• Journal of Korean Academy of Oral Health
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• v.41 no.4
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• pp.290-295
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• 2017

Objectives: Dental plaque emits red fluorescence under a visible blue light near the ultra-violet end of the light spectrum. The fluorescence characteristics of each microorganism have been reported in several studies. The aim of this study was to evaluate changes in red fluorescence of oral microorganisms that is affected by blood in the culture media. Methods: The gram-positive Actinomyces naeslundii (AN, KCTC 5525) and Lactobacillus casei (LC, KCTC 3109) and gram negative Prevotella intermedia (PI, KCTC 3692) that are known to emit red fluorescence were used in this study. Each bacterium was activated in broth and cultivated in different agar media at $37^{\circ}C$ for 7 days. Tryptic soy agar with hemin and vitamin $K_3$ (TSA), TSA with sheep blood (TSAB), basal medium mucin (BMM) medium, and BMM with sheep blood (BMMB) were used in this study. Fluorescence due to bacterial growth was observed under 405-nm wavelength blue light using the quantitative light-induced fluorescence-digital (QLF-D) device. The red, green, and blue fluorescence values of colonies were obtained using image-analysis software and the red to green ratio (R/G value) and red to total RGB ratio (R/RGB value) were calculated for quantitative comparison. Results: The QLF-D images of the AN, LC, and PI colonies showed red fluorescence in all media, but the fluorescence of all bacteria was reduced in TSA and BMM media, compared with in TSAB and BMMB media. Both the R/G and the R/RGB values of all bacteria were significantly reduced in growth media without blood (P<0.001). Conclusions: Based on this in vitro study, it can be concluded that red fluorescence of oral bacteria can be affected by growth components, especially blood. Blood-containing medium could be a significant factor influencing red fluorescence of oral bacteria. It can be further hypothesized that bleeding in the oral cavity can increase the red fluorescence of dental plaque.

• The korean journal of orthodontics
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• v.44 no.3
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• pp.113-118
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• 2014

Objective: The purpose of this in vitro study was to examine the effects of fluoridated, casein phosphopeptide-amorphous calcium phosphate complex (CPP-ACP)-containing, and functionalized ${\beta}$-tricalcium phosphate (fTCP)-containing toothpastes on remineralization of white spot lesions (WSLs) by using Quantitative light-induced fluorescence (QLF-D) Biluminator$^{TM}$ 2. Methods: Forty-eight premolars, extracted for orthodontic reasons from 12 patients, with artificially induced WSLs were randomly and equally assigned to four treatment groups: fluoride (1,000 ppm), CPP-ACP, fTCP (with sodium fluoride), and control (deionized water) groups. Specimens were treated twice daily for 2 weeks and stored in saliva solution (1:1 mixture of artificial and human stimulated saliva) otherwise. QLF-D Biluminator$^{TM}$ 2 was used to measure changes in fluorescence, indicating alterations in the mineral contents of the WSLs, immediately before and after the 2 weeks of treatment. Results: Fluorescence greatly increased in the fTCP and CPP-ACP groups compared with the fluoride and control groups, which did not show significant differences. Conclusions: fTCP- and CPP-ACP-containing toothpastes seem to be more effective in reducing WSLs than 1,000-ppm fluoride-containing toothpastes.

• Journal of Korean society of Dental Hygiene
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• v.19 no.3
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• pp.351-362
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• 2019

Objectives: The study aimed to analyze the factors affecting the maturity of dental biofilm, which was assessed with quantitative light-induced fluorescence-digital(QLF-D), in a sample of Korean older adults. Methods: This cross-sectional study included 67 participants, aged 65 years and older. All participants completed a questionnaire and tests to measure their manual dexterity and handgrip strength, which are parameters that indicate hand function abilities. To evaluate dental biofilm maturity, 804 surfaces of six index teeth were imaged using QLF-D and then quantified as ${\Delta}R$ values. All data were collected from May 25, 2017 to April 30, 2018. The independent t-test, one-way analysis of variance, and step-wise multiple linear regression were performed to analyze the factors associated with the maturity of dental biofilm (${\Delta}R$). Results: The multivariate linear regression analysis revealed that the factor most strongly related to dental biofilm maturity(${\Delta}R$) was manual dexterity (${\beta}=-0.326$), followed by handgrip strength (${\beta}=-0.303$) and use of interdental cleaning devices (${\beta}=-0.283$) (p<0.05). Conclusions: Manual dexterity, handgrip strength, and use of interdental cleaning devices are factors that can predict dental biofilm maturity in adults aged 65 years or older. Therefore, the hand function of a patient should be evaluated first, before assessing the oral hygiene status of the patient or providing him/her with oral health education, and the dental hygienist should provide differentiated oral hygiene care depending on the patient's hand function ability. Finally, dental hygienists should help older adults to recognize the importance of auxiliary oral hygiene devices such as interdental brushes and keep motivating them to use the devices more frequently.

• The Journal of the Korean dental association
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• v.52 no.8
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• pp.472-477
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• 2014

The new paradigm of dentistry require the detection of caries in their earlier stages. To achieve this, a high technology detection device and systematic and organized caries management system are needed. Caries management by risk assessment (CAMBRA) model is representative caries management system that satisfied new paradigm. Dental caries prevention and treatment according to CAMBRA model is patient-centered, risk-based, evidence-based practice. Therefore, individual caries management such as CAMBRA should be performed through accurate assessment of caries disease indicators and comprehensive assessment of caries risk factors and protective factors. Based on the CAMBRA better effectiveness of comprehensive dental caries management including non-surgical treatment will be accomplished.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.202-208
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• 2015

The aim of this retrospective study was to evaluate the relationship between periodontal health condition and the results of a new method such as Cariview which could evaluate the acidity of dental biofilms. Fifty four subjects more than 20 years old were selected for the candidates of this study. The periodontal health conditions of the candidates were divided into 4 groups according to the assessment of X-ray and Quantitative Light-induced Fluorescence-Digital (QLF-D; Inspektor Research Systems BV) images; gingivitis, slight periodontitis, moderate periodontitis, severe periodontitis. The biofilm acidogenicity of each subject was examined using Cariview (All in ONE BIO) according to manufacturer's instruction, and the Cariview score was calculated. The mean differences of Cariview score between 4 groups of periodontal health condition were examined by ANCOVA test with the covariance of decayed, missing, and filled teeth (DMFT) index. As a result, the mean Cariview score was different, however it was not significantly different from the 4 groups (p=0.12). The mean score was the lowest in the gingivitis group ($40.54{\pm}11.01$), and the highest in slight periodontitis group ($57.26{\pm}20.51$). In conclusion, the significant mean differences were not confirmed in Cariview score according to the periodontal health condition.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.34.3-34.3
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• 2020

Faint z ~ 5 quasars with M1450 ~ -23 mag are known to be the potentially important contributors to the ultraviolet ionizing background in the post-reionization era. However, their number density has not been well determined, making it difficult to assess their role in the early ionization of the intergalactic medium (IGM). In this work, we present the updated results of our z ~ 5 quasar survey using the Infrared Medium-deep Survey (IMS), a near-infrared imaging survey covering an area of 85 square degrees. From our spectroscopic observations with the Gemini Multi-Object Spectrograph (GMOS) on the Gemini-South 8 m Telescope, we discovered eight new quasars at z ~ 5 with -26.1 ≤ M1450 ≤ -23.3. Combining our IMS faint quasars with the brighter Sloan Digital Sky Survey (SDSS) quasars, we derive, for the first time, the z ~ 5 quasar luminosity function (QLF) without any fixed parameters down to the magnitude limit of M1450 = -23 mag. We find that the faint-end slope of the QLF is very flat (-1.2) with a characteristic luminosity of -25.7 mag. The number density of z ~ 5 quasars from the QLF gives lower ionizing emissivity and ionizing photon density than those in previous works. These results imply that quasars are responsible for only 10-20% of the photons required to completely ionize the IGM at z ~ 5, disfavoring the idea that quasars alone could have ionized the IGM at z ~ 5.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.3
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• pp.209-217
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• 2015

The purpose of this study was to evaluate the ability of Q-ray view (All-in-one Bio, Seoul, Korea) in detection of proximal caries in primary molars with sound marginal ridges. Thirty two children aged 3-9 years (average $5.6{\pm}1.3$ years old) were chosen, and two examiners evaluated 100 proximal surfaces of primary molars with sound marginal ridges. The teeth were examined with; (a) visual examination, (b) Q-ray view, (c) DIAGNOdent (KaVo, Biberach, Germany) and (d) digital periapical radiography. Kappa statistic was used to assess the agreement between each examination method and the degree of caries progression. The kappa values for enamel caries were 0.15 (visual examination), 0.10 (Q-ray view), 0.25 (DIAGNOdent) and 0.68 (digital periapical radiography). The kappa values for dentinal caries were 0.34 (visual examination), 0.56 (Q-ray view), 0.44 (DIAGNOdent) and 0.70 (digital periapical radiography). Although Q-ray view showed low diagnostic ability in detection of enamel caries, it was effective in detection of hidden proximal caries extended into dentin. Q-ray view would be a useful and simple device which could aid pediatric dentists in detection of hidden proximal caries in primary molars especially when examining uncooperative children or disabled persons.

• Journal of dental hygiene science
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• v.18 no.4
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• pp.265-270
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• 2018

The purpose of this study was to investigate the chemical properties of some commercially available mouthwashes and to ascertain whether the mouthwashes accelerated mineral loss in dental enamel. Five commercially available mouthwashes were selected from the three largest malls in Korea: Perio Total 7 Aqua Cool Mint Strong $Fresh^{TM}$ (PS; LG Household & Health Care Ltd.), Garglin $Original^{TM}$ (Dong-A Pharmaceutical Co., Ltd.), Garglin $Zero^{TM}$ (Dong-A Pharmaceutical Co., Ltd.), Listerine Naturals $Citrus^{TM}$ (LC; IDS Manufacturing Ltd.), and Listerine Cool $Mint^{TM}$ (LM; IDS Manufacturing Ltd.). The composition, pH, and titratable acidity of the mouthwashes were investigated. Six bovine teeth specimens were prepared for each mouthwash group. Each of the six specimens was individually immersed in 30 ml aliquots of mouthwash for 1 minute, 30 minutes, 90 minutes, and 120 minutes, and the samples were placed in a $36.5^{\circ}C$ stirred incubator. The degree of mineral loss (${\Delta}F$) of the tooth surface area exposed to mouthwash, compared with normal teeth, was analyzed by quantitative light-induced fluorescence-digital. The difference in ${\Delta}F$ among mouthwash groups was examined by the Kruskal-Wallis H test (${\alpha}=0.05$). The contents of mouthwashes differed between Listerine and other products, and the pH ranged from 4.09 to 6.75. The titratable acidity of PS was the lowest at 0.63 ml and highest at 9.25 ml for LM. Minor mineral loss was observed when dental specimens were immersed in the Listerine products (LC and LM) for more than 90 minutes, but the degree of mineral loss for Listerine products was not statistically significantly different from that for groups without mineral loss. In conclusion, all five commercially available mouthwashes showed no harmful effects on tooth enamel.

• Journal of Korean Academy of Oral Health
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• v.41 no.1
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• pp.22-27
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• 2017

Objectives: Dental plaque is composed of 700 bacterial species. It is known that some oral microorganisms produce porphyrin, and thus, they emit red fluorescence when illuminated with blue light at a specific wavelength of <410 nm. Porphyromonas gingivalis belongs to the genus Porphyromonas, which is characterized by the production of porphyrin. The aim of this study was to evaluate red fluorescence emission of some oral microorganisms interacting with P. gingivalis. Methods: Five bacterial strains (P. gingivalis, Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, and Fusobacterium nucleatum) were used for this study. Tryptic soy agar medium supplemented with hemin, vitamin K3, and sheep blood was used as a growth medium. The fluorescence emission of bacterial colonies was evaluated under 405 nm-wavelength blue light using a Quantitative Light-induced Fluorescence Digital (QLF-D) camera system. Each bacterium was cultured alone and co-cultured in close proximity with P. gingivalis. The red/green (R/G) ratio of fluorescence image was calculated and the differences of R/G ratio according to each growth condition were compared using the Mann-Whitney test (P<0.05). Results: Single cultured S. mutans, L. casei and A. naeslundii colonies emitted red fluorescence (R/G ratio=$2.15{\pm}0.06$, $4.31{\pm}0.17$, $5.52{\pm}1.29$, respectively). Fusobacterium nucleatum colonies emitted green fluorescence (R/G ratio=$1.36{\pm}0.06$). The R/G ratios of A. naeslundii and F. nucleatum were increased when P. gingivalis was co-cultured with each bacterium (P<0.05). In contrast, the R/G ratios of S. mutans and L. casei were decreased when P. gingivalis was co-cultured with each bacterium (P=0.002, 0.003). Conclusions: This study confirmed that P. gingivalis could affect the red fluorescence of other oral bacteria under 405 nm-wavelength blue light. Our findings concluded that P. gingivalis has an important role for red fluorescence emission of dental biofilm.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.287-294
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• 2014

The purpose of this study is to use basic data of dental hygiene curriculum with a new technique called motivational interviewing of communication skill to demonstrate the effectiveness of the method of oral health care. In this study, we performed oral health care program that has been made in dental hygiene department to university students. It was assigned to the control group and 66 and 32 experimental group based on the date of the first visit time. It conducted motivational interviewing of a total of three times in the experimental group. The analytical results of the measurements obtained in the oral examination and questionnaires. The results were as follows: The experimental group measured value was reduced after the intervention compared to before the PSR to evaluate the state of periodontal, gingival index, calculus index, plaque control record (PCR; O'Leary plaque index), simple plaque scor of Quantitative Light Induced Fluorescnece Digital measurement value (p<0.05). Experimental group decreased more and more the result of changes in the reduction of the average of the PCR. But control group was reduced to 3 weeks and increased back to the middle 16 weeks. There was also support interaction between the measurement point and the groups (p<0.05). Re-visit adherence of fit, 12.1% in the control group, the experimental group was 43.7% in the period of participation in the oral health care program. Thus, visit adherence of the experimental group was higher. In this study, a group that has motivational interviewing, It was able to confirm the improvement of oral health state. Discussion of the motivational interviewing can be applied to oral health care program.