• 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.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.277-283
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• 2019

In this study, low molecular weight chitosan (LC) was added to dental cement liquid at 0, 0.5, 1.0, and 2.0 wt% by weight for surface properties and oral bacteria adhesive of dental cement. The evaluated by net setting time and surface properties of surface energy on the surface roughness. The degree of oral bacterial adhesion was assessed using two strains of oral bacteria, S. mutans and E.coli. The results showed that the setting time at the LC0.5 group increased no statistically difference was observed (p<0.05). The surface roughness statically significant LC2.0 group and oral bacteria adhesion experiment results in contrast to the control group LC0, LC-added experimental group showed a somewhat lower adherent surface statistically significant difference was observed (p<0.05). It seems that this LC proved that surface properties and oral bacteria adhesion effect was demonstrated. Therefore, it was suggest that the additional effects of LC and research on a wide range of substances.

• 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.

• Korean Journal of Microbiology
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• v.21 no.3
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• pp.143-148
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• 1983

The occurrence of PZ-peptidase in Streptococcus sanguis and other oral bacteria was investigated utilizing washed whole cells as the enzyme source and PZ-pentapeptide as its substrate. Under the culture conditions employed in the present study. Streptococcus sanguis strains, fresh isolates as well as laboratory strains, produced a broad range of the enzyme activity (0.5-7.9 unit/mg protein). The strains of both Streptococcus mutans and Lactobacilli showed low levels of activity (0-0.5 unit/mg protein for S. mutans). As compared with the enzyme activities of other bacteria, a moderate range of activity was produced by the strains of Strptococcus mitis nad Strptoccus salivarius. Actinomyces strains, like those of S. sanguis, produced a varying amount of activity (0-9.8 unit/ mg protein). A possible involvement of the oral bacterial PZ-peptidase in the metabolism of human saliva proteins is discussed.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.153-167
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• 2009

The present study was performed to observe the effect of phytoncide on oral normal microflora and the inhibitory effect of the surviving resident oral bacteria on Pr. intermedia. In this study, saliva from each of 20 healthy subjects was treated with 1% phytoncide from Japanese Hinoki (Chamaecyparis obtusa Sieb. et Zucc.). Surviving salivary bacteria were isolated on blood agar plates and identified by 16S rDNA sequencing. In order to select inhibitory isolates against Pr. intermedia, the isolates from the phytoncide-treated saliva were cultured with Pr. intermedia. The results were as follows: 1. Among the 200 surviving resident oral bacterium, 148(74.0%) bacterium inhibit the growth of Pr. intermedia on blood agar plates. 2. The 200 surviving resident oral bacterium were 109 Streptococcus salivarius(54.5%), 25 Streptococcus sanguinis(12.5%), 15 Streptococcus mitis(7.5%). 3. Among the 148 bacteria which inhibit Pr. intermedia, Streptococcus salivarius was 85.3%(93/109), Streptococcus sanguinis was 64.0%.(16/25), Streptococcus mitis was 54.3%(8/15), Streptococcus parasanguinis was 66.7%(6/9), and Streptococcus Alactolyticus was 100%(8/8). Taken together, among the surviving resident oral bacterium, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis were mainly observed to inhibit Pr. intermedia. and they may exert an additional inhibitory activity against the periodontopathic bacterium. Therefore, phytoncide can be used for preventing and ceasing the progress of periodontal disease and halitosis, and thus is expect to promote oral health.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.315-322
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• 2021

The purpose of this study was to examine the correlations of oral myofunction and oral environment for the elderly with systemic diseases and to suggest need to improve oral health for the elderly. Data were collected from 64 elderly over the age of 65, from April to June 2019. Data were surveyed on general characteristics, oral myofunction, oral health-related quality of life, oral bacteria. Analysis was performed using PASW Statistics ver 18.0. The subjects were 43.8% systemic diseases, among them 40.6 percent of the people with more than two. The number of functional teeth was 18.6. Age was negatively correlated with functional teeth(r=-.384, p<.01) and tongue pressure (r=-).104, p<.001). Tongue pressure was a positive correlation with lip force(r=.279, p<.05). Age and total number of bacteria was negative correlation(r=-.336, p<.01). The functional teeth and total number of bacteria was positive correlation(r=.551, p<.001). The number of systemic diseases and total number of bacteria was positive correlation(r=.327, p<.01) the analysis of oral myofunction and oral bacteria in older patients with systemic diseases It was meaningful in suggesting a plan to improve oral health for the elderly. A practical policy plan was required to improve the quality of oral health life in a super-aged society.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5675-5682
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• 2014

As oral diseases are developed by mixed infections, not by any single element, an accurate analysis of the causative microorganisms related to dental caries and periodontal diseases is required. In this study, saliva was collected from selected adults to determine if the bacteria that are well known as the causative microorganisms of dental caries and periodontal diseases would be detected in their saliva. In addition, this study examined whether there would be any differences among adults according to age, smoking, drinking and presence or absence of diseases in the distribution of oral bacteria to determine the risk factors for oral bacteria. The study subjects were 120 adults ranging in age from 20 to 65 years. The experiment data was collected from March 15, to May 2014. The gDNA was collected from the saliva, and the distribution of bacteria for oral diseases was investigated by PCR. The findings of the study were as follows. S. mutans was detected from 72 adults, and P. intermedia was detected from 88 adults. Both bacteria were detected from 54 adults, and no oral bacteria was detected in 14 adults. An analysis of the risk factors of oral bacteria showed that smokers had a 2.8-fold higher risk of S. mutans than nonsmokers, and the former had a 3.5-fold higher risk of P. intermedia than the latter. Drinkers had a 3.3-fold higher risk of S. mutans than nondrinkers. Patients who suffered from systemic diseases had a 4.1-fold higher risk of P. intermedia than those with no diseases. Therefore, smoking, drinking and systemic diseases are factors that increase the likelihood of oral bacteria detection. More periodontal disease bacteria were detected from older adults, and more oral bacteria were found in adults who were in their 20s, as dental caries and periodontal diseases were more common in this age group. The adults in which oral bacteria were detected are more likely to have dental caries or periodontal diseases, and they should try to keep their mouth cavity clean and make regular visits to a dental clinic to prevent possible oral diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.537-545
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• 2016

This research examined the oral environmental factors to identify the risk factors for oral bacteria detection. This study comprised of 60 office workers aged between 20 and 65 years, and was performed from January 15 to February 28, 2015. The study variables measured were the stimulated and unstimulated salivary flow rates, salivary buffering, saliva pH, dry mouth at the dorsum of the tongue and the sublingual region, halitosis, and the degree of tongue-coating as oral environmental factors. To identify the presence of oral bacteria, pathogens were detected by extracting the gDNA of the resting salivary flow rate. The risk of S.mutans detection was 15 times higher with smokers, 1.3~1.6 times higher when the resting or stimulated salivary flow rate was reduced by 1 mm. The risk of P.intermedia detection was 13 times higher in smokers, 4.3 times higher as the severity of oral dryness was lowered, and 4 times higher for adults with a tongue coating than those without. In addition, the risk of detecting TM7 was 5.5 times higher as sublingual dryness was decreased by 1mm. The oral bacterial count will be reduced considerably by smoking cessation education and habits that facilitate a salivary flow rate. Furthermore, adults with good and well-managed dental hygiene are anticipated to have less oral bacteria and fewer dental diseases.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.306-312
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• 2016

Gargle solution has typically been used for the prevention of oral infectious disease such as dental caries and periodontitis. However, the use of most gargle solutions is controversial in application for children because some gargle solutions have harmful side effects. Electrolyzed water is generated by passed an electric current and has antimicrobial activity. The purpose of this study was to investigate and compare the efficacy of electrolyzed water in various conditions for eliminating cariogenic bacteria. Electrolyzed water was generated by a platinum electrode in the presence of sodium chloride at various concentrations. Streptococcus mutans and Streptococcus sobrinus were cultivated into a brain heart infusion broth. After harvesting planktonic bacteria, the pellets were treated with the electrolyzed water and commercial gargle solutions and plated on a mitis-salivarius agar plate. Also, the anti-biofilm activity of the electrolyzed water and commercial gargle solutions was investigated after biofilm formation of S. mutans and S. sobrinus. The bacteria in the biofilm were plated onto a mitis-salivarius agar plate. The plates were incubated, and the colony forming unit was measured. The electrolyzed water containing sodium chloride showed significant antibacterial activity against S. mutans and S. sobrinus as well as some gargle solutions. Furthermore, the electrolyzed water had more disruptive effect on the biofilm of S. mutans and S. sobrinus and killed more bacteria in the biofilm than commercial gargle solutions. The results demonstrate that electrolyzed water may be a useful gargle solution for prevention of dental caries.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.213-221
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• 2013

The mouth rinsing solution currently on the market is used for oral hygiene and reduction of halitosis, and alkaline ionized water is used for drinking purposes. The aim of this germiculture and observation through a microscope is to investigate the effect they have on the oral bacteria, and the results are as follows. 1. The change in the number of cultivated bacteria before and after the use of gargle was most dramatic for Hexamedin. It showed the highest rate of decrease in bacteria by 71.29%, followed by Listerine with 62.25%, Caregargle with 42.26%, Garglin with 33.52%, saline solution with 21.62%, alkaline ionized water with 16.08% and distilled water with 7.67%. 2. After careful analysis of statistics, Hexamedin was found to result in a significant decrease in the number of bacteria after gargling (p<0.05). 3. From observing through an light microscope after gram staining, it was evident that both a number of cocci and a few of filamentous were present before the use of gargle, whereas mostly cocci was present after the use of gargle. 4. The difference in the pH of oral rinses and alkaline ionized water had no significant influence on the number of oral bacteria. In conclusion, Hexamedin and Listerine, with the rate of decrease of bacteria of co71.29% and 62.25% respectively, have proven to be highly effective when applied before dental treatment. Other oral rinses and alkaline ionized water are relatively less efficient in decreasing the number of oral bacteria. Also, the decrease of bacteria is more affected by the antibacterial component of oral rinses than by the change in pH.