• Restorative Dentistry and Endodontics
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• v.17 no.1
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• pp.206-213
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• 1992

The aim of this study was to compare the accuracy of radiographic diagnosis of secondary carious lesions adjacent to composite filling materials with different radiopacity. The level of radiopacity that is most compatible with the radiographic diagnosis of secondary caries was studied in a two part experiment. In the first part, the radiopacity of 6 posterior composites CBP, CF, HM, LF, PQ, P50), enamel and dentin were measured by desitometer and 6 posterior composites divided into 3 groups based on their level of radiopacity compared with enamel and dentin. In the seocnd part, class II composite fillings with or without secondary caries were made in extracted premolar and radiographs of the teeth were examined by 10 dentists to diagnose simulated carious lesion. The following results were obtained: 1. The radiopacity of 6 posterior composites varied between 1.76(PQ) and 6.78(P50)mm Al equivalent. 2. For 4 composites the radiopacity exeeded that of an equal thickness of enamel, and for two the radiopacity was lower than that of dentin. 3. The detection of secondary caries was facillitated when the radiopacity of a composite resin was similar to or slightly greater than that of enamel.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.310-316
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• 2012

A new method for early caries diagnosis was proposed and tested through a home-made optical examination system that used quantitative light fluorescence (QLF) and digital imaging fiber optic transillumination (FOTI) (DIFOTI), with light sources across a wide spectral range, from 350 nm to 1,000 nm. The front-illuminated infrared light scattering image (FIR) showed similar diagnostic abilities to that of DIFOTI. The FIR method was invented based on the observation that caries lesions lose the high transmittance and low scattering properties of benign enamel tissue. There are various methods for the early diagnosis of caries, such as visual examination, exploration, X-ray radiography, QLF, FOTI, and infrared fluorescence (diagnodent). Among them, methods based on optical properties are regarded as having the most potential. A comparative study was performed between the FOTI, QLF, diagnodent, optical coherence tomography, and FIR scattering image methods, using 20 extracted teeth samples with early caries. A scale of lesion measurement based on optical image contrast was proposed. The statistical analysis showed a significant correlation between the DIFOTI and FIR methods (r = 0.35, p < 0.05). However, the QLF and diagnodent methods showed little association with FIR images, as they have different detection principles as compared with FIR. Tomographic images obtained by OCT, using 1,330 nm super luminescent LED as a gold standard of tooth structure, verified that the FOTI and FIR results correctly represented the lack of homogeneity in dental tissue. The newly proposed FIR method attained similar diagnostic results to those of FOTI, but with an easier approach.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.265-273
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• 2019

This study was performed to evaluate clinical use of laser fluorescence (LF) to identify early childhood caries lesions suitable for applying resin infiltration. 20 exfoliated primary molars with proximal caries were selected and cut buccolingually cross the central pit for regarding the mesial and distal surfaces respectively. 27 specimens corresponding to ICDAS code 1 and 2 were selected and the LF values were measured. When infiltrant resin was applied, double staining for microscopy detection has done simultaneously. Tooth samples were sliced with 0.7 mm thick. The maximum lesion depth, maximum penetration depth, and average penetration rate were measured from the confocal scanning laser microscope image. Pearson correlation analysis was performed. The intraclass correlation coefficient of LF values shows excellent agreement. LF values had positive correlation with penetration rate, but not lesion depth and penetration depth. Significant correlation between LF readings and penetration rate was verified in deep enamel caries and dentin caries except shallow enamel caries. Infiltrant resin could penetrate with a higher rate and LF values could be increased in more active caries lesions. In assessing radiologically similar caries lesion, laser fluorescence might be useful for identifying caries activity.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.405-413
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• 2021

The purpose of this in vivo study was to assess the clinical screening performance of a quantitative light-induced fluorescence (QLF) device in detecting proximal caries in primary molars. Fluorescence loss, red autofluorescence and a simplified QLF score for proximal caries (QS-proximal) were evaluated for their validity in detecting proximal caries in primary molars compared to bitewing radiography. Three hundred and forty-four primary molar surfaces were included in the study. Carious lesions were scored according to lesion severity assessed by visual-tactile and radiographic examinations. The QLF images were analyzed for two quantitative parameters, fluorescence loss and red autofluorescence, as well as for QS-proximal. For both quantitative parameters and QS-proximal, the sensitivity, specificity and area under receiver operating curve (AUROC) were calculated as a function of the radiographic scoring index at enamel and dentin caries levels. Both quantitative parameters showed fair AUROC values for detecting dentine level caries (△F = 0.794, △R = 0.750). QS-proximal showed higher AUROC values (0.757 - 0.769) than that of visual-tactile scores (0.653) in detecting dentine level caries. The QLF device showed fair screening performance in detecting proximal caries in primary molars compared to bitewing radiography.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.317-326
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• 2011

QLF-D system composed with DSLR(digital single-lens reflex) camera, and the images of natural enamel caries and artificial caries was developed from 2 days to 14 days captured by QLF-D system. The correlation between lesion depth of the polarized microscope and luminosity ratio of QLF-D image was analyzed and the results were summarized as follows: 1. The Pearson correlation value between the lesion depth of polarized microscope images and luminosity ratio of QLF-D images was 0.969(p<0.01). 2. From Regression analysis of lesion depth from polarized image by demineralized period, the equation was y = 8.67x - 1.16(p<0.05). 3. From Regression analysis of luminosity ratio from QLF-D image by demineralized period, the equation was y = 3.53x + 6.42(p<0.05). From the results, QLF-D system can detect the enamel caries at the very early stage and can monitor the progression of demineralization and remineralization. For the convenient use of QLF-D system in the laboratory, the image analysing software was needed to analyze of interest site of enamel caries lesion.

• Journal of dental hygiene science
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• v.16 no.5
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• pp.349-354
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• 2016

The purpose of this study was to evaluate the efficacy of the newly-developed $Qraypen^{TM}$ (All In One Bio, Korea) system for the diagnosis of early proximal caries by comparing it with the conventional methods of visual inspection and periapical radiography. This study was carried out from July 2015 to April 2016 targeting 32 children aged 7~12 years who visited Y-Dental Clinic for school oral health examinations. Two investigators selected and examined a total of 153 primary molars that had not undergone restorative treatment. Comparisons were carried out between visual inspections, readings of posterior periapical radiography images, and readings of $Qraypen^{TM}$ images. This study revealed that the percentage of interproximal surfaces of primary molar teeth without caries incidence was 83.7% using $Qraypen^{TM}$ imaging and 84.9% using visual inspection and periapical radiography. The differences between the two methods were not statistically significant. Thus, $Qraypen^{TM}$ is expected to be a useful and convenient auxiliary diagnostic device that can facilitate the detection of hidden proximal caries in primary molars.

• Journal of dental hygiene science
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• v.17 no.2
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• pp.116-122
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• 2017

The purpose of this study was to evaluate the detection ability of secondary caries using qunatitative light-induce fluorescence-digital (QLF-D) device. Twenty bovine teeth with cavity on surface were demineralized during 21 days for secondary caries lesion of cavity wall. After 21 days, cavity was filled using composite resin and cut the specimen in half with disc. Fluorescence loss of lesion on surface by time flow, cross sectional lesion, and lesion of filled or unfilled surface were analyzed using analysis software. ${\Delta}F$ (value of fluorescence loss) of the lesion on surface assessed by the QLF-D increased significantly over time up to 21 days. And ${\Delta}F$ value of lesion of filled surface is significantly lower than that of unfilled surface (p<0.001). ${\Delta}F$ of filled surface is 1.31 times of cross section lesion. The correlation of between ${\Delta}F$ of filled surface lesion and ${\Delta}F$ of cross section lesion was showed low agreement (0.026) and correlation of between ${\Delta}F$ of unfilled surface lesion and ${\Delta}F$ of cross section lesion was showed high agreement (0.613). In conclusion, secondary caries can be detected on surface using QLF-D. However, interference of fluorescence of filling material is the points to be especially considered for exact analysis of secondary caries lesion.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.2
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• pp.131-139
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• 2022

This study aimed to evaluate the effectiveness of deep convolutional neural networks (CNNs) for diagnosis of interproximal caries in pediatric intraoral radiographs. A total of 500 intraoral radiographic images of first and second primary molars were used for the study. A CNN model (Resnet 50) was applied for the detection of proximal caries. The diagnostic accuracy, sensitivity, specificity, receiver operating characteristic (ROC) curve, and area under ROC curve (AUC) were calculated on the test dataset. The diagnostic accuracy was 0.84, sensitivity was 0.74, and specificity was 0.94. The trained CNN algorithm achieved AUC of 0.86. The diagnostic CNN model for pediatric intraoral radiographs showed good performance with high accuracy. Deep learning can assist dentists in diagnosis of proximal caries lesions in pediatric intraoral radiographs.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.1
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• pp.85-94
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• 1994

The purposes of this study were clinical comparison and evaluation between digital radiography and conventional radiography for the detection of artificial interproximal caries. Four freshly extracted, unrestored posterior teeth were obtained and caries was simulated by drilling semicircled defects with variable size at the interproximal surface of each tooth. The experiments were performed with IBM-PC/32 bit-DX compatible, video camera(VM-S8200, Hitachi Co., Japan), and color monitor(Multisync 3D, NEC, Japan). Sylvia Image Capture Board for the ADC(analog to digital converter) was used, and spatial resolution was 512 × 480 with 256 gray levels. The obtained results were as follows: 1. At the condition of under exposure, the radiographs were superior to the digital images in readability. Also, as the size of the artificial lesion was increased, readability of the radiographs was elevated. 2. The digital images were superior to the radiographs in readability especially under over exsposure. 3. As the exposure time and size of lesion was increased, the gray level of region of interest of the digital image was decreased proportionally. 4. As the F-value of average gray level of region of interest at individual exposure time and size of lesion, gray level of the all lesion sizes was decreased in comparison with that of the normal enamel.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.2
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• pp.415-433
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• 1998

Digora system is an intraoral indirect digital radiography system utilizing storage phosphor image plate. It has wide dynamic range which allows it to decrease the patient s exposure time and may increase diagnostic ability through image processing (such as edge enhancement, grey scale conversion, brightness change, and contrast enhancement). And also, it can transmit and storage image information. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries between Conventional radiograph and Digora images(unenhanced image, brightness & contrast controlled image, and edge enhanced image). ROC(Receiver Operating Characteristic) analysis, paired t-tests, and F-tests were done for the statistical evaluation of detectability. The following results were acquired: 1. In Grade I lesions, the mean ROC areas of Conventional radiograph, Digora unenhanced image, Digora controlled image, and Digora edge enhanced image were 0.953, 0.933, 0.965, 0.978 (p>0.05). 2. In Grade II lesions, the mean ROC areas of Conventional radiograph, Digora unenhanced image, Digora controlled image, and Digora edge enhanced image were 0.969, 0.964, 0.988, 0.994. Among theses areas, there was just statistical significance between Diagnostic abilities of Digora edge enhanced image and Conventional radiograph (p<0.05). 3. In the Interobserver variability, the ROC curve areas of Digora edge enhanced image was lowermost in these areas, regardless of the Carious lesion depths. In conclusion, intraoral indirect digital system, Digora system, has the potential possibility as an alternative of Conventional radiograph in the diagnosis of proximal caries.