• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.1-11
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• 2009

Essential oils are mixture of volatile, lipophilic compounds originating from plants. Essential oils have potential biological effects, i.e., antibacterial, antifungal, spasmolytic and antiplasmodial activities and insect-repellent property. In this study, five essential oils, namely R, LG, FR, O, and NM, extracted from various aromatic plants were used to test their antimicrobial activity against the oral microorganisms. The effects of essential oils were investigated against eight important bacteria, Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus), Streptococcus sanguis (S. sanguis), Streptococcus anginosus (S. anginosus), Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), Streptococcus sobrinus (S. sobrinus), Staphylococcus epidermidis (S. epidermidis), and Escherichia coli (E. coli). Essential oils, except NM, effectively inhibited the growth of tested oral pathogenic microorganisms dose-dependently. However, the essential oils didn't show a significant inhibitory effect against E. coli and S. epidermidis. Consequently, these results represented that essential oil-mediated anti-microbial activity was prominent against the oral pathogenic bacteria. For example, minimum bactericidal concentration(MBC) of R, LG, FR oil against A. actinomycetemcomitans was very low as 0.078 mg/mL. In addition, minimum inhibitory concentration (MIC) of R, LG, FR, O oil against S. mutans was low as 0.156 mg/mL in vitro.

• Journal of Life Science
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• v.31 no.1
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• pp.100-108
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• 2021

In the oral cavity, there are hundreds of microbial species that exist as planktonic cells or are incorporated into biofilms. The accumulation and proliferation of pathogenic bacteria in the oral biofilm can lead to caries and periodontitis, which are typical oral diseases. The oral bacteria in the biofilm not only can resist environmental stress inside the oral cavity, but also have a 1,000 times higher resistance to antibiotics than planktonic cells by genes exchange through the interaction between cells in the oral biofilm. Therefore, if the formation of oral biofilm is suppressed or removed, oral diseases caused by bacterial infection can be more effectively prevented or treated. In particular, since oral biofilms have the characteristic of forming a biofilm by gathering several bacteria, quorum sensing, a signaling system between cells, can be a target for controlling the oral biofilm. In addition, a method of inhibiting biofilm formation by using arginine, an alkali-producing substrate of oral bacteria, is used to convert the distribution of oral microorganisms into an environment similar to that of healthy teeth or inhibit the secretion of glucosyltransferase by S. mutans to inhibit the formation of non-soluble glucans. It can be a target to control oral biofilm. This method of inhibiting or removing the oral biofilm formation rather than inducing the death of pathogenic bacteria in the oral cavity will be a new strategy that can selectively prevent or therapeutic avenues for oral diseases including dental caries.

• Genomics & Informatics
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• v.21 no.1
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• pp.13.1-13.8
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• 2023

Importance of accurate molecular diagnosis and quantification of particular disease-related pathogenic microorganisms is highlighted as an introductory step to prevent and care for diseases. In this study, we designed a primer/probe set for quantitative real-time polymerase chain reaction (qRT-PCR) targeting rgpA gene, known as the specific virulence factor of periodontitis-related pathogenic bacteria 'Porphyromonas gingivalis', and evaluated its diagnostic efficiency by detecting and quantifying relative bacterial load of P. gingivalis within saliva samples collected from clinical subjects. As a result of qRT-PCR, we confirmed that relative bacterial load of P. gingivalis was detected and quantified within all samples of positive control and periodontitis groups. On the contrary, negative results were confirmed in both negative control and healthy groups. Additionally, as a result of comparison with next-generation sequencing (NGS)-based 16S metagenome profiling data, we confirmed relative bacterial load of P. gingivalis, which was not identified on bacterial classification table created through 16S microbiome analysis, in qRT-PCR results. It showed that an approach to quantifying specific microorganisms by applying qRT-PCR method could solve microbial misclassification issues at species level of an NGS-based 16S microbiome study. In this respect, we suggest that P. gingivalis-specific primer/probe set introduced in present study has efficient applicability in various oral healthcare industries, including periodontitis-related microbial molecular diagnosis field.

• International Journal of Oral Biology
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• v.39 no.3
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• pp.137-143
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• 2014

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.653-657
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• 2022

Oral disease causes a significant health and economic burden worldwide, significantly reducing people's quality of life. Dental caries, a representative oral disease, is caused by S. mutans. Oral pathogenic microorganisms contain lipopolysaccharide (LPS), which can cause an immune response and cause various oral diseases. The purpose of this study was to investigate the antioxidant and antibacterial effects of bamboo leaf extract (BLE) to control oral diseases. THP-1, oral fibroblasts, and S mutans culture medium were treated with bamboo leaf extract at different concentrations of 0-8% to conduct the experiment.. As a result, the antioxidant effect according to the BLE concentration was confirmed in mononuclear cell lines and oral fibroblasts. In addition, the antibacterial effect of S. mutans according to the BLE concentration was demonstrated. Therefore, BLE can be used for the prevention or treatment of oral diseases.

• IMMUNE NETWORK
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• v.12 no.5
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• pp.165-175
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• 2012

Vaccination is one of the most effective methods available to prevent infectious diseases. Mucosa, which are exposed to heavy loads of commensal and pathogenic microorganisms, are one of the first areas where infections are established, and therefore have frontline status in immunity, making mucosa ideal sites for vaccine application. Moreover, vaccination through the mucosal immune system could induce effective systemic immune responses together with mucosal immunity in contrast to parenteral vaccination, which is a poor inducer of effective immunity at mucosal surfaces. Among mucosal vaccines, oral mucosal vaccines have the advantages of ease and low cost of vaccine administration. The oral mucosal immune system, however, is generally recognized as poorly immunogenic due to the frequent induction of tolerance against orally-introduced antigens. Consequently, a prerequisite for successful mucosal vaccination is that the orally introduced antigen should be transported across the mucosal surface into the mucosa-associated lymphoid tissue (MALT). In particular, M cells are responsible for antigen up-take into MALT, and the rapid and effective transcytotic activity of M cells makes them an attractive target for mucosal vaccine delivery, although simple transport of the antigen into M cells does not guarantee the induction of specific immune responses. Consequently, development of mucosal vaccine adjuvants based on an understanding of the biology of M cells has attracted much research interest. Here, we review the characteristics of the oral mucosal immune system and delineate strategies to design effective oral mucosal vaccines with an emphasis on mucosal vaccine adjuvants.

• Journal of Korean society of Dental Hygiene
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• v.17 no.1
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• pp.155-168
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• 2017

Objectives: The purpose of this research is to examine oral pathogen distribution among elderly with dementia in a care facility to understand the importance of preventively managing oral diseases in terms of preventively managing senile diseases. Methods: From 11th August 2015 to 11th October 2015, gingival crevicular fluid was collected from 130 subjects consisting of demented/non-demented elderly people aged above 65 in care facilities located in the regions of Busan/Gyeonggnam. Based on collected data, real-time PCR analysis on oral pathogen was conducted. Results: The demented elderly group consisting of female patients aged from 0 to 79 indicated higher ratios of T. denticola in comparison to the non-demented elderly group, and the demented elderly group consisting of female patients aged above 80 indicated a high ratio of S. mutans. It was confirmed that P. gingivalis and T. forsythensis categorized under the red complex are correlated, and that bacterial species categorized under the orange complex and bacterial species categorized under the red complex are correlated. Conclusions: Because eldery people with demntia are exposed to periodontal disease and dental caries, their oral environments are more vulnerable. In order to improve such environments, it is necessary to provide care facility personnel with an opportunity to receive education to become aware of the importance of oral health, and it is also necessary to compulsorily assign dental hygienists to care facilities so that they can serve as personnel specializing in oral health management.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.454-459
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• 2020

The main cause of oral disease is the formation of tooth surface bacteria, and a chemical mouthwash is used as a suppression method. However, chemical preparations have side effects, so we tried to verify the antibacterial effect of bamboo extract against oral microbes. Subjects were 15 college students as a control group and an experimental group, and the changes in oral microbes before and after the use of distilled water and bamboo extract were compared. Analysis of SPSS Windows ver. 20.0 was used (p<0.05). Results The total number of pathogenic microorganisms further decreased after using bamboo extract solution after using gargling solution between groups.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.291-297
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• 2015

An oral environment is constantly exposed to environmental factors and microorganisms. The periodontal ligament (PDL) fibroblasts within this environment are subject to bacterial infection and allergic reaction. However, how these condition affect PDL fibroblasts has yet to be elucidated. PDL fibroblasts were isolated from healthy donors. We examined using reverse transcription-polymerase chain reaction and measuring the intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$). This study investigated the receptors activated by exogenous bacterial pathogens (Lipopolysaccharide and peptidoglycan) and allergens (German cockroach extract and house dust mite) as well as these pathogenic mediators-induced effects on the intracellular $Ca^{2+}$ signaling in human PDL fibroblasts. Moreover, we evaluated the expression of pro-inflammatory cytokines (interleukin (IL)-$1{\beta}$, IL-6, and IL-8) and bone remodeling mediators (receptor activator of NF-${\kappa}B$ ligand and osteoprotegerin) and intracellular $Ca^{2+}$-involved effect. Bacterial pathogens and allergic mediators induced increased expression of pro-inflammatory cytokines, and these results are dependent on intracellular $Ca^{2+}$. However, bacterial pathogens and allergic mediators did not lead to increased expression of bone remodeling mediators, except lipopolysaccharide-induced effect on receptor activator of NF-${\kappa}B$ ligand expression. These experiments provide evidence that a pathogens and allergens-induced increase in $[Ca^{2+}]_i$ affects the inflammatory response in human PDL fibroblasts.

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.151-156
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• 2007

Antimicrobial action of phytoncide in the mouth decrease odor-producing microorganisms. Also phytoncide has malodor effect by reaction with volatile sulfur compounds. Phytoncide has excellent malodor effect in microbiologically and chemically. This study prove the malodor effect of phytoncide by use ferrous sulfate. So I try to make new treatment method for halitosis. I get the results as follows. 1. The difference of mean value of absorbancy was 0.849 between the mean absorbancy of deposition by add phytoncide to saliva and the saliva only. 2. The difference of mean value of absorbancy was 0.701 between the mean absorbancy of deposition by add phytoncide to distilled water and the distilled water only. 3. The difference of mean value(0.849) in saliva by existence of phytoncide was larger than in double distilled water(0.701) by existence of phytoncide. Therefore, phytoncide make more deposition in saliva than double distilled water by reaction with sulfur compounds. As the results, phytoncide reaction with sulfur compounds in saliva. It take malodor action in liquid state effectively. It is thought, only the toothpaste it knows from in the limit which does not have a side effect by the human body it adds in the oral cavity of the mouth rinse and with the fact that it will be able to use positively in clinic.