Effects of Casting Methods over the Composition Stability of the Dental Casting Alloy

Abstract

Introduction: Alloys with high nickel content have been increasingly used for dental prostheses. The dental casting machines are regularly used to make dental restorations. The effects of the casting of the base metal alloys using acetylene-oxygen flame casting machine and induction casting machine has not much been studied. Aim: To estimate nickel, chromium, cobalt, and molybdenum metals from as-received dental casting alloy of three different brands and to estimate metals from these alloys after fabrication of crown using acetylene-oxygen flame casting machine and induction casting machine. Materials and Methods: This in-vitro comparative study was conducted in the Department of Prosthodontics at School of Dental Sciences, KIMSDU, Karad, Maharashtra, India. Total of 15 crowns were fabricated using acetylene-oxygen flame casting machine and 15 crowns by induction casting machine from three different brands of Dental Casting Alloys (DCA) by lost wax technique. Elemental estimation was done for the as-received pellets and for the crowns fabricated by both methods using X-ray Florescence spectrometry (XRF). Unpaired t-test was used for data analysis. Results: Nickel (Ni), chromium (Cr) and molybdenum (Mo) levels in crowns fabricated by both acetylene-oxygen flame casting and Induction casting technique were significantly decreased (Ni: -2.01% to -5.14%, Cr:-7.35% to -29.51% and Mo: -15.70% to -95.94%) in all brands of dental casting alloys. Cobalt level was not detected in all three brands of fabricated crowns by XRF by either of the casting methods. Conclusion: These observations indicate that the elemental composition of the fabricated crowns is decreased as compared to that of as-recieved crowns, which could be due to the burnout of some amount of elements during casting.

Keywords

• biocompatibility
• corrosion
• fabricated crowns
• leaching