• The Journal of Korean Academy of Prosthodontics
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• v.56 no.1
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• pp.31-39
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• 2018

The collapse of the posterior occlusion destroys the normal occlusal plane and causes excessive wear reducing the vertical dimension. Reduced vertical dimension of occlusion causes not only aesthetic and functional problems but also overloading on the temporomandibular joints and abnormalities of muscle nerve system. In order to improve the collapsed occlusal relationship, it is necessary to consider the change of the vertical dimension. It is necessary to make a precise diagnosis and analysis before the treatment and to evaluate the adaption of patient to the new vertical dimension of occlusion. A patient with excessive overbite often has occlusal problems of tooth wear and tooth eruption. Considering these considerations, overall prosthodontic restoration is required to solve the problem. A patient of 68 year old man in this case who suffered major tooth wear and maxillary posterior teeth loss was treated with elevation of vertical dimension of occlusion by maxillary removable dental prosthesis and mandibular fixed prosthesis.

• Journal of Technologic Dentistry
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• v.39 no.1
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• pp.43-52
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• 2017

Purpose: Physical and chemical properties of gold is most suitable to be restored of teeth to its original state. Recently zirconia was used instead of gold because of esthetical and intimacy of human body. Because of high strength and high abrasion resistance of zirconia, all zirconia artificial tooth lead to wear the original tooth of opposite site. To preserve this original tooth, zirconia artificial tooth covered with dental ceramic glass was used. When joining the zirconia core and dental ceramic glass, difference of their thermal expansion coefficient and wetting ability is generated the residual stress at interface lead to crack. In order to solve this problem, intermediate layer what is called zir-liner was imported to decrease the residual stress and increase the bonding strength. Methods: In this study, to identify the optimum conditions for manufacturing process, various methods to rough the surface of zirconia core were adopted, and vary the thickness of interlayer, and analyzed bond strength. Results: Bond strength of sanding specimens group showed higher than that of non-sanding specimens group, and once applied intermediate layer with sanding specimens showed highest bond strength with 28 MPa. SEM photomicrographs of zirconia cores fired at $1500^{\circ}C$ showed parallel straight lines in sanding and pockmarked surface in blasting surfaces as abrasion traces. Observation of the destruction section after shear test by SEM were carried out. Liner applied non-sanding group and non-liner applied sanding group all showed interfacial crack. Sandblasting group with non-liner showed remained dental ceramic glass on the surface of zirconia. Sandblasting group with once applied liner showed partially remained liner and dental ceramic glass on the surface of zirconia. XRD analysis revealed that sandblasting group showed higher monoclinic peaks than other specimens group and this result was due to the high collision energy for stress induced phase transformation. Conclusions: A study on the improvement of bonding strength between zirconia and dental ceramic glass steadily carried out for the future to practical use.

• Journal of Korean society of Dental Hygiene
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• v.6 no.1
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• pp.49-61
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• 2006

This study was intended to identify the pregnant women's oral health care behaviors and the necessity of active oral care so as to use in the dental hygiene education at dental clinics as basic materials to inform the importance of oral health during pregnancy and instruct how to improve it. And to suggest a dental service direction for dental hygienists, 150 pregnant women who visited the Ostetrics and Genecology Clinics located in tl,e north part of Cholla province were surveyed with questionnaire on their oral care behaviors, from september to October in 2004. The findings were as below: 1. 43.8% of the pregnant women have ever used the dental care institutes within the recent 3 months during pregnancy period. The purpose of the visits was mostly treatment of dental caries, accounting for 40.0%. Next came the treatment of periodontal diseases, accounting for 33.8%. 2. At dental care service, 84.7% of the pregnant women informed the clinic staff of their pregnancy, 12.0% of the pregnant women were having periodical oral examination. 3. 56.7% of the pregnant women have ever inquired about oral care methods, 24.0% of the pregnant women have ever taken any oral health education, of whom 47.1% had higher schooling over graduate school, with a statistically signifiant difference. 4. 55.3% of the pregnant women made changes in their oral care practice after they got pregnant. Change of oral care practices was more obvious in those who had higher schooling background, of whom specialist women accounted 76.9%. Change of oral care practices after pregnancy was statistically significantly different to the academic background and occupation. 5. Of the changes in oral care practice after pregnancy, 51.8% of the pregnant women answered they got sensitive to change in their oral status, and 39.8% increased the frequency of tooth brushing. 6. In selecting a tooth paste after they got pregnant, 58.0% of the women didn't give any special consideration to the kind of tooth paste, while 10.7% women as low selected such tooth pastes that contain fluoride. 7. Pregnant women's route for gathering oral care information was mostly mass media and Internet which accounted for 50.7%.

• Journal of Korean Dental Science
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• v.6 no.1
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• pp.13-21
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• 2013

Purpose: To report the successful results of using chin bone graft and autogenous tooth bone graft material (AutoBT) in alveolar cleft patients. Materials and Methods: Five patients with alveolar cleft defects underwent alveolar bone grafting. Three patients were treated using chin bone graft, and the other two patients underwent AutoBT graft. After implant site development using chin bone graft in the fi rst three cases, endosseous implant restorations were placed. In case #4 and 5, AutoBT graft material was placed to guide the normal eruption of partially impacted maxillary right canine and to the upper docking site after distraction osteogenesis. Result: Successful implant restorations with closure of the oronasal fistula were achieved in alveolar cleft defect reconstruction using either chin bone graft (Case #1, 2, 3) or AutoBT graft material (Case #4, 5). Case #4 showed enlarged follicle of the right maxillary canine, indicating a normal eruption guide pattern. Conclusion: Both chin bone graft and AutoBT graft showed favorable outcomes in reconstructing alveolar cleft defects. Autogenous tooth bone graft opens up the possibility of avoiding harvesting autogenous bone graft with complications and morbidities.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.81-88
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• 2020

This purpose of this study is to develop content that enables repetitive carving practice of the maxillary right central incisor (MRCI) based on augmented reality (AR). For a step-by-step practice of achieving the tooth shape, after creation of the storyboard from the square box shape in step 1 to the completed MRCI block in step 16, three-dimensional (3D) modeling data reflecting the characteristics of the mesial, distal, lingual, and labial surface of the MRCI were generated. An application was built in which 3D modeling data were output on the screen of the learner's mobile device, and image markers suitable for 3D modeling in steps 1 to 16 of the MRCI model were respectively generated. Using this information, the learner could carve a high-quality MRCI by repeatedly performing the tooth shape carving exercises. With AR, we intend to contribute to improved tooth morphology carving skills by linking the theory and practical techniques for a beginners in dentistry.

• The korean journal of orthodontics
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• v.51 no.3
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• pp.157-165
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• 2021

Objective: This study aimed to identify the clinical effectiveness of two different penetration depths of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement. Methods: Twenty-four patients requiring the removal of the upper first premolar teeth were selected and randomly divided into two groups. The control group participants did not undergo MOPs. Participants in the experimental group underwent three MOPs each at 4-mm (MOP-4) and 7-mm (MOP-7) depths, which were randomly and equally performed to either the left or right side distal to the canine. The retraction amount was measured on three-dimensional digital models on the 28th day of retraction. MOP-related pain was measured using a visual analog scale (VAS). Between-group statistical differences in the VAS scores were determined using an independent t-test and those in canine retraction were determined using analysis of variance and post-hoc Tukey test. Results: No significant difference was found between the MOP-4 (1.22 ± 0.29 mm/month) and MOP-7 (1.29 ± 0.31 mm/month) groups in terms of the canine retraction rate. Moreover, both the groups demonstrated a significantly higher canine movement than the control group (0.88 ± 0.19 mm/month). MOPs did not significantly affect the mesialization of the posterior teeth (p > 0.05). Moreover, the pain scores in the MOP-4 and MOP-7 groups were similar and showed no statistically significant difference. Conclusions: Three MOPs with a depth of 4 mm can be performed as an effective method to increase the rate of tooth movement. However, three MOPs with depths of 4-7 mm does not additionally enhance tooth movement.

• Journal of Korean society of Dental Hygiene
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• v.23 no.1
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• pp.73-82
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• 2023

Objectives: This study aimed to evaluate the oral symptoms experiences of Korean adolescents among multicultural families. Methods: Data on 985 participants from the 16th Korea Youth Risk Behavior Web-based Survey were collected and analyzed using complex sample descriptive statistics. Results: The foreign-born mother, foreign-born parents, and foreign-born father rates were 77.2%, 17.3%, and 5.4%, respectively. The toothache, gingival bleeding, tooth fracture, and tooth sensitivity experience rates were 21.3%, 18.8%, 13.3%, and 30.4%, respectively. The tooth fracture rate was highest in the foreign-born parents group (24.6%). The toothache odds ratio (OR) was 1.71 (95% CI: 1.24-2.37) times higher in girls. The foreign-born mother group was 2.47 (95% CI: 1.09-5.60) times higher than that of the foreign-born father or both parents foreign-born groups. The smoking group was 2.03 (95% CI: 1.20-3.43) times higher than that of the non-smoking group. The gingival bleeding OR was 5.11 (95% CI: 1.80-14.53) times higher in the lowest economic status group. The tooth fracture OR was 3.44 (95% CI: 1.01-11.70) times higher in the lowest economic status group. The tooth sensitivity OR was 1.53 (95% CI: 1.14-2.04) times higher in girls. Conclusions: It is necessary to establish a program to promote oral health of adolescents from multicultural families.

• Journal of dental hygiene science
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• v.23 no.3
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• pp.236-244
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• 2023

Background: The size of the tooth whitening market and toothpaste market is increasing worldwide. The purpose of this in vitro study is to confirm and compare the coffee stain removal effects of commercial whitening toothpaste in sound and demineralized teeth, respectively. Methods: A total of 112 flat permanent bovine teeth specimens were manufactured. Half of the surface of the specimen was coated with an acid-resistant varnish and deposited in an artificial demineralizing solution for 65 hours. The varnish applied to half of the specimen was removed and deposited in a coffee solution for 96 hours to induce coloring. Two control and five experimental group toothpastes for teeth whitening were selected and the main components were investigated. Toothbrushing was performed 50, 100, and 150 times for each toothpaste group. A total of four images were obtained: before the start and after 50, 100, and 150 times of brushing to obtain the lightness (L^*) values of the sound and the demineralized tooth surfaces. The difference in the average value between toothpaste groups at each treatment period was analyzed by one-way ANOVA. The difference in the L^* average value according to the number of the brushing was analyzed by repeated measure ANOVA. Results: All toothpastes in the seven groups contained abrasive agents and had different ingredients for each product. Compared to before brushing, the L^* value changed significantly in all toothpaste groups after brushing 50 times (p<0.05). This was common in both the sound and demineralized teeth surfaces. Demineralized teeth had significantly lower L^* values at all brushing times than that in sound teeth (p<0.05). Conclusion: The effect of whitening teeth was different for each toothpaste. Demineralized teeth were more likely to cause coloration than sound teeth, and the coloration was not removed well.

• The Journal of the Korean dental association
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• v.9 no.12
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• pp.823-827
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• 1971

The auther has made an epidemiological study on the oral examination and oral health in 226 Korea Military Nursing School Students. The following results was obtained: 1. The prevalance rate of dental caries was 71.23%. 2. The prevalance rate of D.M.F. was 45.82%. 3. The tooth health index was 77.87%. 4. The prevalance distribution of dental caries was 63.87% in the mandibular and 36.13% in the maxila. 5. Of examined students, 94.0% was brushing twice per day and 6.0% once per day. 6. Of examined students, 98.2% was using the paste form on dentifrice and tooth brush. 7. Of examined students, 22.1% was ignorant of causes of dental caries.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.176-182
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• 2014

This study aimed to arrive at reasonable and realistic prices for professional tooth cleaning (PTC) in order to expand its clinical utilization. The study involved 214 dental implant patients who received PTC. Cross-tabulation, one-way ANOVA, t-test, and stepwise multiple regression were performed for analysis. The mean satisfaction score was 4.60 points, and 92.5% of all subjects were willing to receive PTC consistently. The most common reason to receive PTC was a feeling of refreshment in 84.7%, and 84.1% were willing to pay for PTC. The mean willingness-to-pay price was 28,100 won, and the mode was 10,000 won. Willingness-to-pay price increased as average monthly income and satisfaction level for PTC were higher. The price also increased with age and was higher in women than men. Suggesting and settling reasonable and realistic prices for PTC are expected to be useful in maintaining the long-term health of the dental implant and reducing socio-economic costs.