• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.102-109
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• 2019

Purpose: The purpose of this study was to evaluate the accuracy of three types of intraoral scanners and the accuracy of the single abutment and bridge abutment model. Materials and methods: In this study, a single abutment, and a bridge abutment with missing first molar was fabricated and set as the reference model. The reference model was scanned with an industrial three-dimensional scanner and set as reference scan data. The reference model was scanned five times using the three intraoral scanners (CS3600, CS3500, and EZIS PO). This was set as the evaluation scan data. In the three-dimensional analysis (Geomagic control X), the divided abutment region was selected and analyzed to verify the scan accuracy of the abutment. Statistical analysis was performed using SPSS software (${\alpha}=.05$). The accuracy of intraoral scanners was compared using the Kruskal-Wallis test and post-test was performed using the Pairwise test. The accuracy difference between the single abutment model and the bridge abutment model was analyzed by the Mann-Whitney U test. Results: The accuracy according to the intraoral scanner was significantly different (P < .05). The trueness of the single abutment model and the bridge abutment model showed a statistically significant difference and showed better trueness in the single abutment (P < .05). There was no significant difference in the precision (P = .616). Conclusion: As a result of comparing the accuracy of single and bridge abutments, the error of abutment scan increased with increasing scan area, and the accuracy of bridge abutment model was clinically acceptable in three types of intraoral scanners.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.152-160
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• 2011

Purpose: The aim of this study was to evaluate the volumetric change of teeth after preparation for various designs and margin locations through Micro CT analysis (Skyscan 1076: SKYSCAN, Konitch, Belgium). Materials and methods: The 36 artificial teeth were used to determine reduction volume of upper central incisor. According to the restorative design these 36 teeth were divided into 4 groups and according to the marginal location each group was divided into 3 subgroups. The volume of unprepared teeth was obtained by using Micro CT and the volume of prepared teeth was obtained in the same method. The CT scanned images before and after preparation were superimposed. Results: The volume difference was significantly increased as follows: traditional laminate veneer < full laminate veneer < all ceramic crown < metal ceramic crown. One-way ANOVA and Tukey multiple comparison analyses were used to analyze the data in this study. In each group the volume difference was significantly increased as follows: 1 mm above CEJ < CEJ < 1 mm below CEJ (P<.05). The % volume difference of all ceramic crown and metal ceramic crown was 31 - 48% and that of laminate veneer was 14 - 30%. The volume difference of the traditional laminate veneer was 1/3 of that of metal ceramic crown. The full laminate (1 mm below CEJ) and all ceramic crown (1 mm above CEJ) showed a similar volume difference. Metal ceramic crown showed 13.7% more volume difference than all ceramic crown. Conclusion: There exists the difference in volumetric change according to designs of restoration and margin locations of preparation.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.267-275
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• 2023

To obtain better esthetic results when immediately placing a dental implant, the soft tissue surrounding the implant must be conditioned during healing of the extraction socket. To this end, the emergence profile can be customized through immediate restoration of the provisional prosthesis, and good clinical results can be obtained at the time of definitive restoration in the future, resulting in high patient satisfaction. In this case, horizontal root fracture occurred after trauma to both maxillary central incisors. Immediate implant placement and loading was planned considering aesthetics and alveolar bone condition. By taking an impression using a digital intraoral scanner, a digital diagnostic wax-up was performed to make a more aesthetic prosthesis without applying external force to the traumatized teeth. Based on this, the ideal placement location was determined and immediate implant placement was performed using a 3D printed surgical guide. The provisional prosthesis was restored 5 days after placement, and the definitive zirconia crown was restored through soft tissue conditioning and customization using the shape of the provisional prosthesis for 3 months.

• Restorative Dentistry and Endodontics
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• v.34 no.2
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• pp.87-94
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• 2009

The purpose of this study was to assess the current materials, methods and difficulties according to the year of licence and educational background of Korean dentists in Class II direct composite resin restorations. Total 17 questions were included in the questionnaire. Questions were broadly divided into two parts: first. operator's information. and second. the materials and methods used in Class II posterior composite restoration. The questionnaire was sent to dentists enrolled in Korean Dental Association via e-mail. Total 12,193 e-mails were distributed to dentists. 2,612 e-mails were opened, and 840 mails (32.2%) were received from respondents. The data was statically analyzed by chi-square test using SPSS(v. 12.0.1, SPSS Inc. Chicago, IL, USA). Male dentists among respondents was 79%. 60.3% of the respondents acquired their licences recently (1998-2007), and 77% practiced in private offices. 83.4% have acquired their knowledge through school lectures, conferences and seminars. For the Class II restorations, gold inlays were preferred by 65.7% of respondents, while direct composite resin restorations were used by 12.1 % amalgam users were only 4.4% of respondents. For the restorative technique, 74.4% of respondents didn't use rubber dam as needed. For the matrix. mylar strip (53.4%), metal matrix (33.8%) and Palodent system (6.5%) were used. 99.6% of respondents restored the Class II cavity by incremental layering. Obtaining of the tight interproximal contact was considered as the most difficult procedure (57.2%) followed by field isolation (21 %). Among various bonding systems, 22.6% of respondents preferred SE Bond and 20.2% used Single Bond. Z-250 was used most frequently among a variety of composite resins.

• 대한치과보철학회:학술대회논문집
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• 1994.05a
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• pp.52-52
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• 1994

• 대한치과보철학회:학술대회논문집
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• 1997.11a
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• pp.62-62
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• 1997

• 대한치과보철학회:학술대회논문집
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• 1999.11a
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• pp.36-36
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• 1999

• The Journal of the Korean dental association
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• v.22 no.12 s.187
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• pp.1006-1006
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• 1984

• 대한치과보철학회:학술대회논문집
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• 2006.04a
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• pp.89-89
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• 2006

• Proceedings of the KACD Conference
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• 2002.05a
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• pp.348-349
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• 2002