• International Journal of Oral Biology
• /
• v.41 no.1
• /
• pp.39-43
• /
• 2016

Dental caries, the most common oral disease, is a multifactorial disease caused by interactions among bacteria within the dental plaque, food, and saliva, resulting in tooth destruction. Streptococcus mutans has been strongly implicated as the causative organism in dental caries and is frequently isolated from human dental plaque. Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. Postantibiotic effect (PAE) is defined as the duration of suppressed bacterial growth following brief exposure to an antibiotic. In this study, the in vitro PAE of PDT using erythrosine and light emitting diode on S. mutans ATCC 25175 was investigated. The PAE of PDT for 1 s irradiation and 3 s irradiation were 1.65 h and 2.1 h, respectively. The present study thus confirmed PAE of PDT using erythrosine on S. mutans.

• Microbiology and Biotechnology Letters
• /
• v.51 no.1
• /
• pp.32-36
• /
• 2023

In this study, the effect of sodium hypochlorite on biofilm removal was evaluated using three bacterial strains; Aeromonas hydrophila, Streptococcus mutans, and Yersinia enterocolitica. For maximum biofilm removal in 10 min, sodium hypochlorite is required at 1.65, 0.83, and 0.41 g/l for A. hydrophila, S. mutans, and Y. enterocolitica, respectively. Resistance to sodium hypochlorite was increased by the biofilms of all three tested strains, while the change in bactericidal activity according to sodium hypochlorite concentration was strain-specific. Therefore, we aimed to determine the effective concentration of sodium hypochlorite required for hygiene, considering that higher concentrations are needed to remove biofilms than to kill cells.

• Restorative Dentistry and Endodontics
• /
• v.19 no.2
• /
• pp.372-383
• /
• 1994

Saliva plays an important role in modulating the oral microbial ecology. And it is suggested to influence the initiation and progression of the dental caries. To evaluate the correlations between the salivary antimicrobial agents and the caries susceptibility, the 51 subjects were divided into 3 groups according to caries experience ; caries resistant group, medium caries susceptible group, and high caries susceptible group. Stimulated whole saliva was collected, and the salivary levels were measured for lysozyme, lactoferrin, and secretory-IgA to Streptococcus mutans. The lysozyme level was estimated using Micrococcus diffusion plate, lactoferrin level was determined with a non-competitive avidin-biotin enzyme immunoassay, and the titer of secretory IgA to Streptococcus mutans was assayed with ELISA. The results were as follows: 1. Lysozyme levels of each group showed no significant difference statistically (p>0.05). 2. The caries resistant group and the medium caries susceptible group had significantly higher levels of lactoferrin than the high caries susceptible group (p<0.05). But no clear difference was observed between the caries resistant group and the medium caries susceptible group(p>0.05). 3. The caries resistant group and the medium caries susceptible group showed relatively higher levels of the secretory IgA to Streptococcus mutans than the pigh caries susceptible group, but no significant difference was observed statistically (p>0.05).

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.1
• /
• pp.65-81
• /
• 1997

For the purpose of evaluating the appropriateness of AP-PCR as a facile, rapid and reproducible method for genotyping Streptococcus mutans, and selecting the discriminant primer for it, a DNA fingerprinting was performed on the microorganisms isolated from caries-free children and children with rampant caries, respectively. In the course of selecting appropriate primer for S. mutans genotyping, we chose S2 primer from 6 different primers which shows highest resolution on the agarose gel as well. Nineteen kinds of fingerprint patterns were observed in caries-free children and children with rampant caries which were produced by combination of 7 different fragments. Interestingly, the number of types observed in caries-free children was greater than that in children with rampant caries. And we observed Type 2 was predominant in children with rampant caries (about 80%) and relatively even distribution of each types in caries-free children. Furthermore, it was appeared that the major types in normal control were not or rarely found in children with rampant caries. In conclusion, we could establish simple, rapid and highly reproducible AP-PCR method for genotyping S. mutans. We also found differences in distribution of S. mutans between normal and patient, which suggested that cariogenicity is also dependent on qualitative aspects which is caused by the difference in genotypes of S. mutans in oral cavity.

• Journal of Korean society of Dental Hygiene
• /
• v.14 no.1
• /
• pp.95-100
• /
• 2014

Objectives : The purpose of the present study was to investigate the effect of bamboo charcoal on Streptococcus mutans which is one of the most important causative agents of dental caries. Methods : S. mutans was incubated with or without bamboo charcoal and then changes were observed in its cell viability and antibacterial effect. Oral epithelial cells viabillity(human gingival fibroblast, HGF) was performed using MTT assay. Antibacterial effect was analyzed using a dilution plating method and agar diffusion method. Results : Oral epithelial cells, human gingival fibroblast (HGF) showed a tendency to increase in bamboo charcoal treatment solution concentrations(0.5, 1, 2, 3, 5, 10%). The bamboo charcoal had an antibacterial effect on S. mutans. Antibacterial effect of bamboo charcoal for the bacterium was 58%. Charcoal concentration of 2% and 5% in the inhibition zone showed a minimal growth, but the concentration of 10% bamboo charcoal in inhibition zone revealed a conspicuous antibacterial activity. Conclusions : Overall results suggested that the bamboo charcoal proved to be bactericidal effect on S. mutans.

• Journal of Technologic Dentistry
• /
• v.23 no.1
• /
• pp.75-83
• /
• 2001

This study was conducted to find antibacterial agent against growth of dental caries bacteria. St. mutans KDJ-50 from various medicinal plants of which safety was indetified. Medicinal plants used in this study was dried and grinded after purchased at Daegu yakryung sijang and Kyungsan jungang sijang. Medicinal plants extracted with 80% ethanol at boiling point for 3 hrs was used as antibacterial agent after freeze dried. This study was conducted to find antibacterial agent against growth of dental caries bacteria. St. mutans KDJ-50 from 32 medicinal plants of which safety was indetified. The result of using paper disc method. Caryophylli Flos. Coptidis Rhizoma. Phellodendri Cortex. Schizamdrae Fructs. Myristicae Semen, Crataegi Fructus and Acori Graminei Rhizoma was selected as antibacterial agent. The result of viable cell counting method. the antibacterial activity of Caryophylli Flos was highest among tested 7 medicinal plants followed by Phellodendri Cortex and Coptidis Rhizoma. The extinction effect of the St. mutans by Caryophylli Flos was shown with the addition of 0.5 (w/v) in the medium. The high antibacterial activity was acquired at high extraction temperature and long extraction temperature. The antibacterial activity of Caryophylli Flos was not effected by the concentration of ethanol.

• International Journal of Oral Biology
• /
• v.43 no.1
• /
• pp.37-42
• /
• 2018

It is noted that Streptococcus mutans (S. mutans) triggers dental caries establishment by two major factors: the synthesis of organic acids, which demineralize dental enamel, and the synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Therefore, it is noted that the development of a more effective, substantial and safe preventive agent that works against dental caries and periodontal disease is required at this time. For this reason, the present study was designed to investigate the effect of croton seed ethanol extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. In this case, the ethanol extract of croton seed showed concentration dependent inhibitory activity against the growth, acid production and adhesion of S. mutans. Especially, it is important to note that it has produced significant inhibition at the concentration of 0.1 and 0.2 mg/ml as compared to the control group. Moreover, these results suggest that the application of croton seed extract may be considered to be a useful method for the prevention of dental caries.

• Journal of Applied Biological Chemistry
• /
• v.65 no.4
• /
• pp.337-341
• /
• 2022

In this study, the effect of the combined use of a lipid-soluble n-hexane extract of red ginseng marc (HERGM) and water-soluble arginine, which exhibits anticaries activity, on the growth of Streptococccus mutans was investigated. As a result of checkerboard assay, HERGM and arginine showed a synergistic effect in inhibiting the growth of S. mutans with a fractional inhibitory concentration index of 0.396. Combination treatments of HERGM and arginine resulted in leakage of nucleic acid components and decrease in the viable cell counts of S. mutans, all of which were proportional to the concentration of HERGM. In conclusion, the synergistic effect of HERGM and arginine on the growth inhibition of S. mutans is mainly attributed to HERGM.

• International Journal of Oral Biology
• /
• v.41 no.4
• /
• pp.253-262
• /
• 2016

Streptococcus mutans (S. mutans) is one of the most important bacteria in the formation of dental plaque and dental caries. S. mutans adheres to an acquired pellicle formed on the tooth surface, and aggregates with many oral bacteria. It initiates plaque formation by synthesizing glucan from sucrose, which is catalyzed by glucosyltransferases. Propolis is a resinous mixture produced by honeybees, by mixing saliva and beeswax with secretions gathered from wood sap and flower pollen. Bees prevent pathogenic invasions by coating the propolis to the outer and inner surface of the honeycomb. Propolis has traditionally been used for the treatment of allergic rhinitis, asthma and dermatitis. We investigated the inhibitory effects of propolis ethanol extract on biofilm formation and gene expression of S. mutans. The biofilm formation of S. mutans was determined by scanning electron microscopy (SEM) and safranin staining. We observed that the extract of propolis had an inhibitory effect on the formation of S. mutans biofilms at concentrations higher than 0.2 mg/ml. Real-time PCR analysis showed that the gene expression of biofilm formation, such as gbpB, spaP, brpA, relA and vicR of S. mutans, was significantly decreased in a dose dependent manner. The ethanol extract of propolis showed concentration dependent growth inhibition of S. mutans, and significant inhibition of acid production at concentrations of 0.025, 0.05, 0.1 and 0.2 mg/ml, compared to the control group. These results suggest that the ethanol extract of propolis inhibits gene expression related to biofilm formation in S. mutans.

• Food Science of Animal Resources
• /
• v.40 no.6
• /
• pp.1001-1013
• /
• 2020

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