• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.427-435
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• 2017

The most important factor in the treatment of fully edentulous patients using implants is the shape of the definitive prosthesis. After the shape of the definitive prosthesis is determined, residual bone analysis and selection of the implant type, number and position should be followed. In this case, for restoration of an edentulous patient fully implanted (except the maxillary right lateral incisor) without considering definitive prosthesis, facial esthetics and possibility of fixed type prosthesis were evaluated using complete denture. It was determined that the fixed type prosthesis was possible. Implants that could not be used for the definitive prosthesis were excluded from the treatment plan and fixed type provisional restorations were fabricated. After four months of provisional restorations, the patient showed stable occlusion and esthetic satisfaction. Definitive prosthesis was made of zirconia using CAD/CAM (computer aided design and computer aided manufacturing). The results were satisfactory during the 3 months of follow-up period after termination of treatment.

• The Journal of Advanced Prosthodontics
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• v.12 no.6
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• pp.329-337
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• 2020

PURPOSE. To verify the influence of computer-aided design/computer-aided manufacturing (CAD/CAM) implant-supported prostheses manufactured with cobalt-chromium (Co-Cr) and zirconia (Zr), and whether ceramic application, spark erosion, and simulation of masticatory cycles modify biomechanical parameters (marginal fit, screw-loosening torque, and strain) on the implant-supported system. MATERIALS AND METHODS. Ten full-arch fixed frameworks were manufactured by a CAD/CAM milling system with Co-Cr and Zr (n=5/group). The marginal fit between the abutment and frameworks was measured as stated by single-screw test. Screw-loosening torque evaluated screw stability, and strain analysis was explored on the implant-supported system. All analyses were performed at 3 distinct times: after framework manufacturing; after ceramic application in both materials' frameworks; and after the spark erosion in Co-Cr frameworks. Afterward, stability analysis was re-evaluated after 106 mechanical cycles (2 Hz/150-N) for both materials. Statistical analyses were performed by Kruskal-Wallis and Dunn tests (α=.05). RESULTS. No difference between the two materials was found for marginal fit, screwloosening torque, and strain after framework manufacturing (P>.05). Ceramic application did not affect the variables (P>.05). Spark erosion optimized marginal fit and strain medians for Co-Cr frameworks (P<.05). Screw-loosening torque was significantly reduced by masticatory simulation (P<.05) regardless of the framework materials. CONCLUSION. Co-Cr and Zr frameworks presented similar biomechanical behavior. Ceramic application had no effect on the biomechanical behavior of either material. Spark erosion was an effective technique to improve Co-Cr biomechanical behavior on the implant-supported system. Screw-loosening torque was reduced for both materials after masticatory simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.562-565
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• 2002

Recent technologic innovations have created possibilities for restorative dentistry, such as computer-aided design and computer-aided manufacturing. This article presents a CAD process that has been developed for the fabrication of dental restorations. This process uses a 4-axes driving mechanism and an improved optical displacement sensor, successfully applied in other industries. In optical displacement sensor, the light beam emitted from the LED is converged through the light source lenses and thrown on the object to be detected. When the light beam is reflected from the object, however, it is diffused. The diffused light beam is converged again by the receiver lenses and cast on the optical position detector element as a small spot.

• The Journal of the Korean dental association
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• v.57 no.9
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• pp.524-528
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• 2019

With the advances of CAD-CAM (computer-aided design and computer-aided manufacturing) technology, the field of modern clinical dentistry has been dramatically changed. The first step in the digital workflow for tooth-supported dental prosthesis is a data acquisition with intraoral digital or conventional impression techniques. For the accuracy of intraoral digital impression data, the basic principles of conventional impression should be applied. It is necessary to obtain a good visibility with properly-dried field and well-exposed margin of the prepared abutment. Currently, the equi- or supra-gingival finish line can be recommended as an indication for intraoral digital impression. The scan data are generally exported to '.stl' file format, which has only morphological information of black and whitem while '.obj' file format can store data on color and texture.

• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.245-251
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• 2018

PURPOSE. To evaluate the accuracy of a model made using the computer-aided design/computer-aided manufacture (CAD/CAM) milling method and 3D printing method and to confirm its applicability as a work model for dental prosthesis production. MATERIALS AND METHODS. First, a natural tooth model (ANA-4, Frasaco, Germany) was scanned using an oral scanner. The obtained scan data were then used as a CAD reference model (CRM), to produce a total of 10 models each, either using the milling method or the 3D printing method. The 20 models were then scanned using a desktop scanner and the CAD test model was formed. The accuracy of the two groups was compared using dedicated software to calculate the root mean square (RMS) value after superimposing CRM and CAD test model (CTM). RESULTS. The RMS value ($152{\pm}52{\mu}m$) of the model manufactured by the milling method was significantly higher than the RMS value ($52{\pm}9{\mu}m$) of the model produced by the 3D printing method. CONCLUSION. The accuracy of the 3D printing method is superior to that of the milling method, but at present, both methods are limited in their application as a work model for prosthesis manufacture.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.410-418
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• 2017

Amelogenesis imperfecta characterized as abnormally formed enamel is caused by a defect of unique group of genes. Patients affected by this disease might have difficulties in social and psychological aspects due to non-esthetic teeth as well as functional problems caused by enamel detachment and tooth wear from their early ages. Adult patients with amelogenesis imperfecta can be treated with full-mouth restorations, which make functional and esthetic rehabilitations of severely worn tooth. However, the anterior open bite and lack of occlusal clearance for posterior teeth restorations due to compensatory extrusion are the intervening factors in the prosthetic treatment. Therefore, the determination of anterior tooth lengths, vertical dimension, and anterior guidance should be set carefully. Recently, computer-aided design and computer-aided manufacturing (CAD/CAM) techniques help systematic approaches and enable dentists to reduce time-consuming procedures in the diagnosis and treatment of full-mouth rehabilitation. This case report demonstrates the successful full mouth rehabilitation using a CAD/CAM system in a young adult patient with amelogenesis imperfecta and anterior open bite.

• Journal of Engineering Education Research
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• v.11 no.1
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• pp.85-100
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• 2008

The purpose of this study is development of 'F1 in Schools Program' for elementary school student and validation of the program. Fifteen students were originally chosen from the W elementary school in Cheongju, Chungcheogbuk-Do. The children were tested on their understanding of science and 'F1 in Schools Program'. After developing the 'F1 in Schools Program', it was used in the classroom to evaluate applicability and to examine the responses from students, parents and schools. The program consists of 60 classes and the time of each class is 40 minutes. This study was conducted for 10 days from January 22nd, 2007 to February 2nd, 2007. CAD(Computer Aided Design), CFD(Computation Fluid Dynamics), CAM(Computer Aided manufacturing) and CNC Machine were used in this study and proved to be good materials for students in that they increased the students' participation and imagination. However, the children's cognitive and creative abilities as well as manuals written in English hampered the process. Most students, parents, schools seemed to be satisfied with use of the program. However, the schools showed that there was not enough understanding of the program as a whole. The processes with which students build and inspect using the $CO_2$Model Car not only improves the processing of the model but also enhanced the students scientific understanding related to the car speed.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.160-170
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• 2019

The anterior guidance is one of the important factors in prosthodontic treatment of anterior teeth. The lingual surface shape of anterior restorations is so critical that small errors of treatment procedure can cause discomfort of the patient and disharmony of the dentition. If the anterior restorations are achieved harmonious anterior guidance through the fabrication and adjustment of provisional restorations, it is important to accurately reproduce the lingual surface shape of provisional restorations as the final prosthesis. In this case report, it was used the modified Dahl principle and copy-milled technique of computer-aided design/computer-aided manufacturing (CAD/CAM) system for systematic diagnosis and treatment. Therefore, we tried to reconstruct the restoration shape more precisely by setting the appropriate anterior guidance and superimposing the digital image of the abutment teeth and the provisional restorations. Thus, by promoting functional and esthetic recovery, this case report demonstrates satisfying results to both the patients and dentist.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.367-378
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• 2023

With the recent development of computer-aided design-computer-aided manufacturing technology and 3D printing technology, and the introduction of various digital techniques, the accuracy and efficiency of top-down definitive prosthetic restoration are increasing. In this clinical case, stable occlusion support was obtained through the placement of a total of 9 maxillary and mandibular posterior implants in patient with anterior-posterior crossed occlusion. The edentulous area of the maxillary anterior teeth, which showed a tendency of high resorption of the residual alveolar bone, was restored with a Kennedy Class IV implant assisted removable partial denture to restore soft tissue esthetics. Computed tomography guided surgery was used to place implants in the planned position, double scan technique was used to reflect the stabilized occlusion in the interim restoration stage to the definitive prostheses, and metal 3D printing was used to manufacture the coping and framework. This clinical case reports that efficient and predictable top-down full mouth rehabilitation was achieved using various digital technologies and techniques.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.329-332
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• 2016

Fabricating a surveyed prosthesis beneath an existing partial removable dental prosthesis (PRDP) is a challenging and time-consuming procedure. The computer-aided design/computer-assisted manufacturing (CAD/CAM) technology was applied to fabricate a retrofitted, surveyed zirconia prosthesis to an existing PRDP. CAD/CAM technology enabled precise and easy replication of the contour of the planned surveyed crown on the existing abutment tooth. This technology ensured excellent adaptation and fit of newly fabricated crown to the existing PRDP with minimal adjustments. In this case report, a seventy-year-old male patient presented with fractured existing surveyed crown. Because the existing PRDP was serviceable, new crown was fabricated to the existing PRDP.