• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.13-23
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• 2010

This study was performed to compare the quality of image processing between the newly developed prototype using light emitting diode(LED) and the conventional $DIFOTI^{TM}$ system(EOS Inc., USA). To estimate the optimal light emitting power for the improved images, primary enamel surfaces treated under Carbopol 907 de-mineralizing solution were taken daily during 20 days of experimental periods by both DIFOTI systems. The results of comparative analyses on the images obtained from both systems with polarized image as gold standard can be summarized as follows: 1. Trans-illumination indices of images taken from primary enamel surfaces were decreased with time in both systems. 2. The differences of intensity of luminance between sound and de-mineralized enamel surface in prototype DIFOTI system was shown to be relatively smaller than conventional $DIFOTI^{TM}$ system. 3. From the comparative analysis of images from both DIFOTI system with polarized images as gold standard, the difference between sound and de-mineralized enamel surface of intensity of luminance of $DIFOTI^{TM}$ system was more correlated to polarized images than prototype of DIFOTI system. With the optimal LED emitting power, the control of aperture of digital camera is considered as the another key factor to improve the DIFOTI images. For the best image quality and analysis, the development of the improved image processing software is required.

• Journal of Technologic Dentistry
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• v.10 no.1
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• pp.151-157
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• 1988

For the detection of the active cariogenic factors contributing to caries development, some practical methods such as the Snyder test, estimation of salivary flow rate and salivary buffering capacity test were evaluated statistically by comparing DMFT and DMFS indexes. Total 122 children (62 male and 60 female ; 64 rural and 58 urban) were selected ramdomly from the 6th grade of the primary school and their salivary cariogenic factors were analysed and evaluated. Among the total 122 children, 78.7% was positive in the snyder test in which the marked, moderate and slight caries activities were 29.5%, 30.3% and 18.9%, respectively. In the Snyder test, 74.45% was positive in urban children while 84.48% was positive in rural children. DMFT and DMFS indexes were markedly lower in negative group than positive group of the Snyder test (p<0.01). The mean and standard deviation of stimulated salivary flow rate was 6.97$\pm$2.57 in male and 6.34$\pm$2.54 in female but no significant difference was observed in sexuality. The stimulated salivary flow rate of urban children was slightly higher that of rural but there was no significant difference between them. However, the group that showed below average in the stimulated salivary flow rate was markedly higher in DMFI and DMFT indexes than the group of above average. The mean and standard deviation of stimulated salivary buffering capacity was 7.65$\pm$2.19 in male and 6.80$\pm$1.67 in female. This difference was significant statistically(p<0.05). Stimulated salivary buffering capacity of urban children was higher than that of rural. Increases in stimulated salivary flow rate and buffering capacity had reduced the onset of dental caries of 14-year-old permanent tooth.

• Imaging Science in Dentistry
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• v.39 no.2
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• pp.61-68
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• 2009

Purpose : The purpose of this study was to develop the radiographic technique for detecting the demineralization which is known as indication of dental caries. Materials and Methods: This technique was based on the comparing of multiple radiographs which was irradiated by multiple X-ray spectra. For the meaningful comparing, the multiple radiographs were reconstructed to the dosimetrically consistent images using a standard material. The difference of resulting images of same target with multiple spectra represents the difference of response of material as regards the spectra. Results : We have found about 10% of demineralization of dental hard tissues particularly in the proximal region through the analyzing of differences. Conclusion: Most intriguing thing in this investigation was that the method to analyze difference shows us to an anatomic structure of dental hard tissues even if absolute values of optical density were excluded during the procedures. (Korean J Oral Maxillofac Radiol2009; 39: 61-8)

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.10-21
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• 2015

The purpose of this study was to determine the usefulness of a detection method for Streptococcus mutans in saliva with monoclonal antibodies developed targeting Ag I/II and glucosyltransferases (gtf B, gtf C and gtf D) in Streptococcus mutans. In the three groups tested (adults, minors, and minors under orthodontic treatment), the results of the DMFT scores, the colony density (CFU/mL) in their saliva was measured using $Dentocult^{(R)}$-SM strip mutans, polymerase chain reaction was performed to test whether Streptococcus mutans and Streptococcus sobrinus were present, and Streptococcus mutans detecting tests performed in their saliva using four types of monoclonal antibody were collected. In conclusion, it was demonstrated that the Streptococcus mutants plays more important role in forming dental caries compared to Streptococcus sobrinus, and that the monoclonal antibodies against glucosyltransferases (gtf B, gtf C, gtf D) and Ag I/II of Streptococcus mutans are superior in detecting Streptococcus mutans to $Dentocult^{(R)}$-SM strip mutans or polymerase chain reaction.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.522-530
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• 2009

The purpose of this study was to evaluate the clinical effectiveness of new streptococcus detection system which used monoclonal antibody against Streptococcus mutans. 92 children aged between 2 and 8 were involved in this experiment and their saliva samples were collected for testing. Streptococcus mutans were measured by both monoclonal antibody-based detecting system (Saliva-$check^{TM}$ Mutans) and dip slide detecting system($Dentocult^{TM}$-SM). The results showed that Saliva-$check^{TM}$ Mutans levels had a significant correlation with dfs rate of subjects and the two test kits, Saliva-$check^{TM}$ Mutans and $Dentocult^{TM}$-SM were shown to have a good correlation although they were based on different mechanism.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.199-208
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• 2009

This study was performed to improve the conventional $DIFOTI^{TM}$ system(EOS Inc., USA) by developing the prototype of DIFOTI system which consists of light emitting diode(LED) and digital camera. The images of enamel surfaces treated under Carbopol 907 de-mineralizing solution were taken daily during 7 days of experimental periods by both DIFOTI systems. The results of comparative analyses of obtained images can be summarized as follows: 1. Trans-illumination indices of images taken from sample enamel surfaces were decreased with time in both systems. 2. The difference of intensity of luminance between sound and de-mineralized enamel surface in prototype DIFOTI system was shown to be relatively smaller than conventional $DIFOTI^{TM}$ system. The application of LED light source in prototype DIFOTI system could possibly reduce the amount of current consumption and that could ultimately lead us to the successful development of wireless model with battery. The innovative development of digital camera is undoubtedly expected to create much clearer image despite of wireless transfer. LED and digital camera can be combined into a smaller size but a very important task of improving image manager and analyzing program into a simpler and easier one to manipulate has to be solved.

• Imaging Science in Dentistry
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• v.40 no.1
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• pp.25-32
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• 2010

Purpose : This study was designed to evaluate the efficacy and utility of panoramic radiograph for the improvement of the periodic oral examinations. Materials and Methods : Clinical examinations and panoramic examinations were done for the 242 subjects of oral examinations. The results of panoramic radiograph interpretation were compared with the clinical findings. Two questionnaires were created. One was carried out before the panoramic examination and the other done afterwards, to find out the subjects' cognition and satisfaction for the clinical and panoramic examinations. Results : 1. Panoramic findings showed a higher detection rate of 31.9% for periodontal diseases, and 23.1% for dental caries than clinical findings. 2. The additional abnormalities detected through panoramic examinations were impacted tooth in 81 subjects (33.6%), maxillary sinus abnormalities in 28 subjects (11.6%), condylar abnormalities in 5 subjects (2.1%), congenital and acquired dental anormalies in 59 subjects (24.5%), and other miscellaneous abnormalities in 34 subjects (14.1%). 3. 164 subjects (67.8%) were satisfied with the current periodic oral examination, and 75 subjects (31.1%) hoped for better accuracy. 4. In the first and second questionnaire, 154 subjects (67.0%) and 163 subjects (70.6%) responded respectively that panoramic examination was necessary, and 193 subjects (83.2%) responded that it actually helped. Conclusion : The panoramic examination was revealed to improve the effectiveness of the periodic oral examination and to increase the satisfaction of the subjects of examination.

• Journal of dental hygiene science
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• v.10 no.2
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• pp.101-107
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• 2010

The purpose of this study was to analysis know the important oral environmental factors which affect halitosis components of the adult in order to provide basic data for halitosis prevention and establish a device to eliminate halitosis efficiently. The 97 adults who visited at the Dental Clinic in Metropolis (M=68, F=30) participated in this study that performed from March in 2009 to in 2010. The obtained results through items as caries status, periodontal status, salivary flow, the viscosity, pH, Snyder test, plaque deposit, tongue plaque and halitosis check were as followings. The average shame of halitosis components appeared at hydrogen sulfide 36.71 ppb methyl mercaptan 31.46ppb dimethyl sulfide 54.33 ppb and Ammonia 22.60 ppm. The normality and the detection comparative result dimethyl sulfide above reverse appeared highly at 46.9%, ammonia appeared highly at 52%. According to the Hydrogen sulfide level was a high relationship among age, CPI, tongue coat status, DMFT index which were statistically significant (p<0.05). According to the quantity of hydrogen sulfide level there was relationship where tongue coat status Saliva flow rate considers statistically(p<0.05). The quantity of methyl mercaptan level there was relationship where Dimethyl sulfide level, tongue coat status, Saliva flow rate considers statistically(p<0.05). The quantity of Dimethyl sulfide level there was relationship where Hydrogen sulfide level, ammonia level, tongue coat status, Saliva pH and Saliva flow rate considers statistically(p<0.05). Ammonia level there was relationship where Methyl mercaptan level, CPI, and Saliva flow rate considers statistically(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.506-515
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• 2004

The objective of this study was to compare the rate of in vitro demineralization of bovine permanent (BP), human deciduous (HD) and human permanent (HP) enamel. Twenty aye flattened and polished enamel samples for each group (BP, HD, HP) were immersed in a demineralizing solution (0.1 mol/L lactic acid, 0.2% Carbopol 907, and 50% saturated hydroxyapatite) for 1, 2, 4 or 8 days. All 25 samples from each group were subjected to Quantitative light induced fluorescence analysis (QLF) and 5 samples from each group were randomly selected for Transverse Microradiography analysis (TMR). Integrated mineral loss (IML) and lesion depth (LD) were determined by TMR. The fluorescence radiance (FR) of sound enamel $(FR_S)$, demineralized enamel $(FR_D)$ were determined by QLF and FR ratio $(FR_D/FR_S)$ was calculated. Bovine enamel samples showed significant correlation between FR ratio and lesion depth(p<0.05) and deciduous enamel samples does not showed significant correlation between FR ratio and lesion depth(p>0.05). Permanent enamel samples showed significant correlation between FR ratio and lesion depth(p<0.05) The constant of demineralization time between FR ratio from regression analysis were as follows: bovine enamel was -4.643(p<0.05) deciduous enamel was -5.421(p<0.05) and permanent enamel was -4.435(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.153-158
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• 2004

Preformed stainless steel crown is an useful restorative material for the treatment of badly broken down primary teeth. However iatrogenic damage to adjacent teeth might occur during the process of tooth reduction. Such damages might lead to plaque accumulation and increase the risks of caries initiation. Especially the damage can make a problem in the first permanent molar. Purpose of this study was to investigate an iatrogenic damage to the first permanent molar during preparation of second primary molar for preformed stainless steel crown. Twelve children restored with preformed stainless steel crown to second primary molar were selected. Contact areas were separated with separation elastics, and tooth surfaces were cleaned. After taking negative impression using vinylpolysiloxane impression material, the specimens were examined by scanning electron microscope for the detection of iatrogenic damage. The prevalence of iatrogenic damage was 66.7% and variable appearances and So we can suggest that when preparing teeth for preformed stainless steel crown, we should be careful about adjacent teeth not to make an iatrogenic damage.