• 대한심미치과학회지
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• 제27권2호
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• pp.82-96
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• 2018

3D 프린팅은 삼차원 이미지 정보를 이용하여 레이어로 분할한 후 선택한 소재를 적층하여 가공하는 방법을 말한다. 소재를 적층하는 방법에 따라 다양한 종류의 3D 프린팅이 존재하는데 최근 치과분야에서는 SLA방식과 DLP방식으로 광원을 이용한 경화를 통해 적층 가공하는 3D 프린팅이 널리 보급되어 사용되고 있다. 전악 범위의 3D프린팅 치과용 모델은 전통적인 인상 채득으로 제작된 스톤모델보다는 다소 정확성이 부족한 것으로 보고되었으나, 같은 STL파일을 이용하여 4분악 범위를 3D 프린팅한 모델은 밀링 방법으로 가공한 모델보다 정확하였다. 디자인 소프트웨어의 활용도에 따라 보철치료의 진단, 임시 보철물의 제작, 의치의 제작이 가능하였다. 교정에서는 투명 교정 모델과 브라켓 간접 부착을 위한 트레이 제작이 가능하였다. 임플란트 수술에 있어서 CT를 기반으로 한 정확한 위치에 임플란트를 식립하는 가이드 제작에 활용하고 있다. 출력 방식의 발전으로 인하여 3D 프린터의 출력시간이 계속적으로 단축되고 있으며, 이로 인해 치과 진료실 내에서 3D 프린터가 기존의 전통적인 가공 방법을 대체할 수 있을 것으로 기대한다.

• 대한치과기공학회지
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• 제40권4호
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• pp.231-237
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• 2018

Purpose: The development of the dental technology industry has digitized the dental process. Definition of Digitalization of Dental Implantation Digitalization is the process of model making and prosthodontic processing using 3D CAD and CAM. Currently, it is becoming popular due to the spread of various devices. However, precision evaluation at this stage is an important factor in precision-based dental procedures. Therefore, in this study, we want to analyze the precision of the processed body made with digital dental machine. Methods: The accuracy of digital dental pore devices was evaluated. Specimens were fabricated with 5 types of 3D printers. The external shape was measured with the prepared specimen. The surface roughness was measured. Results: As a result, precision was excellent in order of EP2 specimen, EP1 specimen, and EA2 specimen. The precision of EP3 specimen and EA1 specimen is not excellent. And the precision of the specimen processed with polymer 3D printer is excellent. The accuracy of LCPS type polymer 3D printers is considered to be excellent. Conclusion : 1. Observation of the shape The 3D printer for LCPS system and the 3D printer for SLM $40{\mu}m$ system were found to be precisely processed. 2. Surface roughness results The LCPS system polymer 3D printer has been shown to have a precise surface.

• Journal of Yeungnam Medical Science
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• 제40권3호
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• pp.302-307
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• 2023

With recent developments in digital dentistry, research on techniques and materials for three-dimensional (3D) printing is actively underway. We report the clinical applications and outcomes of 3D printing of temporary crowns fabricated with polylactic acid (PLA) using a fused deposition modeling (FDM) printer. Five participants were recruited from among patients scheduled to be treated with a single full-coverage crown at a dental clinic in a university medical center from June to August 2022. We used 3D-printed crowns fabricated with PLA using an FDM printer as temporary crowns and were assessed for discomfort, fracture, and dislodging. The 3D-printed temporary crowns were maintained without fracture, dislodging, or discomfort until the permanent prosthesis was ready. The average time required for printing the temporary crowns was approximately 7 minutes. The 3D printing of temporary crowns with PLA using an FDM printer is a convenient process for dentists. However, these crowns have some limitations, such as rough surface texture and translucency; therefore, the 3D printing process should be improved to produce better prostheses.

• 대한치과기공학회지
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• 제41권4호
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• pp.255-262
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• 2019

Purpose: Recently, the production technology of dental prosthesis using 3D Printer workpeices has been developed. However, the lack of information on the work processes and casting techniques of materials for 3D printing casting is expected to require research. Therefore, in this study, we intend to cast a Dental DLP 3D Printer workpiece, which is being commercialized, to identify its appearance and internal clearance, and to observe its castability. Methods: Castability of the 3D Printer workpiece was evaluated. The specimen is prepared in a cylindrical shape and in a 1 mm thick coping shape. The control specimen is made of wax and the experimental specimen is made of resin using two types of 3D printers. After casting, the appearance of the casting body was observed and the internal clearance of the coping was measured. Results: RP1 and RP2, cylindrical specimens, were partially cast or fin. When coping-type specimens were measured before casting, the internal clearance of PE2 was more accurate than that of PC and PE1. When coping-type specimens were measured after casting, CE1 was the most accurate in occlusal clearance and CE2n was the most accurate in axial clearance. Conclusion: 1. Exterior observations of the casting body indicated casting defects and fins. 2. Internal clearance observations show that the occlusal clearance of the castings is larger after casting, and the axial clearance of the castings is smaller after casting. 3. It is judged that the RP2 specimen is more likely to be applied for casting than the RP1 specimen.

• 대한심미치과학회지
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• 제30권2호
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• pp.59-70
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• 2021

치과 영역에 디지털 시스템의 유입은 치과의사와 치과기공사에게 큰 영향을 끼쳤다. 그리고 이전 보다 향상된 정확도와 편리함 그리고 업무 효율성 증대를 가져왔다. 그러나 디지털은 모든 것을 해결해주지 못하며 분명 한계도 있다. 따라서 임상가는 전통정식 방식과 디지털 방식의 장단점에 대해 분명히 이해하고 두 방식이 조화를 이루는 본인만의 워크플로우를 설계하는 것을 권유한다. 본편에서는 필자가 임상에서 3D 프린터를 어떻게 활용하고, 적용하고 있는지를 소개하고 있다.

• 한국치위생학회지
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• 제22권6호
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• pp.467-475
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• 2022

Objectives: This study aimed to understand the definitions, types, and principles of computer-aided design/computer-aided manufacturing (CAD/CAM) and scanners due to the introduction of digital workflows. Methods: This study was based on information from the government's law and articles published in academic journals. Results: CAD/CAM is a technology that measures the shape three-dimensionally, saves it as data, designs it into the desired shape, and processes the product. Scanners, which are classified as intraoral and extraoral scanners, measure teeth and the intraoral environment three-dimensionally and convert them into three-dimensional (3D). A 3D printer is a machine that creates a 3D object by layering materials based on a 3D drawing. It can be classified into four types according to the method: extrusion, powder bonding, lamination, and photopolymerization methods. The most used 3D printer methods in dentistry are stereolithograhpy and digital light processing, and they are widely used in prosthetic, surgical, and orthodontic fields. Conclusions: As the dental system is digitized, it is expected that the government will classify the dental hygienist scope of work and the universities will reflect the curriculum; it is necessary to develop excellent dental hygienists, diversify the educational pathways, and establish policies to meet the needs of the increasing number of patients.

• 대한치과기공학회지
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• 제41권4호
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• pp.287-293
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• 2019

Purpose: To evaluate the accuracy of the 3D printed die models and to investigate its clinical applicability. Methods: Stone die models were fabricated from conventional impressions(stone die model; SDM, n=7). 3D virtual models obtained from the digital impressions were manufactured as a 3D printed die models using a 3D printer(3D printed die models;3DM, n=7). Reference model, stone die models and 3D printed die models were scanned with a reference scanner. All dies model dataset were superimposed with the reference model file by the "Best fit alignment" method using 3D analysis software. Statistical analysis was performed using the independent t-test and 2-way ANOVA (α=.05). Results: The RMS value of the 3D printed die model was significantly larger than the RMS value of the stone die model (P<.001). As a result of 2-way ANOVA, significant differences were found between the model group (P<.001) and the part (P<.001), and their interaction effects (P<.001). Conclusion: The 3D printed die model showed lower accuracy than the stone die model. Therefore, it is necessary to further improve the performance of 3D printer in order to apply the 3D printed model in prosthodontics.

• 치위생과학회지
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• 제19권4호
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• pp.238-244
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• 2019

Background: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method. Methods: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups. Results: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP. Conclusion: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

• 대한치과의사협회지
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• 제56권6호
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• pp.339-347
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• 2018

Conventional mouthguard fabrication process which consists of elastomeric impression taking and followed gypsum model making is changing into intraoral scanning and dental model printing with 3D printer. In addition, new 3D printing materials for mouthgurad, 3D Computer-Aided Design(CAD) software for dental appliance, evaluation of a virtual dentoalveolar model for testing virtually 3D designed mouthguard, and lightweight sensor technology will lead dental professionals to the new era of Sports Dentistry, including information technology integrated custom mouthguard fabrication and creating value with analytic data acquired from sensors in mouthguard.

• 대한치과기공학회지
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• 제43권3호
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• pp.71-76
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• 2021

Purpose: In this study, thermal properties were observed by measuring the extent of thermal expansion and the amount of thermal residue that appears upon burnout on a workpiece made by using a dental digital light processing (DLP) three-dimensional (3D) printer. Methods: Thermal properties of workpieces manufactured by using two 3D printers were observed. The specimens were designed in cylindrical form with dimensions 10 mm in diameter and 10 mm in height. The control specimen was made of wax, and the experimental specimen was made of resin. The thermal expansion rate was measured by applying heat to three types of specimens, and burnout residue was measured. Results: The thermal expansion rate of the wax pattern (WP) specimen was 0.93%±0.05%, of the RP1 specimen was 1.30%±0.08%, and of the RP2 specimen was 1.20%±0.09%. Measuring the recovered residue yielded residual amounts of 0.2% for the WP specimen, 1.1% for the RP2 specimen, and 1.8% for the RP1 specimen. Conclusion: 1. From measurements of the workpieces manufactured by dental DLP 3D printing, the thermal expansion rate was found to be higher than that of wax. 2. As a result of measuring burnout residues on the workpieces manufactured by dental DLP 3D printing, the required summoning temperature to obtain suitable castings was determined to >750℃.