• 대한치과의사협회지
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• 제57권4호
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• pp.213-220
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• 2019

Purpose: The aim of this study was to evaluate the red fluorescence characteristics of bacterial dental deposits assessed by quantitative light-induced fluorescence (QLF) technology and confirm whether the red fluorescence can distinguish and evaluate quantitatively accumulation of bacterial dental deposits. Methods: This retrospective cross-sectional study used QLF images captured at a dental clinic from January to December 2016. In each QLF image, a skilled examiner selected one region where the presence of deposits was suspected. Then, the regions were classified into three groups of not detectable deposits(ND), half detectable deposits (HD), and full detectable deposits (FD) by two examiners according to classification criteria. Only those images where the regions of bacterial dental deposits were classified identically by all examiners were used for analysis. The mean red fluorescence intensity (RFI) was defined as the mean value of R/G for all pixels in the regions. The RFI was compared between groups using Welch's ANOVA test, and the Spearman correlation was calculated to assess the association between RFI and accumulation of deposits. Results: In this study, 351 images among the collected images of 605 subjects were finally selected. The mean age of subjects was about 44 years. The R/G values of the ND, HD and FD were 0.73, 1.26 and 1.83 respectively. There were significant differences between all groups (p<0.001), and strong positive correlation was identified between the R/G value and the accumulation of deposits (r = 0.90, p<0.001). Conclusion: The intensity of red fluorescence as observed in the QLF images correlated well with the accumulation maturation of the deposits, which indicates that the QLF technology can be used to evaluate the status of oral hygiene.

• 치위생과학회지
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• 제13권4호
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• pp.403-409
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• 2013

본 연구는 초기우식 진단장비인 QLF-D와 새로운 치아우식활성 검사법인 Cariview를 우식예측 연구에 활용할 수 있는지를 평가하기 위하여, 만 3세 아동 57명을 대상으로 구강검사를 실시한 후 우식경험도를 분석하고 이들 간의 상관성을 평가하여 다음과 같은 결과를 얻었다. 1. 연구대상자의 우식경험도 조사 결과, 우식경험유치지수는 평균 1.84였으며, QLF-D를 이용한 분석 결과는 치면 세균막 부착에 대한 점수가 1.47이었고, 연구대상자 당 평균 1개 정도의 초기우식병소($0.96{\pm}1.21$)가 있는 것으로 나타났다. 또한 Cariview 검사에서 산생성능은 평균 27.52로 나타났고, 연구대상자 중 68%가 저위험군에 속하는 것으로 파악되었다. 2. 우식경험유치지수와 초기우식병소 개수의 상관계수가 0.617, 치면세균막 부착정도(SPS)와는 상관계수가 0.500으로 비교적 강한 상관관계를 확인할 수 있었고(p<0.01), 우식경험유치지수와 Cariview 결과(0.286) 간에는 유의한 양의 상관관계가 나타났다(p<0.05). 그러나 우식유치지수, 우식경험충전유치지수에서는 Cariview 점수와의 상관관계를 확인할 수 없었다. 이상의 결과를 종합해보면, QLF-D를 이용하여 분석한 치면세균막 점수와 초기우식병소는 우식예측에 가장 중요한 영향을 주는 과거 우식경험에 높은 상관성을 보였으므로, 초기우식병소 탐지와 치면세균막 부착 정도를 동시에 파악할 수 있는 QLF-D는 우식예측 연구에 유용한 장비로 활용할 수 있을 것이다.

• 대한치과의사협회지
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• 제56권1호
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• pp.8-16
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• 2018

Purpose: The aim of in vitro study was to compare the diagnostic accuracy to detect non-cavitated enamel caries on smooth surface by using four kinds of the QLF devices. Materials and Methods: A total of 52 human permanent premolars and molars were used. Fluorescence images were captured by the QLF devices (Inspektor Pro, QLF-D, Qraycam, and Qraypen). Fluorescence loss of the QLF was calculated. The severity of lesions was categorized into the following 3 scores using polarized light microscopy: normal (S), enamel demineralization to outer half of enamel (D1), and inner half of the enamel up to the dentin-enamel junction (D2). The Kruskal-Wallis test was used to compare the fluorescence loss among the QLF devices. Spearman rank correlation coefficient between histological scores and fluorescence loss of the devices was calculated. The sensitivity, specificity, and area under the receiver operating curve (AUROC) were calculated to compare their diagnostic accuracies. Results: The correlation coefficients between histological scores and the fluorescence loss of the devices showed 0.77 to 0.81 (P < 0.001). All histological scores, the fluorescence loss among the devices showed no statistical difference. Among the devices, sensitivity, specificity, and AUC values of the fluorescence loss showed 0.84 to 0.94, 0.76 to 0.90, and 0.90 to 0.92, respectively. Conclusions: All QLF devices had no difference with excellent diagnostic accuracies to detect non-cavitated enamel caries on smooth surface.

• 치위생과학회지
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• 제14권2호
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• pp.150-157
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• 2014

본 연구에서는 기존에 임상에서 염색제를 사용한 치면세균막검사와 periodental probe를 사용한 치은지수 평가방법대신 새로운 디지털 형광 장비인 QLF-D를 이용한 검사법의 활용 가능성을 확인하고자 하였다. 염색제를 이용하여 치면세균막지수를 산출하여 연구 대상자를 위험군별로 구분하여 일반적 특성을 확인하였고, 분석 소프트웨어를 이용하여 산출되는 QLF-D score와 전체 및 전치부 치면세균막지수, 치은지수의 상관성을 확인하였다. 정상치은과 치은염에 따른 QLF-D score를 비교하였고, 각 QLF-D score에 따른 치면세균막지수와 치은지수의 평균값을 비교하여 다음과 같은 결론을 내렸다. 연구대상자의 염색제를 이용한 평균 치면세균막지수는 $42.28{\pm}17.90$이었고, 6개의 선택치아의 치은지수는 $1.05{\pm}20.38$로 나타났으며, QLF-D score는 $1.26{\pm}1.50$이었다. 상하악전치부 QLF-D score와 치면세균막염색을 이용하여 평가한 전치부 치면세균막지수의 상관 분석 결과, 유의한 양의 상관관계를 확인하였다(r=0.638, p<0.001). 또한 상하악 전치부 QLF-D score와 periodontal probe를 이용한 치은지수와의 관계를 분석한 결과에서도 두 가지 평가 지표 간에 유의한 양의 상관관계를 보였다(r=0.562, p<0.001). 치면세균막지수와 치은지수에 따른 QLF-D score의 차이를 저위험군과 고위험군으로 분류하여 비교한 결과, 치면세균막지수(p<0.0001)와 치은지수(p=0.007) 모두 저위험군에 비해 고위험군 집단에서 QLF-D score가 통계적으로 유의하게 높았다. QLF-D score에 따른 치면세균막지수 및 치은지수 평균값을 비교한 결과, QLF-D score가 증가할수록 두 가지 지수 모두 통계적으로 유의하게 증가하는 양상을 보였다(p<0.0001). 이와 같은 결과를 통해, QLF-D로 치면세균막을 평가함으로써 치은상태를 모니터링 하는 것이 가능함을 확인하였다. 이를 통해 임상 현장에서 QLF-D를 활용한다면, 비교적 간편하게 구강 이미지를 획득하고 구강 상태를 점수화하여 제시함으로써 술자의 진단 절차가 간편해지고 환자와의 의사소통이 원활해질 수 있을 것으로 사료된다.

• Journal of Korean Academy of Oral Health
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• 제41권1호
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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.

• 대한소아치과학회지
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• 제41권3호
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• pp.218-224
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• 2014

이 논문은 법랑질의 표면미세경도와 QLF의 ${\Delta}F$ 값의 변화를 분석하여 5% 불화나트륨을 함유한 고분자 접착 테잎(NaF-PVA)이 법랑질의 재광화에 미치는 영향을 평가하고자하였다. 시편을 탈회한 후 표면미세경도가 평균 50-100 KHN의 범위를 갖고 QLF의 ${\Delta}F$ 값이 -25에서 -15 범위를 갖는 60개의 시편들을 4그룹으로 나누었다 : 그룹1(대조군), 그룹2(NaF-PVA), 그룹3(불소바니쉬, FluoroDose$^{(R)}$ varnish), 그룹4(Casein phosphopeptide-amorphous calcium phosphate, Tooth mousse plus$^{TM}$). 시편들에 각 제제들을 적용하고 인공타액(artificial saliva)에 담근 후 표면미세경도계와 정량 광 형광기를 이용하여 재광화율을 측정하였다. 그 결과 불소를 함유한 고분자 접착 테잎(NaF-PVA)은 그룹1과 4보다 뛰어나며 그룹3과 견줄만한 재광화 효과를 나타냈다 (p<0.05).

• 한국치위생학회지
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• 제19권3호
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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.

• 대한치과의사협회지
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• 제55권6호
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• pp.413-422
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• 2017

Purpose: The aim of this study was to confirm the validity of the $Cariview^{TM}$, test in adults by assessing correlations between $Cariview^{TM}$, scores and caries experience using a quantitative light-induced fluorescence (QLF) technique. Methods: This retrospective cross-sectional study included 111 patients aged 19-64 years who visited a dental clinic in Seoul from 2015 to 2016, and underwent the $Cariview^{TM}$, test and had their teeth photographed with the Qraycam. Plaque was scraped with sterilized cotton swabs, and then placed in a culture medium and incubated at $37^{\circ}C$ for 48 h. Finally, the degree of color change was evaluated, and scored on a 0-100 point scale. Caries experience index included not only cavitated lesions but also early caries that were detected on white and fluorescence images. Participants were divided into low, moderate and high caries risk groups according to the $Cariview^{TM}$, score, and caries experience was compared between risk groups using ANCOVA. Spearman correlation coefficients were calculated to analyze the associations between $Cariview^{TM}$, scores and caries indices. Result: The mean age of the participants was 40 years, and the mean $Cariview^{TM}$, score was $53.6{\pm}20.7$. The WDMFT and the DMFT indices significantly increased with caries risk, and this increase was significantly different between the low- and high-risk groups. The $Cariview^{TM}$, test scores were significantly correlated with the WDMFT (r = 0.28, P = 0.003) and DMFT (r = 0.29, P = 0.002) indices. Conclusion: The $Cariview^{TM}$, test could be a clinically useful and simple method for assessing caries risk in adults.

• 한국산학기술학회논문지
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• 제21권1호
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• pp.739-744
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• 2020

이번 연구의 목적은 pH, 적정산도, 형광소실도(△F)를 이용하여 혼합주의 부식위험성과 부식능에 대해 평가하고자 하였다. 실험군은 다음과 같이 분류하였다: 소주, 깔라만시+소주, 요구르트+소주, 콜라+소주, 에너지드링크+소주. 혼합주는 소주와 음료수를 7:3의 비율로 혼합하였다. pH와 적정산도(TA5.5, TA7.0; 음료의 pH를 5.5와 7.0까지 끌어 올리는데 필요한 1M NaOH의 양)는 교반하면서 pH미터기를 이용하여 측정하였다. 혼합주의 부식능은 우치를 1, 2, 4, 6시간 동안 침적하였다가 각 시간마다 꺼내어 quantitative light-induced fluorescence (QLF-D)를 이용하여 촬영, 분석하였다. 연구 결과, 혼합주는 평균 pH는 3.17 ± 0.50, 소주의 pH는 8.6 ± 0.01를 나타내었다. TA5.5와 TA7.0는 각각 0.5~18, 0.5~23.5의 분포를 나타내었다. 요구르트 혼합주를 제외한 나머지 혼합주의 △F는 시간이 지남에 따라 증가하였으며, 요구르트 혼합주에서는 부식이 나타나지 않았다. 결론적으로, 깔라만시 혼합주가 가장 강한 산성과 부식능을 보였으며, 요구르트가 가장 약한 부식능을 나타냈다. 혼합주는 치아 법랑질에 강한 부식위험성을 가지고 있으므로, 이에 대한 주의와 교육이 필요할 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.2271-2275
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• 2016

Background: The value of 5-aminolevulinic acid (ALA) in fluorescence detection of peritoneal metastases and the underlying mechanisms were evaluated in patients with peritoneal surface malignancies. Materials and Methods: Oral 5-ALA was administered at a concentration of 20 mg/kg body weight with 50 ml of water 2 hours prior to surgery (n=115). The diagnostic value of 5-ALA based fluorescence production was evaluated following white light inspection during prior to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Then, peptide transporter PEPT1 (ALA influx transporter) and ATP-binding cassette transporter ABCG2 (porphyrin efflux transporter) gene expression was determined with quantitative real time (qRT)-PCR and pathological diagnoses confirmed for all tissue samples. Results: The 5-ALA based photodynamic detection rate was 17% for appendiceal mucinous neoplasms, 54% for colorectal cancers, 33% for gastric cancers, 67% for diffuse malign peritoneal mesotheliomas, and 89% for epithelial ovarian cancer of peritoneal metastases. 5-ALA was detected in all cases of peritoneal metastases originating from cholangiocarcinomas whereas it was not able to detect any in granulosa cell and gastrointestinal stromal tumor cases. Furthermore, PEPT1 was overexpressed whereas ABCG2 expression was downregulated in tumors detected with fluorescence. Conclusions: 5-ALA provided 100% specificity and high sensitivity to detect peritoneal metastases in subgroups of patients with peritoneal surface mailgnancies. ALA influx transporter PEPT1 and porphyrin efflux transporter ABCG2 genes are important in tumor specific 5-ALA induced fluorescence in vivo. Further studies should clarify diagnostic utility of 5-ALA in peritoneal surface malignancies.