• 대한치과보철학회지
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• 제59권1호
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• pp.97-106
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• 2021

임플란트를 사용한 수복치료에서는 보철물을 위한 이상적인 위치에 임플란트가 식립되어야 한다. 치조골이 부족한 환자의 경우에는 최종 보철물을 위한 적절한 연조직 및 경조직 지지를 얻기 위해서 수술적인 처치를 포함한 구강내 처치를 필요로 하게 된다. CAD-CAM 기술을 활용한 보철물 설계는 위와 같은 수술적 처치의 필요성에 대해 임상가가 사전적으로 평가해볼 수 있는 청사진을 제시해준다. 본 증례에서는 CAD-CAM system을 통해 환자의 치료 전 구내상황, 수술적 처치에 대한 예상, 일련의 임시 보철물을 반영하여 최종 보철물을 계획하고 제작하였다. 최종 보철물을 반영하여 제작한 수술용 가이드를 사용하여 임플란트를 식립함과 동시에 치조골 증대술을 시행하였다. 이후 CAD-CAM을 활용하여, 맞춤형 지대주와 1차 및 2차 잠정 수복물을 디자인하고 제작하였으며, 환자의 구내에서 평가를 거친 2차 잠정 보철물과 동일한 형태의 최종 보철물을 제작하였다. 저작, 발음, 심미 기능에 있어서 환자와 술자 모두 만족할만한 결과를 얻을 수 있었다.

• 대한심미치과학회지
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• 제25권1호
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• pp.4-14
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• 2016

CAD/CAM이 치과계에 도입된지도 벌써 꽤 많은 시간이 흘렀음에도 불구하고 현재의 CAD/CAM은 여전히 비효율적이거나 또는 비심미적이다. '효율성' 과 '심미성'이란 두 단어는 지르코이나 보철물에 있어서는 양극에 위치하게 된다. 효율적이기 위해 도재소성없이 monolithic한 지르코니아 보철물을 만들다 보면 비심미적인 경우가 대부분이고, 거꾸로 심미적이기 위해 도재소성 과정을 거치다보면 여전히 사람의 손을 타게되는 비효율성을 피할 수 없기 때문이다. 이 글에서는 지르코니아 보철물의 현주소와 이와 관련된 몇가지 증례들을 보여드리고자 한다.

• 대한치과교정학회지
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• 제50권6호
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• pp.373-382
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• 2020

Objective: To compare computer-aided design and computer-aided manufacturing (CAD/CAM) customized nitinol retainers with standard stainless-steel fixed retainers over a 12-month study period. Methods: This randomized controlled trial (RCT) was conducted on 62 patients randomly allocated to a control group that received stainless-steel retainers or a test group that received customized CAD/CAM nickel-titanium retainers. Four time points were defined: retainer placement (T0) and 1-month (T1), 6-month (T2), and 12-month (T3) follow-up appointments. At each time point, Little's irregularity index (LII) (primary endpoint) and dental stability measurements such as intercanine width were recorded in addition to assessment of periodontal parameters. Radiological measurements such as the incisor mandibular plane angle (IMPA) were recorded at T0 and T3. Failure events (wire integrity or debonding) were assessed at each time point. Results: From T0 to T3, LII and other dental measurements showed no significant differences between the two groups. The data for periodontal parameters remained stable over the study period, except for the gingival index, which was slightly, but significantly, higher in the test group at T3 (p = 0.039). The IMPA angle showed no intergroup difference. The two groups showed no significant difference in debonding events. Conclusions: This RCT conducted over a 12-month period demonstrated no significant difference between customized CAD/CAM nickel-titanium lingual retainers and standard stainless-steel lingual retainers in terms of dental anterior stability and retainer survival. Both retainers eventually appeared to be equally effective in maintaining periodontal health.

• 구강회복응용과학지
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• 제34권3호
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• pp.196-207
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• 2018

임플란트의 장기적인 안정을 위해서는 이상적인 위치와 각도로 임플란트를 식립하는 것이 중요하며, 이를 위해서는 정확한 계획에 따른 정확한 수술과 보철이 중요하다. 본 증례에서는 치조골 흡수가 심하게 진행된 환자에서 CT data 및 진단왁스업을 스캔한 data를 이용하여 CT guided surgery를 시행하고, 단일구조 수복용 지르코니아와 CAD/CAM technique을 이용하여 전악 임플란트 고정성 보철로 수복하여 기능 및 심미적으로 만족할만한 결과를 얻었기에 이를 보고하고자 한다.

• 대한치과보철학회지
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• 제52권2호
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• pp.121-127
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• 2014

광범위한 보철 수복 치료는 수복 부위별로 다양한 고려 요소를 필요로 한다. 특히, 상악 전치부의 교합 계획은 다른 부위보다 더 많은 지식과 기술을 요한다. 전방 유도(anterior guidance)를 결정하는 상악 전치부 설면 외형을 제대로 형성하지 못하면, 기능적인 불편감과 함께 전체 치열의 불안정성을 야기한다. 임시 수복물 장착한 상태에서 적절한 조정을 통해 조화로운 전방 유도를 얻었다면 임시 수복물의 설면 형태를 최종 보철물로 정확하게 구현하는 방법에 주의를 기울여야 한다. 본 증례에서는 CAD/CAM (computer-aided design / computer-aided manufacturing) 시스템의 복제 기법을 활용하여 지대치의 디지털 이미지와 임시수복물의 디지털 이미지를 중첩시켜 보다 간편하게 보철물 형태를 복제하였다. 기존의 방법에 비해 술자는 진료실 시간을 줄일 수 있고, 환자는 기능과 심미 모두 만족할 만한 결과를 얻어 이를 보고하고자 한다.

• The Journal of Advanced Prosthodontics
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• 제9권4호
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• pp.265-270
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• 2017

PURPOSE. This study is to evaluate the internal fit of the crown manufactured by CAD/CAM milling method and 3D printing method. MATERIALS AND METHODS. The master model was fabricated with stainless steel by using CNC machine and the work model was created from the vinyl-polysiloxane impression. After scanning the working model, the design software is used to design the crown. The saved STL file is used on the CAD/CAM milling method and two types of 3D printing method to produce 10 interim crowns per group. Internal discrepancy measurement uses the silicon replica method and the measured data are analyzed with One-way ANOVA to verify the statistic significance. RESULTS. The discrepancy means (standard deviation) of the 3 groups are $171.6\;(97.4){\mu}m$ for the crown manufactured by the milling system and 149.1 (65.9) and $91.1\;(36.4){\mu}m$, respectively, for the crowns manufactured with the two types of 3D printing system. There was a statistically significant difference and the 3D printing system group showed more outstanding value than the milling system group. CONCLUSION. The marginal and internal fit of the interim restoration has more outstanding 3D printing method than the CAD/CAM milling method. Therefore, the 3D printing method is considered as applicable for not only the interim restoration production, but also in the dental prosthesis production with a higher level of completion.

• 대한치과기공학회지
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• 제41권3호
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• pp.203-209
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• 2019

Purpose: The purpose of this study was to investigate the mechanical properties of polymer prosthetic and restorative materials for dental CAD/CAM using two test method; surface characteristics and shear bond strength. Methods: Commercialized CAD/CAM polymer blanks were investigated; One kinds of PMMA, and one PEKK blanks. A total of 20 PMMA and PEKK specimens were prepared, and each group was divided into 10 specimens. Average surface roughness was observed under surface profilometer. The contact angle was measured with a surface electrooptics. The bond strength was evaluated by a universal testing machine at a crosshead speed of 5mm/min. The data were statistically analyzed using independent t-test and Fisher's exact test(P<0.05). Results: The PMMA and PEKK group showed a significant difference in the shear bond strength with the composite resin(P<0.05). The surface roughness of the PEKK group was higher than that of the PMMA group. The fracture mode were observed in PEKK groups with 50% showing adhesive remnant index score. Conclusion: PEEK is used as substructure material and composite veneering material is applied. PEKK resins will contribute to the development of successful products that will provide structural and aesthetic satisfaction.

• The Journal of Advanced Prosthodontics
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• 제15권3호
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• pp.155-170
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• 2023

PURPOSE. This study aims to clinically compare the fitness and trueness of zirconia crowns fabricated by different combinations of open CAD-CAM systems. MATERIALS AND METHODS. Total of 40 patients were enrolled in this study, and 9 different zirconia crowns were prepared per patient. Each crown was made through the cross-application of 3 different design software (EZIS VR, 3Shape Dental System, Exocad) with 3 different processing devices (Aegis HM, Trione Z, Motion 2). The marginal gap, absolute marginal discrepancy, internal gap(axial, line angle, occlusal) by a silicone replica technique were measured to compare the fit of the crown. The scanned inner and outer surfaces of the crowns were compared to CAD data using 3D metrology software to evaluate trueness. RESULTS. There were significant differences in the marginal gap, absolute marginal discrepancy, axial and line angle internal gap among the groups (P < .05) in the comparison of fit. There was no statistically significant difference among the groups in terms of occlusal internal gap. The trueness ranged from 36.19 to 43.78 ㎛ but there was no statistically significant difference within the groups (P > .05). CONCLUSION. All 9 groups showed clinically acceptable level of marginal gaps ranging from 74.26 to 112.20 ㎛ in terms of fit comparison. In the comparison of trueness, no significant difference within each group was spotted. Within the limitation of this study, open CAD-CAM systems used in this study can be assembled properly to fabricate zirconia crown.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.41.1-41.6
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• 2019

Backgrounds: The purpose of this study is to discuss the total joint reconstruction surgery for a patient with recurrent ankylosis in bilateral temporomandibular joints (TMJs) using three-dimensional (3D) virtual surgical planning, computer-aided manufacturing (CAD/CAM)-fabricated surgical guides, and stock TMJ prostheses. Case presentation: A 66-year-old female patient, who had a history of multiple TMJ surgeries, complained of severe difficulty in eating and trismus. The 3D virtual surgery was performed with a virtual surgery software (FACEGIDE, MegaGen implant, Daegu, South Korea). After confirmation of the location of the upper margin for resection of the root of the zygoma and the lower margin for resection of the ankylosed condyle, and the position of the fossa and condyle components of stock TMJ prosthesis (Biomet, Jacksonville, FL, USA), the surgical guides were fabricated with CAD/CAM technology. Under general anesthesia, osteotomy and placement of the stock TMJ prosthesis (Biomet) were carried out according to the surgical planning. At 2 months after the operation, the patient was able to open her mouth up to 30 mm without complication. Conclusion: For a patient who has recurrent ankylosis in bilateral TMJs, total joint reconstruction surgery using 3D virtual surgical planning, CAD/CAM-fabricated surgical guides, and stock TMJ prostheses may be an effective surgical treatment option.

• The Journal of Advanced Prosthodontics
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• 제4권3호
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• pp.162-169
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• 2012

PURPOSE. Fracture of the veneering material of zirconia restorations frequently occurs in clinical situations. The purpose of this in vitro study was to compare the fracture strengths of zirconia crowns veneered with various ceramic materials by various techniques. MATERIALS AND METHODS. A 1.2 mm, $360^{\circ}$ chamfer preparation and occlusal reduction of 2 mm were performed on a first mandibular molar, and 45 model dies were fabricated in a titanium alloy by CAD/CAM system. Forty-five zirconia copings were fabricated and divided into three groups. In the first group (LT) zirconia copings were veneered with feldspathic porcelain by the layering technique. In the second group (HT) the glass ceramic was heat-pressed on the zirconia coping, and for the third group (ST) a CAD/CAM-fabricated high-strength anatomically shaped veneering cap was sintered onto the zirconia coping. All crowns were cemented onto their titanium dies with Rely $X^{TM}$ Unicem (3M ESPE) and loaded with a universal testing machine (Instron 5583) until failure. The mean fracture values were compared by an one-way ANOVA and a multiple comparison post-hoc test (${\alpha}$= 0.05). Scanning electron microscope was used to investigate the fractured interface. RESULTS. Mean fracture load and standard deviation was $4263.8{\pm}1110.8$ N for Group LT, $5070.8{\pm}1016.4$ for Group HT and $6242.0{\pm}1759.5$ N for Group ST. The values of Group ST were significantly higher than those of the other groups. CONCLUSION. Zirconia crowns veneered with CAD/CAM generated glass ceramics by the sintering technique are superior to those veneered with feldspathic porcelain by the layering technique or veneered with glass ceramics by the heat-pressing technique in terms of fracture strength.