were analyzed by ANOVA and Tukey's test.

RESULTS

Log reduction values (SD, CFU.mg(-1)) for Groups I-V were: 5.02 (0.16), 3.96 (0.43), 4.74 (0.26), 4.89 (0.56), and 4.91 (0.40), respectively. There was no statistical difference between the EGCG concentrations and saline solution (P > 0.05). Furthermore, there was no statistical difference between EGCG concentrations (P > 0.05). However, there was a statistically significant difference between the chlorhexidine digluconate group and the other groups (P < 0.05).

CONCLUSION

EGCG at the studied concentrations were not effective in eliminating S. mutans from dentin caries-like lesions.

Influence of sport mouthguards on the ecological factors of the children oral cavity

BACKGROUND

The use of fixed and/or removable dental devices is an attributable factor that may affect the oral cavity homeostasis. The aim of this study was to monitor the oral environmental changes caused by dental devices, as sports mouthguards with the aid of a chair-side test.

METHODS

Sixty children with sports-mouthguards were analyzed at baseline (T0), after 6 months of dental devices use (T1), after a year (T2) and after almost 6 months without using it (T3). At T0, a clinical monitoring was performed and the DMFT index was recorded. At each time of observation, the following parameters were recorded: FMPS, FMBS, unstimulated-flow rate, saliva consistency, resting pH, stimulated saliva, buffer capacity, the CFU/ml of Streptococcus mutans.

RESULTS

In 60 subjects, mean age 9.9 ± 1.2, mean value of DMFT 1.55 ± 1.29,dmf-t 3.43 ± 1.21, FMPS and FMBS values increased significantly at T2. The values of unstimulated flow rate vary significantly within the observation times. The pH value and the buffering capacity reduced significantly at T2. The tests for the detection of S. mutans were negative in all the subjects in several observation times. All patients regularly used fluoridated toothpaste and comply with normal standards of oral hygiene; but over time the patients lost their initial motivation.

CONCLUSIONS

Sport treatment with dental devices dues to changes in oral ecological factors: increases FMPS, FMBS and reduces the buffering capacity and the salivary pH. The use of removable devices increases the retentive plaque surfaces and inhibits the protective effect of saliva.The so-called "chair-side" tests were able to easily monitor patients and to determine the risk of oral disease during sport treatment.

Comparative evaluation of antibacterial activity of total-etch and self-etch adhesive systems: An ex vitro study

Aim:

The aim of this ex vivo study was to compare the antibacterial activity of total-etch and self-etch adhesive systems against Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces viscosus through disk diffusion method.

Materials and Methods:

The antibacterial effects of Single Bond (SB) and Adper Prompt (AP) and aqueous solution of chlorhexidine 0.2% (positive control) were tested against standard strain of S. mutans, L. acidophilus, and A. viscosus using the disk diffusion method. The diameters of inhibition zones were measured in millimeters. Data was analyzed using Kruskal-Wallis test. Mann-Whitney U test was used for pairwise comparison.

Result:

Of all the materials tested, AP showed the maximum inhibitory action against S. mutans and L. acidophilus. Aqueous solution of chlorhexidine 0.2% showed the maximum inhibitory action against A. viscosus. Very minimal antibacterial effect was noted for SB.

Conclusion:

The antibacterial effects observed for the tested different dentin bonding systems may be related to the acidic nature of the materials.

A comparative evaluation of Oratest with the microbiological method of assessing caries activity in children

Aims:

The aim of this study is to find out whether Oratest can be used as a diagnostic tool in assessing the caries activity by evaluating its relationship to the existing caries status and the salivary streptococcus mutans level.

Materials and Methods:

The study sample consists of 90 students divided into two groups. Group I (test group) and Group II (control group) consisting of 30 children for control group and 60 children for test group. The sampling of unstimulated saliva for the estimation of streptococcus mutans was done as per the method suggested by Kohler and Bratthall. The plates were then incubated. Rough surface colonies were identified as streptococcus mutans on a pre-determined area of the tip (approximately 1.5 cm²) were counted for each side of spatula pressed against mitis salivarius bacitracin agar using digital colony counter. The results were expressed in colony forming units (CFU). Oratest was carried out in the same patients after the collection of salivary sample for the microbiological method to evaluate the relationship between the two tests.

Statistical Analysis Used:

The tests used were ANOVA, Pearson Chi-square test, Pearson′s correlation analysis, Mann-Whitney U test and Student′s independent t-test.

Results:

In the control group and test group, when the streptococcus mutans count (CFU) and Oratest time (minutes) were correlated using Pearson′s correlation analysis, the streptococcus mutans counts was found to be in a statistically significant negative linear relationship with the Oratest time. When the caries status of the children, participated in the test group were correlated with mutans count (CFU) and Oratest time, caries status were found to be in a statistically significant positive linear relationship with streptococcus mutans count and in a significant negative linear relationship with Oratest time.

Conclusions:

The test proved to be a simple, inexpensive and rapid technique for assessing caries activity since a significant relationship exists clinically with caries status and microbiologically with the streptococcus mutans count of the individual.

Assessment of the effect of probiotic curd consumption on salivary pH and streptococcus mutans counts

BACKGROUND

Antimicrobial methods of controlling dental caries that include probiotic agents can play a valuable role in establishing caries control in children at moderate to high risk for developing dental caries. Several studies have demonstrated the beneficial effects of use of various Probiotic products including curd. The objective of this study was to compare the effect of short-term consumption of probiotic curd containing Lactobacillus acidophilus and normal curd on salivary Streptococcus Mutans counts, as well as salivary pH.

MATERIALS AND METHODS

Forty, caries-free, 10-12 years old children were selected and randomly allocated to two groups. Test Group consisted of 20 children who consumed 200ml of probiotic curd daily for 30 days. Control Group consisted of 20 children who were given 200ml of regular curd for 30 days. Salivary pH and salivary Streptococcus Mutans counts were recorded at baseline and after 30 days and statistically compared using the Student's t-test.

RESULTS

Consumption of probiotic curd resulted in a statistically significant reduction in S. Mutans colony counts (P<0.001) as compared to regular curd. However, there was a slight reduction in pH (P>0.05) in both the groups.

CONCLUSION

Short-term consumption of probiotic curds can reduce oral S. Mutans counts. However, this caused a slight reduction in salivary pH.

Influence of preventive dental treatment on mutans streptococci counts in patients undergoing head and neck radiotherapy

The aim of this study was to evaluate the influence of chlorhexidine gluconate, sodium fluoride and sodium iodine on mutans streptococci counts in saliva of irradiated patients.

MATERIAL AND METHODS

Forty-five patients were separated into three experimental groups and received chlorhexidine (0.12%), sodium fluoride (0.5%) or sodium iodine (2%), which were used daily during radiotherapy and for 6 months after the conclusion of the treatment. In addition, a fourth group, composed by 15 additional oncologic patients, who did not receive the mouthwash or initial dental treatment, constituted the control group. Clinical evaluations were performed in the first visit to dental clinic, after initial dental treatment, immediately before radiotherapy, after radiotherapy and 30, 60, 90 days and 6 months after the conclusion of radiotherapy. After clinical examinations, samples of saliva were inoculated on SB20 selective agar and incubated under anaerobiosis, at 37ºC for 48 h. Total mutans streptococci counts were also evaluated by using real-time PCR, through TaqMan system, with specific primers and probes for S. mutans and S. sobrinus.

RESULTS

All preventive protocols were able to reduce significantly mutans streptococci counts, but chlorhexidine gluconate was the most effective, and induced a significant amelioration of radiotherapy side effects, such as mucositis and candidosis.

CONCLUSION

These results highlights the importance of the initial dental treatment for patients who will be subjected to radiotherapy for head and neck cancer treatment.

In vitro antibacterial efficacy of Vicryl Plus suture (coated Polyglactin 910 with triclosan) using zone of inibition assays

OBJECTIVES

This study evaluates the in vitro antimicrobial efficacy, of an absorbable suture coated with triclosan (Vicryl Plus(®)) against two bacteria, potential responsible for the development of oral diseases: Pseudomonas aeruginosa and Streptococcus mutans.

METHODS

Vicryl Plus 3-0 and Vicryl 3-0 were tested for their efficiency against P. aeruginosa and S. Mutans. 27 segments 10 cm long each, of every suture, have been tested against P. Aeruginosa and S. Mutans respectively. Every sample has been dipped in a broth culture containing pure dried stocks of P. aeruginosa and S. mutans and placed in a Petri dish right after. Four hours later the sutures have been aseptically removed and placed in a selective culture. The incubation time was 18 hours for P. aeruginosa and 43 hours for S. mutans at 37°C. The antimicrobial efficacy of both sutures was performed by measuring the length of the bacteria-free suture segment.

RESULTS

A statistically significant difference between Vicryl Plus 3-0 and Vicryl 3-0 has been observed, with an higher bacterial growth on Vicryl 3-0 for both bacteria (P. aeruginosa and S. mutans).

CONCLUSIONS

Vicryl Plus presented an antibacterial effectiveness in vitro against both P. aeruginosa and S. mutans.