The Journal of Advanced Prosthodontics

The Korean Academy of Prosthodonitics (대한치과보철학회)
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Mechanical and interfacial characterization of laser welded Co-Cr alloy with different joint configurations

  • Kokolis, John (Department of Biomaterials, School of Dentistry, National and Kapodistrian, University of Athens) ;
  • Chakmakchi, Makdad (Department of Conservative Dentistry, University of Mosul) ;
  • Theocharopoulos, Antonios (Cork University Dental School and Hospital, University College Cork) ;
  • Prombonas, Anthony (Department of Dental Technology, Technological Educational Institution of Athens) ;
  • Zinelis, Spiros (Department of Biomaterials, School of Dentistry, National and Kapodistrian, University of Athens)
  • Received : 2014.06.10
  • Accepted : 2014.09.18
  • Published : 2015.02.27
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Abstract

PURPOSE. The mechanical and interfacial characterization of laser welded Co-Cr alloy with two different joint designs. MATERIALS AND METHODS. Dumbbell cast specimens (n=30) were divided into 3 groups (R, I, K, n=10). Group R consisted of intact specimens, group I of specimens sectioned with a straight cut, and group K of specimens with a $45^{\circ}$ bevel made at the one welding edge. The microstructure and the elemental distributions of alloy and welding regions were examined by an SEM/EDX analysis and then specimens were loaded in tension up to fracture. The tensile strength (TS) and elongation (${\varepsilon}$) were determined and statistically compared among groups employing 1-way ANOVA, SNK multiple comparison test (${\alpha}$=.05) and Weibull analysis where Weibull modulus m and characteristic strength ${\sigma}_0$ were identified. Fractured surfaces were imaged by a SEM. RESULTS. SEM/EDX analysis showed that cast alloy consists of two phases with differences in mean atomic number contrast, while no mean atomic number was identified for welded regions. EDX analysis revealed an increased Cr and Mo content at the alloy-joint interface. All mechanical properties of group I (TS, ${\varepsilon}$, m and ${\sigma}_0$) were found inferior to R while group K showed intermediated values without significant differences to R and I, apart from elongation with group R. The fractured surfaces of all groups showed extensive dendritic pattern although with a finer structure in the case of welded groups. CONCLUSION. The K shape joint configuration should be preferred over the I, as it demonstrates improved mechanical strength and survival probability.

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References

  1. Ayyildiz S, Soylu EH, Ide S, Kilic S, Sipahi C, Piskin B, Gokce HS. Annealing of Co-Cr dental alloy: effects on nanostructure and Rockwell hardness. J Adv Prosthodont 2013;5: 471-8. https://doi.org/10.4047/jap.2013.5.4.471
  2. Al Jabbari YS. Physico-mechanical properties and prosthodontic applications of Co-Cr dental alloys: a review of the literature. J Adv Prosthodont 2014;6:138-45. https://doi.org/10.4047/jap.2014.6.2.138
  3. Byrne G. Soldering in prosthodontics-an overview, part I. J Prosthodont 2011;20:233-43. https://doi.org/10.1111/j.1532-849X.2011.00691.x
  4. Yannikakis S, Prombonas A. Improving the fit of implant prosthetics: an in vitro study. Int J Oral Maxillofac Implants 2013;28:126-34. https://doi.org/10.11607/jomi.2346
  5. Barbi FC, Camarini ET, Silva RS, Endo EH, Pereira JR. Comparative analysis of different joining techniques to improve the passive fit of cobalt-chromium superstructures. J Prosthet Dent 2012;108:377-85. https://doi.org/10.1016/S0022-3913(12)60196-6
  6. Tiossi R, Rodrigues RC, de Mattos Mda G, Ribeiro RF. Comparative analysis of the fit of 3-unit implant-supported frameworks cast in nickel-chromium and cobalt-chromium alloys and commercially pure titanium after casting, laser welding, and simulated porcelain firings. Int J Prosthodont 2008;21:121-3.
  7. Rocha R, Pinheiro AL, Villaverde AB. Flexural strength of pure Ti, Ni-Cr and Co-Cr alloys submitted to Nd:YAG laser or TIG welding. Braz Dent J 2006;17:20-3. https://doi.org/10.1590/S0103-64402006000100005
  8. de Castro GC, de Araujo CA, Mesquita MF, Consani RL, Nobilo MA. Stress distribution in Co-Cr implant frameworks after laser or TIG welding. Braz Dent J 2013;24:147-51. https://doi.org/10.1590/0103-6440201302112
  9. Madhan Kumar S, Sethumadhava JR, Anand Kumar V, Manita G. Effects of conventional welding and laser welding on the tensile strength, ultimate tensile strength and surface characteristics of two cobalt-chromium alloys: a comparative study. J Indian Prosthodont Soc 2012;12:87-93. https://doi.org/10.1007/s13191-012-0118-9
  10. Zupancic R, Legat A, Funduk N. Tensile strength and corrosion resistance of brazed and laser-welded cobalt-chromium alloy joints. J Prosthet Dent 2006;96:273-82. https://doi.org/10.1016/j.prosdent.2006.08.006
  11. Baba N, Watanabe I, Liu J, Atsuta M. Mechanical strength of laser-welded cobalt-chromium alloy. J Biomed Mater Res B Appl Biomater 2004;69:121-4.
  12. Apotheker H, Nishimura I, Seerattan C. Laser-welded vs soldered nonprecious alloy dental bridges: a comparative study. Lasers Surg Med 1984;4:207-13. https://doi.org/10.1002/lsm.1900040213
  13. Huling JS, Clark RE. Compratative distortion in three-unit fixed prostheses joined by laser welding, conventioanl soldering, or casting in one piece. J Dent Res 1977;56:128-34. https://doi.org/10.1177/00220345770560020501
  14. Bertrand C, Le Petitcorps Y, Albingre L, Dupuis V. The laser welding technique applied to the non precious dental alloys procedure and results. Br Dent J 2001;190:255-7.
  15. Baba N, Watanabe I. Penetration depth into dental casting alloys by Nd:YAG laser. J Biomed Mater Res B Appl Biomater 2005;72:64-8.
  16. Al Jabbari YS, Koutsoukis T, Barmpagadaki X, El-Danaf EA, Fournelle RA, Zinelis S. Effect of Nd:YAG laser parameters on the penetration depth of a representative Ni-Cr dental casting alloy. Lasers Med Sci 2013 DOI 10.1007/s10103-013-1502-3.
  17. Watanabe I, Topham DS. Laser welding of cast titanium and dental alloys using argon shielding. J Prosthodont 2006;15: 102-7. https://doi.org/10.1111/j.1532-849X.2006.00082.x
  18. Bertrand C, le Petitcorps Y, Albingre L, Dupuis V. Optimization of operator and physical parameters for laser welding of dental materials. Br Dent J 2004;196:413-8; discussion 407. https://doi.org/10.1038/sj.bdj.4811138
  19. Wulfes H. Precision milling and partial denture constructions. 1st ed. Bremen Germany; Academia Dental; 2005. p.133-5.
  20. Nomoto R, Takayama Y, Tsuchida F, Nakajima H. Nondestructive three-dimensional evaluation of pores at different welded joints and their effects on joints strength. Dent Mater 2010;26:e246-52. https://doi.org/10.1016/j.dental.2010.08.006
  21. Watanabe I, Wallace C. Bond strength of gold alloys laser welded to cobalt-chromium alloy. Open Dent J 2008;2:109-13. https://doi.org/10.2174/1874210600802010109
  22. Srimaneepong V, Yoneyama T, Kobayashi E, Doi H, Hanawa T. Comparative study on torsional strength, ductility and fracture characteristics of laser-welded alpha+beta Ti-6Al- 7Nb alloy, CP Titanium and Co-Cr alloy dental castings. Dent Mater 2008;24:839-45. https://doi.org/10.1016/j.dental.2007.10.002
  23. Watanabe I, Benson AP, Nguyen K. Effect of heat treatment on joint properties of laser-welded Ag-Au-Cu-Pd and Co-Cr alloys. J Prosthodont 2005;14:170-4. https://doi.org/10.1111/j.1532-849X.2005.04040.x
  24. Simchi A, Pohl H. Effects of laser sintering processing parameters on the microstructure and densification of iron powder. Mat Sci Eng A-Struct 2003;359:119-28. https://doi.org/10.1016/S0921-5093(03)00341-1
  25. NaBadalung DP, Nicholls JI. Laser welding of a cobalt-chromium removable partial denture alloy. J Prosthet Dent 1998; 79:285-90. https://doi.org/10.1016/S0022-3913(98)70239-2
  26. Tiossi R, Falcao-Filho H, Aguiar Junior FA, Rodrigues RC, Mattos Mda G, Ribeiro RF. Modified section method for laser- welding of ill-fitting cp Ti and Ni-Cr alloy one-piece cast implant-supported frameworks. J Oral Rehabil 2010;37:359-63. https://doi.org/10.1111/j.1365-2842.2010.02063.x
  27. Nunez-Pantoja JM, Vaz LG, Nobilo MA, Henriques GE, Mesquita MF. Effects of laser-weld joint opening size on fatigue strength of Ti-6Al-4V structures with several diameters. J Oral Rehabil 2011;38:196-201. https://doi.org/10.1111/j.1365-2842.2010.02140.x
  28. Xin XZ, Chen J, Xiang N, Gong Y, Wei B. Surface characteristics and corrosion properties of selective laser melted Co- Cr dental alloy after porcelain firing. Dent Mater 2014;30:263-70. https://doi.org/10.1016/j.dental.2013.11.013
  29. Dharmar S, Rathnasamy RJ, Swaminathan TN. Radiographic and metallographic evaluation of porosity defects and grain structure of cast chromium cobalt removable partial dentures. J Prosthet Dent 1993;69:369-73. https://doi.org/10.1016/0022-3913(93)90182-N
  30. Al Jabbari YS, Koutsoukis T, Barmpagadaki X, Zinelis S. Metallurgical and interfacial characterization of PFM Co-Cr dental alloys fabricated via casting, milling or selective laser melting. Dent Mater 2014;30:e79-88.
  31. Quinn JB, Quinn GD. A practical and systematic review of Weibull statistics for reporting strengths of dental materials. Dent Mater 2010;26:135-47. https://doi.org/10.1016/j.dental.2009.09.006
  32. Takayama Y, Nomoto R, Nakajima H, Ohkubo C. Effects of argon gas flow rate on laser-welding. Dent Mater J 2012;31: 316-26. https://doi.org/10.4012/dmj.2011-158

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