Manufacturing of dental prostheses based on rapid prototyping technology.
1. Recently, rapid prototyping (RP) Not only in the general industry, but also in the manufacturing of medical models. However, the use of RP technology in the medical field is very different from the use of RP technology in manufacturing environments. The establishment of a medical model is basically from the acquisition of computer tomography (CT) Cross-sectional image. Complex data needs to be prepared in advance before the part is built Processing to provide a format that can be recognized by the aCAD package or RP system. It can be seen that in order to obtain the required physical model, data acquisition and processing technology must be combined with RP technology. The acquisition of data, image processing and model production all need to go through a series of processes. The corresponding studies covered methods for designing and manufacturing dental prosthesis using RP technology, as well as RP technology manufacturing processes through several case studies. 2. Methods the steps of making 3D medical models using RP technology are simple (Fig. 1) * 3D digital images; * Data transmission, processing and segmentation; * Design evaluation; * RP medical model making; * Validation of RP medical models. 3D digital images can be obtained using computed tomography- CT imaging data. These imaging techniques are used to model the internal structure of the human body. After the CT or MRI image data is saved, it should be transmitted to the laboratory. The next step is to process this data, which is a very complex and important step, and the quality of the final medical model depends on this data. [ Figure 1 slightly] For this step, the engineer needs a package (Mimics) They can split this anatomical image to achieve high resolution 3D rendering in different colors, make a 3D virtual model, and finally convert the image data scanned by CT or MRI from unicode to STL Stereo printing) File format, which is generally accepted in RPfile format. Surgeons have a very important role in verifying the virtual model built. In some cases, it is more important to have errors due to the engineer\'s misconceptions about the anatomy or some interference in the scanned image. After design evaluation, the appropriate RP technology must be selected according to the purpose of the model itself and the required accuracy, surface finish, visual appearance of the internal structure, the number of colors required in the model, strength, material, mechanical properties, etc. When the RP medical model is manufactured, it should be verified by the surgeon. The model can be applied without errors. 3. CASE STUDIES 3. Case 1: How to accurately and accurately construct the CAD model of oral implants is a major problem. The process of manufacturing through an SLA uses CAD modeling software such as solidworks to form a model design and convert the model to an STL format known to the SLA. The preparation process is followed, including STL file validation, orientation, support generation, slicing, and setup of build parameters. The final step after manufacture includes cleaning, Post Curing and finishing. Therefore, in order to manufacture dental implants, the above steps are carried out by using the SLA5000 machine of watershed TM] 11120 resin, in which the RP model of dental implants is shown in Figure 2 (Rahmati et al. ,2009). During precision casting, these models must be used as sacrificial patterns for the manufacture of final implants using ceramic shells. [ Figure 2:3. 2 Case2: used to manufacture the design of the lower mandible model SLA model of the lower mandible titanium plate as a replacement for the actual bone lost or removed due to tumor implantation in the patient. The implant SLA model is used as a casting mode for the construction of a silicon mold and subsequently the same wax model, which is ultimately used as a consumable for the production of titanium parts through investment casting. In this case, customized design Based on data obtained from the patient\'s lower jaw through cone-shaped Ray Computed Tomography (CBCT) Using the reverse phase technology, the design is made by Kheirollahiet al ( Kheirollahi, etc. , 2009a)is discussed. The custom design phase is initiated by performing a CBCT scan of the patient\'s lower face. Image data is imported into Mimics version 10. 01 edit and three- 3D reconstruction. Figure 3 shows the data processing in the Mimics software. In figure 4, the jaw STL model after processing the patient image is shown. [ Figure 3 slightly][ Figure 4 slightly]3. 3 Case3: Design of tongue side orthodontic appliance in this case a new tongue side orthodontic technique based on customization Custom stand Made a series of pre- The prototype technology of curved wire usingraphid is discussed ( Kheirollahi, etc. , 2009b). For many adults, the stigma in a common orthodontic appliance prevents them from receiving orthodontic care. One way to solve this problem is to hide the braces inside the teeth (Fig. 5). The manufacturing process of the new equipment is fundamentally different from any other language equipment or laboratory procedure. The whole equipment is manufactured using CAD/CAM technology ( Mujagic and others, Wiechmann, 2003. , 2005). Scan these models with a 3D scanner and design the brackets on the computer. RP technology is used in the actual manufacture of tongue side supports. Bending the bow wire is one of the most difficult parts of Orthodontics. In this system, the computer Archwire bending using robot operation is used to make accurate- Arched wires. [ Figure 5 Slightly]4. The discussion of Case 1 shows that with the help of various rptechnology, the manufacture of dental objects such as implants can be done easily and quickly. Otherwise it would be difficult to generate them through other techniques as it has features such as prominent, pointed, and cut-outs. In case 2, the upper mandible image of the patient was imported into Mimics version 10. 01 for editing and 3- The size of the STL model used to make the titanium tray of the lower jaw is rebuilt and made. In the last case, a new tongue orthodontic technique based on customization Custom stand Made a series of pre- Wiwiwiresusing using RP technology was discussed. 5. Conclusion RP technology has been widely used in medicine; However, RP has relatively few applications in the dental field. This paper also discusses the application of rapid prototyping technology in oral repair. With the help of various rptechnology, the manufacture of dental prosthesis can be done easily and quickly, otherwise it is difficult to produce through other technologies. 6. About Kheirollahi, H. ; Abesi, F. ; & Rahmati, S. ; (2009a). Comparison of CT and CBCT for the production of dental models through rapid prototyping techniques, minutes of the Fourth International Conference on Advanced Research on virtual and rapid prototyping (VRAP 2009), Edited by\"P. J. Bartolo et al, innovative development of design and manufacturing, ISBN 0-415-39062- 1. Leah, Portugal. 6- Taylor and Francis Group, October 10, 2009; Rahmati, S. ; & Abesi, F. ; (2009b). New methods for the design and manufacture of tongue orthodontics application based on rapid prototyping technology, minutes of the Fourth International Conference on Advanced research of virtual and rapid prototyping (VRAP 2009), Edited by \"P. J. Bartolo et al. , development of design and manufacturing innovation, ISBN 0-415-39062- 1. Leah, Portugal. 6- M. Leiria Mujagic Taylor and Francis Group, October 10, 2009. C. Fauquet, C. Galletti, C. Palot, D. & Wiechmann,J. Mah. 2005. Digital design and manufacturing of the Lingualcarebracket system. J Clin Orthod. ; 39:375-382. Rahmati, S. ; Kheirollahi, H. ; & Azari, A. Analysis and manufacture of newly designed dental implants using rapid prototyping techniques, minutes of the Fourth International Conference on advanced research for virtual and rapid prototyping (VRAP 2009), Edited by\"P. J. Bartolo et al, innovative development of design and manufacturing, ISBN 0-415-39062- 1. Leah, Portugal. 6- Leiria Wiechmann, D. Taylor and Francis Group, October 10, 2009. 2003. New stent system for tongue-side orthodontic treatment. The second part: the first clinical experience and further development. JOrofac Orthop. 64, (372-388)