• The Journal of Korean Academy of Prosthodontics
• /
• v.56 no.3
• /
• pp.188-198
• /
• 2018

Purpose: Recently, according to the development of digital technology, computer aided design/computer aided manufacture (CAD/CAM) system is widely used for fabrication of various dental prostheses in the field of dentistry. This study aims to survey the present state and awareness of CAD/CAM system on domestic dental field, and to supply the advice for the application of the new system. Materials and methods: In this questionnaire survey was conducted for a total of 298 dentists, dental hygienist and dental technicians of the whole country including the dental hospital of Seoul National University for two months from November to December, 2016 through mail. Results: The most important purpose to consider when purchasing a dental CAD/CAM milling machine were the performance of the milling machine (64.43%) and the use of milling machine was the highest with 49.33% of manufacturing for dental prosthesis and customized implant abutment. In addition, more than 60% of respondents answered positively about the purchase of new milling machine if the CAD/CAM milling machine was improved to satisfactory performance. Conclusion: This survey results show that the improved CAD/CAM milling machine would be play an important role in the dental industry in preparation for digitization and the 4th industrial revolution.

• The Journal of Advanced Prosthodontics
• /
• v.9 no.4
• /
• pp.265-270
• /
• 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.

• Journal of the Korean Society of Safety
• /
• v.8 no.4
• /
• pp.54-60
• /
• 1993

The purpose of this study is to develop a CAD/CAM system for automatic creation and manufacturing of three dimension objects. The computer system used in this study made RAM 2M, CPU 80386, VGA graphic card. The results in this paper are as follows ; 1. By interconnect PC(personal computer) and NC(numerical control) milling machine with RS232C connector, we was constructed with CAD/CAM system. 2. The developed algorithm in this study is able to be design of three dimension object on the computer CRT and manufacturing of NC milling machine. 3. Because of design and modifying on the PC of objects, we can be saving time, cost and improvable precision of objects. 4. Essentially, we expect industrial accident to reduse according as we takes advantage of CAD/CAM system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.6 no.6
• /
• pp.555-559
• /
• 2005

The object of this study is in introduce CAD/CAM application technology for manufacturing rotary compressor side block. CAM systems consist of CAD(Solidworks), CAM(I-MASTER) software and CNC milling machine. CAM software is used to simulate the tool path and generate G-code for CNC programming.

• Journal of Technologic Dentistry
• /
• v.37 no.1
• /
• pp.9-15
• /
• 2015

Purpose: The purpose of this study was to compare the accuracy of the maxillary three-unit fixed dental prosthesis (FDPs) made using two CAD/CAM milling machines : DCM Group(Dentaim CAD/CAM milling machine), WCM Group(Wieland CAD/CAM milling machine). Methods: Each of 10 duplicate models was scanned by blue light scanner(Identica, Medit, Korea), and the three-unit FDPs (STL file) was designed using DelcamCAD. A total of 20 three-unit FDPs was fabricated, comprising 2 groups of 10 specimens each (shrinkage ratio is 1:1). The first three-unit FDPs STL file was used as a CAD reference model (CRM). Obtained STL files by scanning the inner surface of three-unit FDPs were convened into the point clouds-ASC II files. Discrepancies between the point clouds and CRM were measured by superimposition software. Statistical methods to analyze the data were used non-parametric method. The mean (SD) values were compared by a Mann-Whitney U-test. Type one error rate was set at 0.05. Results: WCM group had small discrepancies with $2.17{\mu}m$ of mean value compared to $4.44{\mu}m$ in DCM group. The accuracy values between the two groups showed a sratistically significant difference (Table 2, p<.05). Conclusion: The accuracy of the three-unit fixed dental prosthesis(FDPs) made of two CAD/CAM milling machines were statistically different. Accuracy with which the prosthesis made of WCM group was superior.

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

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.448-453
• /
• 2017

The purpose of this study was to compare the marginal discrepancy of coping crowns according to manufacturing method and materials by using the CAD/CAM system to compare the optimum manufacturing method and materials. The coping crowns were fabricated by using manufacturing methods and materials, and marginal fit was measured using the replica technique. For comparative analysis of manufacturing methods and materials, analysis of variance was performed. One-way ANOVA was performed to compare and analyze different mean values. For the milling method of the alloy, 114.6 was obtained for the MM group, 111.4 for the MS group, 67.2 for the MSC group, and 50.9 for the MSS group, respectively, using the milling/sintering method. In the milling/sintering method of ceramic, 35.6 and 36.3, respectively, were obtained for the SLME group and SLMR group, respectively. However,there was a significant difference according to the material. The milling/sintering method of the ceramic material gave the lowest value, and it was verified by the optimal method. However, marginal discrepancy of coping crowns fabricated using the CAD/CAM system is applicable to the clinic since it corresponds to acceptable numerical values in clinical practice.

• Korean Journal of Agricultural Science
• /
• v.22 no.1
• /
• pp.11-23
• /
• 1995

The CAD/CAM system for the manufacturing automation is the newest technology in mechanical engineering area and becomes the important research subject nowadays. Most of all hardwares and softwares for the CAD/CAM system used in the our manufacturing companies such as automobile company are developed by the foreign country and the purchasing price of them is very expensive but their applicability to a certain area is very limited. This study was conducted to develope a CAD/CAM system for the design and the automatic manufacturing of the iron pattern shaped with 3 - dimensional free curved surface, and to test its applicability to the design and the manufacturing of the rotary blade. The results obtained from the study are as follow; 1. The CAD system which can process graphic procedures from the free curved surface shaped data was developed with personal computer. 2. The CAM main program was developed. This main program could produce CL data from CAD data file by checking the tool interference according to the cutting mode. 3. The sub. program which can simulate the tool trace from the CL data was developed. 4. The post processor for the Deckel FP2NC NC milling machine from CL data file was developed and the sub program could transmit NC program through modem to NC milling machine was developed. 5. The developed CAM system seemed to be applicable to any other system. Because the measuring results of the cross sectional thickness of the plastic model from the manufacturing iron pattern by the system showed that this system could properly check the tool interference. 6. In took 75~90 hours to manufacture two iron patterns of rotary blade. For the sake of convenience in applying to the other systems, this system was developed in BASIC and FORTRAN computer language and minimum portion of machine language as possible.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.4
• /
• pp.550-553
• /
• 2006

This study used the 3D CAD/CAM system in manufacturing die plates to improve productivity. UG NX 3.0 was used as 3D CAD/CAM software, with the created NC code transmitted to the CNC Milling and Wire Cut Electric Discharge machine. The die plate was then automatically machined.

• Journal of Biosystems Engineering
• /
• v.16 no.3
• /
• pp.228-238
• /
• 1991

Cam plays very important roles due to continuous requirement for the high-speed and automation of the machinery. A large number of studies of cam curve were carried out by many researchers, and CNC milling and machining center for manufacturing cam have been widely used recently. The purpose of this study was to develop a CAD/CAM system for cam using QuickBasic language in 16-bit PC for application of cam design and manufacturing. Results obtained were as follows : 1. It was possible to input data by entering cam angle and its corresponding R, from 0 to 360 deg. of cam angle. The tediousness at entering data was minimized because of the same data format for both cylindrical cam and disc cam, and free format used for data file. 2. It was possible to design cam by choosing only the number of cam curve because of developing the CAD/CAM program with dimensionless method of cam curves including widely used 19 kinds. After selecting the number of the cam curve, the CAD/CAM system automatically shows the characteristics of cam motion enough to help a designer to decide : displacement, velocity, acceleration and jerk. 3. It was possible to execute, in an efficient way, both the cam profile synthesis and the generation of NC program for CNC machining center by using the input data. 4. This NC program generated by the CAD/CAM system developed here, was evaluated as positive in relation with actual manufacturing experiments and thought to be useful in its application without any modification. It can be said that this CAD/CAM system could be used by the beginners to design and manufacture the cam automatically as the system consists of very simple dialogue methods. In addition, self-developed QuickBasic would be would used as a basic tool for further stuides in this area of research, together with application.