Comparison of different cleaning procedures to decontaminate zirconium oxide surface after polishing.

Abstract

To evaluate the efficacy of cleaning protocol in decontamination of organic compounds from polished zirconium oxide samples. A total of 24 rectangular plate specimens were sintered from zirconium oxide. All samples were polished with commercially available polishers (course, fine, and superfine) and polishing paste. During the first step of the protocol, all specimens were cleaned with steam. After that, samples were randomly assigned to one of three groups (n = 8 each): A, B, and C. In group A, no additional cleaning was performed, while specimens of group B underwent an ultrasonic cleaning in distilled water. Group C specimens were cleaned in an ultrasonic bath with a special detergent solution. After washing, samples were subjected to energy-dispersive x-ray spectroscopy (EDX) and scanning electron microscope examination. In order to detect organic materials, the level of carbon atoms was measured. EDX analysis revealed that samples in group A had the highest percentage levels of carbon atoms (9.57 ± 3.67) on the surface compared to the other cleaning protocols. The group B cleaning protocol resulted in lower carbon levels (4.73 ± 3.56), but the difference was not significant from only steam-blasted ones (P = .439). All specimens in group C had no detectable carbon atoms (0), which implies that all wax molecules had been removed (P < .05). Only following the group C cleaning protocol can total decontamination of the polished zirconium surface from organic compounds be expected. Therefore, it is advised to employ an ultrasonic bath with detergent solution for cleaning procedures of zirconium abutments before delivery.