EFFECT OF COBALT-CHROMIUM ALLOY RE-USE IN DENISTRY ON ITS CASTABILITY VALUE

Mehreen Imran, Muhammad Raza, Muhammad Sartaj Khan, Yousaf Hayat

Abstract


Background: Re-use of dental casting alloy is a routine practice, which is carried out with the motive to conserve resources. There have been studies on the re-use of alloys but a controversy exists as to the proportioning ratio of fresh to used alloy and the number of time an alloy can be recast. The objective of the study was to measure the effect of addition of 50% by weight used alloy to the fresh Cobalt-Chromium alloy on the castability. Methods: In the present in-vitro experimental study A total of 20 specimens were cast by flame centrifuge, using modified Whitlock‘s method. The total sample size was divided into four groups of five specimens each. Group 1 was the control group with 100% fresh alloy cast once. In group 2, 3 and 4, a 50% by weight cut off of previous castings were mixed to the fresh alloy. The re-used alloy for the group 2 and 3 was further aged or exposed to flame casting separately. The number of completely cast segments were counted and castability value was calculated according to the Whitlock‘s formula. Result: There was no significant difference of castability value among all the tested group (p=0.085). Conclusion: Within the limitations of the present study, it is recommended that commercial Co-Cr-Mo alloy can be re-used six times without affecting its castability, when 50% fresh alloy is added on each re-use.

Keywords: Castability; Cobalt; Chromium; Alloy


Full Text:

PDF

References


Sweeney WT. Cristobalite for dental investment. J Am Dent Assoc 1933;20:108–19.

Powers JM, Sakaguchi RL. Casting and soldering procedures. In: editors. Craig‘s Restorative Dental Materials. 12th ed: St. Louis, Mo.: Mosby Elsevier; 2006. p.411–41.

Leinfelder KF. An evaluation of casting alloys used for restorative procedures. J Am Dent Assoc 1997;128(1):37–45.

Baltes H, Brand O, Fedder GK, Hierold C, Korvink JG, Tabata O, et al. Microengineering of Metals and Ceramics: Part I: Design, Tooling, and Injection Molding. Vol. 30. John Wiley & Sons; 2008.

Hero H, Waarli M. Effect of vacuum and Super-temperature on Mold Filling during Casting. J Dent Res 1991:99(1):55–9.

Carreiro Ada F, Ribeiro RF, Mattos Mda G, Rodrigues RC. Evaluation of the castability of a Co-Cr-Mo-W alloy varying the investing technique. Braz Dent J 2005;16(1):50–5.

Antony K. Wear-resistant cobalt-base alloys. J Met 1983;35(2):52–60.

Kelly JR, Rose TC. Nonprecious alloys for use in fixed prosthodontics: A literature review. J Prosthet Dent 1983;49(3):363–70.

Slokar LJ, Matkovic T, Matkovic P. Microstructure and hardness of Co-Cr-Ti alloys for dental castings. Metalurgija 2004;43(4):273–7.

Bertrand C, Poulon-Quintin A. Proposals for optimization of laser welding in prosthetic dentistry. J Prosthodont. 2010;19:69–76..

Ucar Y, Akova T, Akyil M S, Brantley WA. Internal Fit Evaluation of Crowns Prepared Using a New Dental Crown Fabrication Technique. Laser-Sintered Co-Cr Crown. J Prosthet Dent 2009;102(4):253–9.

Khuraif AA, Ramamoorthi M. Fatigue behaviour of Recasted Removable partial denture alloys. Int J Dent Clin 2011;3(4):20–2.

Utilization of non-ferrous scrap. [Internet]. [cited 2013 Apr 22]. Available from: http://nzic.org.nz/ChemProcesses/metals/8C.pdf

Brantley WA. Wrought alloys. In: Anusavice KJ, Phillips RW, editors. Phillips’ science of dental materials. 11th ed. St. Louis, Mo: Saunders; 2003. p.621–53.

Yannikakis SA, Zissis AJ, Polyzois GL. Removable partial denture repairs: A survey. Quintessence Dent Technol. 2000;23:184–190

McCabe JF, Walls AWG. Base Metal Casting Alloys. In:, editors. Applied Dental Materials 8th edition, Oxford (UK), Blackwell Science; 1998. P.63–8.

Glekin J. Dixon H. Unrevelling India Part 3. Demography.weblog. [Internet]. [cited 2012 Jan]. Available from: https://www.google.com.pk/#q=Unrevelling+India+Part+3.+Demography.weblog&*

Naylor WP, Moore BK, Phillips RW, Goodacre CJ, Munoz CA. Comparison of two tests to determine the castability of dental alloys. Int J Prosthodont 1990;3(5):413–52.

Palaskar J, Nadgir DV, Shah I. Effect of Recasting of Nickel: Chromium Alloy on its Castability. J Indian Prosthodont Soc 2010;10(3):160–4.

Whitlock RP, Hinman RW, Eden GT, Tesk JA, Dickson G, Parry EE. A practical test to evaluate the castability of dental alloys. J Dent Res 1981;60:404–404.

Khamis E, Seddik M. Corrosion evaluation of recasting non–precious dental alloys. Int Dent J 1995;45(3):209–17.

Presswood RG. The castability of alloys for small castings. J Prosthet Dent 1983;50(1):36–9.

Dern WM, Hinman RW, Hesby RA, Pelleu GB Jr. Effect of a two-step ringless investment technique on alloy castability. J Prosthet Dent 1985;53(6):874–6.

Hong JM, Razzoog ME, Lang BR. The effect of recasting on the oxidation layer of a palladium-silver porcelain alloy. J Prosthet Dent1988;59(4):420–5.

Nelson DR, Palik JF, Morris HF, Comella MC. Recasting a nickel-chromium alloy. J Prosthet Dent 1986;55(1):122–7.

Palaskar J, Nadgir DV, Shah I. Effect of recasting of nickel–chromium alloy on its porosity. Contemp Clin Dent 2010;1(4):237–42.

Palaskar JN. Effect of recasting of Nickel-chromium alloy on its Hardness. Int J Dent Clin 2010; 2(4):8–11.

Al-Khafagy MT. Evaluation of some properties of prepared dental base-metal alloys. Ph.D thesis. Coll Dent Univ Baghdad 2003.

Al-Hueaizi AF, Al-Khafaji AM. The effect of recasting on the castability of the prepared Co-Cr dental base-metal casting alloys. J Baghdad Coll Dent 2017;19(1):24–27.

Harcourt H. The remelting of cobalt-chromium alloys. Brit Dent J 1962;112:198–204.

Mosleh I, Abdul-Gabbar F, Farghaly A. Castability evaluation and effect of recasting of ceramo-metal alloys. Egypt Dent J 1995;41(4):1357–62.

Nakhaei MR, Ghanbarzadeh J, Gokharian R. The effect of recast base metal alloys on crown‘s marginal accuracy. J Med Sci 2008;8:599–602.


Refbacks

  • There are currently no refbacks.


Contact Number: +92-992-382571

email: [jamc] [@] [ayubmed.edu.pk]