• 한국치위생학회지
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• 제13권5호
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• pp.889-900
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• 2013

Objectives : Molecular biology techniques were employed to assess diversity of bacterial in children's dental caries. Methods : DNA of germs was extracted and the diversity of the 16S rRNA clones was analyzed by amplified rDNA restriction analysis and sequencing. The experimental samples were pit and fissure caries (PC), deep dentinal caries (DC), smooth surface caries (SC), and supragingival plaque (PQ) from 50 children of age less than 12 years old. The control group was healthy teeth supragingival plaque (HT). Thirty clones from each 16S rRNA clone library of 5 samples were randomly selected, thus a total of 150 clones were analyzed. Results : Amplified rDNA restriction analysis uncovered 18, 20, 11, 17, and 22 phylotypes from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and supragingival plaque, respectively. Sequencing analysis found the dominance of Actinomycs naeslundii and Fusobacterium nucleatum in the healthy teeth; Leptotrichia sp. in the pit and fissure caries; Actinomyces sp., Streptococcus mutans, and Rahnella aquatilis in the deep dentinal caries; Streptococcus mutans and Actinomyces sp. in the smooth surface caries; Enterobacter hormaechei and Streptococcus sanguinis in the supragingival plaque. Conclusions : Clonal analysis identified 6 phyla, 20 genera, and 51 species.

• 한국치위생학회지
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• 제18권5호
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• pp.843-852
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• 2018

Objectives: The study aimed to isolate the abundant bacteria in dental caries in children and to investigate the bacterial species involved in addition to those that have been previously reported. Methods: The specimens were collected from the supragingival plaques of each dental caries area, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, and from healthy subjects in the control group. Bacteria were cultured from these specimens, DNA was extracted from the isolated bacteria, and the 16S rRNA gene sequences were analyzed and identified. Results: Based on the results of the 16S rRNA gene sequence analysis for the 90 strains of dominant bacteria from the 45 specimens, 5, 7, 8, 7, and 13 species were identified from the supragingival plaques from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, respectively. In healthy teeth, Actinomyces naeslundii dominated. Corynebacterium durum, Ralstonia pickettii, and Streptococcus intermedius showed equal distribution. The dominant bacterial species in dental caries, S. sanguinis, showed the greatest difference in prevalence in pit and fissure caries. In deep dentinal caries, S. mutans and Lactobacillus rhamnosus were dominant; in smooth surface caries, S. mutans and S. sanguinis were dominant; and in the supragingival plaques of dental caries, S. sanguinis and S. mutans were dominant. Conclusions: The bacterial species isolated from dental caries encompassed four phyla, eight genera, and 22 species. In addition, the SS1-2 strain, belonging to the genus Neisseria, was identified as a new species from among the isolated strains.

• 대한치과의사협회지
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• 제9권4호
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• pp.151-157
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• 1971

Freshly extracted permant teeth were examined by electron microscope according to the Filmy replica method. Preparatory method with hydrochloric acid or proteolytic enzyme treatment was used in order to injure the structural composition of enamel surface to compare between the natural carious defects and the etched samples used in this study. The natural carious defects were chalky white or brown discolored portions at the smooth enamel surface without having visible loss of enamel substances. The findings were as follows: 1. The first caries attact initiated from the mineralized portion of rod sheath which is located at the top of enamel rod. 2. The caries developed downward along the rod sheath interprismatic substances and enamel rods subsequently. However, the caries involvement of interprismatic substances and enamel rods occured almost at the same time. 3. The rod sheath attached to the remineralized smooth emael surface was located at the top of enamel rod.

• 미생물학회지
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• 제54권1호
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• pp.81-83
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• 2018

Neisseria 속 균주 KEM232는 사람 평활면 치아우식 부위로부터 분리하였다. 균주 KEM232의 유전체는 G + C 비율이 58.5%, 2,369개의 유전자와 2,210개의 단백질 코딩 유전자, 108개의 위유전자, 51개의 RNA 유전자 그리고 한 개의 CRISPR array를 포함한 단일 원형 염색체로 구성되었으며 그 크기는 2,371,912 bp였다. 균주 KEM232의 최 근연종은 Neisseria baciliformis 로서 두 균주 사이의 16S rRNA 유전자 염기서열의 유사도는 96.8% 그리고 유전체의 평균 염기 동일성은 84%였다.

• 대한치과의사협회지
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• 제12권10호
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• pp.763-766
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• 1974

The electron microscopic observation on the browny discolored enamel spot on smooth surface of permanent teeth was performed by mean of the Filmy Replica method and obtained the following: 1) The browny discolored enamel spot on smooth surface of permanenet teeth was identified as a dental caries.

• 대한화장품학회지
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• 제17권1호
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• pp.39-47
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• 1991

Dental caries has been reported to be infectious disease by Streptococcus mutans(S. mutans). The ability of S. mutans to produce dental plaque has been shown to be related to glucan synthesis from sucrose by glucosyltransferase (GTase). Glucan is known to play an important role in the initiation of smooth surface caries. For preventing dental caries by traditional medicines, two hundred kinds of natural products were assayed for inhibiting activity against S. mutans and GTase. During the assay course, we chose some active plants against S. mutans and GTase and then applied these plant extracts to toothpaste.

• 대한소아치과학회지
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• 제34권2호
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• pp.183-191
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• 2007

본 연구는 Digital Imaging Fiber-Optic Trans-Illumination(DIFOTI)이나 Laser Fluorescence(LF)를 이용한 방법이 평활면 법랑질 초기우식증의 재광화 정도를 정확하게 monitoring 할 수 있는지의 여부를 평가하기 위하여 진행되었다. 우치 법랑질로부터 얻어진 인공 우식 절편을 특별히 제작된 의치에 식립한 다음, 10명의 실험 참가자들이 구강 내에 장착하고 3주 동안 불소 양치용액을 사용하도록 한 다음 Confocal Laser Scanning Microscopy(CLSM)로 측정된 병소 깊이를 gold standard로 사용하여 DIFOTI와 LF로 측정 된 우식 절편의 재광화 정도를 비교 평가한 후 다음과 같은 결론을 얻었다. 1. DIFOTI에 측정된 광도 백분율이 재광화 기간이 지남에 따라 증가하였으며, CLSM에서 측정된 병소 깊이와 유의한 역상관관계를 보였다(r=-0.683, p<0.01). 2. LF 측정치는 재광화 기간이 경과함에 따라 증가하였으며 CLSM에서 측정된 병소 깊이와 유의한 상관관계를 보였다(p<0.05). 3. CLSM 촬영 결과 500 ppm 불소 양치군이 0 ppm 불소 양치군보다 빠른 속도로 병소 깊이가 감소하는 양상을 보여 주었다.

• 대한소아치과학회지
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• 제24권1호
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• pp.313-324
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• 1997

The aim of the present study was to describe an safe and convenient method for the early detection of enamel caries using laser fluorescence. Fluorescence from natually carious lesion of human teeth illuminated by an argon laser(488nm) was observed and photographed using barrier filter. Intact enamel was found to fluorescence with a yellowish light. Whereas, incipient caries lesions in the enamel were dearly visible as dark areas in contrast to the fluorescence surroundings. For evaluation of accuracy of this method, lesion depth measured by the laser fluorescence in light microscope was compared with that polarizing microscope. The results from the present study can be summarized as follows : 1. Enamel caries of smooth surface was observed as pale white spot and undefined outline in ordinary light. Whereas, lesion was clearly visible as dark spot in laser fluorescence. 2. There was no difference between ordinary light view and laser fluorescence in occlusal surface and interproximal surface. 3. There was no significant difference between the lesion depth observed by laser fluorescence with light microscope and polarizing microscope. Apparent correlation exists between two groups.

• 대한소아치과학회지
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• 제27권1호
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• pp.40-44
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• 2000

연구목적은 새로운 레이저형광측정기술을 응용한 휴대용 우식진단기구인 Diagnodent를 사용한 우식진단법의 검사자내 신뢰도를 분석하는 것이었다. 발거된 사람 대구치와 소구치를 대상으로 열구를 3회, 평활면을 5회 반복 검사하였다. 측정치들의 평균치간 차이의 유의성을 t-검사로 검정하였고 측정치들간의 상관성을 Pearson 상관계수와 Spearman 순위상관계수로 산출하였으며 척도 신뢰도분석으로 검사자내 신뢰도를 분석하였다. 연구성적에서, 열구측정치들 간에 유의한 차이는 없었으나, 평활면측정치들간에는 10개 조합 중 2개에서 유의한 차이가 있었다(P<0.05). 그러나, Pearson 상관과 Spearman 순위상관은 모두 상관계수 0.9 이상의 유의한 상관성을 나타내었고(P<0.01), 신뢰도의 값은 열구측정에서 0.9980 내지 0.9981로, 평활면측정에서 0.9992로 산출되었다. Diagnodent를 사용한 우식진단법은 생체외에서 한 검사자가 반복 검사를 시행하였을 때 완전한 일치에 가까운 재현도, 곧 매우 높은 검사자내 신뢰도를 가지고 있는 것으로 나타났다.

• 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.