Effects of Electrobrightening on the Fit Surface of Cobalt- Chromium RPD Frameworks

Purpose: The purpose of this study was to compare 3 different electrobrightening techniques and 3 electrolytic solutions in their effects upon the fit surface of cast cobaltchromium frameworks. Materials and Methods: Fifty cast cobalt-chromium frameworks, which were subsequently divided into batches of 10, were prepared according to a standard protocol. Three electrobrightening techniques were tested initially using a single brand of electrolyte (Croform) and a batch of 10 frameworks per technique. The loss of metal by weight was determined from the fit surface of each casting. The least corrosive technique of these 3 was used again with 2 other brands of electrolyte (Nobilium and E501) in a repetition of the protocol. The fit surfaces of 8 random samples cut from each batch of electrobrightened castings were viewed by scanning electron microscope (SEM). Results: Statistical analysis applying a one-way analysis of variance and Bonferroni's multiple comparison of means test demonstrated that one immersion of the framework for 10 minutes at 1 amp when used in conjunction with Nobilium electrolyte removed the least metal (P = 0.001). The SEM study suggested that the Nobilium electrolyte also produced the smoothest surface. Conclusion: Electrobrightening techniques affect the amount of metal removed, and the electrolytic solution used influences the resultant surface.