• Journal of Technologic Dentistry
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• v.41 no.4
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• pp.305-317
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• 2019

Purpose: The purpose of this study is to provide basic data for the improvement of dental care service for patient care. Methods: The survey period was from December 10, 2018 to June 10, 2019. The subjects were 180 patients who were treated with dental implant in 20 dental hospitals and clinics in Daejeon and Gyeonggi province. A total of 145 questionnaires were analyzed except for 35 copies which were unreliable or difficult to analyze. Results: The most important care method for prolonging the life time of dental implant prosthesis was the highest rate of correct brushing (39.4%), and a majority in the subjects used oral hygiene products (91.0%). With regard to discomfort after dental implant prosthesis, food particles between the teeth showed the highest response (49.7%), and discomfort with gum infections and bleeding and reduced mastication increased significantly with age (p<0.05), whereas feeling of irritation decreased significantly with age (p<0.05). Conclusion: This study is meaningful in that it approached the perception and discomfort of prosthesis from the patients' point of view. It needs to establish the basic data to improve dental treatment service for patient care.

• Journal of Technologic Dentistry
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• v.14 no.1
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• pp.15-21
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• 1992

• Journal of Technologic Dentistry
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• v.2 no.1
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• pp.61-62
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• 1980

• Structural Engineering and Mechanics
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• v.64 no.6
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• pp.819-826
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• 2017

The effects of thermocycling procedure and material shade on the mechanical properties and wear resistance of resin-based dental restorative materials are investigated. The modulus of elasticity, hardness, plasticity index and wear resistance are determined for the conventional composite, the nanohybrid composite and the nanofilled dental composites. Disc-shape samples are prepared from each material to investigate the effects of thermocycling procedure on the mechanical properties and wear resistance of different types of dental restorative materials. In this respect, a group of samples is thermocycled and the other group is stored in ambient conditions. Then nano-indentation and nano-scratch tests are performed on the samples to measure their mechanical properties and wear resistance. Results show that the A1E shade of the dental nanocomposite possesses higher modulus of elasticity and hardness values compared to the two other shades. According to the experimental results, the mean values for the modulus of elasticity and hardness of the A1E shade of the nanocomposite are 13.71 GPa and 1.08 GPa, respectively. The modulus of elasticity and hardness of the conventional dental composite increase around 30 percent in the oral environment due to the moisture and temperature changes. The wear resistance of the dental composites is also significantly affected by moisture and temperature changes in the oral conditions. It is observed that thermocycling has no significant effect on the hardness, plasticity index and wear resistance of the nanohybrid composite and the nanocomposite dental materials.

• Journal of Technologic Dentistry
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• v.38 no.1
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• pp.9-22
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• 2016

Purpose: The Purpose of this study are to describe the Dental field of present health insurance for custom-made prosthetic implant by dental technicians' work. Results: A total of 300 dental technicians working at dental laboratories in Korea were randomly selected and surveyed, 206(68.7%) of them were used for the statistical analysis. Conclusion: Average daily working time was 10 hours 66%. The average cumulative credit of the clinic for dental prosthesis fabrication rates was Less than 10 million won(21.8%), 10~80 million won(11.7%), more than one hundred million won(1.5%). Remake dental prosthesis was one more than the monthly average of 98.5%. Causes of remake dental prosthesis was dentist impression 83% but did not pay 62.5%. Dental technicians Implant production period was 7 days(48.5%), 10 days(35%) was commissioned by dentists production time is 5 days(46.1%), 7 days(36.5%). President of dental laboratories 3.86 points and dental technicians 3.06 points knew differently about starting of implant health insurance coverage(p<.001). They alike were in favor of insurance coverage for the implant. Dental technicians were lower by 2.36 points for work do you know whether your health insurance application of dental prostheses. Dental technicians are 2.16 points on whether confidence in the pores payment of insurance coverage dental prosthesis, dental laboratory president was lower by 1.85 points. They are very low with 1.97 points on whether confidence in the rate payment of health insurance coverage dental prosthesis(p<.01). The implant prosthesis abutment selected, the abutments designed, design of the implant upper prosthetic, the upper prosthetic fitting dental technicians participate of dental laboratory president showed higher score (p <.05). Conclusion: Hours of dental technicians were making this short period of remake dental prosthesis-related dental prosthesis. Dental clinic and a detailed representation of the dental prosthodontic fabrication request is required for communication between the laboratory in order to reduce the remake of a dental prosthesis, dental insurance coverage written dental prosthodontic fabrication request should be legislated. Implant classification standard medical practice 1-3 Step conduct a thorough costing a total of no. 73 of the correct classification standard medical practice in addition to eight times defined by the act of dental technicians should be defined.

• Journal of Technologic Dentistry
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• v.7 no.1
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• pp.13-18
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• 1985

Casting alloys, both precious and non-precious, were by heat in order to observe the change in HB and the results were : 1. The hard treatment showed 1.4 - 1.5 times as high as the soft treatment in HB. 2. The experiment shows that Au-Pt should be contained more than 75% to prevent color change. 3. Cu by hard teatment played the greatect part in creasing the solidity of Ag-Cu alloy. 4. Casting Co-Cr alloys showed little difference of HB in heat treatment.

• Journal of Technologic Dentistry
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• v.41 no.4
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• pp.279-285
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• 2019

Purpose: The dental CAD / CAM system has been popular with the development of the digital dental industry. Zirconia is a typical material in dental CAD / CAM systems. Zirconia crowns are classified into single layer and double layer. This study is about the double layer crown of zirconia. The surface roughness, bond strength and fracture patterns of the zirconia surface were observed. Methods: Zirconia blocks were cut using a low speed cutter. Sintered to form a plate shape (6mm × 6mm × 3mm). The prepared specimens were surface treated in four ways. Surface roughness and bond strength were measured. And the fracture pattern was observed. Results: Result of surface treatment of zirconia. The surface roughness test results were as ET 2.87 ㎛, ST 2.67 ㎛, LT 2.44 ㎛, AT 2.41 ㎛, CN 2.08 ㎛ order. Bond Strength results were as LT 25.09 MPa, AT 23.27 MPa, ST 21.27 MPa, ET 21.09 MPa, CN 16.12 MPa order. Fracture patterns showed cohesive failure of 25-50% of the bond area. Conclusion: Surface roughness, bond strength and fracture pattern of the zirconia surface were observed. Etching the surface treatment of zirconia materials has been shown to affect the surface roughness. Zirconia special binder treatment has been shown to affect the bond strength improvement.

• Journal of Technologic Dentistry
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• v.37 no.4
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• pp.213-218
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• 2015

Purpose: The purpose of this study compared of reproducibility of prepared tooth impression scanning utilized with white and blue light scanners. Methods: To evaluate reproducibility with white and blue light scanners, the impression of premolar were rotated by $10^{\circ}{\sim}20^{\circ}$ and scanned. These data were compared with the first 3-D data (STL file), and the error sizes were measured (n=5). Independent t test was used to evaluation the reproducibility of impression of premolar with white versus blue light scanners through discrepancies of mean, RMS (${\alpha}=0.05$). Results: Discrepancies of mean with regard to reproducibility were $11.2{\mu}m$, $5.8{\mu}m$, respectively, with white and blue light scanners (p<0.047). And discrepancies of RMS with regard to reproducibility were $33.4{\mu}m$, $18.8{\mu}m$, respectively, with white and blue light scanners (p<0.045). Conclusion: Our results indicate a good reproducibility of prepared tooth impression digitized with blue light scanner more than that with white light scanner.

• Journal of Technologic Dentistry
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• v.45 no.2
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• pp.48-53
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• 2023

Purpose: This study aimed to provide the basic data for dental barrel finishing by observing the abrasiveness of the metal body according to the time of the barrel finishing. Methods: This study included three types of Co-Cr alloys. The specimens were manufactured by casting method using 10-mm diameter wax spheres (n=10). The cast alloys were polished for 60 minutes at intervals of 5 minutes in barrel finishing. The weight and volume of the specimens were measured, and the rate of change was calculated. The data obtained from the three groups (α=0.05) were compared and analyzed using one-way ANOVA. Results: As a result, the overall volume and weight of the group decreased after grinding compared with the control group. Conclusion: When grinding dental barrel finishing, no difference was observed in the processing rate depending on the type of alloy and the processing rate of the alloy body is within 30 minutes; hence, dental barrel finishing can be effectively used for grinding.

• Journal of dental hygiene science
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• v.8 no.2
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• pp.51-56
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• 2008

This research surveyed, from 17 March 2008 to 25 March 2008, 261 students, 1,2,3 grade, who study in the a dental laboratory technology of college placed in Suwon. We sent them out each three questionnaire and surveyed their family and friends including themselves. We got back 584 paper out of 783 paper which we sent out and used as data of analysis. When choosing a dental clinic, we used a Pearson Correlation to understand a relation of variables connected with a medical service. The result showed that every each fields have a positive correlation and especially a correlation between a physical environment and an ability of dentist is showed most highly and a correlation between a basic element of clinic and a traffic convenience is showed a meaningful positive in that order.