Powder bed fusion in dentistry: Comparison
Please note this is a comparison between Version 2 by Catherine Yang and Version 1 by Agata Szczesio-Wlodarczyk.

Complex dental component which are individually tailored to the patient can be obtain due to new 3D printing technology. Understanding the manufacturing and post-production processes is essential in order to obtain a product which can be used in clinical applications.

  • Powder Bed Fusion
  • Selective Laser Sintering
  • Selective Laser Melting
  • Electron Beam Melting
  • Dentistry

1. Introduction

CoCr-based alloys are commonly used in dentistry because of their excellent corrosion resistance and outstanding mechanical properties, such as high stiffness. Since its development in 1907, lost wax casting is still the dominant method of dental metal processing [1]. Unfortunately, this technique has some limitations, one of which is the fact that metal shrinks during its transition from the liquid to the solid phase, and this shrinkage should be taken into account when preparing the part for casting. Additionally, pores and other defects are usually present in the structure of the cast element [2,3], the process is time-consuming and requires certain skills for the operators [4], and CoCr alloys are difficult to treat and process because of their high hardness [5].

CoCr-based alloys are commonly used in dentistry because of their excellent corrosion resistance and outstanding mechanical properties, such as high stiffness. Since its development in 1907, lost wax casting is still the dominant method of dental metal processing [1]. Unfortunately, this technique has some limitations, one of which is the fact that metal shrinks during its transition from the liquid to the solid phase, and this shrinkage should be taken into account when preparing the part for casting. Additionally, pores and other defects are usually present in the structure of the cast element [2][3], the process is time-consuming and requires certain skills for the operators [4], and CoCr alloys are difficult to treat and process because of their high hardness [5].

Nowadays, metallic materials are processed by computer-aided design and computer-aided manufacturing (CAD–CAM) (

Table 1) that allows 3D structures to be produced based on data (appropriate conversed–segmented) regarding individual organs, bones or blood vessels obtained from medical imaging devices such as magnetic resonance imaging (MRI), computed tomography (CT), cone beam tomography (CBCT) or ultrasound (USG). Segmentation and analysis software is available as open source versions (e.g., InVesalius or 3D Slicer) and as a paid version with extended functionality (Materialize Mimics, Amira or Dolphin 3d). Three-dimensional models can also be obtained using 3D scanning; this is the most common type of solution used in Dentistry (i.e., in prosthetics and orthodontics), using optical scanners employing photogrammetry or scanning with structured light. The 3D data obtained in this way are used for the design of prosthetic restorations, orthodontic appliances, surgical templates or individualized implants using dedicated CAD software [6,7,8,9].

) that allows 3D structures to be produced based on data (appropriate conversed–segmented) regarding individual organs, bones or blood vessels obtained from medical imaging devices such as magnetic resonance imaging (MRI), computed tomography (CT), cone beam tomography (CBCT) or ultrasound (USG). Segmentation and analysis software is available as open source versions (e.g., InVesalius or 3D Slicer) and as a paid version with extended functionality (Materialize Mimics, Amira or Dolphin 3d). Three-dimensional models can also be obtained using 3D scanning; this is the most common type of solution used in Dentistry (i.e., in prosthetics and orthodontics), using optical scanners employing photogrammetry or scanning with structured light. The 3D data obtained in this way are used for the design of prosthetic restorations, orthodontic appliances, surgical templates or individualized implants using dedicated CAD software [6][7][8][9].

Table 1.

Computer-aided design/computer-aided manufacturing (CAD/CAM) processes currently upgraded into dentistry.

References

  1. Myszka, D.; Skrodzki, M. Comparison of Dental Prostheses Cast and Sintered by SLM from Co-Cr-Mo-W Alloy. Arch. Foundry Eng. 2016, 16, 201–207.
  2. Craig, R.G. Materiały Stomatologiczne, 12th ed.; Powers, J.M., Sakaguchi, R.L., Shaw, H., Shaw, J.G., Eds.; Edra Urban and Partner: Wrocław, Poland, 2008; ISBN 9780323081085.
  3. Anusavice, K.; Shen, C.; Rawls, H.R. Phillips’ Science of Dental Materials, 12th ed.; Saunders: St. Louis, MO, USA, 2012.
  4. Antanasova, M.; Kocjan, A.; Kovač, J.; Žužek, B.; Jevnikar, P. Influence of thermo-mechanical cycling on porcelain bonding to cobalt–chromium and titanium dental alloys fabricated by casting, milling, and selective laser melting. J. Prosthodont. Res. 2018, 62, 184–194.
  5. Reclaru, L.; Ardelean, L.C. Current Alternatives for Processing CoCr Dental Alloys Lucien; Elsevier Inc.: Cambridge, MA, USA, 2018; Volume 1–3, ISBN 9780128051443.
  6. Ferraiuoli, P.; Taylor, J.C.; Martin, E.; Fenner, J.W.; Narracott, A.J. The accuracy of 3D optical reconstruction and additive manufacturing processes in reproducing detailed subject-specific anatomy. J. Imaging 2017, 3, 45.
  7. Hasan, H.A.; Alam, M.K.; Yusof, A.; Matsuda, S.; Shoumura, M.; Osuga, N. Accuracy of three dimensional CT craniofacial measurements using mimics and InVesalius software programs. J. Hard Tissue Biol. 2016, 25, 219–224.
  8. Haleem, A.; Javaid, M. 3D scanning applications in medical field: A literature-based review. Clin. Epidemiol. Glob. Health 2019, 7, 199–210.
  9. Javaid, M.; Haleem, A.; Kumar, L. Current status and applications of 3D scanning in dentistry. Clin. Epidemiol. Glob. Health 2019, 7, 228–233.
  10. Gabor, A.-G.; Zaharia, C.; Stan, A.T.; Gavrilovici, A.M.; Negruțiu, M.-L.; Sinescu, C. Digital Dentistry—Digital Impression and CAD/CAM System Applications. J. Interdiscip. Med. 2017, 2, 54–57.
  11. Revilla-León, M.; Klemm, I.M.; García-Arranz, J.; Özcan, M. 3D Metal Printing–Additive Manufacturing Technologies for Frameworks of Implant- Borne Fixed Dental Prosthesis. Eur. J. Prosthodont. Restor. Dent. 2017, 25, 143–147.
  12. Beaman, J.J.; Deckard, C.R. Selective Laser Sinterng with Assisted Powder Handlng. U.S. Patent 4,938,816, 3 July 1990.
  13. Höganäs, A.B. Höganäs Handbook for Sintered Components. Available online: https://www.hoganas.com/globalassets/download-media/sharepoint/handbooks---all-documents/handbook-2_production_of_sintered_components_december_2013_0675hog_interactive.pdf. (accessed on 20 June 2020).
  14. Anestiev, L.A.; Froyen, L. Model of the primary rearrangement processes at liquid phase sintering and selective laser sintering due to biparticle interactions. J. Appl. Phys. 1999, 86, 4008–4017.
  15. Alageel, O.; Wazirian, B.; Almufleh, B.; Tamimi, F. Fabrication of Dental Restorations Using Digital Technologies: Techniques and Materials. In Digital Restorative Dentistry: A Guide to Materials, Equipment, and Clinical Procedures; Tamimi, F., Hirayama, H., Eds.; Springer: Cham, Switzerland, 2019; pp. 55–91.
  16. Revilla-León, M.; Özcan, M. Additive Manufacturing Technologies Used for 3D Metal Printing in Dentistry. Curr. Oral Health Rep. 2017, 4, 201–208.
  17. Vandenbroucke, B.; Kruth, J.P. Selective laser melting of biocompatible metals for rapid manufacturing of medical parts. Rapid Prototyp. J. 2007, 13, 196–203.
  18. Yap, C.Y.; Chua, C.K.; Dong, Z.L.; Liu, Z.H.; Zhang, D.Q.; Loh, L.E.; Sing, S.L. Review of selective laser melting: Materials and applications. Appl. Phys. Rev. 2015, 2, 1–21.
  19. Murr, L.E.; Gaytan, S.M.; Ramirez, D.A.; Martinez, E.; Hernandez, J.; Amato, K.N.; Shindo, P.W.; Medina, F.R.; Wicker, R.B. Metal Fabrication by Additive Manufacturing Using Laser and Electron Beam Melting Technologies. J. Mater. Sci. Technol. 2012, 28, 1–14.
  20. Singh, R.; Singh, S.; Hashmi, M.S.J. Implant Materials and Their Processing Technologies; Elsevier Ltd.: Amsterdam, The Netherlands, 2016; ISBN 9780128035818.
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