• 구강회복응용과학지
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• 제30권1호
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• pp.71-80
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• 2014

골흡수가 심한 환자에서 임플란트를 이용한 전악 수복의 경우 치은과 치아의 외형을 심미적이면서도 기능적으로 회복하기 위해서는 보철물 제작에 있어 신중을 기해야 한다. 이러한 전악 수복 증례에서 CAD/CAM 시스템이 높은 정확성을 가지는 보철물 제작을 가능하게 함으로써 사용이 증가하고 있다. 최근에 임상에서 티타늄이나 지르코니아의 단점을 보완하면서 높은 생체적합성을 가지고 CAD/CAM 시스템으로 제작할 수 있는 팔라듐-은(Pd-Ag) 합금이 개발되어 사용되고 있다. 본 증례에서는 상악 전부 무치악 환자에서 임플란트를 식립하고 도재의 chipping이나 파절의 위험을 감소시키기 위해 Pd-Ag 합금을 이용해 제작된 임플란트 고정성 보철물로 수복한 환자에 대해 보고하고자 한다.

• The Journal of Advanced Prosthodontics
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• 제15권1호
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• pp.44-54
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• 2023

PURPOSE. To assess the clinical performance of monolithic CAD-CAM lithium disilicate glass-ceramic (LDGC) crowns and metal-ceramic (MC) crowns provided by predoctoral students. This study also assessed the effects of patient and provider-related factors on their clinical performance as well as patient preference for these types of crowns. MATERIALS AND METHODS. Twenty-five patients who received 50 crowns (25 LDGC CAD-CAM and 25 MC) provided by predoctoral students were retrospectively examined. LDGC CAD-CAM crowns were milled in-house using the CEREC Bluecam system and cemented with either RelyX Unicem or Calibra Esthetic resin cements. MC crowns were cemented with RelyX Unicem cement. Clinical assessment of the crowns and the supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Patients' preference was recorded using a visual analog scale (VAS). The results were statistically analyzed using log-rank test, Pearson Chi-squared test and Kaplan-Meier survival analysis. RESULTS. Twelve complications were observed in the MC crown group (9-esthetic, 2-technical and 1-biological). In comparison, 2 complications in the LDGC CAD-CAM crown group were observed (1-technical and 1-esthetic). The 6-year cumulative survival rates for MC crowns and LDGC CAD-CAM were 90.8% and 96%, respectively, whereas the success rates were 83.4% and 96%, respectively. Overall, patients preferred the esthetic outcomes of LDGC CAD-CAM crowns over MC crowns. CONCLUSION. The high survival and success rates, low number of complications, and the high level of patients' acceptance of monolithic LDGC CAD-CAM crowns lend them well as predictable and viable alternatives to the "gold standard" MC crowns.

• The Journal of Advanced Prosthodontics
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• 제8권4호
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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.

• 대한장애인치과학회지
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• 제13권2호
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• pp.95-98
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• 2017

본 증례는 다운 증후군이 있는 환자의 구강 재건 시 CAD/CAM 시스템 사용의 이점을 모색해보았다. 다운 증후군 환자들의 경우, 보철물 파절의 위험성이 크며 불가피하게 보철물을 재제작할 경우, CAD/CAM 시스템의 기존 데이터를 이용하여 최소한의 기공 과정만 진행하여 보철물을 빠른 시일 내에 재제작할 수 있다. 결과적으로 이는 심미적 및 기능적 개선을 통해 삶의 질을 높일 수 있는 보철물 제작 시 환자의 불편감과 치과의사의 노력을 최소화하는 방법이다.

• 대한심미치과학회지
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• 제22권1호
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• pp.22-29
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• 2013

일반적으로 심미 보철을 진행하기 위해서는 초진 시부터 카메라를 사용해서 최종 보철물을 고려하며 여러 가지 분석을 한다. 이 부분에서 많은 치의들이 디지털카메라를 사용하고 있는 현실을 볼 때, 우리는 이미 digital impression을 시작하고 있는 것이 아닐까 생각한다. 최근 세계적인 photographer들도 필름카메라에서 디지털카메라로 넘어오는 추세가 많아지고 있는 것처럼 심미 치과학에서도 CAD/CAM은 향후 우리가 추구하고자 하는 심미 영역에서의 또 한가지 방향성을 제시해 줄 수 있지 않을까 하는 생각이 든다. 흔히 디지털이라고 하면 편의성, 경제성 등을 먼저 떠올리는 경향이 있다. 그러나 치과 임상적 관점에서 기존의 analog방식을 존중하며 CAD/CAM system이 가지는 그 특수성과 우수성을 고민하고 이를 개선, 발전시키는 것 또한 중요하다고 생각된다. 다만 아쉬운 것은 CAD/CAM 장치와 소재가 급격히 발전하는 이유로 인하여 reference, follow-up이 어려운 경우가 많다. 이에 digital은 변화하는 속도가 굉장히 빠르기 때문에, 여러 가지 소재와 장치들을 접해보고 경험해보면서 그에 맞게끔 발맞춰 적용해 볼 수밖에는 없지만 임상에 적용하여 보다 좋은 결과 얻기 위해서는 전통적인 방식이 기본바탕이 된 상태에서 이루어져야 한다는 점을 강조하고 싶다. 본 연구에서는 심미적 관점에서 전통적인 방식과 CAD/CAM과의 조화 통해서 어떤 접근을 할 수 있는지에 대해서 살펴보고자 한다. 그리고 CAD/CAM 보철이 'Digital art' 영역에 한 축의 역할을 할 수 있기를 기다리고 열망한다.

• 대한치과기공학회지
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• 제40권1호
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• pp.27-32
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• 2018

Purpose: This study was performed to investigate processability of the dental zirconia block. Most of the CAD/CAM zirconia restorations utilize the partially sintered blocks, which are sintered at a temperature lower than $1100^{\circ}C$. Methods: Partially sintered zirconia samples were prepared $40{\times}30{\times}10mm$ and surface treatment by #2000 sandpaper. Scratch hardness was determined by the procedure of ASTM G171-03 using a scratch hardness tester(KS TECH, Korea) equipped with a real time load detector to measure tangential force during scratching. The scratch rate was 30 mm/min. Results: Scratch hardness(Hs) increases steeply with increase in the loads. The highest Hs was sampl 1.42 GPa and lowest was sample 0.42 GPa. Conclusion : The machinability of partially sintered CAD/CAM zirconia blocks can be optivized by manipulation of Hs.

• The Journal of Advanced Prosthodontics
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• 제12권6호
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• pp.344-350
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• 2020

PURPOSE. Recently introduced hybrid and reinforced glass ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials have been used for full-coverage restorations. However; the effect of adjustment and type of materials on internal and marginal adaptation are unknown. This study aimed to evaluate and compare the marginal and internal adaptations of crowns made of three different CAD/CAM materials before and after adjustment. MATERIALS AND METHODS. One acrylic resin maxillary first molar was prepared and served as the master die. Thirty-six restorations were fabricated using CAD/CAM system (CEREC Omnicam, MCXL) with three materials including lithium disilicate (IPS e.max CAD), zirconia-reinforced lithium silicate (Suprinity), and hybrid ceramic (Enamic). Internal and marginal adaptations were evaluated with the reference point matching technique before and after adjustment. The data were analyzed using mixed ANOVA considering α=.05 as the significance level. RESULTS. The effect of adjustment and its interaction with the restoration material were significant for marginal, absolute marginal, and occlusal discrepancies (P<.05). Before adjustment, Suprinity had lower marginal discrepancies than IPS e.max CAD (P=.18) and Enamic (P=.021); though no significant differences existed after adjustment. CONCLUSION. Within the limitations of this study, crowns fabricated from IPS e.max CAD and Suprinity resulted in slightly better adaptation compared with Enamic crowns before adjustment. However, marginal, axial, and occlusal discrepancies were similar among all materials after the adjustment.

• 대한치과의사협회지
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• 제54권3호
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• pp.191-197
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• 2016

In the past, restoration of implant crown, ready-made abutment produced by implant manufacturer could only be used. Using straight, angled abutment, there was a limit in adaptation multiple implants. Recently, with the development of implant and CAD/CAM technology, CAD/CAM customized abutment use has become possible which is different from the past when restoration was possible with only prefabricated abutment. Not only it makes emergence profile possible which is similar to natural teeth, but also it makes insertion path possible on CAD in multiple implant restorations. However, on anterior teeth which dental esthetics is very important, another restorations which are formed with natural colored gingiva area could be required. Titanium-based zirconia prostheses which have titanium connection and zirconia structure from 1mm above fixture platform are alternative. Therefore, the purpose of this review is to analyze the characteristics, advantages and disadvantages of the abutment which is used in multiple implant restorations, and to choose right abutment when clinical trials.

• The Journal of Advanced Prosthodontics
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• 제12권6호
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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.

• Restorative Dentistry and Endodontics
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• 제44권3호
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• pp.23.1-23.9
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• 2019

Objectives: The aim of this study was to investigate the microshear bond strength (${\mu}SBS$) of different universal adhesive systems applied to hybrid computer-aided design/computer-aided manufacturing (CAD-CAM) restorative materials repaired with a composite resin. Materials and Methods: Four types of CAD-CAM hybrid block materials-Lava Ultimate (LA), Vita Enamic (VE), CeraSmart (CS), and Shofu Block HC (SH)-were used in this study, in combination with the following four adhesive protocols: 1) control: porcelain primer + total etch adhesive (CO), 2) Single Bond Universal (SB), 3) All Bond Universal (AB), and 4) Clearfil Universal Bond (CU). The ${\mu}SBS$ of the composite resin (Clearfil Majesty Esthetic) was measured and the data were analyzed using two-way analysis of variance and the Tukey test, with the level of significance set at p < 0.05. Results: The CAD-CAM block type and block-adhesive combination had significant effects on the bond strength values (p < 0.05). Significant differences were found between the following pairs of groups: VE/CO and VE/AB, CS/CO and CS/AB, VE/CU and CS/CU, and VE/AB and CS/AB (p < 0.05). Conclusions: The ${\mu}SBS$ values were affected by hybrid block type. All tested universal adhesive treatments can be used as an alternative to the control treatment for repair, except the AB system on VE blocks (the VE/AB group). The ${\mu}SBS$ values showed variation across different adhesive treatments on different hybrid CAD-CAM block types.