Comparison of Two Different Electro Polish Temperature on Cobalt Ion Release of Chromium Cobalt Alloy in Artificial Saliva with Atomic Absorption Spectrophotometry

Abstract

Introduction: Metals are widely used in direct and indirect restorative materials, both in prosthetics and orthodontics. The biocompatibility of these metals depends on their chemical nature, the number of ions released, and the period of contact of these metals. This study aims to compare two different electropolish temperatures on the release of cobalt ion from chromium-cobalt alloy. Materials & Methods: In this experimental study, 24 wax patterns were cut in the form of a circle with a diameter of 15 mm and a thickness of 1 mm. Then, the samples were sprued and invested. Burn out and casting were used to cast the alloy. The samples were sandblasted and polished with aluminum oxide. They were randomly divided into two 12-number groups and electropolished at 45° and 55° C. Samples were placed in artificial saliva and sent to atomic absorption spectrophotometer for 15 and 30 days to read the cobalt. Data were then analyzed by Independent t-test and Paired t-test (p value = 0.05). Results: The average release of cobalt from chromium cobalt alloy on the 30th day was higher than the 15th day at both 45°C and 55°C. This difference was significant at 45°C (p value = 0.036) while not significant at 55°C (p value = 0.0754). Regarding the comparison of the ion release at 45° and 55°C, the difference was not significant on the 15th day (p value = 0.067) and 30th day (p value = 0.0754). Conclusion: The amount of cobalt ions released from the cobalt-chromium alloy at 45°C is fewer than at 55°C over time.