• The Journal of Advanced Prosthodontics
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• v.6 no.3
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• pp.207-214
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• 2014

PURPOSE. This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material. MATERIALS AND METHODS. Polymerized PMMA denture acrylic disc ($20mm{\times}2mm$) specimens containing 0 (control), 10, 50, 100 and 200 mg/L of PtN were fabricated respectively. The obtained platinum-PMMA nanocomposite (PtNC) was characterized by TEM (transmission electron microscopy), SEM/EDX (scanning electron microscope/energy dispersive X-ray spectroscopy), thermogravimetric and atomic absorption spectrophotometer analysis. In antimicrobial assay, specimens were placed on the cell culture plate, and $100{\mu}L$ of microbial suspensions of S. mutans (Streptococcus mutans) and S. sobrinus (Streptococcus sobrinus) were inoculated then incubated at $37^{\circ}C$ for 24 hours. The bacterial attachment was tested by FACS (fluorescence-activated cell sorting) analysis after staining with fluorescent probe. RESULTS. PtN were successfully loaded and uniformly immobilized into PMMA denture acrylic with a proper thermal stability and similar surface morphology as compared to control. PtNC expressed significant bacterial anti-adherent effect rather than bactericidal effect above 50 mg/L PtN loaded when compared to pristine PMMA (P=.01) with no or extremely small amounts of Pt ion eluted. CONCLUSION. This is the first report on the synthesis and its antibacterial activity of Pt-PMMA nanocomposite. PMMA denture acrylic loading PtN could be a possible intrinsic antimicrobial denture material with proper mechanical characteristics, meeting those specified for denture bases. For clinical application, future studies including biocompatibility, color stability and warranting the long-term effect were still required.

• Journal of Pharmacopuncture
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• v.26 no.1
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• pp.44-52
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• 2023

Objectives: Dental caries is one of the most prevalent human diseases worldwide. The disease initiates with bacterial adherence to the tooth surface followed by the formation of dental plaques. Mutans streptococci and Candida albicans are principal oral microorganisms involved in the initiation and development of dental caries. Phytochemicals have been shown to possess promising antimicrobial properties against a wide range of microorganisms and can be used for the prevention and treatment of dental caries. Herein, we reviewed literature on plants that are traditionally used for their antimicrobial properties or possess promising anticariogenic activity. We selected aerial parts of Scrophularia striata (S. striata) and galls of Quercus infectoria (Q. infectoria) and investigated their antimicrobial activity against cariogenic microorganisms. Methods: Water soluble fractions were obtained from hydroalcoholic extracts of S. striata and Q. infectoria and their antimicrobial activity against Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), and Candida albicans (C. albicans) was evaluated separately and in combination. The extracts were then used for preparing an herbal mouthwash whose stability and tannic acid content were evaluated over 60 days. Results: Q. infectoria gall extract possesses efficient antimicrobial activity that was synergistically enhanced in the presence of S. striata extract. Mouthwash prepared using these extracts showed desirable organoleptic characteristics, antimicrobial activity, and stability. Conclusion: Extracts of S. striata and Q. infectoria galls can be used together for preparing dental products with effective anticariogenic properties. Our study highlights the importance of extensive pharmacological investigations when using herbal products alone or in combination with other chemical substances.

• Journal of Korean society of Dental Hygiene
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• v.14 no.1
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• pp.117-122
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• 2014

Objectives : The purpose of the study is to investigate the activities of Nelumbo nucifera leaf extracts on Streptococcus mutans, Streptococcus mitis, Streptococcus sobrinus, Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola. Methods : The inhibitory effect of lotus leaf extracts on the growth of oral bacteria was assessed in experiments with extracts from freshly harvested and pulverized lotus leaves and bacterial cultures of dental caries. Results : The results showed that N. nucifera extracts possess antimicrobial activity on all bacterial strains. The minimal inhibitory concentration (MIC) values varied from 4 mg/ml to 10 mg/ml against antimicrobial activity. The relative growth ratio (RGR) against of N. nucifera extracts were determined as 50% in concentration of 4.0 mg/ml. The extract of N. nucifera was effective in reducing on the glucosyltransferase (GTase) activity of six strains in vitro. Conclusions : Methanol extracts of lotus leaves showed antimicrobial effects on three bacterial species causing dental caries and three bacterial species causing periodontitis, as well as inhibitory effects on GTase activity.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.493-504
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• 2017

Objectives: This study aimed to find out the antimicrobial activities of Ramaria botrytis (Fr.) extracts against oral pathogens. Methods: The antimicrobial activities of Ramaria botrytis (Fr.) extracts were evaluated against oral pathogens by the disc diffusion assay, and the minimum inhibitory concentrations (MICs) of ethyl acetate extracts were determined by broth dilution method. The strains used in this study were Staphylococcus aureus, Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus, Streptococcus anginosus, Streptococcus ratti, Streptococcus criceti, Actinomyces israelii, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. Results: The ethyl acetate extract of Ramaria botrytis (Fr.) effectively inhibited the growth of oral bacteria compared with acetone or ethanol extract. The ethyl acetate extract exhibited MIC values ranging from 3.75 to 15.00 mg/ml, and it showed antimicrobial activity against both Gram-positive and negative oral bacteria. Conclusions: The ethyl acetate extracts from Ramaria botrytis (Fr.) showed the antimicrobial activities against ten oral bacteria. Thus, the extract of Ramaria botrytis (Fr.) may be considered as an effective natural antimicrobial agent for the prevention of oral pathogens.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.447-456
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• 2006

In this study, the antimicrobial effects of Horseradish (Armoracia rusticana) root extracts against oral pathogens were investigated, and also compared with that of chlorhexidine. The following 7 microorganisms were used in this study, Streptococcus mutans ATCC 25175, Streptococcus sobrinus(d) ATCC 27607, Lactobacillus casei ATCC 393, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Actinobacillus actinomycetemcomitans ATCC 29522. Candida albicans ATCC 10261. Horseradish root extracts and chlorhexidine were tested to determine their minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC). The results of this study can be summarized as follows : 1. Horseradish root extracts showed antimicrobial effect against the tested oral pathogens. MIC and MBC of this extracts were 30-125, 125-500ppm, respectively. Especially, it was the most effective against C. albicans of other tested microorganisms. 2. Chlorhexidine also showed antimicrobial effect against the tested oral pathogens. MIC of chlorhexidine range between 0.15 and 2.5%, MBC are 0.4-2.5%. In conclusion, it was suggested that AIT had similar antimicrobial effects in the lower concentration, compared with that of chlorhexidine.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.200-206
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• 2010

In this study, we investigated the antibacterial effect of 69 oriental medicinal herbs (OMHs) on Actinomyces viscocus, Streptococcus sobrinus, and two strains of Streptococcus mutans as oral bacteria. Methanol extracts of OMHs were used in the first antibacterial test, and then boiled water, ethanol, methanol, and ethyl acetate extracts of C. japonica, C. sappan, P. mume, and S. chinensis were used in the second test. Boiled water extract of C. japonica was shown to have the most superior effect on oral bacteria. The extract yield of boiled water extract of C. japonica was 22%, and the growth of oral bacteria was almost inhibited at over a 180 mg/ml concentration. Antibacterial effect compound analyzed by UPLC method was identified as berberine, and the content was 25.54%. In addition, the extract appeared to be stable at $121^{\circ}C$ for 15 min.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.684-695
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• 2003

The aim of this study was to investigate the effect of composite resin components on proliferation and glucan synthesis by cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus. Light curing pit and fissure sealant was chosen for evluation. Specimens were eluted in deionized water for 10 minutes, 1, 12, and 24 hours. Extracts of specimens were diluted into 1/2, 1/4, and 1/8 with addition of BHI broth and BHI-YS. Bacteria were cultured in media included eluted components, and measured optical density($A_{600}$). The following results were obtained 1. 1/4 concentration of elutes for 10 minutes significantly inhibited the proliferation of S. mutans, whereas 1/2, 1/8 concentration of elutes stimulated it. Also, exacts, especially 1/2, 1/4 concentration, for 1 hours stimulated it. But exacts for 12, 24 hours had not effects on the proliferation of S. mutans. 2. 1/4 concentration of elutes for 10 minutes inhibited growth of S. sobrinus, whereas extracts for 1, 12, 24 hours had not effects on the proliferation of S. sobrinuss. 3. Extracts from composite resin stimulated total growth of S. mutans more than growth control group, where as inhibited it of S. sobrinus. 4. Extracts from composite resin, especially 1/4 concentration of it for 10 minutes increased the formation of water insoluble glucan of S. mutans. But elutes for 1, 12, 24 hours, and 1/8 concentration of it for 10 minutes inhibited it. 5. Except 1/4 concentration of elutes for 10 minutes, extracts decreased the formation of water insoluble glucan of S. sobrinus. 6. Total amount of formated glucan was 3-fold higher in S. mutans than in S. sobrinus.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.364-366
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• 2004

The purpose of this work was to investigate the effect oftea catechin, epigallocatechin gallate (EGCG) on killing of oral bacteria. The antibacterial activity of 2.5 mg/ml and 5.0 mg/ml EGCG was investigated for target bacteria of which initial cell number was approximately adjusted to $10^{7}ml$. The antibacterial activity of EGCG was proportional to the concentration according to colony-forming unit(CFU) of target bacteria enumerating on selective and complex media. Streptococcus mutans and Streptococcus sobrinus at 5mg/ml EGCG were completely killed within 8 hrs. Lactobacillus plantarum and Lactobacillus acidophilus were also killed within 2 hrs and 4 hrs under the same conditions, respectively. Oral bacteria at 2.5 mg/ml EGCG were completely killed within 10 hr. Colony numvers of S. mitis and S. salivarius treated with 2.5 mg/ml EGCG were decreased on MS solid media and no colony was observed on the media within 12 hrs. In consequence, EGCG would be a natural and effective compound that kill oral bacteria being caused of bad breath, plaque and gingivitis, and for preventing and treating dental caries.

• Journal of dental hygiene science
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• v.18 no.3
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• pp.147-154
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• 2018

This study aimed to evaluate the antimicrobial effects of Acanthopanax sessiliflorum fruit (ASF; Ogaza) extracts on Streptococcus mutans and Streptococcus sobrinus, which are agents that cause dental caries, and on Streptococcus mitis and Streptococcus salivarius, the microbial flora of the oral cavity. The ASF extracts obtained using 70% ethanol were fractionated in the order of ethyl acetate and n-Butanol, concentrated under reduced pressure, and lyophilized to give powdery solvent extracts. The antimicrobial activity of ASF extracts from each solvent was examined using the disk diffusion method. As a result, only those extracts obtained using an ethyl acetate solvent showed antimicrobial activity. These extracts were selected, and the minimum inhibitory concentration was measured by disk diffusion method at various extract concentrations. Results showed a minimum inhibitory concentration of 32 mg/ml. The viable cell count was measured to confirm the minimum bactericidal concentration. Results showed a minimum bactericidal concentration of 64 mg/ml. In the cytotoxicity test using normal human dermal fibroblast cells, the absorbance value of the test group was similar to that of the control group at 0.64, 1.28, and 6.4 mg/ml. The bacteria and their colonies were examined using a scanning electron microscope. Boundaries between the antimicrobial activity region and non-antimicrobial activity region were observed around the paper disk, which was immersed in the extract with 32 mg/ml concentration. Bacterial colonization was not observed in the area with antimicrobial activity. This finding suggests that ASF extracts can inhibit the growth of some microorganisms in the oral cavity, in addition to the effects of these extracts known to date. In particular, ASF extracts may be used as a preparation for preventing dental caries by adding the extract to the toothpaste or oral mouthwash.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.217-223
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• 2017

PURPOSE. This study investigated the effects of silver nanoparticle (SN) loading into hydraulic calcium silicate-based Portland cement on its mechanical, antibacterial behavior and biocompatibility as a novel dental bone substitute. MATERIALS AND METHODS. Chemically reduced colloidal SN were combined with Portland cement (PC) by the concentrations of 0 (control), 1.0, 3.0, and 5.0 wt%. The physico-mechanical properties of silver-Portland cement nanocomposites (SPNC) were investigated through X-ray diffraction (XRD), setting time, compressive strength, solubility, and silver ion elution. Antimicrobial properties of SPNC were tested by agar diffusion against Streptococcus mutans and Streptococcus sobrinus. Cytotoxic evaluation for human gingival fibroblast (HGF) was performed by MTS assay. RESULTS. XRD certified that SN was successfully impregnated in PC. SPNC at above 3.0 wt% significantly reduced both initial and final setting times compared to control PC. No statistical differences of the compressive strength values were detected after SN loadings, and solubility rates of SPNC were below 3.0%, which are acceptable by ADA guidelines. Ag ion elutions from SPNC were confirmed with dose-dependence on the concentrations of SN added. SPNC of 5.0 wt% inhibited the growth of Streptococci, whereas no antimicrobial activity was shown in control PC. SPNC revealed no cytotoxic effects to HGF following ISO 10993 (cell viability > 70%). CONCLUSION. Addition of SN promoted the antibacterial activity and favored the bio-mechanical properties of PC; thus, SPNC could be a candidate for the futuristic dental biomaterial. For clinical warrant, further studies including the inhibitory mechanism, in vivo and long-term researches are still required.