• Journal of Oral Medicine and Pain
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• v.30 no.2
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• pp.141-148
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• 2005

Since many reports for the influence of the essential oils on the oral microorganism were presented, it is important to use the essential oils in clinical field. At the present day which emphasized the quality of life, oral malodor is one of the serious problems, so we need to try to decrease of oral malodor. This study was designed to make on evidence of the effect of essential oils to oral malodor clinically and to develop on effective treatment for oral malodor by using the dental paste which contains essential oils. 40 dental students volunteered to participate in this study and double blind test was used. At the beginning, all subjects were measured their morning malodor prior to this experiment, at the 3cm posterior to their incisal edge of the oral cavity by Halimeter(Interscan Co. Chatsworth, CA). After that we divided the students in half into two groups A and B. We have supplied different tooth pastes, dental paste A and B, to two groups respectively. The dental paste B contained essential oils which are tea tree, lemon and peppermint. All students used different tooth pastes everyday for 3 weeks. And all students were measured their morning malodor every week with the same method by using Halimeter. This study was resulted that ; 1. The dental paste which contains essential oils has continuously decreased the morning malodor during the whole period of experiments. 2. The number of students with increase in their morning malodor was generally decreased in the group B who used the toothpaste which contains essential oils, compared with the group A who used the toothpaste which didn't contain essential oils on the 2nd and 3rd week of the experiment. 3. In the group B, the average data on increasing rate of morning malodor was less than in the group A. 4. In the 2nd and 3rd week of the experiment, the data on the rate of morning malodor of the group B was generally decreased continuously compared with the group A. These results have statistically significance under 95% confidence interval of the difference.(p$\leq$0.05) As the result, the toothpaste which was containing essential oils was effective in decreasing the morning malodor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.693-700
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• 2020

This study compared the accuracy and reliability of definitive casts fabricated from a digital impression and conventional impression technique. A master model with the prepared upper full-arch tooth was used. Samples of ten plaster models and ten polyurethane models were duplicated using a selected standard master model. Six linear measurements were recorded between the landmarks, directly on each of the stone models and the polyurethane models on two occasions by a double examiner. The Wilcoxon signed-rank test, interclass correlation coefficient (ICC), measurement error (MSE), and limit of agreement (LoA) were used for statistical analysis. The ICC ranged from 0.76 to 0.99 when comparing the stone models and polyurethane models. The mean difference between the stone models and polyurethane models ranged from 0.09mm to 0.20mm, suggesting that stone models might be slightly larger than polyurethane models. Based on this study, the accuracy of the polyurethane models in evaluating the performance of an oral scanner and subtractive technology was acceptable. Further studies will be needed on patient subjects under clinical conditions that may involve missing or malpositioned teeth and fixed dental prostheses because this study was limited to use a standard master model and duplicated sample models in a laboratory setting.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.85-95
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• 1984

This study was performed to investigate the intestinal parasites (especially cestoda) in the guts of Theragra chalcogramma in Korea. The cestode larvae collected were morphologically observed and measured, and at the same time, microscopical study was done with the section slides of the cestode larvae. They were identified on the basis of the descriptions by Schmidt and Yamaguti. The results obtained in this study are as follows: 1. The cestode larvae were identified as Khawia sinesis, Eulacistorhynchus chiloscyllius, Tentacularia coryphaenga, Pssudonybelinia odontasantha and Nybelinia Zingualis. These are new species reported in Korea. 2. The characteristics of Khawia sinesis are its scolex lacking loculi and broad, fat and fimbriate shape. Its neck is not separated from the body but a little constricted. 3. Eulacistorhynchus chiloscyzzius is characterized by fairly long and acraspedote scolex. The bulbs are long; retractor muscles are attached to bases of the bulbs. The two bothridia are oval or round in shape and lacking posterior notch. The tentacles are long and poeciloacanthus; double chainette present. 4. Tentacularia coryphaenea is characterized by its long craspedote and subcylindrical scolex. The bothridia are separated, without free borders and spinous. The tentacles are short, slender, armed with solid hooks in spirals, similar except the base of tentacle. The tentacle sheaths are not twisted. The bulbs are ellipsoidal. 5. Pseudonybelinia odontacantha is characterized by its craspedote scolex. The tentacles are inserted near anterior margin of bothridia and armed with hooks in spirals ascending left to right. The hooks are similar, throughout tentacle, with feeble curve and provided with a tooth-like protuberance on the ventral side. The bulbs are three times longer than its width. The posterior margins of bothridia have a pair of eversible ciliated pits; or fossettes. 6. Nybelinia lingualis is characterized by its short and craspedote scolex. The bothridia are separated, with free boarders. The tentacles are cylindrical, armed with solid and similar hooks in quincunxes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.121-126
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• 2018

The oral hygiene of patients admitted to the ICU (Intensive Care Unit) is very important. Critically ill patients are basically immunocompromised ones because of the high risk of infection by various pathogenic bacteria. The mouth is not only the primary site of infection, but also the site of systemic infections. The purpose of this study was to design a mouthpiece type vacuum oral cleaner for the oral care of seriously ill patients. A 3D CAD modeling and flow analysis model were established for a double structure type cleaner and standard tooth model, and their pressure and flow characteristics were analyzed. The pressure inside the oral cleaner was almost constant, but the velocity distribution showed a large difference between the inside and outside of the teeth. The velocity at the center region inside of the teeth was the highest, and the speed decreased as the distance from the center increased. In the analysis of the case where the suction tube was replaced by the drainage tube, the velocity at the center of the outer portion of the teeth was the highest. In order to increase the effectiveness of the oral cleaner, alternating between suction and drainage is proposed, and a design complement to increase the speed of the molar region is required.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.102-107
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• 2003

At orthodontic treatment, we have made every effort to get rigid anchorage which is not stirred when teeth move. As a result, the miniscrew that is rigid anchorage was invented recently, and now it is used widely. Concerning the advantage of miniscrew, it is reduced dependence of extraoral anchorage and it shortens treatment time for rapid tooth movement. In contrast, the defect of miniscrew is falling off it resulted from increasing of the mobility. So the purpose of this research is to be of help to prognose clinical use of miniscrew, which is inserted for intraoral anchorage, by investigating and comparing the failure rate of miniscrew for loading time. This study researches the failure rate of miniscrew for teeth movement at the orthodontic treatment. The failure rate of miniscrew in mid course, after inserting 147 miniscrews in 51 patients, is 13%(20/147). It showed no statistically significant differences as compared man with woman, maxilla with mandible, double-head with uni-head miniscrew, and drilling and non-drilling before inserting the miniscrew. In comparison below twenties with over twenties and the times that we give load to miniscrew, it produced that the failure rate of miniscrew is 9.7% higher in the case of below the twenties than over the twenties. Also, the failure rate of loading immediately is 10.8% higher than loading after 7 days. According to using driver for the insertion of miniscrew, the failure rate of miniscrew is higher in the case of using machined driver than in the case of using hand driver when the level of significance is 95%. According to the research, we can suppose that the failure rate has no concern with using miniscrew on man or woman, maxilla or mandible, the shape of head, and drilling or non-drilling before insertion of miniscrew. Therefore, we can choose eclectic miniscrew as demands. In addition, we must notify the patient, below twenties, to be possibility of high failure rate. And It is strongly recommended to give load after $1{\sim}2$ weeks for healing of the insertion area.

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.87-94
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• 2009

Purpose: The aim of this study was to compare the effectiveness of hydroxyapatite containing toothpaste with positive control toothpastes in reducing dentine hypersensitivity. Materials and methods: This clinical trial was a double-blind, randomized, parallel group comparison of two, namely hydroxyapatite containing toothpaste and strontium chloride containing toothpaste. A total of 55 subjects were included in this study. The subjects were given randomly assigned one of the two toothpastes after received tooth brushing instruction at baseline. Some clinical indices(PI, GI, PD), verbal rating score(VRS) for sensitivity to stimulus, the effect in relieving sensitivity and visual analogue scale(VAS) for sensitivity at baseline, week 2, week 4 and week 8 were assessed. All data were evaluated by intention-to-treat analysis. Results: Overall, PI and GI scores were significantly reduced compare baseline in all groups(p<0.05). In addition, there was significant difference in PI at 4 weeks and in GI at 4, 8 weeks between groups. The proportions of subjects relieved sensitivity were 70.4% in experimental group and 57.1% in control group at 8 weeks respectively. The VRS for sensitivity to three kinds of stimuli and VAS for sensitivity decreased according to time, there was no overall difference between two groups(p>0.05). Conclusion: This study demonstrated that the new hydroxyapatite containing toothpaste was similarly effective in reducing dentine hypersensitivity with pre-existing benchmark toothpaste.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.456-466
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• 2019

As digital dentistry technology is being developed, it is being used in various ways. This case covers how digital dentistry technology is being applied on the treatment of patients with loss of vertical dimension due to worn dentition and multiple loss of teeth. The loss of vertical dimension was carefully assessed and recovered, and implants were placed with surgical guides, designed considering the final restoration. The movement of the mandibular was measured with the electronic instrument for recording mandibular movement. Wax-up process was done with Naturgemäße Aufwachs-Technik (N.A.T.) and Natural functional reconstruction (N.F.R.). It was scanned, and the provisional restoration was fabricated using Computer-Aided-Design/Computer-Aided-Manufacturing (CAD/CAM) technology, and the adjustment process was done at the clinic to meet with the satisfaction both functionally and esthetically, and then, using double scanning and CAD/CAM technology, it was carried out as a final restoration. As a result, the patient obtained satisfying results, utilizing the benefits of digital dentistry technology and traditional methods.

• 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.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.495-505
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• 2019

This study reported the treatment of a patient with excessive worn dentition and limited maxillo-mandibular space for restoration, utilizing the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. After the thorough examination of the patient's occlusal vertical dimension (OVD), full mouth rehabilitation was planned with increase of the OVD. The patient was satisfied with the provisional restorations establishing the increased OVD. The horizontal and vertical data of the patient's jaw relation that the provisional restorations contained were transferred to the definitive metal ceramic fixed prostheses by double scanning and three-dimensional printing. After the fixed restorations were cemented to the abutments, electronic surveying and three-dimensional printing were used to fabricate metal frameworks for the patient's removable partial dentures. The mandibular definitive removable prostheses were delivered to the patient's mouth and the full mouth rehabilitation procedures were completed. The digital technologies used for this case produced fixed and removable restorations satisfactory in masticatory, phonetic and aesthetic functions to both the patient and the dental clinician.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.338-350
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• 2022

Purpose: Various studies have investigated 3-dimensional (3D)-printed implants using Ti6Al-4V powder; however, multi-root 3D-printed implants have not been fully investigated. The purpose of this study was to explore the stability of multirooted 3D-printed implants with lattice and solid structures. The secondary outcomes were comparisons between the 2 types of 3D-printed implants in micro-computed tomographic and histological analyses. Methods: Lattice- and solid-type 3D-printed implants for the left and right mandibular third premolars in beagle dogs were fabricated. Four implants in each group were placed immediately following tooth extraction. Implant stability measurement and periapical X-rays were performed every 2 weeks for 12 weeks. Peri-implant bone volume/tissue volume (BV/TV) and bone mineral density (BMD) were measured by micro-computed tomography. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were measured in histomorphometric analyses. Results: All 4 lattice-type 3D-printed implants survived. Three solid-type 3D-printed implants were removed before the planned sacrifice date due to implant mobility. A slight, gradual increase in implant stability values from implant surgery to 4 weeks after surgery was observed in the lattice-type 3D-printed implants. The marginal bone change of the surviving solid-type 3D-printed implant was approximately 5 mm, whereas the value was approximately 2 mm in the lattice-type 3D-printed implants. BV/TV and BMD in the lattice type 3D-printed implants were similar to those in the surviving solid-type implant. However, BIC and BAFO were lower in the surviving solid-type 3D-printed implant than in the lattice-type 3D-printed implants. Conclusions: Within the limits of this preclinical study, 3D-printed implants of double-rooted teeth showed high primary stability. However, 3D-printed implants with interlocking structures such as lattices might provide high secondary stability and successful osseointegration.